In this ESO-MIDAS Courier
Contents
1. The display level is defaulted to F for full display and can be set to S for short and X for very short display Setting it to N produces no display Besides the descriptor STATISTIC some other descriptors are written updated in the STATIS TICS IMAGE command The integer descriptors WINDOW_FROM and WINDOW_TO are fi lled with the start and end pixels of the area specifi ed in the area parameter The real descriptor LHCUTS which contains the minimum and maximum of an image in LHCUTS 3 4 is only updated when the statistics of the complete frame are computed If a histogram is calculated also the real descriptor HIST_BINS and the integer descriptor HISTO GRAM are written to the image The number of bins and the binsize the low excess and high excess boundaries and the number of excess bins 0 or 2 are stored in that order in HIST_BINS Descriptor HISTOGRAM holds the histogram i e HISTOGRAM 1 number of pixels in fi rst bin which is the lower excess bin if lo hi_exc parame ter is given HISTOGRAM 2 number of pixels in second bin and HISTOGRAM n number of pixels in last bin which may be the high excess 2 By carefully choosing the excess bins also in that case one could get a good approximation of the median 3 If you convince your MIDAS site manager to add that line to the general login prg in MIDASHOME MIDVERS prim proc you have that defau2. European Southern Observatory MIDAS Courier Newsletter of the MIDAS Users Community Volume 5 Number Editorial During the last half year the MIDAS group experi enced an increasing impact of the VLT construc tion and its planned instrumentation on its activities The result is that we have entered the anticipated phase where most of the manpower in the MIDAS Group is spent on VLT related issues Examples are the in house development of the data reduction software for UVES ISAAC as well as further development of the on line functionalities of MIDAS in particular in the area of interprocess communication Because these on line capabilities will be part of the core of the forthcoming 9SNOV release sufficient time has been reserved for thor ough testing Therefore the release cycle for the 95NOV release has already started internally with a freeze of the a release last April In the first half of August the B test version will be frozen and will be sent to our external test sites allowing for two extra months of test time More about the 9ISNOV release can be found under General News on page 2 Although the VLT instrumentation now requires our attention also improvements and develop ments of data reduction software for La Silla have to continue To set priorities here in the beginning of the year the software tools ESO MIDAS offers for off line calibration and reduction of data com ing from
3. ESO and meant for announcements of releases and patches of ESO MIDAS Messages are archived in the same way as for the midas users mailing list and can also be retrieved by ftp To subscribe to these mailing lists send a mail to majordomo eso org with the following com mand in the body of your email message sub scribe midas users email or subscribe midas announce email where email should be your e mail address System News Several important features have been added in the MIDAS system software and will be available in the 9SNOV release The command SET MIDAS has been upgraded to support data fi les MIDAS procedures and executa bles in different directories SET MIDAS PATH directory specifi es a search path for MIDAS procedures executed with the command simi lar to the PATH variable in Unix SET MIDAS DPATH dir and SET MIDAS EPATH dir do the same for data fi les and MIDAS executables program modules All MIDAS applications accept images in FITS format as input i e you don t need to convert from FITS to the internal MIDAS format before access ing an image For example to display the FITS fi le myimage fits you can use LOAD IMAGE myim age fits directly New images however are always created in MIDAS binary format Tables in FITS format are not supported at the moment due to their possible very complex structure e g one FITS table can encapsulate several MIDAS tables Subframe
4. faint objects m lt 18 with high resolution R AA gt 20000 In the study of interstellar and intergalactic medium where the absorption lines from tenuous and relatively cold T lt 5 104 K clouds are sought in the spectrum of bright background sources this resolution allows to observe these narrow lines with an instrumental FWHM lower than their intrinsic width This makes it possible to derive independently the column density N and the Dop pler width rather than estimating them from the curve of growth analysis A typical application of these techniques is the study of the Galactic clouds that trace the gas content and the metallicity inside the Galaxy and of the absorption systems found in the spectra of high redshift quasars that trace the evo lution of the primordial structures While the reduction of echelle spectra to 1 dimen sional calibrated spectra may be accomplished with several packages like the Echelle context no similar tool existed for the analysis of their absorption features This is in part due to the diffi culty of designing an application which fulfi Is the from the fi tting of the line profi le requirements of providing a flexible easy to oper ate user interface and allowing to fi t lage systems composed of hundreds of lines The fi t of heavy element systems indeed may require the simulta neous fi t of diferent lines spread far away in the spectrum For these lines it is often necessary
5. for spec package solved for VMS Disabling interrupts for background processes Linux Help on line for Linux and Solaris Script cleanm sh works for OSF 1 Bug fi xed in EDIT ABLE on VMS LD_LIBRARY_PATH not necessary any more for Solaris Simplifi cation of CCD keyword initialization Correction for CCD read out direction COLUMN ROW Fix LOAD LUT with non interpolated LUTs Error on Solaris solved for EXTRACT OPTIMAL in the ECHELLE context Segmentation violation fi xed for IBM 6000 with CREA GUI HELP Corrected long slit command RESPONSE LONG New GUIs XFilter Requires calibration data Speed up LOAD IMAGE More precise help text and error message for DECONVOLVE IMAGE Bug fi xed for APPEND option in OUTWPE FITS on OSF 1 Initialize IDIDEV correctly STATIST IMAGE with cursor option had strange character trailing in output Solaris 2 3 Make parameter type check in procedures more robust Add support for zoom windows to the EXTRACT TRACE command Modify output format for values to fi x problems on IBM AIX Skip warnings on missing fi les when using in INTAPE command Fix setting of graphics cursor if display window open CENTER GAUSS can handle data with low values e g 10e 15 Correction row col numbers on top of plot Monitor does not print ERROR IN CHILD for executables located on midwork New GUI CREATE GUI FILTER calibration data in calib directory Ne
