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LMS User Manual

1. The function of the right mouse button B3 is for measuring distances as in the default SkyCat setup Click the right mouse button to define a reference position release the button then drag the mouse the angular distances between the actual cursor position and the reference position is displayed in arcsecs or in arcmin arcsecs To stop the measurement press the right mouse button again Caveat Rotating or shifting the mask deletes all slits Therefore first position the mask correctly then select the reference and guide stars and finally position the slits Note When large zooming is used the green handling circle might be no longer visible on the canvas In this case there are three possibilities e zoom out of the canvas using z e drag the white rectangle in the lower left pan window to scroll the canvas to the appropriate position e use the scroll bars of the canvas only if SkyCat has been started with the scroll command line option as is done by Ims sh 3 3 Reference Stars and Target Acquisition The selection of appropriate reference stars within LMS will be the most important task to ensure that the science targets will be on the slits Reference stars have to be selected from the data set which is used for slit positioning Before taking a MOS spectrum these reference stars are identified on the image taken during the target ac quisition sequence From their measured positions the tran
2. Local Catalogs Load from file Chapter 3 Mask Preparation This section first gives an overview of the mask preparation and then describes the basic operations in some detail 3 1 Overview A typical LMS session should consists of the following steps 1 change to the bin sub directory in the LMS root directory start SkyCat LMS by typing 1ms sh load a FITS frame and or a catalog initialize and position the mask configure the instrument set the slit parameters select reference stars select guide stars position the slits on the mask o ON DOO FF W PY save the setup 3 1 1 Loading a FITS File or a Catalog Before the mask can be initialized a field has to be defined by either loading a FITS image or a catalog into SkyCat It is also possible to load a catalog on top of a FITS image To load a FITS image use Open in the SkyCat File menu In case no FITS image is available select Image Servers from the SkyCat Data Servers menu and choose one of the image sources Similarly catalogs can be down loaded from the Data Servers Catalogs menu Local catalogs can be accessed via Data Servers Local Catalogs Load from file 3 1 2 Initializing and Positioning the Mask Once a field is defined the mask can be initialized by pressing Init Mask
3. star than the reference star within about 10 arcsecs and the reference stars should be at least about 10 arcsecs away from the edge of the field of view 3 4 Finding Guide Stars for the LBT LMS can be used to verify if there are appropriate guide stars in the patrol field of the auto guider When the Guide Stars add button is pressed LMS shows a red contour limiting the guide probe patrol field The guide stars have to be located inside this contour Guide stars should not be selected from the region overlapping with the LUCIFER field white square because positioning of the guide probe inside the LUCIFER field causes vignetting and stray light The useful guide star brightness range is 11 to 15 mag In case no guide star is found guiding is not possible and the observation cannot be carried out Guide stars can be retrieved using on line catalogs which can be overlaid on the FITS image Press the button Data Servers and Catalogs to access on line catalogs The relative position offset between guide stars on one side and reference stars and science objects on the other side can be up to 10 Therefore guide star positions can be taken from other sources than science objects and reference stars 3 5 Instrument settings After initializing the mask LMS visualizes the focal field boundaries as a white square Two white lines in north south direction inside this square confine the 2 5 arcm
4. Local catalogs are implemented as simple ASCII files in tab table format This is the same format that is used to return query results from remote catalogs The results of catalog queries are always returned in the format of a tab separated table of values The column headings are separated from the data by a dashed line Title comments Keyword value ID RA DEC MORE PREVIEW NGC5457 FD2 14 02 22 489 54 17 58 29 M http P http NGC5457 FLD2 14 02 22 489 54 17 58 29 M http P http Lines starting with are considered as comments and are ignored Keyword value combinations specify the catalog from which the data are extracted non standard usage of columns and how to plot the sources This information is used by SkyCat The line containing ID RA DEC specifies the meaning of the values in the columns listed below and is mandatory The keywords have to be tab separated For usage with LMS the first three columns are required Any number of other source parameters e g magnitude redshift size priority can be included here but have no effect for usage with LMS The columns MORE and PREVIEW have special meanings and are not visible in the query result window The two columns contain HTTP URLs pointing to locations providing more information on the source and images respectively In case the columns are not empty the buttons More Info and Preview below the list window are activated if the correspo
5. The gbr file contains the information required for cutting the mask and the slits including the mask contour the holes for mounting of the mask and the mask ID Freeware programs like gerbv are available on the web for viewing this file Visual inspection can be useful to check the masks before cutting or to clarify the mask identity by comparing an image taken through the mask with the gerber file image The epsf file contains a mask image for direct viewing in case no gerber file viewer is available This image does not contain the mask ID File name conventions The ims file has the format mos lt d gt lt ddd gt lt project gt 1ms In this string the first dis 1 for LUCIFER 1 and 2 for LUCIFER 2 ddd is a 3 digit counter which is incremented by 1 each time an Ims file is saved leading zeros are omitted project is an up to 8 characters long string which can be set in the LUCIFER1 2 Config Layout ProjectName menu If no project is specified the file name reduces to mos lt d gt lt ddd gt 1ms Mask name and mask identification number Each mask has a unique identification number ID Ims keyword INS MASK ID and a mask name Ims keyword INS MASK NA The ID is cut into the mask sheet When saving a mask setup a third keyword INS MASK NAID is created and also stored in the lms file The format of its value is Mdddcccccccc dddddd which is equivalent to M lt INS MASK NA gt lt INS MASK ID gt St
6. pixel for seeing limited imaging Default is the N 1 8 spectroscopy camera In combination with grating 2 and 3 it can make sense to use the N 3 75 camera Changing the camera effects the blue rectangle accessible array area back imaged on the focal field For the N 3 75 camera the field is nearly identical with the detector projection For the N 1 8 camera the field is smaller than the array The camera focal lengths are defined in the isf file together with the fixed collimator focal length they define the magnification between focal field and detector array Band Filter choose one of the LUCIFER band filters z J H K Ks HK where HK covers H and K band default is K with grating 3 see next menu item Selecting a band filter also selects a default grating and disables the grating menu buttons not compatible with the selected filter e g LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 26 the HK filter can be used only with grating 2 and the z and J filters can be used only with grating 1 Gratings choose one of the 3 LUCIFER gratings Grating 1 can be used with all filters except HK It is operated in different orders 5 for z to 2 for K and provides the highest resolution Grating 2 has been design for wide band spectroscopy and is always used in first order It is primarily combined with the HK filter but can also be used with the H K and Ks filters The resolution is less than half of the grat
7. 3 Real Time Display User Manual VLT MAN ESO 17240 0866 4 Astronomical Catalog Library User Manual GEN SPE ESO 19400 0949 All these documents are available on the ESO web pages 1 5 Acknowledgments We thank ESO for the permission to use and modify the FIMS source code for our application Chapter 2 Overview and Requirements 2 1 The LMS Concept LMS the LUCIFER Mask Simulator is a LUCIFER observer support software It is based on FIMS ESO s FORS Instrument Mask Simulator LMS is a plug in to the ESO SkyCat tool a browser for as tronomical images and catalogs SkyCat either displays a FITS image or source positions loaded from a catalog LMS overlays the contour of the LUCIFER field of view or the mask area together with the contour of the accessible detector area back projected on the telescope focal plane Within the LUCIFER field of view MOS slits can be positioned and reference stars can be selected In addition guide stars can be selected in the guider patrol field which partially overlaps with the LUCIFER field LMS is written in Tcl Tk and has been tested under OpenSuse Linux 10 3 to 11 2 using SkyCat 2 7 3 and SkyCat 3 0 The SkyCat LMS package can be installed and used at the user s home institute 2 2 Some technical details 2 2 1 Linux Installation Besides the LMS package an itcl interpreter is required which is part of standard Linux installations The LMS package can be downloaded from the MPE LUCIFER web
