Reusable code. A lot ot a
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1. a separate file which can be modified by the computer group to change behavior without recompiling e Reusable code A lot of attention has been given to both high level and low level tools A user interface language was developed to handle forms and invoke runtime control packages Device control libraries were developed to take care of the tedious details These features are what allowed us to create the Fabry P rot session in three days One source code tree Using the T1 network between Waimea and the summit allowed us to keep a single copy of the up to date source code This guaranteed that we never used an old version by mistake Nor were we making changes in two different places that then had to be reconciled e Multiple releases A release technology was created that allowed us to make formal releases By having multiple releases on the system we could engineer in radical changes without affecting current operation In summary there has been a very low rate of problems caused by computer change At the same time the com puter group has felt free to service custom needs as well as make progress in whatever direction was required 6 The Future While first semester 1989 has seen the completion of the original data acquisition and computer upgrade project it should not be thought of as a static situation There are not only new features being requested but there are new instru ments on the horizon What we have2. deux composantes de la radio source 3C208 1 s par es de 3 9 secondes d arc obtenu par Hammer et Le F vre en D cembre 88 Un spectre de 45 min a permis de confirmer le redshift de la composante principale associ e la radio source z 1 02 et de montrer que la composante faible de magnitude R 21 6 est une galaxie de Seyfert d avant plan z 0 156 Figure 7 Le signal bruit final est de 5 sur le continu de la Seyfert pour une dispersion de 10 A pix avec le CCD TH1 Ces donn es mettent en vidence un autre cas de contamination de source 3CR par une galaxie d avant plan 3C208 1 doit tre amplifi e de plus de 0 5 mag en optique et 0 75 mag en radio et apr s correction la puis sance radio intrins que de la source n est plus suffisante pour qu elle soit inclue dans le catalogue 3CR Olivier Le F vre The Relative Performances of the UV Prime and Herzberg Spectrographs Blueward of 4000 1 Background Measurements of atmospheric extinction indicate that Mauna Kea is an excellent site from which to perform obser vations at near ultraviolet wavelengths CFHT currently has two spectrographs which are used in this spectral region the coud which offers three dispersions for high resolution work and UV Prime which is restricted to a single intermedi ate resolution configuration Because of the fixed configura tion of UV Prime a UV resolution gap exists and programs which require observations at resolutions
3. were re observed using the Herzberg spectrograph and PHX1 CCD The optical set up of the Herzberg was identical to that used for the lab tests and a wide slit was used to minimize light loss Slit losses for the UV Prime data were also negligible Unfortunately the night was not photometric and the stars were observed through varying amounts of cirrus
4. created is a foundation and technology that not only supports our past and current endeavors but our future plans as well Of course these projects will continue to be in addition to the daily challenge iring data ot acquiring data Jon Brewster 3 00E9 YJ 4 aua aO om 3CR208 1 2 5069 2 components A QSO mg 19 3 z 1 02 B Seyfert mr 20 8 z 0 156 2 00E9 1 50E9 j d A B 3 9 arcsec 1 00E9 LE li oll 4 Le Reducteur Focal du CFHT Modes Longue Fente et PUMA Le r ducteur focal du CFHT utilis jusqu alors en mode multi spectroscopie PUMA a t dot d un mode longue fente la fin 88 et utilis avec le CCD PHX1 de 7 de bruit de lecture en Juin 89 A cette occasion nous rappelons les principales caract ristiques de cet instrument sp cialis pour la spectroscopie d objets faibles tout en offrant une capacit d imagerie Une description compl te de l instrument et de son fonctionnement est donn e dans le User s manual for long slit and multi spectroscopy with the focal reducer and PUMA disponible sur demande La combinaison optique comprends les diff rents tages suivants Plan focal F 8 longue fente ou masque PUMA peu vent y tre ins r s lentille de champ collimateur Roue filtres 9 75 mm quatre positions Roue Grisms 9 65 mm quatre positions 2 filtres 2 Grisms e Objectif F 2 9 CCD ll est donc possible de s lectionner une conf