6. 364 Report Reports PRs In the start the usage of the GUI in the XHELP button FEEDBACK was rather dis appointing most of the incoming PRs more than 90 were composed using normal editing tools That situation has slightly improved currently around 30 of the PRs conform to the GNATS format standard that facilitates automatic handling by the GNATS system and faster processing by the MIDAS Group With the improved GUI see below we hope that this number will further increase ESO MIDAS Problem Reports Received per month 70 May 94 Jun 94 Jul94 Aug 94 Sep 94 Oct 94 Nov 94 Dec 4 Jan 95 Total Problem Reports received 364 Figure 1 Histogram distribution showing the number of MIDAS Problem Reports received in the period May 1994 till January 1995 Newsletter of the ESO MIDAS Users Community ESO MIDAS Courier Vol 5 No 1 July 1995 ESO MIDAS Problem Reports Time Received to Feedback Figure 2 Distribution of the feedback time i e time between open and feedback state The feed back time ordinate in days is plotted for all 364 PRs abcissa received in the period May 1994 left till January 1995 right In spite of the fact that the majority of incoming PRs were actually requests for support two thirds 66 2 of the PRs were sent using the class sw bug which almost certainly resulted from the default setting of the class fi eld The other scores 1995 They reflect the PR s related t
7. 94NOVpl1 patches_94NOVpl1 1 tar Z 150 KB 94NOVpl1 patches_94NOVpl1 2 tar Z 305 KB Notes 94NOVpl10 0 is not available any more by ftp patches_94NOVpl0 1 upgrades your old 94NOVp10 0 to 94NOVp11 0 94NOVpl1 tar Z is the complete MIDAS distribution for 94NOVpI1 0 patches_94NOVpl1 1 is an upgrade for 94NOVp11 0 patches_94NOVpl1 2 is an upgrade for 94NOVpl1 1 The next patch release 94NOVp 2 0 will be available in July 1995 New in 94NOVp I0 0 Compared to 93NOV ANSI C and POSIX 1 compliance for MIDAS Standard Interfaces 64bits CPU architectures supported DEC OSF1 PLOT package in ANSI C including 3 dim tables Redirection of Input Output for MIDAS commands supported Refurbishment of the DO Data Organizer package The GUI for the DO package Access to tapes implementation of the Generic tape driver Compared to 94MAY The GNU readline library as the default line editor Data Decompression on the fl y for compressed FITS fi les Access to Remote Tapes with Machine independent Data Structures Upgrade of the CCD context Upgrade of ECHELLE and LONG contexts The GUI for the IRSPEC package A New Astrometry context GNATS The New Problem Report System Upgrade of GUI XHELP including a problem report form Newsletter of the ESO MIDAS Users Community 14 ESO MIDAS Courier Vol 5 No 1 July 1995 Upgrade of Display Subsystem New or fixed in 94NOVpI1 0 Compilation problem
8. PUTE IMA res blabla 12 bdf 20 Correct keyword naming max 8 chars Bug fi xed in MODIFY GCURSOR for 1 dim frame Fix column area mode with exact median for STATIST IMAGE Make the DIserver more robust 15 Newsletter of the ESO MIDAS Users Community 16 ESO MIDAS Courier Vol 5 No 1 July 1995 The ESO MIDAS Courier is published twice per year by the ESO MIDAS Group of the European Southern Observ atory Contributions as well as suggestions and comments are invited and can be sent to the editor In particular authors of ESO MIDAS application software that would be of general interest for the ESO MIDAS community are invited to make this software available If you are not on the mailing list and want to receive future issues of the Courier contact the editor More updated information about ESO MIDAS can be obtained from the ESO MIDAS Bulletin Board accessible via anonymous ftp or via WWW The ESO MID ASTM Courier The following MIDAS Support services are available Editor Rein H Warmels for sending suggestions comments or to obtain help Typeset by FrameMaker TM when problems arise Published by the European Southern Observatory Karl Schwarzschild Stra e 2 Telephone 49 89 32006456 D 85748 Garching bei M nchen Telex 5282822 eso d Federal Republic of Germany attn ESO MIDAS Telefax 49 89 3202362 attn ESO MIDAS EARN MIDAS DGAESOS51 Internet midas eso org Anonymous ftp _ftphost hq e
9. Sera AOPEN originators within ESO The Temang 15 change request Display Graphical User Interfaces percent of the PRs come from other coun a A n rapnics ontext Bcneile tries with the US as the main source The Priority medium relatively high number of PRs from ESO can be explained by the usage of MIDAS Originator Rein Warmels Release bg4Novpld at the telescopes at La Silla and software development by others than MIDAS Group members at ESO In Figure 1 the number of PR s in the period May 94 Jan 95 is displayed One can clearly recognise the two peaks in the distribution in June 1994 and January Figure 3 The new layout MIDAS Problem Report Graphical User Interface gener ated by the FEEDBACK button on the XHelp GUI With respect to the previous version the layout has been simplified The buttons on the right now show less ambig uous definition of the various PR catego ries The context button sets the specific MIDAS context to which the PR applies OK Environment System SunOS ns2 4 1 3 1 sundm Architecture sung Command Synopsis Describe here the problem indicate if relevant how to repeat and how to fix it Save As Clear Cancel Newsletter of the ESO MIDAS Users Community excluded around one to two days Problems that take more time to resolve are generally not related to applications but mostly fall in the category sys gt tem A New Graphical User Interface Clearly th
10. Vir tual Machine PVM message passing library which is available in the public domain PVM is written in C language with also a Fortran interface Such a library provides the necessary tools to write multiplatform applications PVM has been devel oped jointly by University of Tennessee the Oak Ridge National Laboratory and Emory University Although other similar products are available we have focused our attention on PVM because it is available for a large number of platforms Newsletter of the ESO MIDAS Users Community 10 A metacomputing environment is based upon four basic tools a Metacomputer Defi nition tool a Scheduler a Master process and one or more Slave processes We have attempted to defi ne a para metrization for the whole system allowing the sys tem manager to easily redefi ne the Metacomputer For each Extended MIDAS command one enters one or more descriptive entries in the Metacom puter Defi nition ble Each of these entries includes the command name the target hostlist the target executable pathname the maximum allowed memory occupation and a weight parameter defi n ing in some so far arbitrary scale the host per formance in executing the given command The Metacomputer Defi nition Bol should in principle be used to maintain a dynamic defi nition of the meta system to account for new CPUs machines temporarily unavailable restrictions on the Meta computer processes on given CPUs etc The Schedule