8. slit editing menu is pressed for the first time even if no changes have been made The lengths of the two arrows correspond to 10 mm on the mask The arrows point in positive x parallel to the dispersion direction and y direction This coordinate system should help to estimate the required changes in the slit center position The coordinate system disappears if the zoom factor is changed or the editing menu LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 16 of another slit is opened No plausibility check is implemented for the modified slit position While slits can be created only inside the white square limiting the FOV they can be placed outside the FOV by changing their positions in the slit menu Be careful to stay within the white square Auto Slit option In case a catalog has been loaded into SkyCat selecting the Auto s1it item in the LUCIFER1 2 automatically places slits on the sources listed in this catalog which are located inside the blue rectangle defining the spectrally unclipped area In case the unclipped area is larger than the LUCIFER field slit positions are limited to the field Slits are placed starting with the first catalog position inside the blue rectangle The program then goes down the list and checks for each source if it is inside the blue rectangle If so the program checks if the spectrum from the slit on this object would interfere with other spectra If not the slit is created No other cri
9. Center Slit This option centers the slit on a source The method will significantly improve the slit positions for point sources and other relatively compact targets A SkyCat feature with the centroid algorithm a single click on the target and the centroid might fail Click somewhere with the left mouse button B1 hold the button while moving the mouse wait until you see the target in the center of the pick object window and release the mouse button now Slits behind the green circle The left mouse button while used on the location of the green circle is defined to move the mask It is only possible to put a slit behind the green circle with the Center Slit functionality as described above click somewhere keep the left mouse button pressed while moving the mouse behind the green circle wait until you see the target in the pick object window and release the mouse button ProjeciName is used when storing the output files with the Save option lt projectname gt is an up to 8 character long user defined name If no project name is defined this part of the file name is omitted The project name is a LMS internal way to distinguish between different set up files More important at the telescope the Ims files are required for the MOS acquisition procedure In case no project is defined two Ims files can by chance have the same name i e the same number which can lead to acquisition of the wrong field Ther
10. can be used to position slits automatically on catalog po sitions First you have to load a local catalog or do a query on one of the catalogs available on the web via the SkyCat menu Then the mask has to be initialized and positioned in the field Slits can now be positioned on the catalog sources by pressing the Auto Slit button in the LUCIFER menu The program goes through the catalog starting with the first source it first checks if the source is inside the white rectangle of the LUCIFER field If this is the case a slit is positioned on the source For the following sources the same position check is made If the source is inside the white rectangle another test is made to check if the spectrum from this source would overlap with spectra from already positioned slits If this is not the case a slit is positioned on this source otherwise the source is skipped After entering reference targets from the same catalog and guide stars the mask can be saved At this instance the objects on which slits have been positioned are deleted from the catalog loaded into SkyCat but not from the original catalog and from the SkyCat main window In the Ims file the catalog source names are entered behind the INS TARGxxx NAME keyword of the corresponding slits In case there are sources left in the field you can shift the mask image so that these sources are inside the white rectangle After dropping the mask at the new position the p
11. for Slit Width holds WaveLength Range specify the wavelengths range and the center wavelength in nm and re draw the mask with the new wavelengths region boundaries Default values are set when a filter is selected Note that there is a fundamental difference between setting the center wavelength and setting the limits The center wavelength is defined as the wavelength at the position of the slit image Changing this value physically tilts the grating and thus shifts the observable spectral range across the array Naturally the grating tilt and therefore the change in center wavelength is limited by the instrument design The physical limit is 5 LMS calculates the tilt from the center wavelength and the instrument configuration and gives a warning if the tilt is too large On the other hand the wavelengths range is not a physical instrumental configuration option but is only used as a graphical aid see Auto Slit button The real spectrum length is usually limited by the array borders or by the filter width The default wavelength range as given in the pop up window shows the band filter FWHM range The wavelengths limits defined by the array size are displayed close to the lower corners of the array irrespective of the band filter transmission En tering wavelengths limits outside the filter band is ignored Camera choose one of the 2 LUCIFER cameras N 1 8 0 25 pixel for spectroscopy N 3 75 0 12
12. handles FITS images and source catalogs while LMS handles the LUCIFER instrument con figuration the positioning of the MOS slits and the selection of reference and guide stars The relation between the program modules and the input and output files is sketched in Fig 2 1 SkyCat Tool LMS 7 plugin reload project cat lt mos gt lt ec gt lt project gt lms lt mos gt lt ec gt lt project gt gbr lt mos gt lt ec gt lt project gt epsf Y observation preparation mask cutting Figure 2 1 Interaction between SkyCat and LMS input and output files LMS requires at least two input files LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 5 e A FITS image and or a source catalog to be loaded into SkyCat by default located in lms PREP but the path can be modified images and catalogs can also be downloaded via the Data Servers menu and e the instrument summary file ISF located in Ims_vxxx lib mos The ISF is an ASCII file containing all relevant instrument and telescope parameters like camera and collimator focal lengths grating parameters filter central wavelengths and bandwidths detector pixel size and pixel numbers and telescope plate scale Individual files exist for LUCIFER 1 and 2 LMS produces three output files which are written to 1ms SET 1 The Ims file contains the instrument parameters and the telescope pointing set during the ses sion as well as the sl
13. in the LUCIFER menu This action initializes the LUCIFER menu items loads the instrument parameters from the ISF file and draws a mask in standard configuration N 1 8 camera K band filter grating number 3 At this stage the screen should look like in figure 3 1 On top of a fits image or the source positions from a catalog the 4arcmin x 4arcmin LUCIFER field for the N1 8 and the N3 75 camera is drawn as a white square Inside this square two vertical white lines limit the central region 2 5 arcmin wide of acceptable defocus due to the deviation of the cylindrical mask from the focal sphere 6 square reference apertures of 0 5 arcsec width are positioned close to the upper edge of the mask for alignment purposes They are marked by the cyan labels 1 to 6 The small red rectangle close to aperture 6 indicates the area occupied by the mask ID number cut into the mask In the upper left corner of the SkyCat main window the rotation angle of the mask and the mask cen ter coordinates are indicated Immediately after mask initialization the rotation angle is zero and the mask center is identical with the image or the catalog center By dragging the green dot at the mask center the mask can be shifted across the field By clicking the green dot with the center mouse but ton the mask rotates counter clockwise in steps defined the Rotation Step sub menu of the LUCIFER LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MA
14. in the telescope image plane the arrows point towards the positive x horizontal line and y direction vertical line The lines should be helpful for changing the slit center position The lines are deleted if the parameters of another slit are modified or if the image is redrawn e g when zooming in or out Note that slit number 14 does not exist It has been deleted and the following slits are not renumbered Slits can be deleted by either center clicking on the number label next to the slit or by left clicking on one of the number labels at the edges of the spectral bars LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 13 3 2 Basic Movements and Functionalities The central green circle on the mask image Fig 3 2 has the function of handling the mask as a whole In the following the 2 mouse buttons left middle are designated B1 and B2 Their functions when clicking on the central green circle are e B1 mark current mask position e B2 rotate LUCIFER1 2 and hence the mask counter clock wise on the screen The default step size is 5 The step size can be controlled from the Rotation Step button in the LUCIFER1 2 Config Layout menu e Shift B2 rotate LUCIFER1 2 and hence the mask clock wise e B peg and move Changes telescope pointing position and hence moves the mask
15. indicated in Fig A 1 The telescope does not provide SW for guide star selection therefore it has been implemented within LMS AGw Patrol Field AGw r theta stage theta limits K ll i LUCIFER 4 Field of View AGw r theta stage radial limit The center of rotation Gregorian Focal 11 diameter r the Gregorian rotator center Figure A 1 The LBT guide star patrol field A B C and D indicate the software limits for the guider patrol range With respect to the field center the coordinates of A B C and D in mm are A 184 26 B 171 24 C 136 147 and D 155 125 To avoid vignetting guiding should be limited to a radial distance of 4 5 from the LUCIFER field center In addition a strip of 1 arcmin width along the edges of the LUCIFER field should be avoided This strip can be reduced or even ignored for MOS observations depending on the slit position e g the strips on the E and W side are not relevant as long as slits are within the recommended region of 2 5 width in EW direction The ARC AB is part of of circle of 612 5 mm radius about M 0 612 5 The values for A B C D have been supplied by LBT Guider operation during LUCIFER commissioning indicated that the actual patrol field is smaller An update for these values is required 28
