I spent the afternoon working my way through the Poopsy user comments, and I
found a number of common threads that should be considered before the next generation
of POOPSY is released. They are as follows:
DD: This is indeed the problem. In queue mode, or for Gemini, the target
list will have to be precise. Parsing a TeX table is a lot of work.
Asking for individual fields is the only way to insure that all releated
information have been submitted....
DD: Easy to implement, will be in POOPSY 2.
DD: I thought it was already quite good.
DD: OK, please suggest one ;->
DD: Network should improve when all research institutions switch toInternet 2.
Some users also pointed out bugs, and I will leave these to you guys
to address.
Overall, I am quite happy with the responses from Canadian users -
by and large the comments are favourable, and the community appears ready to
use the Gemini version of POOPSY. While the comments from the French side
are much more negative, this is due largely to the Net connectivity issue,
rather than the actual structure of Poopsy.
Tim (Davidge)
There is a pressing need for options for the immediate future of the CFHT to be clearly developed and evaluated. France has recently undergone a planning exercise, summarized in the Arcachon document. This document states that the future of CFHT beyond 2005 is open. Canada is currently engaged in a similar exercise, which has lead to a proposal to immediately upgrade the CFHT to a wide field 8m.
Therefore we urge the SAC to support the funding of an engineering and planning
study of the proposal for an immediate upgrade to a widefield 8m. The study
should also provide estimates of what would be required to upgrade the existing
CFHT to maintain competitive status and make maximum use of the site. Details
that should be provided by these studies include, but are not limited to:
From Carlberg et al for wf8m proposal
Dear SAC members
There are two areas where I believe strong action is required by SAC to exploit the uniqueness of CFHT, one of the most important facilities available to our communities, before we are eclipsed by others. These are:
1) An integrated large, deep, optical multicolour imaging survey
2) Queue scheduling for priority targets with AOB
In my opinion, we have nearly "missed the boat" on both of these,
but if we start immediately, we likely still have an opportunity to ensure that
our communities reap major benefits in two areas where our instruments (CFH12K
and AOB) are unarguably the best. Furthermore, a large CFH deep imaging survey
will place our communities in a more competitive position to exploit the new
ground-based and space-based facilities as they come into operation.
1) In my view, small uncoordinated imaging surveys of random bits of the sky is virtually a waste of CFHT time when contrasted to what could be achieved with coordinated surveys of larger areas. The latter could simultaneously serve a multitude of projects (including some we haven't even thought of yet) for many users.
Proposal # 1: devote 25% of CFHT time to a big survey, releasing the data to CFH community (only) ASAP.
2) AOB and AOB + OASIS also present opportunities for CFHT to be "Number 1", a non-negligible factor in today's funding climate. The problem with AOB observations (as I'm only too well aware), is that in addition to the usual observing constraints (principally transparency and seeing), AO observations are doubly constrained because both the guide star and target are adversely affected (e.g., clouds make the guide star fainter, so the correction is poorer in addition to the target being fainter). There are some "classic" projects like determining the mass of Sgr A* by getting orbits of stars via proper motions or solving the mystery of the double nucleus of M31 with OASIS spectroscopy that CFHT MUST do. Leaving such projects entirely to the vagaries of the weather is again a waste of CFHT's unique capabilities.
Proposal # 2: Queue schedule at least the top-ranked AOB proposals to ensure they get done. There are usually other projects with bright guide stars that could almost be done in any conditions.
David Crampton
Dear John,
Please find below an update of the description of the Espadons project. Most of the information is available on the Espadons webpage:
http://www.omp.obs-mip.fr/omp/umr5572/magnetisme/espadons.html,
Please do not hesitate to contact me again if you need further details.
Best regards,
- Claude (Catala)-
1. ESPADONS: Science drivers.
see http://www.omp.obs-mip.fr/omp/umr5572/magnetisme/espadons/science.html
up-to-date
2. ESPADONS: Scientific requirements and technical characteristics see
http://www.omp.obs-mip.fr/omp/umr5572/magnetisme/espadons/technical.html
update: the accomodation of the polarimeter/interface module we have been studying
up to now is behind Cass bonnette. Mounting the instrument behind AOB will be
feasible (with the beam going straight through the
AOB without correction), and this configuration will be studied soon. Accomodation
behind MOS/OSIS presents some difficult mechanical problems, that we may not
be able to solve.
3. ESPADONS: Expected performances see
http://www.omp.obs-mip.fr/omp/umr5572/magnetisme/espadons/performances.html
up-to-date - in particular, see the table comparing overall efficiencies of spectrographs on 8m and 4m class telescopes.
