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HAWK-I Template Reference Guide

1. EUROPEAN SOUTHERN OBSERVATORY Organisation Europ ene pour des Recherches Astronomiques dans l H misph re Austral Europ ische Organisation f r astronomische Forschung in der s dlichen Hemisphare ESO European Southern Observatory Karl Schwarzschild Str 2 D 85748 Garching bei M nchen Very Large Telescope HAWK I Template Reference Guide Doc No VLT MAN ESO 14800 4076 Issue 95 Date 27 August 2014 G Carraro and the HAWK I team Prepared ee eu is den debe eed bee eneeye ees Date Signature C Dumas Approved Name Date Signature A Kaufer Released Name Date Signature HAWK I Template Reference Guide VLT MAN ESO 14800 4076 il Change Record Issue Rev Date Section Parag affected Reason Initiation Documents Remarks 1 Oct 26 2004 all first version prepared for FDR 2 Mar 23 2007 all second version prepared for coding and PAE 3 Dec 03 2007 all P81 version for phase 2 81 0 Dec 23 2007 1 3 2 3 3 4 2 4 4 3 2 4 3 4 4 4 8 Correction of mistakes 81 1 Jan 8 2008 4 2 4 exposures and offsets 83 0 Dec 19 2008 4 2 4 minimum DIT 84 0 May 29 2009 4 2 4 minimum DIT and minor modifications 84 1 Jun 26 2009 4 2 4 change of offset scheme 86 0 Aug 02 2010 4 3 inclusion of Fast Photometry templates 88 0 Feb 07 2011 no news 91 0 Sep 06 2012 no news 92 0 Mar 01 2013 no new
2. positions are set by the parameter SEQ JITTER WIDTH i e the sky exposures are distributed in a box offset from the initial telescope position By default there is no random jitter offset before the first exposure The template allow the user to specify whether the starting observation will be on the object or on the sky this is done with the keyword SEQ OBSTYPE which should contain the type of the first observation The Number of AB or BA cycles defines the number of OBJECT SKY or SKY OBJECT cycles to be executed These cycles are executed in ABBA sequences E g if SEQ NABCYCLES is set to 3 then 6 exposures will be taken in an ABBAAB sequence In addition the template provides the flexibility to set independently the number of NDIT subintegra tions for the OBJECT and SKY frames SEQ NDIT OBJECT defines the number of subintegrations on the object and SEQ NDIT SKY defines the number of subintegrations on the sky The total integration time excluding overheads is defined in seconds by DIT x SEQ NDIT OBJECT SEQ NDIT SKY x NEXPO x SEQ NABCYCLES Thus the total integration time on the sky and on the object can be adjusted so that the S N on the object is optimised Remember that the 1 minute per telescope position rule her means that HAWK I Template Reference Guide VLT MAN ESO 14800 4076 16 6 fa Y A aa d CARS A a sel Ka Gg Ba DEC E Le Offset P A Sky Fositions A A AA SC Zo S Le ae G et e
3. HAWK I Template Reference Guide VLT MAN ESO 14800 4076 end it leaves the system in the dark position __ 000 29
4. DETECTOR Offset coordinate type selection SEQ QUADRANTS no 1 4 1234 Selected quadrants SEQ RETURN no TF T Return to origin SEQ SHOW GRAPH yes TF T Show quick look graphics Fixed values Parameter Hidden Value Label DPR CATG yes TECHNICAL Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes STD Data product type This template see Table 19 determines the zero point variations as a function of position on the detector mosaic It is used in combination with HAWKI_ img acq Preset see Sect to point towards a stellar field ideally containing a few hundred bright uncrowded sources A series of exposures is taken in a NXN grid of offsets 200 pix during stable conditions The resulting images are used to determine the relative photometry as a function of detector position The user can select one or all quadrants 4 4 3 HAWKI_img tec Astrometry Table 20 Parameters of HAWKI_img tec Astrometry HAWKI_img_tec_Astrometry tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no NODEFAULT Filter Name SEQ FILEID yes Astrometry Filename id SEQ NEXPO no 1 1000 1 Number of exposures SEQ NOFFSET no 1 1000 NODEFAULT Number of offsets within a box SEQ OBSTYPE LIST no OS 0 Observation type list O S SEQ OFFSET COORDS no SKY DETECTOR DETECTOR Offset coord
5. Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no NODEFAULT Filter Name SEQ ANGLE START no 180 180 SEQ ANGLE STEP no 1 100 SEQ ANGLE STOP no 240 240 SEQ FILEID yes Flexure Filename id SEQ NEXPO no 1 1000 1 Number of exposures SEQ OBSTYPE LIST no OS O Observation type list O S SEQ RETURN no T F T Return to origin Fixed values Parameter Hidden Value Label DPR CATG yes TECHNICAL Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes ASTROMETRY STD Data product type This template determines the absolute scale and flexure as the second step of the astrometry calibration It is used in combination with HAWKI_img_acq Preset see Sect It points towards a standard astrometric field configures the instrument and acquires one 1 image per position angle of the telescope adapter rotator as it scans the angles from SEQ ANGLE START to SEQ ANGLE END in steps of SEQ ANGLE STEP Typically this is part of the earthquake procedures and it is described in Table 21 4 4 5 HAWKI_img tec DetTest The characteristics of the detectors such as read out noise dark current bad pixels linearity persistence etc are monitored periodically This can be achieved with the calibration templates listed above in particular with HAWKI_img_cal Darks However several characteristics such as linearity and co
6. SKYOFFSET ALPHA and SEQ SKYOFFSET DELTA parameters The RTD is then set up to subtract this fixed pattern from all subsequently displayed images The integration time for the acquisition images is defined by the DIT and NDIT parameters After the first target image is acquired the observer can change DIT and NDIT interactively In the case of a fixed pattern if DIT and or NDIT are changed the telescope offsets again and the observer is given the option to store another fixed pattern before the telescope returns to the nominal position This loop can continue until the user has identified the target Once the observer is satisfied with the acquisition image he she is prompted for an offset to center the target This is done interactively by drawing an arrow on the screen with the left hand button of the mouse At this point a window which lists the pixel co ordinates at the start and the end of the arrow will appear The user can either accept the offsets cancel or edit the co ordinates directly If the offsets are accepted the telescope offsets by the desired amount and a new image 1The user nevertheless must check in the HAWKI User s Manual for the maximum brightness allowed as this template can not be used if the bright star violates those limits HAWK I Template Reference Guide VLT MAN ESO 14800 4076 8 is acquired The user is given the possibility to refine the position if necessary Once the user is satisfied the templat