16. observations Just press the in the file select menu from the default file name extension as any other user defined set up When e g the Load SetUp LMSROO button and edit the filter entry field 1ms to adf and load the technical mask lib mos mos1 004 standard adf aperture definition file is selected LMS will recognize the adf file extension and will change to technical mask mode To switch back to the default normal mask mode press Quit Mode then Init Mask Remark The mask is initialized in normal mode Therefore the 6 reference apertures are plotted on the mask these apertures don t exist on technical masks MASK ID Tag ADF mode contents 990 063 PINHOLE mos1 063 standard adf technical pinhole array 990 001 PINHOLE mos1 001 standard adf technical pinhole array 990 031 BLIND mos1 031 standard adf technical blind mask 990 034 SLIT_100 mos1 034 standard adf single slit 1 00 arcsec longslit 990 029 SLIT_075 mos1 029 standard adf single slit 0 75 arcsec longslit 990 032 SLIT_050 mos1 032 standard adf single slit 0 5 arcsec longslit 990 065 SLIT_025 mos1 065 standard adf single slit 0 25 arcsec longslit Table 6 1 List of LUCIFER technical masks 27 Appendix A Guider Patrol Field The auto guider is installed in front of LUCIFER A movable camera can pick up a star in the region around the LUCIFER field as
17. r t the reference stars This also implies that the telescope image scale and the pixel scale of the fits image or the source positions in a catalog have to be known to about 7 1074 2 4 2 Pre Images with LUCIFER Pre images taken with both LUCIFER instruments can be used for mask preparation However the following aspects should be considered when processing images for mask preparation e Pre images are take with the N 3 75 camera resulting in a 4 x4 field In case the mask is shifted and or rotated for slit positioning part of the mask will be outside the image area Moreover the useful part of the auto guider patrol field is outside the image area in any case The latter can be overcome by extracting stars from a catalog because the relative position accuracy is not critical in this case but it is normally desirable to have the full field for source and reference star selection Therefore a small mosaic centered on the science field should be recorded the single images should be distortion corrected merged into one FITS image and provided as input for LMS e LMS anticipates distortion corrected LUCIFER images Distortions have been measured by imag ing a sieve mask on the detector Images have to be distortion corrected before combining them to a mosaic LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 6 Remark 1 Presently no adaptive optics available seeing limited operation 1 arcsec wide slits should be use
18. the WCS scale derived from the FITS frame header The MOS slit positions are less accurate in this case 2 4 4 Input Catalogs and Frame less Modes A frame less mode is also offered No FITS frame is required but a WCS area is defined for the LUCIFER mask This mode can be used if a target list with high astrometric quality is available Reference stars have to be selected from stars with the coordinates known in the same astrometric coordinate system To load a catalog from the web proceed as follows e File Clear to clear the display and to purge the WCS e Data Servers Catalogs Guide Star Catalog or load another target catalog with reliable as trometry satisfying the requirements of section 2 4 1 e in the catalog query window specify the virtual field RA DEC rmin 0 rmax and press Search LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 7 e adjust the image brightness by scrolling with e press B 4 left mouse button the color bar below the main SkyCat window in case the virtual field or the source positions are not visible LUCIFER Init Mask and proceed further as in frame mode To save this catalog in the PREP directory select the menu item File Save as from the catalog query window Choose a file name and the extension cat To reload the catalog use Data Servers
19. y e press B2 on the slit number label next to the slit to purge the slit Presently two MOS slit types are supported STRAIGHT rectangular slit optionally tilted with respect to the dispersion direction and CIRCLE just a circle Slit positions are not checked for plausibility but 1 slits are created only if the mouse pointer is inside the LUCIFER field white square 2 the mouse pointer is outside the green central dot 3 the mouse pointer is outside the inner circle around a reference star 4 the mouse pointer is outside the red rectangles indicating the areas occupied by the spectra of already created slits This has the following consequences 1 If a slit is generated close to the edge of the field of view part of the slit might be outside the field 2 If a slit is created close to the spectrum of another slit the spectra can overlap 3 When the slit position or the slit length is modified via the slit parameter entry form window the slit might be shifted outside the field or spectra might overlap It is in the responsibility of the user to check that the slits are inside the field of view and that spectra do not overlap Center Slit option The center slit option selectable from the configuration menu will significantly im prove the slit positions for point sources and other relatively compact targets A SkyCat feature with the centroid algorithm a single click on the target and the algorithm might fail
20. Click somewhere with the left mouse button B1 hold the button while moving the mouse wait until you see the target in the center of the Pick Object window and release the mouse button now Centering may not be possible if the object extends beyond the Pick Object window In this case reduce the zoom factor of this window until the source is fully inside the window Slits behind the green circle or on reference stars The left mouse button while used on the location of the green circle is defined to move the mask It is only possible to put a slit behind the green circle with the Center slit functionality as described above click somewhere outside the green circle keep the left mouse button pressed while moving the mouse behind the green circle wait until you see the target in the Pick Object window and release the mouse button The same procedure applies to the inner circle around a reference star In case a slit is to be placed on a reference star activate the Center Slit functionality click outside the circles around the reference star and when the image in the Pick Object window becomes active move the mouse pointer on the source Modifying slit parameters The last two lines of the slit parameter entry form display the slit center position in mm on the mask measured from the mask center They are meant for minor adjustments of the slit position A small coordinate system next to the slit appears when the Enter button in the
21. LUCIFER LMS User Manual LMS Version 1 60 Document Number Issue Number Issue Date Prepared by LBT LUCIFER MAN 030 Issue 1 0 July 8 2010 R Hofmann MPE Garching Contents 1 Introduction 1 etl OCODE ita tate etd A dine er de th tr Meca TO te oo tee ve don alla 1 122 CHANGES amp amp a5 g Sansa e a ae Pee SA BOO Se ae A 1 4 37 ADDleViAllONS 12 a e stata At ad amp A edge Aa 2 1 4 Reference Documents oel ss ase aa aa ea a a aa a E e a a ee 2 1 5 Acknowledgments ee 2 2 Overview and Requirements 3 24 The EMS Concept iii Aaa ae a A AAA AAA ees 3 2 2 Some technical details o o 3 2 2 1 Linux Installation o oo 3 2 2 2 Other Operating Systems o e e 3 2 2 3 Directories and PathS 0 N NA a a aa e aeaa A A e 3 2 2 4 Start up of LMS 0 00002 ee 4 2 2 5 Input and outputfiles A AE e 4 2 30 EMS MOIES Ear A A o A a 5 2 4 Inputframes and catalogs 0 o e o 5 2 4 1 Astrometric Requirements o o ee 5 2 4 2 Pre lmages with LUCIFER o o o e e o 5 2 4 3 Requirements for Contributed Input Images o o 6 2 4 4 Input Catalogs and Frame less Modes o o eee 6 3 Mask Preparation 8 LOVE tt o o AS e it tE 8 3 1 1 Loading a FITS File ora Catalog o o e 8 3 1 2 Initializing and Positioning the Ma
22. N 030 9 mask rotation angle reference center detector and center coordinates apertures wavelength green dot outline X Skycat version 2 77 z_goodsn prio5 mask118 fits 1 File View Graphics Go Data Servers LUCIFERI minimum wavelength limits of spectrally maximum wavelength for central slit unclipped field for central slit Figure 3 1 Screen shot of SkyCat with a FITS image loaded and a mask initialized in the default configuration K band filter GRATING 3 N1 8 camera The mask is centered on the image Config Layout menu When the shift key is pressed while clicking the center mouse button the mask rotates clockwise In this situation left clicking anywhere inside the white square creates a slit at the mouse pointer position with default parameters 4 arcsec long 0 5 arcsec wide Caveat Shift and rotate the mask before positioning any slits Moving the mask will delete all slits 3 1 3 Configuring the instrument The white square is enclosed in a blue rectangle which indicates the spectroscopically usable detector area spectra can extend beyond the field of view in dispersion direction The size of this rectangle depends on the camera selected The blue rectangle in figure 3 1 refers to the N 1 8 camera for the N 3 75 camera the blue rectangle nearly coincides with the white square and for the N 30 camera not yet implemented it occupies only the central 0 5arc