11. e introduction of the GNATS system has helped in managing the incoming problems more effi ciently than in the past In addition the GNA S PR database and tools offer possibilities to query through the PR s and do statistics that improve our understanding of the MIDAS usage and problems However the other goal i e to have a largely auto matic administration of the PR is not reached yet As mentioned in the introduction a prerequisite for ESO MIDAS Courier Vol 5 No 1 July 1995 that is a correct format of the PR This can be obtained by using the PR GUI in the XHELP GUI using the FEEDBACK button We would like once again to draw your attention to the XHELP GUI and its FEEDBACK button in order to facilitate easy forwarding of PR s and automatic processing We have improved the lay out of the interface by eliminating less relevant buttons and by redefi ning some category buttons In addition the default PR class is now support PRs related to a context can be indicated by push ing the context button which pops up a listing of the available contexts Figure 3 contains a repro duction of the new PR FORM We hope it will enjoy rapidly growing usage FITLYMAN A New Tool for Absorption Spectra Analysis Adriano Fontana Osservatorio Astronomico di Roma Pascal Ballester European Southern Observatory Introduction The introduction of Echelle spectrographs on 4 m telescopes has allowed the observation of
12. either by answering at a sequence of questions that guide the user to the correct sequence of operations to be preferred when new lines are defi ned or by Normal ized Flux wo oO N a Wavelength cA gt Loading amp initializing data gt Wait please lt n adone gt Spectrum from 5200 05 to 7021 63 18212 points FITLYMAN MENU FILE PARAMETERS OPERATIONS GRAPHICS lsa V e session New 3S TANDARD MINIM define W indow Riecover session I terate edit Param Plot Backwards se Tiup load from lo G fileedit Limits plot Forward E ND edit Minuit Cursor Direct minimize FIT LYMAN 25 AUG 34 FE Purpose FIT LYMAN is an interactive program For the fitting of absorption lines in high resolution spectra It uses a menu driven interface to allow the user to specify the lines to be fitted and displays the data on the default graphic window It performs a global chi square minimization using the MINUIT package developed at CERN A complete trace of all the fits performed is stored in suited tables and can be used to re start minimization For a full explanation of the menu functions please refer to the manual Syntaxi FIT LYMAN spec outtab log session eraphiY N spec spectrum in table Format Table must contain 4 columns WAVE STDEV MORMFLUX and FU Tt can be crea
13. ems e ANSI FORTRAN 77 and ANSI C compilers e PostScript for hardcopy e RPC and TCP IP sockets for interprocess communication New developments and releases will be verifi ed only on a limited set of UNIX platforms available to us locally and conforming to the specifi cations above This policy will only have a limited impact on current VMS users of MIDAS as VMS OpenVMS is unlikely to change signifi cantlythe current version of MIDAS runs on these platforms and OpenVMS offers POSIX compatibility The main concern would be that new applications are not tested automat ically The reduced level of testing for VMS OpenVMS has been discussed with all current MIDAS VMS sites and in the ESO Users Committee before the decision was made We will make a beta release of MIDAS available to a user site willing to perform the validation of the VMS installation of MIDAS General System and Application News The MIDAS Group European Southern Observatory General News New Release 9SNOV The new release of MIDAS release 9SNOV is now in its alpha state This release will be of importance for the commissioning of the VLT instruments since it will include the communica tion routines needed for the on line use of MIDAS at the VLT Because of the importance we have anticipated an extended test period and plan to release the B release in August Test reports for the B release are as usual expected to come until the beginning of Novembe
14. ewsletter of the ESO MIDAS Users Community fi er whose value is stored in the output table At the same time the full initial confi guration together with the same identifi ey is stored in three log tables At a later time these tables can be either consulted for the interpretation of the results or used to re start the minimization Fur thermore a batch procedure BATCH LYMAN is supplied which allows for the automatic non interactive fi t of a whole spectrum using the confi gurations stored in the log tables The User Interface of FITLYMAN has been designed to satisfy two different and almost oppo site requirements it must allow the user to handle and modify all the parameters needed for the mini mization reducing as much as possible the time required to do it To fulfi 1 the MIDAS requirements ESO MIDAS Courier Vol 5 No 1 July 1995 about compatibility with any kind of terminal and environment we have designed a menu driven User Interface that uses both the standard I O devices keyboard screen and the standard MIDAS graphic window An example of a working session with FITLY MAN is shown below It introduces the user to all the functions available in the program such as modifying the input parameters loading saving previous confi gurations modifying the set up options of the program or accessing the graphic device The parameters that specify a line confi gu ration may be entered or modified