7. SEQ WIN NY no 0 2048 2048 Nb of rows for each window stripe SEQ WIN STARTX no 1 127 1 First column of window within a stripe SEQ WIN STARTY no 1 2047 1 First row of window within a stripe TEL AG GUIDESTAR no NONE SETUPFILE CATALOGUE Telescope Guide Star Selection CATALOGUE TEL GS1 ALPHA no 0 0 RA of telescope guide star TEL GS1 DELTA no 0 0 DEC of telescope guide star TEL ROT OFFANGLE no 360 0 360 0 0 Position Angle on Sky deg TEL TARG ADDVELALPHA yes 100 100 0 Add Velocity Alpha TEL TARG ADDVELDELTA yes 100 100 0 Add Velocity Delta TEL TARG ALPHA no NODEFAULT TEL TARG DELTA no NODEFAULT TEL TARG EQUINOX no 2000 3000 2000 Equinox TEL TARG NAME no NODEFAULT Name of the Target Fixed values Parameter Hidden Value Label DPR CATG yes ACQUISITION Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes OBJECT Data product type TEL TARG OFFSETALPHA no 0 0 Alpha offset for the target arcsec TEL TARG OFFSETDELTA no 0 0 Delta offset for the target arcsec This is the acquisition template for the recently as of P86 offered Fast Photometry mode It is described in details in the User Manual Table 7 summarises its properties HAWK I Template Reference Guide VLT MAN ESO 14800 4076 10 4 2 Science Templates The four science observing templates provide various strategies for the nodding between object and sky positions and for the jitter offsets between the images taken
8. SETUPFILE CATALOGUE Telescope Guide Star Selection CATALOGUE TEL GS1 ALPHA no 0 0 RA of telescope guide star TEL GS1 DELTA no 0 0 DEC of telescope guide star TEL ROT OFFANGLE no 360 0 360 0 0 Position Angle on Sky deg TEL TARG ADDVELALPHA yes 100 100 0 Add Velocity Alpha TEL TARG ADDVELDELTA yes 100 100 0 Add Velocity Delta TEL TARG ALPHA no NODEFAULT TEL TARG DELTA no NODEFAULT TEL TARG EQUINOX no 2000 3000 2000 Equinox TEL TARG NAME no NODEFAULT Name of the Target Fixed values Parameter Hidden Value Label DPR CATG yes ACQUISITION Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes OBJECT Data product type HAWK I Template Reference Guide VLT MAN ESO 14800 4076 9 4 1 6 Fast Photometry Acquisition template Table 7 Parameters of Fast Photometry Acquisition template HAWKI_img_acq_FastPhot tsf To be specified Parameter Hidden Range Default Label DET DIT no 0 001 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ BADAG yes T F F Ignore AG SEQ BADAO yes T F F Ignore AO SEQ PRESET yes TF 7 Preset telescope SEQ SKYFLAT no T F 7 Take initial sky frame SEQ SKYOFFSET ALPHA no 10 RA offset to sky SEQ SKYOFFSET DELTA no 10 DEC offset to sky SEQ WIN NX no 0 128 128 Number of columns for each window stripe
9. exposures NOT a sum a fact that has to be kept in mind by the user when reducing the data HAWK I Template Reference Guide VLT MAN ESO 14800 4076 11 SEQ SHOW GRAPH This hidden parameter controls at execution time whether to display a utility window that shows the offsets that will be requested by the template It keeps track of which offsets have been observed and the current observation offset DET SATLEVEL This keyword controls the reading mode of the HAWAII 2RG arrays It is defined as 60 25 000 counts of the detector full well SEQ CATG This keyword can be either SCIENCE or TECH but for normal operation must be set only as SCIENCE Note that for all science templates if the template is aborted the telescope will return to origin i e the position on sky at the beginning of the template before any offset was performed 4 2 1 HAWKI_ img obs AutoJitter Table 8 Parameters of HAWKI_img_obs_AutoJitter HAWKI_img_obs_AutoJitter tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT DET SATLEVEL no 32768 40000 25000 SATLEVEL INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ CATG no TECHNICAL SCIENCE SCIENCE Observation Category SEQ FC ST yes T F F Use flexure compensation SEQ FILEID yes AutoJitter Filename id SEQ JITTER WIDTH no 5 60 NODEFAULT Jitter Box W
10. versus the average count level of the frame An image containing for each pixel the slope of the regression is the flat field frame 4 3 3 HAWKI img acq TwPreset Table 15 Parameters of HAWKI_img_acq TwPreset HAWKI_img_acq_TwPreset tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no NODEFAULT Filter Name SEQ PRESET yes TF T Preset telescope TEL AG GUIDESTAR yes NONE SETUPFILE CATALOGUE Telescope Guide Star Selection NONE TEL GS1 ALPHA yes 0 0 RA of telescope guide star TEL GS1 DELTA yes 0 0 DEC of telescope guide star TEL ROT OFFANGLE no 360 0 360 0 0 Position Angle on Sky deg TEL TARG ADDVELALPHA yes 100 100 0 Add Velocity Alpha TEL TARG ADDVELDELTA yes 100 100 0 Add Velocity Delta TEL TARG ALPHA no NODEFAULT TEL TARG DELTA no NODEFAULT TEL TARG EQUINOX no 2000 3000 2000 Equinox TEL TARG NAME no NODEFAULT Name of the Target TEL TARG OFFSETALPHA no 999 999 0 0 Alpha offset for the target arcsec TEL TARG OFFSETDELTA no 999 999 0 0 Delta offset for the target arcsec Fixed values Parameter Hidden Value Label This template does a simple telescope preset in view of taking twilight flats The instrument parameters should be set to values used in the subsequent imaging template so that the instrument will be already set up for the start of t
11. RETURN no TF 7 Return to origin SEQ SHOW GRAPH yes T F T Show quick look graphics Fixed values Parameter Hidden Value Label DPR CATG yes SCIENCE Data product category DPR TECH yes IMAGE Data product technique parameter is not changed The total number of images taken by this template is SEQ NEXPOx SEQ NOFFSET At the end of the template the telescope is returned to the original position if the parameter SEQ RETURN is set to true T If not the telescope is not moved at the end of the template The total integration time is defined in seconds by DIT NOFFSET x NEXPO x 5 NDIT i 1 where NDIT i are the elements of the List of NDIT 4 2 5 Fast Photometry template This template is used for windowed observations and it is described in detailed in the user manual It is offered only in BURST mode both for service and visitor operations HAWK I Template Reference Guide VLT MAN ESO 14800 4076 18 y E N Position Angle 45 deg gt e 4 3 5 gt e 8 jl 2 gt e 7 6 L L X Figure 4 Illustration of the HAWKI_img_obs_GenericOffset template The black dots rep resent the position of a star which was originally at the center of the field In this example SEQ OFFSET COORDS is set to DETECTOR and the the telescope is moved in X and Y according to the list of offsets E N Position Angle 45 deg L L X Figure 5 Illustration of the HAWKI_img_obs GenericOffset template The