4. ESPADONS: Cost, project team, agenda see
http://www.omp.obs-mip.fr/omp/umr5572/magnetisme/espadons/team.html
update: The canadian share of the cost (approx. 150,000 USD) has been secured,
and comes in addition to the french 80,000 USD already obtained in 1998. The
70,000 USD expected from the french ministery of research
and education in 1999 will in fact be part of a global allocation of the ministery
to our laboratory (contrat quadriennal), the total amount of which will be known
by the end of May. We are very optimistic about this request. However, whatever
its outcome, it is in fact up to our laboratory to define how much funds it
will put into Espadons. Since Espadons is the very top priority of our laboratory,
it is obvious that most of these 70,0000 USD will be available for it, even
at the expense of other less prioritary projects. Ideally, the 100,000 USD that
we expect from CFHT should be available in 1999, so that we can order all the
necessary optics, and the project does not suffer any additional delay. If this
is not possible, and if this amount comes partly in 1999 and partly in 2000,
this will result in an unavoidable (but perhaps short) delay of the project.
The agenda of the project presented on the web page is still valid. As of today (april 99), the optical design is complete, and the mechanical design is well under way: the mechanical design of the fiber interface is complete (direct Cass version), that of the polarimeter is under way, and finally the design of the spectrograph itself will consist of a mere adaptation of that of Feros, the drawings of which are at our disposal. We believe the whole design will be complete by the end of the summer 99.
The CCD-chip we plan to use is one of the two EEV 2kx4k engineering grade CCD
acquired for the development of Megacam. The tests of these devices have shown
that they are perfectly suited for Espadons. They will not be used after mid-2000,
and the Megecam team at CEA is ready to make one of them available to us. For
the case this would finally not be feasible what whatever reason, we have sent
a funding request to Region Midi-Pyrenees,
to cover both the acquisition of another 2kx4k chip, and the acquisition and
developement of the CCD controller (SDSU-II). We plan to use the housing of
the MOCAM camera, which we will adapt to host a 2kx4k chip. All the work concerning
the CCD camera will be done at Observatoire Midi-Pyrenees, by Francis Beigbeder.
6. Operation of Espadons at the telescope
Espadons is being designed in order to minimize the operation cost at telescope.
The spectrograph itself is a single-configuration instrument, with no movable part. Once aligned and adjusted by our team, it will not require any additional human intervention for the rest of its life, in principle. Filling up the CCD dewar will be the only remaining action, and can be made automatic quite easily.
The polarimeter and fiber-interface will also be mounted and aligned by our team, and in principle will not require any additional re-alignment during its lifetime.
Therefore, each time the instrument will be installed at Cassegrain, or behind the AOB, the operation requested from CFHT staff will be:
- to install the fiber interface/polarimeter at Cass (4 to 6 bolts to tighten). This interface will weigh about 30 kg, and can easily be installed by two men with no additional machinery (this is what we do at TBL with the MUSICOS interface, which has a similar weight). About 10 minutes of work is required for this operation.
- to install and plug the power supply and the various control cables. 15 minutes. Note that the Espadons power supply could be installed permanently on the side of the telescope, which would reduce the amount of time needed for this operation.
- to install the fiber head at the end of the interface/polarimeter: 5 minutes
- to check the alignment of the fibre with respect to the instrument optical axis: this will be done by putting the instrument in a special check-up mode; a light beam is being sent up the fiber from the spectrograph end, and the position of the image of the fiber at polarimeter end with respect to the guiding hole is checked; this can be done either with the help of a small eye-piece installed on the side of the polarimeter/interface unit, or else with the help of the guiding camera (we still have to make a decision on this). Normally the fiber should come to its nominal position right away, in which case the whole process will take about 5 minutes. If it does not, then the position of the guiding hole will have to be slightly re-adjusted. We have the experience of doing this at TBL/Musicos, and the operation takes about 10-15 minutes. The design of Espadons will be similar, with the additional simplification that the fiber will be twice as large as for Musicos, which will make its adjustement much easier. Altogether, the whole operation, including the (unfrequent) re-adjustement of the guiding hole, will last less than 15-20 minutes, for one man alone.
In conclusion, mounting and aligning Espadons will require less than one man-hour at the beginning of each run. Dismounting it at the end of a run will take up about 30 man-minutes.
The numbers quoted above are confirmed by the operation of Musicos at TBL, whose fiber interface and polarimeter are based on a similar design.
The goal of this project is to construct an instrument which will enable us
to obtain integral field (2 spatial dimensions) spectra in the near-Infrared
with a spatial resolution comparable to that of HST. The specific proposal is
to use 200 microlenses and fibres to link the Adaptive Optics Bonnette (AOB)
and the OSIS IR spectrograph. The combination will allow 200 spectra to be obtained
simultaneously of areas 3" in diameter with a spatial resolution of 0"15
and a spectral resolving power of R~200-2000.