15. frame the Point Spread Function and the number of itera tions The command fi rst checks the loads of the various CPU servers predefi ned for the command The most suitable one could be another worksta tion in Arcetri or e g the Connection Machine 200 at the Scuola Normale Superiore in Pisa The weight factor specifying the performance of the CM200 should in principle include also an esti mate of the larger cost of transferring the data to Pisa and back so that a slightly slower CPU in Arcetri would be preferred if available The user will be unaware of the computer actually perform ing his calculations In another case a user might want to carry out a median fi Iter operation which is available in a fully parallel multi CPU version In this case the Scheduler would fi nd in the Metacomputer defi ni tion table both entries for single CPUs and multiple CPUs entries The most suitable entry therefore could be in principle either a single machine where only one Slave process carries out all the calcula tions or a number of inhomogeneous CPUs each elaborating a portion of data The actual splitting and pasting back of the data of the various Slave processes must be carried out by the Master At the current stage of our implementation the Metacomputer defi nition and the scheduling algo rithm are static and only very few commands have been implemented Deadline for the next ESO MIDAS Courier The next issue of the ESO MIDAS C
16. g pixel coordinates since it does not bother with other statistical quantities it is usually faster The application procedure histogram re calculates the histogram of an image and copies it to a 1 dim frame For example a histogram tiburon balena will calculate a histogram with 256 bins of frame tiburon bdf and store it in the frame balena bdf The context STATIST provides more specialized Statistical applications and tests SET CONTEXT STATIST will enable the commands ASSOCI ATE RANK COMPARE 2SAM FTEST VAR KSTEST 1SAM and STEST MEAN which work on columns of tables See the help of these com mands for more detailed information 4 Unless you want to check the drawing speed of your X ter minal 5 For fi nding other specifi c pixel values check out the FIND PIXEL command Newsletter of the ESO MIDAS Users Community ESO MIDAS Courier Vol 5 No 1 July 1995 13 MIDAS 94NOV Patch File Summary from the ftp account The following text contains a listing June 1995 of patches for the ESO MIDAS for the 94NOV and release The patch fi les can be obtained fom ft phost hq eso orgor 134 171 40 2 Message courier 168 MIDAS 94NOV Release Patch Information FTP location for 94NOV and patches Ftp host ftphost hq eso org 134 171 40 2 Directory 94NOV Files README vms README unix 94NOVp10 patches_94NOVp10 1 tar Z 593 KB 94NOVpl1 tar Z 11 MB
17. institutes in Europe and in the US What will happen to the unlucky ones who will fi nd themselves with 100 8192 x 8192 pixel images from their latest VLT run and will need to reduce the data on a three genera tions old UNIX box The answer to the question lies in metacomputing A metacomputer is simply a number of inhomoge neous computers interconnected by a hopefully fast network able to solve a single suitably well posed problem The Italian National Research Council CNR and the national phone company Telecom have experimentally installed in Pisa and Florence a fi ber optics network running at 110 Mbit s with a 34 Mbit s interconnection between the two cities Such a network has been the ideal ground for experimenting with a meta computer version of MIDAS Our goal was to be able to run MIDAS on a metacomputer in a fully transparent way i e the user does not know and does not need to know which computer is actually computing for him The system must take care of all this The user sits quietly on his good old work station and issues commands as usual the most computationally expensive commands however are not executed locally The command and the rel evant data are sent through the network to some suitably powerful computer which returns the result automatically when fi nished Our initial goal is to test the principle rather than produce a com plete Metacomputer MIDAS Our implementation is based upon the Parallel
18. l F and H the median value is approxi mated via the histogram of the image to speed up the execution time This works pretty well if there are no runaway data like e g saturated columns in a CCD frame which are far outside the rest of the data intensity range In that case you get a meaningless approximation of the median value because of the large size of the bins of the histo gram Therefore two more statistics levels G and X are Newsletter of the ESO MIDAS Users Community 12 supported which calculate the precise value of the median implying that the complete image or cho sen area of it has to be sorted Level G is like F full statistics generating all statistical quantities the histogram and the exact median level X is like R reduced statistics but additionally produces the exact median The difference in execution time for the F or G sta tistics level is negligible for small frames i e images with up to 512 512 pixels For larger images however the exact calculation of the median takes signifi cantly longer approx 4 times for a 1024 1024 image and about 7 times for a 2048 2048 image The default statistics level is still F because of backwards compatibility You can change that eas ily via the CREATE DEFAULTS command i e put the line CREATE DEFAULTS STATIS TICS IMAGE GF into your private login prg and STATISTICS IMAGE will always calculate the exact median
19. limits of the regions Tables with such columns are for example generated by the GET CURSOR com mand with table output For 2 dim images the ROW and COLUMN options indicate that the sta tistics should be done on all rows or columns indi vidually For 3 dim images the PLANE option does the statistics on all xy planes of the cube Since these options have to be distinguished from table names they have to be entered exactly e g COLUMNS will be interpreted as using the table option with table COLUMNS tbl as input however upper or lowercase does not matter The next two parameters bins and lo hi_exc deter mine the no of bins used in the histogram calcu lated from the input image You either enter the no of bins via n for n bins or the size of each bin then the no of bins is calculated from that value inside the STATISTICS command The default is 256 bins If you want to avoid outlying pixel values you can specify the beginning and end of the data interval you want to work in via the lo hi_exc parameter which specifi es low and high excess val ues i e the end of the lower excess bin and the 1 For table freaks the STATISTICS TABLE command plays a simi lar role start of the higher excess bin in the histogram Then the histogram and all other statistics will be calculated only in that interval The number of bins will be incremented by two e g in the default case we have 258 bins in the resulting his