23. N Bee le ee 24 5 9 Status Paneli 2 2242 ea RRR ERR DA eee A ee e T 24 50 Config Layout ote ostias aa GR Pe a ea eee ee ei 25 5 10 1 Instrument Configuration o o e e 25 5 10 2 Graphical Layout Options ee 26 5 10 3 Special Options 2 o 26 6 Technical Masks 27 A Guider Patrol Field 28 List of Figures 2 1LMS 3 1 Screen shotMenus 0 0 00000000 2 ee 3 2 Screenshot Mask A 1 The LBT Guide Star Patrol Field 111 List of Tables 6 1 List of LUCIFER technical masks 1v Chapter 1 Introduction 1 1 Scope This manual explains the usage of the LUCIFER Mask Simulator LMS It should be used together with the LUCIFER user manual 1 2 Changes Attention Masks prepared with LMS version 1 4 or lower cannot be used for observing after February 2010 Ims files generated with version 1 4 or lower should not be loaded into LMS version 1 50 or higher The major changes of LMS 1 50 as compared to LMS 1 4 are 1 The sign of the mask rotation angle has been changed to comply with the sign convention of the LBT instrument rotator As a consequence a new telescope pointing mode had to be introduced for MOS observations 2 Measured values for the LUCIFER pixel scales are now used instead of the design values 3 Only one gerber file is generated which can be read by the LBT cutting machine as well as by the machine of the supplier in Munich 4 Sl
24. When pressing the add button a red polygon appears which indicates the guider patrol field This field partially overlaps with the LUCIFER field If possible select a guide star out side the LUCIFER field Take into account that the pickup unit of the guide probe covers about 1 arcmin x 1 arcmin on the sky and is mounted on a solid bar Therefore if the guide star is inside or close to the LUCIFER field an area of this size will be vignetted and reflections from the probe can be visible in the image At least one guide star is required and selection of the guide star is in the responsibility of the observer at the LBT It may be necessary to rotate the mask in order to have a guide star inside the guider patrol field 3 1 6 Slit Positioning Once LUCIFER is configured the slit parameters are set and the reference and guide stars have been selected the slits can be positioned on the mask Slit positioning can be achieved in 3 different ways 1 A left mouse click anywhere within the white square will create a slit at the cursor position 2 Pressing the Center Slit button in the Config Layout sub menu opens the Pick Object win dow known from the reference target and guide star selection Within the white square click the left mouse button wait until the image in the Pick Object window moves with the mouse cursor then drag the mouse until the source is located close to the center of the Pick Ob
25. arting from left the sub string ddd contains the three digit number of the LMS internal counter cccccccc is the up to 8 char long string containing the user defined project name both of which also appear in the file names dddddd is a six digit random number between 900 101 and 999 999 representing the mask ID values between 900000 and 900 100 are reserved for technical masks When a mask has been cut it can be identified by this ID LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 17 Before the mask is saved a project name should be defined Otherwise the file names differ only by the three digit counter and it can easily happen that files submitted from different groups have the same names This can cause confusion when the Ims files have to be assigned to the corresponding masks Chapter 4 Local Catalogs In case no FITS image is available for slit positioning a local catalog can be used instead Catalogs can be downloaded from the web or generated by the user SkyCat provides tools for downloading storing and editing catalogs In this chapter we first describe the catalog format required by SkyCat and LMS then we explain how to set up a local catalog from a remote catalog query and finally we elaborate on generating catalogs from the scratch 4 1 Catalog Format Here we give a concise description of the catalog format A detailed description can be found in chapter 2 of the Astronomical Catalog Library User Manual 4
26. as follows 1 In the catalog window click the Options menu and then Set Plot Symbols 2 Anew window with the title Plot symbols for lt filename gt appears and a message pops up that no plot symbols have been defined for this catalog 3 The uppermost sub window lists the columns used for plotting and the plot parameters assigned to these columns The window should be empty at this stage 4 In the columns window mark a column in the Not Used field and move it to the Used field by clicking the lower blue arrow More than one columns can be selected Plot conditions and symbol size can only be defined for columns in the Used field 5 Use the default plot symbol circle or select a different symbol by clicking on the blue bar in the line Symbol and then select one of the symbols displayed 6 In the same way select the symbol color by clicking on the line Color or keep the default value black and white which is best suited for colored background 7 Next define the symbol size by entering a number or an expression in the line Size You can always use a number a typical value is 3 to 10 depending on the image size In case a magnitude column has been chosen the plot symbol size can be defined by the magnitude For example if mv has been chosen the plot symbol size can be defined as 15 mv which plots a zero magnitude star as a circle with diameter 15 and a ten magnitude star with diameter 5 Obj
27. ch slit number 16 has been positioned Slit number 7 is outside the blue rect LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 12 Area of imag be examined 973 0 r 295 0 y 4 51337e 05 12 37 29 563 zZ z Image Statistics 62 16 25 09 3 2000 A Figure 3 2 Screen shot of the slit generation process using Center Slit The mask has been shifted but not rotated relative to the image angle its spectrum will be clipped on the red side All slits are 1 arcsec wide but their lengths and tilts have been set individually e g to align the slit along the major axis of an object The tilt of the major axis against the x axis horizontal in this case is listed in the Pick Object window The tilt of the slit is measured against the y axis The rotation angle of the slit is positive if it is rotated from the y axis towards the x axis Slit parameters can be modified by left clicking on the slit width label next to the slit image In this case an entry window appears which lists the slit width and length in arcsec the slit tilt in degrees and the slit center position in mm from the mask center When the Enter button in this entry window is pressed for the first time even without changing parameters two white arrows spanning a coordinate system are displayed like the ones next to slit number 16 in Fig 3 2 Their lengths correspond to 10mm on the mask
28. d reference star positions on one side and the guide star positions on the other side is not stringent offsets of the order 10 arcsec are allowed Once the guide star has been found the reference objects can be aligned by telescope offset and instrument rotation This implies that guide stars can be extracted from different sources than science objects reference stars 2 Guide stars are not observed by LUCIFER but by the AGW auto guider and wavefront sensor unit Therefore although the guider can pick up stars in the LUCIFER field the guide stars should be located at least 1 arcmin outside the LUCIFER field to avoid vignetting and stray light from the auto guider 3 The auto guider rotates with LUCIFER on the instrument rotator and therefore the guide star field is fixed relative to the mask Therefore if no guide star is located north of the mask rotate the mask until a guide star is above its upper edge to avoid vignetting by the probe 4 Brightness range for guide stars 11 to 15 mag 5 For each pointing one guide star is required For small offsets two pointings can share the same guide star as long as it stays within the guider patrol field 5 9 Status Panel The button Status Panel creates a top level window showing the current status of the LMS session The contents of the three fields e Instrument Setup LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 25 MOS Slits Session i
29. d to minimize slit losses by seeing In case a single LUCIFER pre image no mosaic is used the mask is centered on the image and the slits are positioned inside the white rectangle indicating low defocus see Fig 3 2 no distortion correction is required Remark 2 LUCIFER provides FITS images which are NOT compliant with the astronomy imaging stan dard but are flipped about the north south axis i e east is to the right of north SkyCat and LMS handle this case correctly therefore the mask image is also flipped as compared to standard images and the slits are correctly positioned for both LUCIFER and standard images 2 4 3 Requirements for Contributed Input Images Images from other telescopes require careful and accurate astrometric calibrations and WCS FITS headers If no FITS frame is available it is possible to use the image server facilities of SkyCat to download a sky image from one of the available on line archives Note that also here the requirement for positional accuracy applies as stated in section 2 4 1 The standard orientation for sky maps and images is north to the top and east to the left meaning RA is decreasing with increasing pixel number image fits header keywords CDELT1 lt 0 and CDELT2 gt 0 If the input frame does not provide world coordinates the FITS header can be edited by using either a FITS header editor or emacs Verify this step very carefully A faulty or inaccurate setting of the frame s world coo