12. a Er Object Positions g e RA Offset Figure 3 Illustration of the HAWKI_img obs FixedSkyOffset template The black dots in the central square represent the position of a star which was originally at the center of the field The other square represents the mean position of the SKY frames both DITxSEQ NDIT OBJECT xNEXPO and DITxSEQ NDIT SKYxNEXPO shall both exceed one minute of time 4 2 4 HAWKI_img obs_GenericOffset This template has the flexibility to do any sequence of telescope offsets either in detector or sky coordinates It is one of the most widely used templates see Table 11 Telescope offsets are defined as lists with the parameters SEQ OFFSET1 LIST and SEQ OFFSET2 LIST The offsets are relative to the previous position in RA and DEC or in X and Y depending on the SEQ OFFSET COORDS parameter and they are defined in arcsec Fig 4 and 5 show how it works Additionally the observation type can be defined for each image and is entered as a list in the parameter SEQ OBSTYPE LIST 0 stands for Object and assigns the DPR CATG header keyword to SCIENCE S stands for Sky and assigns the DPR CATG header keyword to SKY The number of exposures per offset is defined in the parameter SEQ NEXPO The number of offsets to be performed is determined by SEQ NOFFSET it can be different from the number of elements in the aforementioned offset lists Lists do not need to have the same length If the number of offsets is larger
13. a copy of the P2PP Manual available that can be found at http www eso org sci observing phase2 P2PPSurveys P2PP3Documentation html Observing blocks generally consist of an acquisition template and a small number of user selected science or calibration templates Notice that the target information is entered in what is called the Target package in the tabbed section located at the bottom of the P2PP tool window while the acquisition template describes how to acquire the target In addition service mode OBs contain the observing constraints set and the scheduling information which are entered in the same tabbed section of P2PP The observing templates which are described below are lists of keywords parameters of the respective templates that define the configuration and setup to be used for the respective observations Parameters are either available in P2PP for being set up by the user or they might be hidden from the user in P2PP when the value is frozen to a default in order to compact and to simplify the appearance of the parameter lists Hidden parameters can not be changed by the users but could be modified in real time by the instrument operators Since hidden parameters will be rarely changed during science observation runs we might not provide an extensive explanation in the template reference section 3 2 Acquisition and science templates Unlike for many other ESO instruments there are only a few templates available for HAWK I T
14. at the selected object and sky positions The most simple and recommended templates are AutoJitter and AutoJitterOffset AutoJitter will automatically take exposures in an AAAA sequence where A refers to the OBJECT position The GenericOffset template allows to specify any sequence of object and sky positions The FixedSkyOffset also automatically takes exposures in an ABBA sequence with positions jittered with respect to each other but nods to a fixed user defined sky position The respective A object positions are randomly jittered with respect to each other and so are the respective B sky positions FixedSkyOffset will take an ABBA or an BAAB sequence depending on whether SEQ OBSTYPE is set to O or S respectively The common parameters to these templates are described here DET DIT and DET NDIT are the user defined detector integration time DIT for all exposures target and sky and the number of DITs NDIT to be averaged by the electronics before the frame is written to disk While the DIT is common to both object and sky NDIT can be set independently for object and sky for all templates that move to a sky position Number of exposures per offset SEQ NEXPO defines the number of exposures to be taken at each offset position It can be set to values different from one 1 in the cases where more than one exposure shall be taken at each on off position before nodding to the next on off offset position For typical applicatio
15. black dots rep resent the position of a star which was originally at the center of the field In this example SEQ OFFSET COORDS is set to SKY and the telescope is moved in RA and DEC according to the list of offsets the stars move in the opposite direction HAWK I Template Reference Guide VLT MAN ESO 14800 4076 19 Table 12 Parameters of Fast Photometry template HAWKI_img _obs_FastPhot tsf To be specified Parameter Hidden Range Default Label DET BURST MODE no FT T Toggle Burst Mode DET DIT no 0 001 3600 NODEFAULT DIT secs DET NCORRS NAME yes NonDest NonDestNsamp Fowler Non destructive sampling readout mode FowlerNsamp NonDest name DET NDIT no 1 1000 1 NDIT DET NDITSKIP yes 0 0 DITs to skip DET NDSKIP yes 0 0 Samples skipped per DIT DET SATLEVEL no 32768 40000 25000 SATLEVEL INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ BADAG yes T F F Ignore AG SEQ BADAO yes T F F Ignore AO SEQ CATG no TECHNICAL SCIENCE SCIENCE Observation Category SEQ EVENT DATE no 0 Absolute date of future event SEQ EVENT TIME no 0 Absolute time of future event SEQ FILEID yes FAST Filename id SEQ JITTER WIDTH no 0 60 NODEFAULT Jitter Box Width arcsec SEQ NEXPO no 1 1000 NODEFAULT Number of exposures per offset SEQ NOFFSET no 1 1000 NODEFAULT Number of offsets within a box SEQ POISSON yes 1 100 10 Random throw generator SEQ RETURN n
16. de VLT MAN ESO 14800 4076 13 4 2 2 HAWKI_img obs_AutoJitter0ffset Table 9 Parameters of HAWKI_img obs_AutoJitter0ffset HAWKI_img_obs_AutoJitterOffset tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET SATLEVEL no 32768 40000 25000 SATLEVEL INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ CATG no TECHNICAL SCIENCE SCIENCE Observation Category SEQ FC ST yes T F F Use flexure compensation SEQ FILEID yes AutoJitterOffset Filename id SEQ JITTER WIDTH no 5 60 NODEFAULT Jitter Box Width arcsec SEQ NABCYCLES no 0 100 NODEFAULT Number of AB or BA cycles SEQ NDIT OBJECT no 1 1000 1 NDIT on OBJECT positions SEQ NDIT SKY no 1 1000 1 NDIT on SKY positions SEQ NEXPO no 1 1000 NODEFAULT Number of exposures per offset SEQ OFFS2B yes 0 100 3 Constant offset for 2 nd B SEQ POISSON yes 1 100 10 Random throw generator SEQ RETURN no TF 7 Return to origin SEQ SHOW GRAPH yes T F T Show quick look graphics SEQ SKYTHROW no 0 1800 NODEFAULT Sky Offset Throw Fixed values Parameter Hidden Value Label DPR CATG yes SCIENCE Data product category DPR TECH yes IMAGE Data product technique Figure 2 illustrates what the template does and Table 9 list the involved parameters This template moves the telescope alternatively between object and sky positions The ob