20. links relations among them that refl ect the physical condition in the cloud responsi ble for the absorption The lines can be forced to share the same velocity relative to the earth red shift the same column density N and or the same b value Of course both the thermal bx and or the turbulent by component of b will be properly scaled with the masses of the ions Any combination of lines and links is allowed the only limit being the maximum number of independent parameters that the program can handle currently 100 In general the number of free parameters depends on the kind and number of link imposed for instance when the lines are forced to have the same absorption redshift there is only one actual free parameter i e the redshift not one for any individual central wavelength The absolute freedom in specifying links with these rules is a powerful tool when the ionization and metallicity of a system is investigated and also to correct for possible systematic errors for instance two lines far away in the spectrum e g Sill 969 and Sill 52 6 might be forced to have the same b and N but different redshifts to allow for some wavelength calibration uncertainties The input data have to be stored into a MIDAS table containing wavelength normalized flux standard deviation and instrumental FWHM for each pixel A tool for the conversion of the usual image data to this format is supplied Both pixel size and resolu
21. lt for all users at your site ESO MIDAS Courier Vol 5 No 1 July 1995 binn HIST_BINS 1 Whereas STATISTICS IMAGE produces one set of statistical quantities when used on the complete frame or single subframe of it all other area options generate this set for each of the specifi ed subframes e g for all rows with the ROW option Setting the parameter outtab to a table name indi cates that all the output should be stored in that table In particular the minimum will be stored in a column labelled MIN the maximum in a column labelled MAX and so on The outtab parameter is ignored if the full frame or just one subframe is processed The last parameter is the plotflag which controls the plotting of the computed histogram so it is only applicable to statistics levels F G or H It can be set to P Plot or N NoPlot to switch the plot ting on or off If no graphics window exists it is created with default sizes Specifying the plotfl ag as P with the area options ROW or COLUMN is normally not very useful The values which are stored in descriptor STA TISTIC are also saved in the real keyword OUT PUTR so they can be used by other MIDAS applications Also the total no of pixels and the pixel numbers of the minimum and the maximum are saved in the integer keyword OUTPUTI Like STATISTICS IMAGE the command FIND MINMAX fi nds the minimum and maxi mum value of an image and the correspondin
22. n the 94NOV release midas 94NOV monit communi c Application News Upgrades of CCD context The CCD package has been upgraded The pipe line processing is now exclusively based on the Data Organizer association table A separate reduc tion table is not needed any longer Also the flat sky and illumination frames can now be used in the pipe line calibration procedure As a result of the CCD monitoring programme of the La Silla CCDs Newsletter of the ESO MIDAS Users Community the MIDAS test procedures to analyse the test data have been upgraded For more information about the CCD test package see the previous issue of the Courier FITLYMAN package A new package for the analysis of absorption spec tra has been implemented in the Lyman context The context has been developed at the Osservato rio Astronomico di Roma and allows for fi tting of Voigts profi les to a lage number of absorption lines in a normalized spectrum A detailed descrip tion can be found on page 6 Echelle package and XEchelle The Echelle context has been refurbished to sup port world coordinates allowing to use different sub windows of the CCD in the same calibration run A Graphical User Interface has also been ESO MIDAS Courier Vol 5 No 1 July 1995 developed for this version of the package An arti cle describing the new features in more detail will appear in the next issue of the Courier This new version of the package and the GUI
23. o the installa tion of the 94MAY and the 94NOV releases Apart from these two peaks the average number of PRs is about 30 a month i e one or two per day Obviously for MIDAS users all what counts is the actual time that elapses between sending the PR and receiving a solution or at least a work around The GNATS PR system as we use it knows four states of the PR open analysed feedback and closed To measure the response time we have used the time between when the PR has been received and has entered the open state and the time when it has turned into the feedback state When entering this state the problem is supposed to be solved and a note is sent to the originator for checking Figure 2 shows the feedback time for each PR The high peaks in the fi gure with feedback times of over 20 days have been identifi ed as PRs that either were duplications in the PR data base Because of the default setting or otherwise incorrect or incor rectly treated PRs As can be seen in the last part of the fi gure these administrative problems have been solved after November 94 The average feedback time is provided the outliers in the fi gure are Problem Report F r in the class fi eld were support 25 4 i ass ategory doc bug 3 6 change request 3 4 support Installation Tables Around 50 percent of all PRs come from sw bug Distribution Help amp Documentation ESO member states and 35 7 percent have aati
24. ourier Volume 5 Number 2 will be published in the month of December 1995 This issue will include information concerning on going projects of the MIDAS Group Please send your contributions preferably in computer readable format to the MIDAS account or to the editor before October 31 1995 see back page for mail address Newsletter of the ESO MIDAS Users Community ESO MIDAS Courier Vol 5 No 1 July 1995 11 Expeditions in the MIDAS Jungle Counting Pixels Klaus Banse European Southern Observatory This time we want to have a closer look at the com mand which most likely is the very fi rst command you execute on a newly acquired frame namely the STATISTICS IMAGE command It is quite a complex command with numerous options which we will explore in some detail The fi rst one is thearea parameter which specifi es on which part of the image we want to compute the statistics By default we work on the complete frame specifying a subframe in the usual MIDAS syntax restricts the statistics to only that part of the image The other options do the statistics on multiple subframes If the image is currently dis played we can use the option CURSOR to choose via a cursor rectangle the subframes regions of the image where we calculate the statistics in Another way to work on different subframes is to use the table option by giving a table name This table should contain standard columns containing the