Scientific rationale.
FILAO will permit the CFH astronomical community to carry out front-line science in a number of astrophysical topics. For Galactic work, the main gains are from the high angular resolution and the ability to observe important near-IR diagnostic lines. For local universe extragalactic work, the main gains are the ability to combine optical and near-IR diagnostic lines at high angular resolution. At higher redshift we have the ability to continue to use important "optical" diagnostic lines which are redshifted into the near-IR. The high angular resolution allows us to study kinematics of a wide varietyof objects with unprecedented resolution, opening up important areas of research into the formation and evolution of galaxies. Although the field size is small, so are the bright areas of most targets (e.g., planetary features, nuclei of nearby galaxies, AGNs of all types, galaxy lenses, very high redshift objects) that are accessible to a 3.6m telescope. It is precisely on these types of objects that we need to concentrate in order to exploit the power of AOB in a timely fashion.
Instrumental set-up
The AOB delivers corrected images at the AOB focus with a focal ratio f/20. To have an efficient packing coefficient and a spatial resolution of 0.15", the incoming beam is expanded to a focal ratio of f/200 to illuminate an input area of 200 hexagonal micro-lenses, 0.5 mm in size. These lenses, which are also used to reduce the focal ratio degradation, provide an f/6.6 beam to the 0.05-mm fibre core. At the fibre output, an f/4 beam is recovered and passes through a linear micro-lens array which feeds the OSIS spectrograph with the appropriate f/8 beam. The fibre bundle output is inserted in an OSIS slide identical to the standard ones.
During observations, the MOS-OSIS spectrograph is on the floor, connected by a 23-m optical link, hanging from the AOB focus. There is no special software interface with the telescope and OSIS spectrograph. The operation is of the same type as the MOS-ARGUS link, and it will be transparent to OSIS that it is being fed by a fibre link rather than direct skylight.
At the SAC request (via J.G. Cuby) a second sampling scale is supplied with 0.4" per micro-lens. To deliver the two scales requested, a simple manual zoom transfer optical system is introduced between the AOB focus and the fibre bundle.
At present, we have a fibre bundle made of 213 fibres clad in a shield by Eurofo. We have the input lens array (made by AOA) and the output linear lens array is being made especially for us by the ENST de Bretagne. We are currently working on the micro-lens and fibre coupling. After many attempts, we just received a sample of holes made with an eximer laser on a special glass substrate that has the required level of precision (a few microns). Next we will glue the microlens and fibre assemblies together. The special OSIS slide to accommodate the output bundle has been built.
Planning
This project has been proceeding slowly for two reasons: 1) existing committments from other projects, 2) delayed delivery of the required OSIS 1K detector.
At OPM, the initial slow pace was because the DAEC team was involved in the
ESO FUEGOS VLT project. This is not any more the case. We have also had to modify
our design two times: first to deliver the two spatial samplings which is not
so simple, and then after the FOA III conference (December 1997) to change our
procedures to take advantage of new knowledge about IR fibre behaviour. This
had an impact on the output micro-lenses that could not be found on the market
and we have had to have them developed by ENST Bretagne. We spent also some
time
attempting to drill precision holes, before discovering the eximerlaser drilling
facility. In early May, we will have a 3 month technician to insert and glue
the fibres in the hole array. In September, a technician will also come for
3 months and should complete the project, barring unforseen problems. To be
honest, we should say that the project should be seen as continuing on a best
effort basis.
A wide range of fundamental astrophysical problems has been explored in the
past two decades at spectral resolutions of 40,000 to 60,000 on 4-m class telescopes
- from explorations of the Lyman-alpha forest in QSO spectra, detection of stellar
accelerations induced by planetary companions, identification of high degree
stellar non-radial oscillations impossible to detect photometrically, and the
mapping of stellar surfaces. This work will
intensify with existing and new spectrographs on both 4-m and 8-m class telescopes;
in the case of CFHT, with the proposed fibre-fed instrument, ESPADONS. ESPADONS
will also provide CFHT users with the exciting prospect
of high-resolution (R=50,000) spectropolarimetry, and with the upcoming decommisioning
of CASPEC at ESO such capabilities will be unique for a 4-m class telescope.
Detailed information regarding ESPADONS, and its science
drivers may be found at: http://www.obs-mip.fr/omp/astro/magnetisme/espadons.html
A few observatories, including CFHT with it's high-resolution GECKO spectrograph, have opened up new frontiers by actually resolving the narrow lines formed in the photospheres of cool stars and in the interstellar and intergalactic media. But despite the importance of such studies, there are no plans for optical spectroscopy at resolutions R > 100,000 with any space telescope. And of the sixteen 8-m class telescopes being planned or built, only Subaru is definitely slated to have such a high-resolution spectrograph (HDS, with R = 100,000). There is a proposal to install a pier-mounted spectrograph (R = 135,000) on Gemini-South, but this is pending approval and funding.