17. de star TEL ROT OFFANGLE no 360 0 360 0 0 Position Angle on Sky deg TEL TARG ADDVELALPHA yes 100 100 0 Add Velocity Alpha TEL TARG ADDVELDELTA yes 100 100 0 Add Velocity Delta TEL TARG ALPHA no NODEFAULT TEL TARG DELTA no NODEFAULT TEL TARG EQUINOX no 2000 3000 2000 Equinox TEL TARG NAME no NODEFAULT Name of the Target TEL TARG OFFSETALPHA no 999 999 0 0 Alpha offset for the target arcsec TEL TARG OFFSETDELTA no 999 999 0 0 Delta offset for the target arcsec Fixed values Parameter Hidden Value Label DPR CATG yes ACQUISITION Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes OBJECT Data product type This template is functionally identical to HAWKI_img_acq Preset apart from having a few more parameters see Table and it is intended for acquisition of RRM imaging OBs HAWK I Template Reference Guide VLT MAN ESO 14800 4076 7 4 1 4 HAWKI_img_acq MoveToPixel Table 5 Parameters of HAWKI_ img acq MoveToPixel HAWK img_acq MoveToPixel tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ PRESET yes TF 7 Preset telescope SEQ SKYFLAT no TF 1 Take initial sky frame SEQ SKYOFFSET ALPHA no 10 RA offset to sky SEQ SKYOFFSET DELTA no 10 DEC offset to
18. e finishes If the parameter SEQ PRESET is set to F then the telescope will not move This can be useful in visitor mode to use the functionality of the template setting up the instrument checking refining the position without having to fully preset the telescope again and thus saving a little time N B the interactive pop up windows are usually displayed before new images have arrived on the RTD Therefore users are strongly advised to carefully check that a new image has arrived before clicking on these windows e g for storing a fixed pattern for changing the DIT and NDIT The image displayed on RTD at the end of the template is saved to disk See Table 5 for details 4 1 5 HAWKI_img acq MoveToPixelRRM An identical version for RRM observations is available see Table 6 Table 6 Parameters of HAWKI_img_acq MoveToPixelRRM HAWKI_img_acq_MoveToPixelRRM tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ PRESET yes TF 7 Preset telescope SEQ RRM REGISTER yes FT T Register OB in RRM system SEQ RRM VISITOR no FT F Allow RRM activation in VISITOR mode SEQ SKYFLAT no TF T Take initial sky frame SEQ SKYOFFSET ALPHA no 10 RA offset to sky SEQ SKYOFFSET DELTA no 10 DEC offset to sky TEL AG GUIDESTAR no NONE
19. ence of e g a pinhole array to analyse the filter wheel reproducibility properly the data taken are then used to monitor the instrument s transparency throughput The used set of parameters is summarised in Table 23 Table 23 Parameters of HAWKI_img_tec_FilterWheel HAWKI_img_tec_FilterWheel tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT SEQ FILEID yes FilterWheel Filename id SEQ FILT1 LIST no Ks H J Y BrG OPEN NODEFAULT Filter 1 List SEQ FILT2 LIST no NB2090 CH4 NB1190 NB1060 H2 Filter 2 List OPEN NODEFAULT SEQ NEXPO no 1 1000 1 Number of exposures Fixed values Parameter Hidden Value Label DPR CATG yes TECHNICAL Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes FLAT Data product type One can give a list of filters for both filter wheel FW 1 and 2 The template starts working through the list given for FW1 It sets a filter e g J and takes an image then move back to the filter defined as first in that list and moves back i e to J and takes another image It was originally meant to test the filter wheel reproducibilty but not having e g a pinhole array it is not possible Instead we use this to take internal flats to monitor the transparency of the optics Once the OB ran through the list of FW1 it then repeats the same procedure for FW2 At the
20. entionally 24 HAWK I Template Reference Guide VLT MAN ESO 14800 4076 25 4 4 Technical Templates The technical templates serve to calibrate the instrument but cannot be used by the regular ob server Instead they are executed at regular intervals to monitor the instrument or adjust verify telescope or instrument parameters after an intervention 4 4 1 HAWKI gen tec StandBy Table 18 Parameters of HAWKI gen _tec StandBy HAWKI gen _ tec Standby tsf To be specified Parameter Hidden Range Default Label INS WHAT no DAY NIGHT CALIB DAY Fixed values Parameter Hidden Value Label This template puts the system in mode standby For the default value of the parameter INS WHAT DAY this means that the TCS is ignored and the instrument is set to standby See Table 18 HAWK I Template Reference Guide VLT MAN ESO 14800 4076 26 4 4 2 HAWKI_img_tec_IlluFrame Table 19 Parameters of HAWKI_img tec_IlluFrame HAWKI_img_tec_IlluFrame tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no NODEFAULT Filter Name SEQ FILEID yes IlluFrame Filename id SEQ GRID SIZE no 1 50 NODEFAULT Offset grid size SEQ NEXPO no 1 1000 1 Number of exposures SEQ OBSTYPE LIST no O S NODEFAULT Observation type list O S SEQ OFFSET COORDS yes SKY DETECTOR
21. h specified DIT and NDIT which should correspond to the DIT and NDIT of the exposure to correct for 4 3 2 HAWKI_ img cal TwFlats Table 14 Parameters of HAWKI_ img cal TwFlats HAWKI_img_cal_TwFlats tsf To be specified Parameter Hidden Range Default Label SEQ DIT ADJUST no T F T Adjust DIT SEQ DIT LIST no NODEFAULT List of DITs SEQ FILEID yes TwFlats Filename id SEQ FILT LIST no NODEFAULT Filter List SEQ NCYCLES no 1 100 10 Number of cycles SEQ NDIT LIST no NODEFAULT List of NDITs SEQ NEXPO no 1 1000 1 Number of exposures Fixed values Parameter Hidden Value Label DPR CATG yes CALIB Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes FLAT Data product type This template see Table 14 is the one currently used to obtain twilight flat frames for HAWK lI with the telescope at zenith and without tracking It is typically started up to one hour before sunset if red narrow band flat field are needed The template cycles through a series of filters to determine the best DIT and NDIT to obtain a high initial count level on the frames i e 25000 HAWK I Template Reference Guide VLT MAN ESO 14800 4076 22 ADUs After this exposures are taken cycling through the filters obtaining frames with fixed DIT and NDIT and decreasing count levels The pipeline processes the series of frames doing a linear regression for the count levels of each pixel