25. r After fi nal verifi cation the offi cial 9SNOV will then be announced and distributed Patches for the 94NOV release Till now three patch levels for the 94NOV version have been released 94NOVpl1 0 94NOVpl1 1 and 94NOVpl1 2 They can be obtained from the anonymous ftp account from the directories 94NOV unix and 94NOV vms More details about these patches can be found in the back of this Cou rier New patch levels will be announced via the midas users mailing list see below MIDAS mailing lists The midas users andthe midas announce Newsletter of the ESO MIDAS Users Community ESO MIDAS Courier Vol 5 No 1 July 1995 mailing lists are installed to facilitate discussions about ESO MIDAS and to inform its users The midas users mailing list is un moderated Articles will be sent to the e mail addresses of the subscribers as they are posted All messages to the list are archived The archives are available via Majordomo using the get midas users lt filename gt command send index midas users in the body of a message to majordomo eso org for the index of fi les you can get or via anonymous FIP from host ftphost hq eso org in directory midaspub midas users The archives are broken down by year and month and are stored in fi les named midas users YYMM The copy of the archive available by anonymous FTP is updated every night at 2am local time The midas announce list is moderated by
26. r receives a request from the Master process concerning a given command to be exe cuted It checks the Metacomputer defi nition and chooses the most suitable CPU to execute the com mand based on the given restrictions and ideally on a scheduling algorithm aimed at achieving CPU load balance Once the most suitable entry in the Metacomputer Defi nition ble has been selected the Scheduler returns this information to the Mas ter which activates the processes on the usually remote host s and transfers the relevant data The Master process is from the fi nal user point of view simply the Extended MIDAS command which is issued However in our scheme the Mas ter manages inter process synchronization and data transfer All dialogue between the Master and the other processes and tools remains fully hidden and the user is totally unaware of which CPU s is are actually performing the calculation he needs The Slave processes are the ones that actually carry ESO MIDAS Courier Vol 5 No 1 July 1995 out the calculation In the simplest case there is only one slave process active In some cases the calculation itself can be parallelized and therefore several processes can be activated on different hosts Let us focus on some concrete examples A user in Arcetri with a limited CPU power workstation needs to carry out 50 iterations of a Richard son Lucy deconvolution on a large image He specifi es simply the input frame the output
27. rs are the central wavelength Ac the column density N and the Doppler broadening b In general the Doppler broadening of a line may be due to the intrinsic thermal broadening bg 2kT m 2 and to a turbulent motion of the gas br V2or where ovis the inner velocity dispersion When transition from different ions are observed it is possible to discriminate between the two cases for the thermal component of the broaden ing indeed the b values of different atoms scale with the masses as jo bjon2 Mion2 Miony while in the turbulent case they remain essentially equal To allow for a complete analysis of the physical conditions of the absorbing clouds both types of b values can be accounted for in comput ing the line profi le each line is thus parameterized by four different parameters Ac N bg br and the Voigt profi le is computed using ab value b by b This unique feature combined with the possibility of constraining the different param eters in a flexible way see below allows for the simultaneous fi tting of diferent ionic transitions to yield meaningful values for both the turbulent and thermal broadening An extensive set of atomic parameters is supplied it allows for the fi tting of several ionic transitions found in absorption spectra and can be easily expanded by the user himself It is possible to fi t simultaneously diferent ions or from different transitions of the same ion specify ing several
28. s of MIDAS images specifi ed in the usual MIDAS syntax via name x1 y1 z1 x2 y2 z2 can now be used in all commands instead of the full image E g Midas gt fft freq itest lt lt 128 128 will do an FFT only on the lower left 128x128 window of frame itest bdf Pipes symbol l as in Unix are implemented to connect MIDAS to Host commands as well as Host to MIDAS commands E g Midas gt read descr lola Sgrep CUNIT will just dis play the contents of the descriptor CUNIT of image lola bdf AndMidas gt Spwd write keyw inputc fi lls character keywordINPUTC with the current directory string As an important step towards On line MIDAS which is MIDAS plus additional functionality required for using MIDAS on line at the VLT we implemented in the 94NOV release a set of Com munication Interfaces which provide access to MIDAS in a client server mode With these inter faces user processes clients can use services of a separate MIDAS session server running on the same Unix system or on a different system in a net work The commands CONNECT BACKGROUND SET BACKGROUND and DISCONNECT BACK GROUND supporting connection and interaction of several MIDAS sessions in parallel are also based on the communication interfaces A complete description of these interfaces can be found in the last revision 1 3 of the MIDAS Envi ronment document June Ist 1995 An example of a program using these interfaces is also included i
29. so org 134 171 40 2 WWW http http hq eso org ISSN 1018 3051 midas info midas html Newsletter of the ESO MIDAS Users Community
30. ted using the CONVERT LYMAN command Info on Sora bateh lymar fit lyman a Popup the history list of previously queried commands Overview History Search News Print Feedback Contexts Example of a FITLYMAN session The Main Menu is shown in the bottom left window The graphic win dow over it displays a fit performed on a complex metal system at z 2 768 Lines fitted are from the top Alj679 CIV1 550 CIV 1548 Sill 1526 CIV doublet has been fitted with three components lower ionization ele ments with five Data from Giallongo et al 1993 and J Wampler Newsletter of the ESO MIDAS Users Community ESO MIDAS Courier Vol 5 No 1 July 1995 9 directly accessing to their values to modify few parameters plotted too You can also use the cursor in the graphic window to enter the wavelengths needed to specify some parameter e g fi rst guess central wavelength or the intervals over which the x is computed The input spectrum and the fi tted profi le are plot ted on the active graphic window Optionally the standard deviation and or the residuals may be MIDAS on a Metacomputer M Stiavelli I Lisi Scuola Normale Superiore Pisa Astronomers visiting ESO in the eighties would often do so to make use of the computing facilities for data reduction the so called MIDAS Room At the time only few institutes were able to afford the dedicated hardware needed to properly reduce the large amo