30. e USNO as well as on user defined catalogs These catalogs have to be compliant with the require ments for astrometric accuracy section 2 4 1 and for target catalogs to be used with SkyCat and LMS chapter 4 The Auto Slit program takes the current mask coordinates RA and DEC and position angle PA Start ing from the top of the catalog the program searches for targets located inside the blue rectangle defin ing the area of unclipped spectra or within the white square limiting the field whichever is smaller If a target inside the blue rectangle is found the program checks if the spectrum of a slit centered on this target interferes with the spectrum of any of the already existing slits If this is not the case the slit is positioned on the target otherwise the target is skipped Auto Slit does not move or rotate the mask Therefore the best mask position and orientation has to be set before starting the Auto Slit function Since Auto Slit positions the slits on the targets in the order they appear in the catalog this order be comes important for crowded fields High priority sources should be positioned at the top of the catalog 5 6 Save This saves the current mask settings and creates three files in the SINSROOT 1ms SET directory using the syntax lt mode gt lt counter gt lt projectname gt lt ext gt where e lt mode gt is always mos1 or mos2 in LMS e lt counter gt is incremented with each save operation i
31. ects fainter than 15 magnitude are not plotted in this case The default units for the symbol size are image pixels 8 In case a column like mv has been selected for plotting a condition should be specified to avoid error messages in case no magnitude is listed for a source For example type mv lt 15 in the line Condition Several conditions can be combined like mv amp amp mv lt 15 where the first conditions prevents application of the plot size expression to symbols with undefined mv which causes an error message Conditions can be defined only for columns listed in the Used field 9 When all required parameters have been defined press the Add Symbol button The plot param eters should appear in the uppermost sub window 10 Press the Apply button The symbols should be plotted on a virtual field or on a FITS image if loaded 11 Close the plot symbol window LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 21 12 Save the settings using the File Save as menu of the catalog window You can overwrite your original catalog source data have not been changed but several lines containing the catalog file name and the plot parameters have been added to the header All plot parameters can be modified at any time via the Set Plot Symbols sub menu 4 4 Local Catalogs and Auto Slit As already mentioned the Auto Slit function
32. efore a project name should always be chosen to make the Ims file names more unique All other functions are kept as convenient as possible All positioning actions can be done by pointing with one of the two mouse buttons B1 B2 to one of the graphical elements The function of mouse button B3 is still for measuring distances as in the original SkyCat The SkyCat function of B2 canvas scrolling is overloaded but not overwritten with the rotate mask function Chapter 6 Technical Masks In the previous chapters the generation of multi slit masks for science observations has been described LMS also offers the option to set up observations with long slit masks so called technical masks which are permanently stored at the LBT but not necessarily continuously available in the instrument Long slit masks cannot be modified but the observer can use LMS to select reference and guide stars Therefore only the 1ms file is saved in this mode The existing technical masks are listed in Table 6 The first three masks are for maintenance only the others are single slit masks for science All available technical masks are coded as LUCIFER aperture definition files ADF They are copied from the default directory LMSROOT 1ib mos to the s ET_DIR directory each time LMS is started After having specified the band filter and the grating a technical mask can be used to prepare
33. er wavelength range can be chosen via the Config Layout WaveLength Range menu This choice has no physical effect but re draws the border lines of the unclipped area LMS recognizes if the user defined wavelengths limits are outside the filter band and replaces these values by the default band limits The WaveLength Range menu also permits selection of the center wavelength the wavelength at the slit image This setting has a physical effect in that it tilts the grating to move the selected wavelength to the slit image Hint Using the Config Layout menu from the LUCIFER1 2 menu is rather tedious because it closes after each setting This can be avoided by clicking on the dashed line at the top of the Config Layout menu The click creates a stand alone configuration window which stays open until explicitly closed by the user LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 15 3 6 Creating Slits Beside the basic key bindings for mask positioning See section 3 2 and the LUCIFER menu items LMS provides the following bindings e press B1 to create a MOS slit within the LUCIFER field white square e press B1 on the slit number label at the edge of the detector contour blue rectangle to purge the slit e press B1 on the slit width label to configure this slit width length tilt center position in x and
34. erence targets by a comma separated list e g 7 3 in the purge menu The reset button erases all entries in the reference target list Selected reference targets will be highlighted via a cyan circle The parameters of the chosen reference targets will be shown in the Pick Ob ject window To exit the selection process press the button Close in the Enter Object window twice The sub menus are e plot to plot the reference targets on the screen e show to list the reference targets and their positions e add to add further reference targets The forbidden area for reference target selection is outside the red square which is essentially the contour of the LUCIFER field of view purge to purge individual reference targets from the list e g enter 1 4 to purge targets 1 and 4 verify to check that all reference targets can be handled by LUCIFER e reset to delete the complete list of reference targets 5 8 Guide Stars At the LBT the observer has to provide the guide stars for his observations For this purpose the menu item Guide Stars has been added This menu has the same sub menus as the Reference Targets menu and they work in the same way However the guide stars selection procedure is quite different from the reference star selection procedure for the following reasons 1 Since the guide stars are used for tracking only the relative accuracy between slit an
35. in wide central area of small defocus defocus is caused by the deviation of the cylindrical mask from the focal sphere The back image of the accessible detector area on the focal plane is presented by a blue rectangle The two vertical blue lines inside this rectangle confine the field within which slits can be placed without spectral clipping for a given camera grating filter combination Slits can be set beyond this boundary but some parts of the specified spectral range will be lost The default camera filter grating combination is N 1 8 camera Ks band filter GRATING3 the selec tion of these elements is done from the Config Layout menu for details see section 5 10 Selection of a band filter will automatically select the optimum grating and disable the radio buttons for gratings not available with this filter The Help Grating Info info shows allowed filter grating combinations together with the spectral orders the band filter center wavelengths and the 50 limits as read from the Instrument Summary File ISF Please note that for some combinations the spectrum does not fit on the array In this case the two blue boarder lines limiting the unclipped area are connected to the corresponding array edges by red diagonals indicating that no unclipped spectrum can be recorded To avoid confusion the diagonal lines are displayed only if Labels is activated in the LUCIFER1 2 Config Layout menu A small
36. indow Now select the Enter Object window and press Enter A blue circle appears around the star indicating that the reference star has been added to the list Press the Pick object button in the Pick Object window to select the next reference star LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 11 In case the cross is not centered on the stellar image press the Pick object button inthe Pick Object window again and try to position the mouse pointer closer to the star before clicking the left mouse button If the stellar image is larger than the window reduce the zoom factor by clicking on the small z in the Pick Object window before starting another selection To finish the reference star selection click twice the Close button in the Enter Object window Reference stars must be positioned within the red square No check is made when the star is selected but the positions can be verified by pressing verify in the Reference Targets sub menu The reference and the guide star positions are checked automatically before saving a mask and the result of this check is displayed in an information window In case one of the check fails the observation cannot be executed 3 1 5 Guide Star Selection The procedure to select a guide star is the same as for a reference star It is controlled by the Guide Stars sub menu
37. ing 1 resolution Grating 3 is optimized for K band spectroscopy and has a similar resolution as grating 2 which can be doubled with the N 3 75 camera without loosing spectral coverage in K 5 10 2 Graphical Layout Options These options have no influence on the instrument configuration and on the mask properties they are aids for the mask preparation e Rotation Step select the rotation angle of the mask per mouse click Default is 5 degrees mask rotation position angle per click with B2 clock wise or shift B2 anti clock wise on the green central circle of the mask e Color change the color of the mask The colors of the green handling circle and the blue square array area are not affected Default Yellow Red e Labels configuration option of the active mask The telescope pointing and the orientation of the mask are shown Slits are numbered at the edge of the mask and next to the slit image In addition a label indicating the slit width is drawn next to slit The wavelengths limits defined by the array size are shown close to the lower corners of the array projection blue rectangle The central wavelength is shown on the upper edge of the array at the two blue lines limiting the spectral range without clipping by the array 5 10 3 Special Options These options provide means for slit positioning and for project administration e