22. he instrument works in a single observing mode imaging The templates are listed below together with the short description of the functionalities HAWK I Template Reference Guide VLT MAN ESO 14800 4076 4 The functionality of the acquisition and science templates is generally identical to the equivalent ISAAC now decommisioned SW imaging templates Table 1 Acquisition and science HAWK I templates acquisition templates functionality comment HAWKI_img_acq_Preset Simple telescope preset recommended HAWKI_img_acq_PresetRRM Simple telescope preset for RRM observations HAWKI_img_acq_MoveToPixel Interactive target acquisition HAWKI_img_acq MoveToPixelRRM Interactive target acquisition for RRM observations HAWKI_img_acq_ FastPhot Acquisition in windowed mode science templates HAWKI_img_obs_AutoJitter imaging with jitter no offsets recommended for low density fields HAWKI_img_obs_AutoJitter0ffset imaging with jitter and random sky offsets recommended for extended objects HAWKI_img_obs_FixedSky0ffset imaging with jitter and fixed sky offsets when random sky is not suited HAWKI_img_obs_GenericOffset imaging with user defined offsets HAWKI_img_obs_FastPhot imaging in windowed mode When HAWK I will be upgraded to make use of the adaptive secondary UT mirror in 2015 an AO acquisition template will be added if its functionality cannot be merged into the regular acquisition templates 3 3 Calibration and technical template
23. he first science template No RTD image is dumped on disk at the end of this template No telescope guide star is used during twilight thus that set of parameters is hidden The guideprobe is parked automatically Parameters are specified in details in Table 15 4 3 4 HAWKI img cal SkyFlats This template takes images of empty fields during twilight to determine the flat field while the telescope is only tracking i e no offsets See Table 16 for details 4 3 5 HAWKI_img cal StandardStar This template is used for imaging standard stars in order to determine the zero point of the photometry It is similar to the HAWKI_img obs_GenericOffset template see Sect but the DPR keywords are set appropriately for automatic pipeline reduction i e DPR CATG CALIB DPR TYPE STD and DPR TECH IMAGE This template is used in combination with HAWKI_img_acq_Preset see Sect 7 HAWK I Template Reference Guide VLT MAN ESO 1 4800 4076 23 Table 16 Parameters of HAWKI_img cal SkyFlats HAWKI_img_cal_SkyFlats tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no NODEFAULT Filter Name SEQ FILEID yes SkyFlats Filename id SEQ NEXPO no 1 1000 1 Number of exposures Fixed values Parameter Hidden Value Label DPR CATG yes CALIB Data product category DPR TECH yes IMAGE Data product
24. idth arcsec SEQ NEXPO no 1 1000 NODEFAULT Number of exposures per offset SEQ NOFFSET no 1 1000 NODEFAULT Number of offsets within a box SEQ POISSON yes 1 100 10 Random throw generator SEQ RETURN no T F 7 Return to origin SEQ SHOW GRAPH yes T F T Show quick look graphics Fixed values Parameter Hidden Value Label DPR CATG yes SCIENCE Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes OBJECT Data product type This template offsets the telescope between exposures according to a random pattern of offsets automatically determined within the template It is ideal for long integrations on sparcely populated fields and does not require a long list of offsets to be defined The offsets are distributed randomly within a box whose size is defined by the parameter SEQ JITTER WIDTH in arc seconds with the condition that the distance between any two points in a series of ten values note SEQ POISSON is greater than a certain minimum This is intentionally done to ensure that the 5 frames before and after any frame are spatially not too close and can be safely used for creating sky frames without residual objects for sky subtraction 3The hidden SEQ POISSON parameter plays a dual role here note that it is not the seed for the random number generator In the first place it gives the number of contiguous frames that will satisfy a minimum distance constraint that is the distance between an
25. inate type selection SEQ OFFSET1 LIST no 600 600 NODEFAULT List of X or RA offsets arcsec SEQ OFFSET2 LIST no 600 600 NODEFAULT List of Y or DEC offsets arcsec SEQ RETURN no TF 7 Return to origin SEQ SHOW GRAPH yes T F T Show quick look graphics Fixed values Parameter Hidden Value Label DPR CATG yes TECHNICAL Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes ASTROMETRY OBJECT Data product type The astrometric solution is determined in two steps In the first step the average distortion solution is determined using the astrometry template described in this section and originally fol HAWK I Template Reference Guide VLT MAN ESO 14800 4076 27 lowing the method outlined in Anderson et al 2006 A amp A 454 1029 see RD 2 Now a new pipeline recipe has been developed in house and is part of the public HAWKI pipeline http www eso org sci software pipelines hawki hawki pipe recipes html In a second step the absolute scale and flexures are determined see below 7 This template is used in combination with HAWKI_img_acq Preset see Sect Any astrometric field can be used The template performs 25 large 200 pix offsets with 5 exposures of 60s in J at each offset Parameters are described in Table 20 4 4 4 HAWKI img tec Flexure Table 21 Parameters of HAWKI_img_tec_Flexure HAWKI_img_tec_Flexure tsf To be specified
26. ject positions of the telescope are randomly distributed around the object initial telescope position and within a box whose dimensions are set by the parameter SEQ JITTER WIDTH in arcsec The minimum value for this parameter is 5 arcsec By default there is no random jitter offset before the first exposure The sky positions are at a constant distance defined by the parameter Sky Offset Throw from the original telescope position but at an angle randomly distributed between 0 and 360 degrees i e the sky exposures are distributed on a circle surrounding the initial telescope position The Number of AB or BA cycles defines the number of OBJECT SKY AB or SKY OBJECT BA cycles to be executed These cycles are executed in ABBA sequences E g if Number of AB or BA cycles is set to 3 6 exposures will be taken in an ABBAAB sequence Notice that in the part of the cycle where two Bs are next to each other it is necessary to offset the second sky field from the first The offset for this second frame is determined by the keyword SEQ OFFS2B the telescope is offseted to the NE or SW depending on the sign of the value entered by an amount equal to SEQ OFFS2B In addition the template provides the flexibility to adjust the number of subintegrations NDIT separately for OBJECT and SKY frames SEQ NDIT OBJECT defines the number of subintegrations on the object and SEQ NDIT SKY defines the number of subintegrations on the sky The t