5. d for the lab tests was an Osram 1000 watt lamp which was mounted inside a box with a UV transmitting diffusor as an output window Power to the lamp was controlled with a VARIAC power supply and the output at a given setting was found to be reproduceable to within a few percent The source was placed directly in front of each spectrograph slit and a spacer unit was used to position the apparatus at a distance appropriate for the focal ratio of each spectrograph Arc exposures were also recorded to provide a wavelength calibration The slit environments of both spectrographs were found to have light leaks and although it was possible to reduce these somewhat the remaining scattered light restricted the usable data range to between 3600 and 3900 A After cor rection for geometrical factors our laboratory results show that the Herzberg spectrograph which was configured with blue optics Grating 6 166 A mm dispersion lambda blaze 4200 A and the TH1 CCD is more sensitive than UV Prime and RCA3 from 3600 A to 3900 A Specifically we find that the ratio of the recorded signals in units of elec trons detected per wavelength interval and in the sense Herzberg UV Prime varied from 1 4 at 3600 A to 1 3 at 3900 A 3 Sky Measurements The sky data were recorded during the night of April 11 12 1989 Two spectrophotometric flux standards Feige 34 and Feige 66 which had been observed previously with UV Prime under photometric conditions
6. different from those available with either the coud or UV Prime currently cannot be accommodated Page 10 The situation is exacerbated by the limited range of pro grams which can be done with UV Prime due to the short comings of the detector The spectrograph design is such that a dedicated detector is required and the CCD currently in use RCA3 suffers from a low quantum efficiency in the UV and a high read noise 55e Therefore in an effort to expand the spectroscopic capabilities of CFHT in the UV we have undertaken a program to evaluate the performance of the Herzberg spectrograph in this wavelength range Al though originally designed to have UV capabilities in prac tice the Herzberg has only been used for programs redward of 3500 A Our primary goal was not to determine the abso lute efficiency of this spectrograph but rather to compare its overall performance including detector to that currently available with UV Prime Two sets of measurements were made The first were in the lab where the relative efficien cies of the spectrographs were determined using an artificial source The TH1 CCD was used as the detector for the Herzberg spectrograph The second set of measurements were made on the sky Two spectrophotometric flux stan dards which had been observed previously with UV Prime under photometric conditions were observed with the Herzberg spectrograph using the PHX1 CCD 2 Lab Tests The calibration source use
7. iguration imagerie ou spectroscopie Le tableau donne l chelle spa tiale et les dispersions mesur es en A pixel pour les 3 CCDs utilisables cette table corrige celle du manuel d utilisation distribu avant le 1 Juin 89 Table 1 Grism B400 A 5200 Grism V150 a 6100 Grism 0600 a 5900 arcsec pixel Il est possible d ins rer dans le plan focal une fente ou un masque multi objets PUMA 1 La proc dure ins rer retirer la fente ou le masque s effectue manuellement sur l instru ment Le support de fente peut recevoir des fentes de 0 5 2 5 avec une longueur de 45 Un mouvement fin en rotation permet un aligne ment pr cis de la fente avec les lignes du CCD Un logiciel a t d velopp pour la spec troscopie multi objet avec la machine PUMA construite par l Observatoire de Toulouse Il 500 5000 5500 6000 5 00 9 Mgl z 1 02 4 50E9 L LL ee li 4500 5000 5500 6000 lambda angstroms Figure 7 i 6500 7000 6500 7000 permet entre autres la s lection grossi re des objets avec le curseur sur une image du champ pr alablement obtenue suivi du calcul pr cis de leur positions un contr le des positions pour viter un recouvrement des spectres l addition de trous sur le fond de ciel l envoi d ordres de percage des trous la machine PUMA Les trous de 6 300 um sont perc s avec une pr ci sion de 10 um dans un clinquant dont le sup port peut tre ensuite ins
8. r dans le plan focal F 8 Une proc dure compl te de selection des objets et cr ation d un masque prend environ 15 minutes Une proc dure d offset precis du t lescope Page 9 a parall lement t mise en place pour permettre un posi tionnement mieux que 0 2 sur le ciel On utilise pour cela le miroir de la bonnette pouvant tre d plac avec une pr ci sion de 10 um soit mieux que 0 1 dans le plan F 8 Tout en utilisant une toile guide l offset s effectue en trois temps identification de la cible et calcul de l offset de la bonnette offset de la bonnette offset du t lescope pour replacer l toile guide dans la boite de guidage Ce dernier point as sure que l toile a suivi exactement le mouvement de la bonnette Cette proc dure a t utilis e avec succ s en D cembre 88 et Juin 1989 D s les prochaines observa tions de 89ll les offsets de la bonnette et du t lescope se ront effectu s en m me temps l tape ultime tant d avoir la proc dure compl te command e par le HP9000 utilis pour l acquisition des donn es Actuellement des flexions internes li es l optique de guidage de la bonnette entrainent une d rive des objets de l ordre de 1 par heure dans le plan focal de l instrument par rapport au plan focal de la cam ra de guidage Ce probl me est en cours d investigation et nous recommandons des poses maximales de 45 minutes Nous montrons comme exemple le spectre des
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