38. instrument files stored in the 1ib sub directory and that the data tree is home lt user gt 1ms containing fits files in the PREP the log files in the LOG and the output files grb Ims epsf in the SET sub directory lt user gt refers to the user s home directory These paths can be modified by editing the corresponding lines with a simple text editor Please make sure that the path to the Ims directory is correct The output directories are created by the start script in case they don t exist LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 4 2 2 4 Start up of LMS LMS is started from the LMSROOT bin directory by calling the script 1ms sh with or without a param eter defining the instrument e lms sh e lms sh 11 e lms sh 12 where the first two commands start SkyCat with the LUCIFER1 menu while the third one starts SkyCat with the LUCIFER2 menu LUCIFER2 sub menus are not yet implemented Besides 11 and 12 the following arguments are also valid 1 1 12 Lucifer1 2 and LUCIFER1 2 Ims sh sets the paths to directories used by LMS when run for the first time creates the hidden default directories 1ms LOG Ims PREP 1ms SET in the user s home directory defines environment variables configures the plug ins for SkyCat and starts SkyCat LMS is accessible via the LUCIFER menu in SkyCat Mainly this menu is described here 2 2 5 Input and output files SkyCat
39. it center positions can be modified in the slit menu positions are given in mm focal plane relative to the mask center Changes made between LMS 1 50 and 1 51 1 The variable 1vchost has been removed to avoid problems with different operating systems The only effect being that the name of the computer on which the mask was generated is no longer listed in the Ims file 2 Ared rectangle is drawn close to reference aperture 6 This rectangle indicates the area occupied by the mask ID number No slit spectrum should interfere with this rectangle 3 The correction for thermal contraction of the mask in LUCIFER 0 0025 shrinking during cool down from ambient to 200 C has been removed from the code Instead the thermal contraction is taken into account by adapting the telescope plate scale Thus the distinction between LUCIFER images and external images or catalogs is obsolete Changes made between LMS 1 51 and 1 52 1 In the SkyCat window the sign of the mask rotation angle listed together with the telescope pointing was wrong This has been corrected the rotation angle displayed is now consistent with the angle listed in the Ims file TEL ROT OFFANGLE 2 The equations determining the positions of the blue lines limiting the area of unclipped spectra in the field of view have been corrected Changes made between LMS 1 52 and 1 53 1 The mask center position no longer changes when a mask that has been shifted relative
40. it parameters and the positions of reference and guide stars Reload this file to recover the LMS session 2 The Gerber file gbr contains the information required for mask cutting The mask configuration stored in the Gerber file can be displayed by a freeware viewer like gerbv 3 The epsf file contains a postscript image of the mask for direct viewing in case a Gerber file viewer is not available the mask ID is not shown in this image 2 3 LMS Modes LMS supports two modes MOS mode and technical mask mode In MOS mode new masks can be generated and the three output files just mentioned are stored In technical mask mode an existing long slit mask is loaded and only the 1ms file is saved For more details see chapter 3 on mask preparation and chapter 6 on technical masks 2 4 Input frames and catalogs 2 4 1 Astrometric Requirements For preparing observations with LMS a FITS file with appropriate world coordinate keywords World Coordinate System WCS in the header is required Alternative inputs are catalogs in frame less mode Accurate target coordinates are required The target positions relative to the coordinates of reference stars must be known very well because the reference stars are used for mask alignment A maximum astrometric error of 1 6 of the slit width can be tolerated Compromises in the astrometry will cause slit losses For 0 5 wide slits every single target coordinate must be known to better than 0 1 w
41. items in the LMS menu and its sub menus LUCIFER1 2 Init Mask section 5 1 Reset Mode section 5 2 Load Setup section 5 3 Quit Mode section 5 4 Auto Slit section 5 5 Save Setup section 5 6 Reference Targets section 5 7 Guide Stars section 5 8 Status Panel section 5 9 Config Layout section 5 10 5 1 Init Mask The mask can only be initialized if a WCS is defined i e if a FITS image or a catalog has been loaded Pressing this button plots the focal field white square and the current instrumental mask over the sky image or the catalog field The two white lines within the square limit the area of acceptable defocus due to the deviation of the cylindrical mask from the focal sphere The closely spaced red lines near the top of the field indicate the area in which the six reference apertures 0 5 x 0 5 are positioned The mask ID number indicated by a red rectangle is also cut in this area The blue rectangle is the back projection of the accessible detector area onto the focal plane its size changes with the camera selected For the two blue lines inside the rectangle refer to the Labels option in the Config Layout sub menu The mask is initialized and oriented according to the underlying FITS image the 6 reference slit are aligned along the northern edge of the mask slit number 1 is next to the eastern edge The ro
42. iteria can be combined and attributed to different plot symbols Usually the size of the plot symbol is related to the source brightness e g by entering a relation like 20 SFmag 3 in the line Size In addition special conditions can be selected for plotting a source E g e 1 inthe line Conditions prevents the plot of sources with an eccentricity differing from one All these values can be set and modified by the user Remark The syntax for calculations and conditions is the standard Tcl Tk syntax e the value of a variable e is e The second menu item in the query window Edit works only on local source lists Therefore a list loaded from a catalog server has to be locally stored and then reloaded before it can be edited Editing includes removing of a selected source adding new sources and editing parameters of a selected source New sources can be entered by typing their coordinates and ID into the input window Alternatively in case an underlying FITS image is available the Pick Object mode can be used in the same way as for reference target and guide star selection Unfortunately the coordinates are not automatically transferred from the Pick Object window to the Enter object entry form However the values can be copied and pasted between the two windows The LUCIFER menu in the query window can be used to add magnitude and priority columns which have no effect in the present LMS ver
43. ject window release the mouse button and wait until the source center position is indicated and the slit appears on the mask 3 In case a catalog has been loaded click on Auto Slit in the LUCIFER menu Slits will be positioned in the blue rectangle or the white square whatever is smaller starting with source position 1 in the catalog In case the spectrum of a new slit would overlap with an already existing spectrum this slit will not be generated Fig 3 2 depicts a typical situation for creating slits using the Center Slit option The FITS image is the same as in Fig 3 1 but the mask has been shifted off center and the image has been magnified by pressing the Z button above the pan window in the lower left corner of the SkyCat window The cyan circles numbered 1 to 5 are centered on the reference targets The yellow circle number 1 is centered on the guide star Reference slits number 1 to 6 close to the upper edge of the mask are used for alignment checks and cannot be modified by the user The red rectangle close to alignment slit number 6 indicates the position of the ID number cut into the mask No slits should be positioned between the reference slits and the upper edge of the mask to avoid interference with spectra from these slits and from the slits making up the ID number Slits number 7 to 16 have been generated using the Center Slit option The Pick Object window shows the source on whi
44. lt values are 4 arcsec length and 0 5 arcsec width 7 Close the Config Layout window 3 1 4 Reference Star Selection Once the instrument and slit parameters are set reference stars should be selected in the LUCIFER field of view At least three reference stars are required to check and correct the telescope pointing and the instrument rotation angle More than three reference stars will reduce the inaccuracies Because the telescope pointing and the orientation of the instrument the mask on the sky are derived from the reference star positions in the image the reference targets should be taken from the same source FITS image or catalog as the science objects To select reference stars click on the Reference Targets sub menu then select add The white frame indicating the LUCIFER field of view becomes red and an information window pops up press the OK button after you have read the text Then an input window appears into which the coordinates of the reference star can be entered In case a FITS image is available press the Pick object button Another window appears which in its upper part shows a small area of the fits image around the cursor position Move the cursor to a star in the fits image When the star is close to the center of the Pick Object window press the left mouse button After a short time a cross should appear at the center of the star and its coordinates are displayed in the w