27. mplate This will save time In general one should not put objects of interest at the very center of the array as the four quadrants are spaced by 150 pixels HAWK I Template Reference Guide VLT MAN ESO 14800 4076 6 Table describes the parameters of this template No RTD image is dumped on disk at the end of this template If TEL AG GUIDESTAR is set to CATALOGUE then the guide star selection is left to the telescope operator who will interactively identify a suitable guide star from the GSC2 in which case the keywords TEL GS1 ALPHA and TEL GS1 DELTA will be ignored If TEL AG GUIDESTAR is set to SETUPFILE then the user has to specify the guide star by providing its coordinates in the keywords TEL GS1 ALPHA and TEL GS1 DELTA 4 1 3 HAWKI img acq PresetRRM Table 4 Parameters of HAWKI_img_acq PresetRRM HAWKI_img_acq_PresetRRM tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ PRESET yes TF 1 Preset telescope SEQ RRM REGISTER yes FT T Register OB in RRM system SEQ RRM VISITOR no FT F Allow RRM activation in VISITOR mode TEL AG GUIDESTAR no NONE SETUPFILE CATALOGUE Telescope Guide Star Selection CATALOGUE TEL GS1 ALPHA no 0 0 RA of telescope guide star TEL GS1 DELTA no 0 0 DEC of telescope gui
28. ns it remains set to one e g for classical ABBA sequences Number of AB or BA cycles SEQ NABCYCLES defines how often the AB cycle is repeated If set to one the template will take a simple AB sequence one offset If set to two it will take a ABBA object sky sky object sequence If set to three it will take a ABBAAB sequence an so on For best sky subtraction the number of cycles should be set to a value of two or larger Number of offset positions SEQ NOFFSET the above number of AB cycles is replaced in the AutoJitter and GenericOffset template by the number of offset positions NOFFSET In the AutoJitter template the offsets are determined randomly within a box In the GenericOffset template the offset positions are defined by the OFFSET1 and OFFSET2 lists Typically both lists will have the same length if not the shortest list and maybe even the longest list will repeat itself until NOFFSET frames have been obtained SEQ FC ST This keyword controls whether to use software flexure compensation During com misioning it was found that flexures were negligible so that the parameter is hidden and has the default value of F for all templates SEQ FILEID This parameter determine the string to be attached to the file names of the images in the instrument workstation It is hidden so it can not be set by the user it can only be set by the operator at Paranal 2 Note that the frames will contain the average of the NDIT
29. nversion factor require a set of internal flat fields with various illumination in order to be determined This is the purpose of this template Note however that HAWK I has no internal calibration source i e the images are acquired on the dark Nasmyth screen using the Ks filter see Table 22 4 4 6 HAWKI_img tec_FilterWheel This template is used to exercise the filter wheel and it is part of the daily instrument startup sequence It was originally meant to determine the reproducibility of the filter wheel positioning HAWK I Template Reference Guide VLT MAN ESO 14800 4076 28 Table 22 Parameters of HAWKI_img tec DetTest HAWKI_img_tec_DetTest tsf To be specified Parameter Hidden Range Default Label INS FILT NAME no NODEFAULT Filter Name SEQ DARKS NEXPO no 0 100 0 Number of dark exposures SEQ DET DIT LIST no 1 List of DITs SEQ DET DIT NSTEPS no 1 Number of DIT steps for each DIT LIST entr SEQ DET DIT STEPS no 0 DIT steps for each DIT LIST entry SEQ DET NDIT LIST no 1 List of NDITs SEQ DET NDIT NSTEPS no 1 Number of NDIT steps for each NDIT LIST entry SEQ DET NDIT STEPS no 0 NDIT steps for each NDIT LIST entry SEQ FILEID yes Det Test Filename id Fixed values Parameter Hidden Value Label DPR CATG yes TECHNICAL Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes FLAT Data product type recording thermal images of the Nasmyth screen In the abs
30. o TF 7 Return to origin SEQ SHOW GRAPH yes T F T Show quick look graphics Fixed values Parameter Hidden Value Label DPR TECH yes IMAGE Data product technique DPR TYPE yes OBJECT Data product type HAWK I Template Reference Guide VLT MAN ESO 14800 4076 This page has been left empty intentionally 20 HAWK I Template Reference Guide VLT MAN ESO 14800 4076 21 4 3 Calibration Templates With the exception of the StandardStar one these templates are only available to the users on the mountain They are used by the staff at Paranal to carry out the short amd medium term calibrations of the instruments A more detailed description of their utility can be found in RD 1 4 3 1 HAWKI_img_cal Darks Table 13 Parameters of HAWKI_ img cal Darks HAWKI_img_cal_Darks tsf To be specified Parameter Hidden Range Default Label SEQ DIT LIST no NODEFAULT List of DITs SEQ FILEID yes Darks Filename id SEQ NDIT LIST no NODEFAULT List of NDITs SEQ NEXPO no 1 1000 1 NEXPO per DIT in list Fixed values Parameter Hidden Value Label DET WIN NX yes 0 Number of columns DET WIN NY yes 0 Number of rows DET WIN STARTX yes 1 First column of window DET WIN STARTY yes 1 First row of window DPR CATG yes CALIB Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes DARK Data product type This template see Table 13 acquires a number NEXPO of darks wit
31. observation of a large astrometric field and to characterize the detector Two further technical templates are available to measure any flexure and misalignment with respect to the telescope optical axis rotating the instrument while observing a stellar field and to measure the positioning accuracy reproducibility of the filter positioning Other technical templates exist for instrument maintenance HAWK I Template Reference Guide VLT MAN ESO 14800 4076 5 4 Template Description 4 1 Acquisition Templates 4 1 1 Introduction Telescope presets can only be done via acquisition templates Telescope presets move the telescope to the requested coordinates and allow the telescope operator to select a telescope guide star and start the active optics Additionally these templates set up the detector and the instrument Observation templates on the other hand only deal with telescope offsets and not with telescope presets The HAWKI_img_acq MoveToPixel acquisition template dumps an image to disk the HAWKI_img_acq Preset template does not These dumped images are aimed at keeping track of the field position and orientation before starting the observation and are part of the images distributed to users In general it is not necessary for the acquisition and the subsequent observation templates to have the same DIT and NDIT 4 1 2 HAWKI_img_acq Preset Table 3 Parameters of HAWKI_img_acq Preset HAWKI_img_acq_Preset tsf To be