31. th catalog option in SUBTRACT ICAT Fix problems with positive declination in COMPUTE AIRMASS Help fi le in the ECHELL95 package was missing Include opt SUNWspro lib in LD_LIBRARY_PATH to install MIDAS Correction in the command FILTER ECHELLE Bug fi x for MODIFY GCURSOR Bug fi x for GET GCURSOR output format for DECterm windows Bug fi xed for XHELP on PC Linux Bug fi x for overplotting coordinate box and contours on display window Implementation of 2dim gauss fi tting with calculation of angle of major axis CENTER IQE Solves bug in COPY DISPLAY for SG IRIX Modifi cations in the inmidas script to use Ektronik emulator Correct the command COPY TABLE for tables in RECORD format Bug fi x for the INTEGRAVE APERTURE command Another bug fi x for the command MODIFY GCURSOR make_options for HP does not include IPW library CREATE GUI IRSPEC added to the list of GUIS Fix for plotting of error bar when using logarithmic axes Generate MIDAS shared libraries on IBM RS6000 AIX Generate MIDAS shared libraries on SG IRIX 5 3 Correction in the XHelp resource fi le for X11 R4 Bug fi xed in Long context command ERASE LONG Keep cursor rectangle size for different applications Fix LOAD IMAGE for 1 dim frames Command EXECUTE CATALOG Do not ask for confi rmation with delete option Make CENTER GAUSS more robust Bug fi xed in OUTAPE FITS with the APPEND option on HP and Linux Fix COM
32. the La Silla telescopes have been reviewed Without going into details the overall situation in the optical part of the spectrum both imaging and spectroscopy seems satisfactory However a clear lack of calibration and reduction software was noted in the area of infrared imaging To improve in this area we are now working on new on and off line software for the IRAC2 cam era We anticipate to have a basic version available in the 9SNOV release Whether or not we will be able to support other infrared instruments on La Silla e g TIMMI or Come On Plus will depend July 1995 on available manpower As a result of limited manpower and after consul tation of the MIDAS sites involved it has been decided to reduce the support of VAX VMS sites However since MIDAS is built using standards like X11 POSIX we believe that this policy will only have a limited impact on current VMS users of MIDAS More detailed information about this subject can be found on the next page To improve in the area of user support a number of additional services have been implemented in the first half of 1995 Among those are the midas users and midas announce mail ing lists meant for general discussions and announcements More about these lists can be found below Another service is the availability of a MIDAS FAQ frequently asked questions file on our anonymous ftp account The FAQ contains answers to all sorts of questions from installation related s
33. tion can vary along the spectrum Gaps may exist in the spectrum The numerical minimization is performed using the MINUIT package which has been developed at CERN It allows for the simultaneous minimiza tion of up to 100 free parameters equivalent to at least 33 independent absorption lines The user can choose among different minimization algo rithms or strategies For instance some parameters may be fi xed at the fi rst iteration to fi nd a reasona ble fi rst guess solution and then released to achieve the fi nal result this procedure is particu larly useful to fi nd meaningful solutions in com plex situations The original MINUIT package can also be used in interactive mode since this option is not compatible with the MIDAS command lan guage it has been disabled in FITLYMAN Never theless all its relevant functions can be invoked from the User Interface this solution eliminates also the need of learning the MINUIT command language MINUIT may perform an accurate error analysis by computing either the covariance matrix and or more detailed statistics as non para bolic errors or scans and contour levels in the x space In principle the results of each minimization depend on several parameters that specify a the line confi guration b the regions of the spectrum where the x is computed and c the MINUIT commands used To keep track of these parameters each minimization is associated to a unique identi N
34. to test different confi gurations fe number of compo nents and constraints on them before a satisfying fi t is achieved In the analysis of lyman c forest on the contrary hundreds of independent lines are fi tted that must be identifi ed by the user Introduc tion The lack of a software tool properly tailored for all the different aspects of this problem has moved us to the realization of FITLYMAN a new package available in the Lyman context of the MIDAS 94NOV release that we present in this paper This code is the evolution of a former version developed at the Osservatorio Astronomico di Roma Giallongo et al It allows the fi t of Wigt profi les to a lage number of absorption lines in a normalized spectrum through the numerical mini mization of x Its main features are the flexibility in specifying the line confi guration a fast user interface the full documentation on all the fi t per formed ensuring also recursivity Special care has Newsletter of the ESO MIDAS Users Community ESO MIDAS Courier Vol 5 No 1 July 1995 been taken to maximize the effi ciency of the user operations FITLYMAN provides recursiveness and allows to recover previous confi gurations Main features We describe here the most important features of FITLYMAN For a more complete description of the commands and algorithms please refer to the ESO MIDAS User s Manual Each absorption line is modelled by a Voigt profi le whose paramete