45. min x 0 5arcmin of the white square The inner vertical blue lines enclose the area of unclipped spectra For a slit positioned within this area the spectrum fits completely on the detector If the slit is outside this area its spectrum will be clipped on one side The positions of these two blue lines depend on the camera the filter and the grating selected addition the line positions can be changed by modifying the extreme wavelengths and the center wavelength in the WaveLengthRange sub menu of the Config Layout menu Changing the extreme wavelengths has no physical effect but is a good method to indicate the unclipped LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 10 area for a spectral range of interested e g if only one line is to be observed The two numbers close to the upper end of the blue lines indicate the central wavelength Changing this number affects the grating tilt which is limited to about 5 degrees Central wavelengths which require a larger tilt are not allowed and will be ignored The numbers close to the lower left and right corner of the blue rectangle are the theoretical extreme wavelengths imaged on the detector for a central slit the actual wavelengths range may be smaller due to the band filter used For better identification of the spectrally clipped areas diagonal lines connect the corners of the blue rectangle indicating the usable detector area to the e
46. mum radius In case no FITS image has been loaded the center coordinates and the search radius in arcmin have to be entered manually The minimum radius should be set to zero otherwise an annulus between minimum and maximum radius is searched The limiting object magnitudes and the maximum number of objects listed can also be defined entering these numbers is not mandatory Once the search area and the other parameters are defined press the Search button to start the query A list of sources with names coordinates and additional parameters appears the additional parameters are catalog specific and the source positions are marked either on an empty virtual field or on the FITS image To see the sources symbols it may be necessary to adjust the image brightness by dragging the mouse cursor along the color bar below the main window In case you are satisfied with the source list save it as a local catalog by opening the File menu in the query window and then select Save as Use the extension cat to save the list in the PREP directory In case only a few objects from a long source list are plotted have a look at the Options Set Plot Symbols menu in the query window In the upper part the plot symbols window lists the parameters used to define plot criteria the symbol plotted and other parameters symbol size condi tions etc Several cr
47. n order to avoid overwriting previous set ups of the same project name e lt projectname gt is an 8 character user defined name See section 5 10 3 e lt ext gt is one of lms gbr epsf where lms is used by LMS to re load a set up and for observation preparation since it contains telescope pointing and slit positions gbr contains the slit information in Gerber format and is used for mask cutting epsf contains a mask image including the mask contour centering slots reference aper tures and science slits but not the mask ID number Please keep all output files produced by LMS they could be useful later if a problem occurs during observation During the save procedure in a first step the reference targets are verified and the user is asked again if the set up should be saved Follow the recommendation and don t save set ups that will fail at the LBT At least three but for better alignment accuracy five to seven reference sources must be specied before saving the mask LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 24 5 7 Reference Targets MOS target acquisitions have to be aligned using reference stars Select up to 10 reference targets ideally close to the slit positions Reference targets can be specified at any time during an LMS session but no longer during the save sequence Press LUCIFER Reference Targets add to add reference targets Purge ref
48. nd points of he two blue lines limiting the spectrally unclipped area For several instrument configurations no unclipped area may exist In this case the blue diagonal lines change their color to red If this happens either choose a different instrument configuration or limit your wavelengths range The instrument configuration should be done in the following way 1 Open the LUCIFER menu click on the Config Layout button and then on the dashed line in the sub menu This opens the Config Layout sub menu in its own window which does not close after each parameter selection 2 Select your wavelength range by pressing one of the buttons in the Band Filter sub menu The optimum grating for this band filter is set automatically 3 In case a different grating should be used click the Grating sub menu The allowed gratings are high lighted Some filters work only with one grating e g for HK only GRATING 2 is available for z only GRATING 1 For details on the gratings please refer to the LUCIFER user manual 4 Click the WaveLengthRange window to change the central wavelength and the desired upper and lower wavelength limits if required 5 Select the camera from the Camera sub menu Normally the N 1 8 camera is used for spec troscopy 6 Select the slit length and slit width from the Slit Length and Slit Width sub menus defau
49. nding source is highlighted Under SkyCat 2 7 More Info tries to launch Netscape which is no longer available on most systems The column headings are separated from the data by a dashed line For the Auto S1it function LMS uses the first three columns only Again the columns are tab separated The ID can be any unique character string composed of alphabetic characters numbers and underscores RA and DEC are listed in hh mm ss ss and ddd mm ss sss format for equinox J2000 The valid keywords and formats are summarized in the following table LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 19 Meaning Keywords accepted by LMS Value unique identification character strings containing catalog source name number ID Id name target star object right ascension RA Ra ra position in format hh mm ss ss J2000 declination DEC Dec dec position in format ddd mm ss ss J2000 4 2 Creating a Local Catalog from a Web Search The simplest way to create a local catalog is to search one of the catalogs available on the web These catalogs are accessible from SkyCat via the Data Servers Catalogs menu which displays a list of catalogs Clicking an item of this list opens a query window In case a FITS image has already been loaded press the Set From Image button in the window to set the search area in the catalog defined by the center coordinates and the maxi
50. page The download file is named lms_vxxx tar gz where xxx represents the version number After unzipping the package change to the 1ms_vxxx bin directory This directory contains the start script Ims sh and the SkyCat and AP automatic positioning software binaries In case 1ms_vxxx is located in the user s home directory execute the shell script to start LMS type 1ms sh Otherwise open the script and modify the path LMSROOT in line 49 to point to the LMS directory See below then run the script 2 2 2 Other Operating Systems LMS also runs under Mac OS The corresponding SkyCat executable is not part of the LMS package and has to be downloaded from the ESO web pages 2 2 3 Directories and Paths We have kept the default FIMS directory structure for program and file locations In case you want to organize your setup differently just modify the paths in the Ims sh script Starting in line 49 of the script the directory structure is listed LMSROOT LMSROOT SHOME 1ms_vxxx SF_DIR SLMSROOT 1lib mos NS_ROOT SHOME NS_USER 1ms REP_DIR SINS_ROOT SINS_USER PREP OG_DIR SINS_ROOT SINS_USER LOG SET_DIR SINS_ROOT SINS_USER SET HUW HHH The first line defines the path to the LMS directory the forth line defines the name of the data directory This list assumes that the program tree is home lt user gt 1ms_vxxx with the Ims sh start script stored in the bin sub directory and the programs libraries and
51. rdinates will be carried over in all further steps In particular the frame scales CDELT1 CDELT2 are very sensitive while an offset between the WCS and the optical positions in the frame of less than 10 arcsec can be corrected by the alignment procedure To verify the correct setting of WCS keywords load your modified frame into SkyCat select File Open and watch the a and values in the panel when moving with the mouse over the sky field For further verification you can use the AstroCat facilities to download e g all appropriate tar gets from catalogs like the Guide Star Catalog or the USNO catalog Data Servers Catalogs Guide Star Catalog at ESO Set from Image Search and compare the optical positions in the frame with the catalog positions The WCS FITS header keywords describe a linear map projection scale hence non linear effects caused e g by the telescope or instrumental optics are not accounted for The WCS FITS header key words of LUCIFER1 and LUCIFER2 images contain the local scale in the center of the focal field center of the array the optical axis LMS supports frames with a minimum size of 1 x 1 If the image size is close to the lower size limit coordinate translations in particular the positions of the mask elements outside the frame are no longer calculated via the built in WCS package but are extrapolated linearly from
52. revious slits are deleted from the image and you can press the Auto Slit button again New slits are then positioned on the remaining sources After entering reference targets and guide stars this masks can also be saved Again the sources on which slits have been positioned are deleted from the catalog and from the screen This procedure can be continued until the catalog is empty The session can be interrupted after saving a mask In this case the last version of the catalog should be saved under a new name using the File Save as menu in the catalog window This catalog file can be reloaded later to continue the slit positioning session A known problem with Auto Slit When slits are positioned using Auto Slit and reference targets and or guide stars are positioned by typing their coordinates into the Enter Object window some slit images and circles around reference and guide stars are slightly offset relative to symbols representing the catalog objects by less than 0 5 arcsec This seems to be related to the pixel size of the internal graphics screen relative position changes with zoom and does not affect the correct positioning of slits and does not affect the accurate slit positioning The slit coordinates stored in the Ims file are identical to the object coordinates listed in the catalog Chapter 5 LMS Menu Reference This section gives a comprehensive description of all pull down menu