32. otal integration time excluding overheads is defined in seconds by DIT x SEQ NDIT OBJECT SEQ NDIT SKY x SEQ NEXPOXSEQ NABCYCLES Thus the total integration time on the sky and on the object can be adjusted so that the S N on the object is optimised Remember that the 1 minute per telescope position rule here means that both DITxSEQ NDIT OBJECT xNEXPO and DITX SEQ NDIT SKY x NEXPO shall both exceed one minute of time HAWK I Template Reference Guide VLT MAN ESO 14800 4076 14 Sky throw Jitter Box Width Object Positions Figure 2 Illustration of the HAWKI_img_ obs_AutoJitterOffset template The black dots in the central square represent the position of a star which was originally at the center of the field The other squares represent the position of the SKY frames HAWK I Template Reference Guide VLT MAN ESO 14800 4076 15 4 2 3 HAWKI_ img obs_FixedSky0ffset Table 10 Parameters of HAWKI_img obs FixedSky0ffset HAWKI_img_obs_FixedSkyOffset tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET SATLEVEL no 32768 40000 25000 SATLEVEL INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ CATG no TECHNICAL SCIENCE SCIENCE Observation Category SEQ FC ST yes T F F Use flexure compensation SEQ FILEID yes FixedSky Offset Filename id SEQ JITTER WIDTH no 5 60 NODEFAULT Jitter Bo
33. r of DIT NIR Near Infra Red NDR Non Destructive Read OB Observing Block OS Observing Software OT Observing Tool P2PP Phase 2 Proposal Preparation tool RRM Rapid Response Mode HAWK I Template Reference Guide VLT MAN ESO 14800 4076 QE RD RON RTD UT Quantum Efficiency Reference Document Read Out Noise Real Time Display Unit Telescope VLT 8m telescope HAWK I Template Reference Guide VLT MAN ESO 14800 4076 3 2 Instrument Modes and Configurations HAWK I has only one 2 instrument mode direct imaging and fast photometry Only the two filter wheels and detector can be configured set up in the instrument e Filters 4 broad band and 6 narrow band e Detector set up of the exposure time DIT NDIT NEXPO 3 Template Overview This section provides a brief overview of the HAWK I templates Each template is described in more detail in the subsequent sections 3 1 General remarks All scientific and calibration observations with ESO instruments are prepared by building observing blocks OBs as a sequence of the available templates for the specific instruments This is performed with the help of the phase 2 proposal preparation tool P2PP The scheduling of these OBs is done on the site with P2PP in visitor mode and with a special Observing Tool OT in service mode The execution of the OBs is then done with the broker of observing blocks BOB It will be convenient while reading this manual to have
34. s The calibration plan RD 1 describes in more detail the procedure to acquire the calibration data required by the scientific observations The currently available calibration and technical templates are the following Table 2 Calibration and technical HAWK I templates calibration templates functionality comment HAWKI_img_cal_Darks series of darks HAWKI_img_acq_TwPreset acquisition for flat field HAWKI_img_cal_TwFlats imaging twilight flat field at zenith no tracking HAWKI_img_cal_SkyFlats imaging twilight flat field at empty fields tracking only HAWKI_img_cal_StandardStar imaging of standard field technical templates HAWKI_gen_tec_StandBy set system to mode Standby HAWKI_img_tec_IlluFrame imaging of illumination field HAWKI_img_tec_Astrometry imaging of astrometric field HAWKI_img tec_Flexure measuring instrument flexure center of rotation HAWKI_img_tec DetTest detector test monitoring HAWKI_img_tec_DetLin detector linearity check HAWKI_img_tec FilterWheel filter wheel positioning accuracy The calibration templates are designed to obtain twilight flat fields dark frames standard stars for all broad band filters typically at the center of each detector The technical templates are used to obtain illumination frames by placing a standard star in several points of a regular grid on each detector an astrometric distortion solution either by jittered images of a dense astrometric star cluster field or the
35. s 94 0 Jun 14 2014 fixed some bugs spotted by C Dumas 95 0 Aug 27 2014 no news HAWK I Template Reference Guide VLT MAN ESO 14800 4076 Contents HAWK I Template Reference Guide VLT MAN ESO 14800 4076 1 1 Introduction 1 1 Purpose and Scope This document describes in some detail the observing calibration and technical templates for HAWK I The tables and descriptions are based on the HAWK I Instrument Package IP version 127 19 1 2 Instrument Summary HAWK I is a wide field 7 5 x 7 5 NIR 0 9 2 5 um camera operating only in direct imaging mode To completely define an exposure users have only to specify the target package that is target RA Dec and EPOCH plus non sidereal motion rates if any and the instrument configuration filter and exposure parameters DIT NDIT NEXPO and NOFFSETS 1 3 Applicable and reference documents 1 3 1 Applicable documents none 1 3 2 Reference documents HUM HAWK I User s Manual VLT MAN ESO 14800 3486 RD 1 HAWK I Calibration Plan VLT PLA ESO 14800 3214 P2PP P2PP User s Guide VLT MAN ESO 19200 1644 1 4 Abbreviations and acronyms AD Applicable Document ADU Analog Digital Units AO Adaptive Optics BOB Broker of Observation Blocks DCR Double Correlated Read DIT Detector Integration Time ESO European Southern Observatory ETC Exposure Time Calculator GSC Guide Star Catalogue HAWK I High Acuity Wide field K band Imager NDIT Numbe
36. sky TEL AG GUIDESTAR no NONE SETUPFILE CATALOGUE Telescope Guide Star Selection CATALOGUE TEL GS1 ALPHA no 0 0 RA of telescope guide star TEL GS1 DELTA no 0 0 DEC of telescope guide star TEL ROT OFFANGLE no 360 0 360 0 0 Position Angle on Sky deg TEL TARG ADDVELALPHA yes 100 100 0 Add Velocity Alpha TEL TARG ADDVELDELTA yes 100 100 0 Add Velocity Delta TEL TARG ALPHA no NODEFAULT TEL TARG DELTA no NODEFAULT TEL TARG EQUINOX no 2000 3000 2000 Equinox TEL TARG NAME no NODEFAULT Name of the Target Fixed values Parameter Hidden Value Label DPR CATG yes ACQUISITION Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes OBJECT Data product type This template presets the telescope and allows the operator to interactively center the field In visitor mode the interactive part of the template will be executed by the instrument operator under the supervision of the visiting astronomer In service mode it is mandatory that users send detailed information including finding charts for the field centering It should be used when very precise e g lt 2 3 centering of the field is required or to move a bright star to one of the gaps etc In general one should not put objects of interest at the very center of the array as the four quadrants are spaced by 150 pixels At the beginning of the template one fixed pattern image is acquired in an offset position defined by the SEQ