35. togram The following options parameter consists of 2 characters the fi rst character the statistics level serves as a flag for different statistics options and the second character the display level specifi es the amount of output generated by the STATISTICS IMAGE command The default for the statistics level is F which stands for full statistics producing the following statistical quantities 11 values minimum maximum mean value standard deviation 3rd moment qth moment intensity median smallest mode no of bins bin size of histogram calculated over the part of the input image specifi ed via thearea option These values are displayed on the terminal and also stored in the real descriptor STATISTIC of the image Level R reduced statistics will compute only the fi rst 7 quantities of the list above and no histogram is produced for the input image Setting the level to S short statistics leads to the calcula tion of the fi rst 4 quantities only if the level is M minmax only the fi rst 2 quantities are computed and again no histogram is generated Since no his togram is produced the parameters bins and lo hi_exc are ignored for levels R S and M For level H histogram a histogram is generated and the minimum maximum as well as the last 4 quantities of the list above are computed Except the median value all the statistical quanti ties are computed in a straightforward manner With leve
36. ubjects to reduction and calibration pack ages The compressed FAQ file midas faq doc Z can be obtained via anony mous ftp ftphost hq es org 134 171 40 2 It is located in the directory pub midaspub 94NOV doc In this ESO MIDAS Courier Testing of ESO MIDAS on VMS Open VMS systems General System and Application News One Again MIDAS Problem Reporting FITLYMAN ANew Tools for Absorption Spec tra Analysis MIDAS on a Metacomputer Expeditions in the MIDAS Jungle Counting Pix els MIDAS 94NOV Patch Files ESO MIDAS Courier Vol 5 No 1 July 1995 ANNOUNCEMENT Testing of new ESO MIDAS releases With the increased pressure from the VLT project with respect to the on line version of MIDAS we fi nd it difi cult to maintain the high level of verifi cation of releases on NX VMS platforms similar to the one we maintain for UNIX systems In addition our access to and experience with VMS as well as OpenVMS systems have been signifi cantly reduced especially since the ROSAY MPI project has moved to Unix OSF 1 on their DEC Alpha systems In order to save internal manpower for maintenance and release thereby strengthening the develop ment of a high quality on line version of MIDAS for the commissioning phase of the VLT we will base future development maintenance and distribution of MIDAS on the following software require ments e Operating system conforming to POSIX 1 and POSIX 2 e X11 and OSF Motif display syst
37. unts of CCD data produced by a typi cal observing run on a big telescope With the advent of UNIX workstations with X11 interfaces data reduction facilities became much more afford able and the need for such centralized data reduc tion systems diminished In the near future a new generation of instrument will become available and start pouring out 8192 x 8192 pixel images These kinds of images will be essentially intractable on present day workstations and will require either the use of new algorithms and data reduction proce dures or the use of larger not so common CPU servers Take for instance a Fast Fourier Transform which is the basis of many deconvolu tion and fi ltering algorithms Its complexity scales as N log N where N is the total number of pixels i e FFTs on 8192 x 8192 pixel frames take 260 times the number of operations needed by a 1024 x 1024 pixel frame Although one cannot exclude that top line workstations available in a few years will be able to cope with this amount of operations it is likely that they will be affordable only by a few lucky ones In fact it was relatively easy for all institutes to install the fi rst generation of work stations bought with the money made available by the dismissal of central computers Once every body had a workstation on his desk further improvements slowed down and it is easy to check that workstations old by even two or three genera tions are not uncommon even in the best
38. w or fixed in 94NOVpI1 1 Tutorial for the DO package reads data from demo data instead from demo raw Tutorials for WAVELET and OPTOPUS accept the AUTO argument Fix LOAD IMAGE for images of data type unsigned short int with scaling factor gt 1 MIDAS can be compiled with GNU C compiler on Silicon Graphics Fix active image channel settings Removing obsolete commands in 94NOV Test for Fortran to C interface more robust Cosmetic changes in the inmidas script AUTO option for the TUTORIAL ECHELLE command Fix problem with param P3 only nomem without mem sizes in CREATE DISPLAY Increase max size of PSF to 101x101 pixels Enable input of ASCII data fi les with very lage record size Correction for upper lower case in plot device names Bug fi xed of the command MODIFY GCURSOR for AX VMS Corrections for NULL device use in plot packages Fix MAGNITUDE commands when bright objects are in the background Newsletter of the ESO MIDAS Users Community ESO MIDAS Courier Vol 5 No 1 July 1995 Fix EXTRACT CURSOR with xpix ypix specifi ed Fix for incorrect descriptor TBLCONTR for table plotting Fix for lower case display and graphics window names Bug fi xed for assignment of incorrect plot window New or fi xed in 94NOVpl 1 2 Fix no of pixels for loading images with scale lt 1 Avoid MINMAX calculation for LOAD IMAGE cuts a b Fix problem wi
39. will be distrib uted with the B release of MIDAS and in 9SNOV Developments for the IRAC2 camera A new IRAC2 context is being worked on in order to improve the calibration and reduction tools for infrared imaging The new package will be geared towards the reduction of IRAC2 data and will con tain on and off line routines like sky determina tion and subtraction correction for dithered frames and mosaicing Like the CCD package the IRAC2 package will use the MIDAS Data Organ izer for classifying and association of the calibra tion and science frames A basic implementation will be available in the 9SNOV release Comments and suggestions for this new context can be sent to rwarmels eso org Once again MIDAS Problem Reporting Rein Warmels European Southern Observatory Introduction The previous issue of the ESO MIDAS Courier Vol 4 No 2 October 1994 contains an overview of the GNATS problem report system that is used by the MIDAS Group to keep track of reported problems After having worked with the system for about one and a half year and having dealt with over 700 reports we have made a brief evaluation Below some statistics will be presented about the reports received in the fi rst year of usage In addi tion the new graphical user interface GUI for forwarding MIDAS Problem Reports is presented Some Statistics During the period May 1994 till February 1995 the MIDAS account received a total of
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