53. s self explaining 5 10 Config Layout This cascaded menu contains instrumental configuration options and options for the graphical layout of the mask All instrument parameters are written in the 1ms file to keep track of the instrument con figuration selected for a specific mask However the mask itself does not depend on the instrument configuration and the observer is free to set other instrument parameters during observation 5 10 1 Instrument Configuration This section defines the LUCIFER hardware options and the overall slit parameters Slit parameters can be modified individually after slit creation The first menu item is the dashed tear off line Clicking on this line opens a new window for the configuration menu This windows stays open until you explicitly close it The sub menu closes automatically after each click Slit Type choose one of the 2 currently supported slit types STRAIGHT or CIRCLE Default is STRAIGHT The maximum number of MOS slits is 200 Slit Width choose a slit width between 0 25 and 15 default is 0 5 Changing this value effects newly created slits but not already existing slits After creation the parameters of an individual slit can be adjusted by left clicking on the slit width next to the slit image requires Labels on Slit Length choose a slit length between 2 0 and 20 0 default is 4 For modification and re definition the same as
54. sion This may change in upcoming versions 4 3 Building Your Own Catalog With the format information from section 4 1 it is relatively simply to build a local catalog Just execute these steps LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 20 1 In a text editor create a new empty file 2 Type in the row with the header information for the catalog At least three tab separated keywords e g ID Ra Dec are required more can be added but have no effect in LMS 3 Type the next line which contains only dashes 4 Enter the tab separated parameters for the first source a name and the coordinates in the format specified in the table at the end of section 4 1 5 Enter the tab separated parameters for the other sources one source per line 6 Save the file with the extension cat in the PREP directory Now this local catalog can be loaded into SkyCat Start LMS as usual then open the menu Data Servers and Local Catalogs In this menu click the last line Load from file In the file selec tion window go to the PREP directory and select your catalog file then press the OK button the catalog is loaded and the catalog query window containing the source list pops up If you load the catalog for the first time you will not see any source positions plotted The reason is that no plot symbol has been defined in the catalog header To define the plot symbols proceed
55. sk 0 o e 8 3 1 3 Configuring the instrument o o e e 9 3 1 4 Reference Star Selection 0 o 00000 e o ee 10 3 1 5 Guide Star Selection 0 0 o e ee 11 381 26 SIE POSINONING ti o LA A AA ee ee SE 11 3 2 Basic Movements and Functionalities 0 cee eee ee e 13 3 3 Reference Stars and Target Acquisition o o e 13 3 4 Finding Guide Stars fortheLBT o o e e 14 LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 11 3 5 Instrument settings o 14 3 00 Creating SIMS tt ae ea SA AAA A 15 3 7 Saving MASKS iaria eee Bak a a amp eee ee ee ee a dada ks 16 4 Local Catalogs 18 4 10 Catalog Formate io a BEE be tied eee ee ee a eae ei 18 4 2 Creating a Local Catalog from a Web Search o o e 19 4 3 Building Your Own Catalog e 19 4 4 Local Catalogs and Auto Slit o oo 21 5 LMS Menu Reference 22 Sl ltt Mask scr ar atte E A Gk A A ae ad arenas a 22 52 RESO MOG Ss asc teeters A A a 22 5 9 oad Setup cca tee as ee a aa eee ee ele ed 22 54 QUIE MOOG cies Se covet a EE Sek are GME Sh E A dd aia Ara ai 6 Soe E 23 pOr AUO Slit sme cee ns Ste fe atthe ae Se eae WE arte ie eet 23 5 6 SaVew be Ada eee ee ee ERE ERAS eS Pe See Ae EEE Hee e 23 5 7 Reference Targets aa a ee e e ee 24 5 8 GUIAS Stars urna a a Be O
56. slation and rotation offsets are calculated and these values are used for telescope pointing correction and instrument rotator angle correction At the LBT finding the corrections and communicating them to the telescope is in the responsibility of the observer The absolute positions of MOS slits and thus the correct mask ID are verified by mask images typically taken during daytime using the calibration source These images will also be used to measure the position and rotation angle of the mask in the focal plane from the positions of the six reference slits along the top edge of the mask It is the responsibility of the observer to check the correct alignment and positioning of the mask A general rule for the selection of reference stars For MOS observations it will be required to correct rotation and position offsets between the pre image and the actual telescope pointing with high accuracy A minimum of 3 reference stars are needed for this alignment but we recommend that the user defines at least 5 reference stars These should be widely spread over the field in which the science slits have been set The procedure how to select reference stars is explained in section 5 7 It is mandatory to select unsaturated point sources as reference stars which are bright enough to achieve a high signal to noise ratio within an integration time of typically 1 minute There should be no brighter LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 14
57. tator angle 1 x position angle on the sky is zero The orientation of the FITS image is indicated in the small window on the lower left of the SkyCat GUI 5 2 Reset Mode Pressing this button deletes all slits but keeps the reference targets and the guide stars 5 3 Load SetUp This menu item configures the initialized mask by reading all relevant telescope instrument and mask parameters from an x ms file which has been saved during a previous session Be careful to load the setup for the FITS image or catalog in use In case the wrong setup file is read no error message is issued but normally the mask image is no longer visible because it is located outside the sky area displayed in the SkyCat window The name of the FITS image associated with an 1ms file is listed in the comment lines at the top of the ms file 22 LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 23 5 4 Quit Mode This menu item deletes the mask and de activates all LMS features 5 5 Auto Slit The automatic positioning of MOS slits requires a catalog which lists at least source names and source positions Slits will be positioned on the catalog positions even if an FITS image with deviating source positions has been loaded together with the catalog Remember to take the reference targets also from the catalog and not from an underlying image Automatic MOS slit positioning works for several on line catalogs like GSC SIMBAD NTT archiv
58. teria are involved in slit placement Therefore high priority objects should be placed at the top of the catalog For details on how to set up a local catalog refer to chapter 4 Slit constraints 1 Individual slit lengths are restricted to 20 arcsec for mechanical stability reasons It is however not excluded to produce larger multi slits or unusual slit geometries by punching several individual slits next to each other with some space in between However such large multi slits may cause mask sheet bending and are thus to be discussed with the observatory staff 2 In LMS the number of slits has been limited to 200 In practice this limit should never be reached because it implies an average slit length of about 1 arcsec which is impractical 3 7 Saving Masks When all slits have been created the mask configuration has to be saved At this point three files all with the same name but with different suffixes are created 1ms x gbr epsf The 1ms file contains the information for telescope pointing and instrument rotation all slit parameters including slit center coordinates in WCS units not for the 6 reference apertures and in mask coordinates mm x and y the WCS coordinates of the reference targets and of the guide stars as well as the LUCIFER configuration parameters This file can be reloaded to restore the session It is also used as input to produce the telescope control system script for observation with this mask
59. to the image center is reloaded The mask can now be shifted all over a large FITS image without restric tions 2 Using the Auto Slit option with a rotated mask no longer changes the sign of the mask rotation angle LUCIFER LMS User Manual Issue 1 60 LBT LUCIFER MAN 030 2 3 Acheck for at least three reference star has been implemented A warning appears when the mask is saved with less than three reference stars 4 Adescription of how to generate a SkyCat compatible catalog has been added to the manual Changes made between LMS 1 53 and 1 60 1 The Auto S1lit functionality has been implemented in Tcl Tk The C code binary AP is obso lete This eliminates the problems with compiling the C code on operating systems other than LINUX 2 The part of this manual dealing with local catalogs and source lists has been rewritten 3 The display of the array back projection on the focal plane has been modified Only the contour of the accessible array area is plotted l e the full width of the array over which the spectra can extend is indicated but the height is limited to the field height 1 3 Abbreviations FOV field of view ISF instrument summary file LMS LUCIFER mask simulator WCS World Coordinate System Ra and Dec 1 4 Reference Documents The following documents are referenced in this document 1 FORS1 2 FIMS Manual VLT MAN ESO 13100 2308 2 The ESO SkyCat Tool Programmer s Manual VLT MAN ESO 19400 1552

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