37. specified TEL TARG OFFSETALPHA TEL TARG OFFSETDELTA no no NB1060 H2 NODEFAULT 999 999 0 0 999 999 0 0 Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name SEQ PRESET yes TF 7 Preset telescope TEL AG GUIDESTAR no NONE SETUPFILE CATALOGUE Telescope Guide Star Selection CATALOGUE TEL GS1 ALPHA no 0 0 RA of telescope guide star TEL GS1 DELTA no 0 0 DEC of telescope guide star TEL ROT OFFANGLE no 360 0 360 0 0 Position Angle on Sky deg TEL TARG ADDVELALPHA yes 100 100 0 Add Velocity Alpha TEL TARG ADDVELDELTA yes 100 100 0 Add Velocity Delta TEL TARG ALPHA no NODEFAULT TEL TARG DELTA no NODEFAULT TEL TARG EQUINOX no 2000 3000 2000 Equinox TEL TARG NAME no NODEFAULT Name of the Target Alpha offset for the target arcsec Delta offset for the target arcsec Fixed values Parameter Hidden Value Label This template does a simple telescope preset It is the easiest template to use when objects can be easily identified against the sky background It should not be used if the user wants a pointing accuracy that is better than few arcsec The instrument parameters should be set to values used in the subsequent imaging template in order to have the instrument already set up for the start of the first science te
38. technique DPR TYPE yes FLAT Data product type Table 17 Parameters of HAWKI_img cal StandardStar HAWKI_img_cal_StandardStar tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET NDIT no 1 1000 1 NDIT INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ BADAO yes T F F Ignore AO SEQ FILEID yes StandardStar Filename id SEQ NEXPO no 1 1000 NODEFAULT Number of exposures per offset SEQ NOFFSET no 1 1000 NODEFAULT Number of offsets SEQ OFFSET COORDS no SKY DETECTOR DETECTOR Offset coordinate type selection SEQ OFFSET1 LIST no 600 600 NODEFAULT List of X or RA offsets arcsec SEQ OFFSET2 LIST no 600 600 NODEFAULT List of Y or DEC offsets arcsec SEQ RETURN no TF 7 Return to origin SEQ SHOW GRAPH yes T F T Show quick look graphics Fixed values Parameter Hidden Value Label DPR CATG yes CALIB Data product category DPR TECH yes IMAGE Data product technique DPR TYPE yes STD Data product type Note that the template serves to determine the zero point only illumination corrections see Thus it is enough to observe the standard at one position it is not necessary to scan each detector Its parameters are listed in Table 17 It is not used to determine HAWK I Template Reference Guide VLT MAN ESO 14800 4076 This page has been left almost empty int
39. than the number of elements in a list the list is restarted from the beginning as many times as needed until the correct number of frames have been acquired The lists can have any length however having lists of different lengths can become extremely confusing It is good practice to use lists of equal length or lists with only one value if one 4Note that now in this HAWK I does not differ anymore from the other ESO instruments HAWK I Template Reference Guide VLT MAN ESO 14800 4076 17 Table 11 Parameters of HAWKI_ img obs_GenericOffset HAWKI_img_obs_GenericOffset tsf To be specified Parameter Hidden Range Default Label DET DIT no 1 6762 3600 NODEFAULT DIT secs DET SATLEVEL no 32768 40000 25000 SATLEVEL INS FILT NAME no Ks H J Y BrG NB2090 CH4 NB1190 Filter Name NB1060 H2 NODEFAULT SEQ CATG no TECHNICAL SCIENCE SCIENCE Observation Category SEQ FC ST yes T F F Use flexure compensation SEQ FILEID yes GenericOffset Filename id SEQ NDIT LIST no NODEFAULT List of NDITs SEQ NEXPO no 1 1000 NODEFAULT Number of exposures per offset SEQ NOFFSET no 1 1000 NODEFAULT Number of offsets SEQ OBSTYPE LIST no O S NODEFAULT Observation type list O S SEQ OFFSET COORDS no SKY DETECTOR DETECTOR Offset coordinate type selection SEQ OFFSET1 LIST no 600 600 NODEFAULT List of X or RA offsets arcsec SEQ OFFSET2 LIST no 600 600 NODEFAULT List of Y or DEC offsets arcsec SEQ
40. x Width arcsec SEQ NABCYCLES no 0 100 NODEFAULT Number of AB or BA cycles SEQ NDIT OBJECT no 1 1000 1 NDIT on OBJECT positions SEQ NDIT SKY no 1 1000 1 NDIT on SKY positions SEQ NEXPO no 1 1000 NODEFAULT Number of exposures per offset SEQ OBSTYPE no OS 0 Type of first observation SEQ OFFSET COORDS yes SKY DETECTOR SKY Offset coordinate type selection SEQ POISSON yes 1 100 10 Random throw generator SEQ RETURN no TF 7 Return to origin SEQ SHOW GRAPH yes T F T Show quick look graphics SEQ SKYOFFSET ALPHA no 10 RA offset to sky SEQ SKYOFFSET DELTA no 10 DEC offset to sky Fixed values Parameter Hidden Value Label DPR CATG yes SCIENCE Data product category DPR TECH yes IMAGE Data product technique This template moves the telescope alternatively between object and sky positions The object positions of the telescope are randomly distributed around the object initial telescope position and within a box whose dimensions are set by the parameter SEQ JITTER WIDTH in arcsec The minimum value for this parameter is 5 arcsec The involved parameters are summarised in Table 10 while an illustration of what the template does in presented in Fig 3 The sky positions are also randomly distributed around a fixed offset position defined by the parameters SEQ SKYOFFSET ALPHA and SEQ SKYOFFSET DELTA from the original object tele scope position The box dimensions of the random sky
41. y pair in the set of contiguous frames will be at least dmin It is also HAWK I Template Reference Guide VLT MAN ESO 14800 4076 12 E N D Position Angle 45 deg LU x Figure 1 Illustration of the HAWKI_ img obs AutoJitter template The black dots represent the position of a star which was originally at the center of the field The value of the SEQ JITTER WIDTH parameter corresponds to the full width of the square box in which the offsets are generated Defining too wide a box may lead to poor image overlap Conversely too small a value may lead to poor sky subtraction near extended objects A value of 30 arcsec or less is adequate for sparcely populated stellar fields The minimum value is set to 5 arcsec Note also that the mosaic gap is approximately 15 so to ensure that all points on sky are sampled by a minimum number of observation the user should choose the SEQ JITTER WIDTH and the SEQ NOFFSET parameters appropriately By construction there is no telescope offset before the first exposure The parameters for this template are summarised in Table 8 and illustrated in Fig 1 The total integration time excluding overheads is defined in seconds by DIT x NDIT x NEXPOx NOFFSET used together with the dimensions of the jitter box Sx and Sy in the definition of dmin Sx x Sy dmin 4f SEQ POISSONV2 For more detail see Devillard 1999 ASP 172 333 HAWK I Template Reference Gui

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