Capable of R = 120,000, GECKO represents a rare observational ability on a 4-m class telescope. It has already produced important results such as the detection of molecular band-like structure in certain diffuse interstellar bands, the discovery of high-degree nonradial pulsations in lambda Bootis stars (which is helping to resolve the mystery of the origin of these metal-deficient stars), measurements of the isotopic abundances of Pt and Hg in the HgMn stars (which indicate that current theories for the origin of these peculiar abundances are incorrect), the detection of photospheric velocity fields in A-type stars, lower limits to the interstellar 9Be line equivalent widths seven times better than previous values, and observations of interstellar OH in the difficult 3072-3082A wavelength region.
GECKO also represents an important step toward achieving the critical velocity resolution of 1 km/s. At 3km/s, one can resolve line widths typical of a 10^4 K plasma. Observations at R = 600,000 with the UHRF on AAT have revealed an increasing number of discrete velocity components in cold clouds and resolved the hyperfine splitting (Delta v = 1.05 km/s) of the Na I D lines in clouds where T < 500 K. High-resolution surveys show that the frequency of interstellar line widths increases for half-widths <0.2 km/s and, in the Trapezium, there are differences in cloud structure and velocity over scales of a few tenths of a parsec.
There are specific questions of isotope ratios, excitation, and velocity in addition to cloud structure which can only be answered with a resolution approaching 1 km/s. For example: what is the interstellar 7Li/6Li ratio in different clouds?
The University of Texas planet-search team has demonstrated that a resolution greater than 100,000 is essential to achieve long-term radial velocity precision close to 1 m/s. This will make it possible to detect extrasolar planets less massive than Jupiter, and perhaps investigate solar-type oscillations in main sequence stars to probe their structure. The extrasolar planet community also argues that the similarity of the stellar rotation period and planetary orbital period in the tau Boo system is due to tidal interactions. A resolution greater than 100,000 is necessary to search for line-profile distortions which are expected to be associated with such tidal effects.
At the same time, spectral synthesis is undergoing a vigorous revival, offering the prospect of models of stellar photospheres and global parameters of unprecedented accuracy. With data at 1 km/s resolution, we could obtain very precise temperatures, granular velocities, rotation velocities and magnetic cycles for solar- and later-type stars. Recent work is also extending this to early-type stars.
There is considerable interest in the activity of solar-mass stars at all stages of their evolution, particularly as it affects our climate. Rotation is the critically important variable and there is a basic need to improve the Doppler images of slowly rotating stars up to spectral resolutions of R = 250,000. Exposures times for these often relatively faint stars must be short to minimise phase smearing and hence 4m or larger telescopes are essential. GECKO has, in fact, recently provided the highest "indirect" spatial resolution ever obtained for a star other than the sun: Doppler imaging of the weak-lined T-Tauri star HDE 283572 has provided surface resolution of 1 degree, or the equivalent of 3.3 micro-arcsec! Optical interferometry is unlikely to be able to provide such surface maps for V=9 stars for many years.
GECKO is a uniquely powerful high-resolution instrument with high throughput (albeit with limited wavelength coverage), which will only begin to achieve its full potential in 1999 with the finer grain 4726 x 2048 EEV CCD. This detector will finally allow GECKO to cover a full spectral order (for example 60A at 3800A; 130A at 8200A) as intended in the original design, thus increasing its effective throughput by a factor of two. GECKO is also unique in being an echellette, thereby avoiding strong spectral curvature and significant amounts of scattered light which limit the effectiveness of conventional high-order echelle instruments. This enables precise definition of the continuum level and hence a high degree of photometric accuracy necessary for measuring equivalent widths and line variations to precisions of a fraction of a mA.
As Dr. Catala stated at the 1998 CFHT Users Meeting, the general discussion (http://www.cfht.hawaii.edu/Reference/Proceedings/discussion/ index.html#instrumentation) at the close of the meeting seemed to indicate that CFHT's high-resolution spectroscopy community feels a need for data obtained both with full spectral coverage at moderately high resolution (R~50,000) and with high-resolution (R~120,000 and preferably higher). The science capabilities of both instruments, ESPADONS and GECKO, are very complementary and equally strong.
We would like to reiterate this idea with the current document. The current justification for eliminating one of ESPADONS or GECKO in favour of the other rests entirely on operation cost concerns at CFHT, and not on the relative scientific merits of each instrument. ESPADONS has been described by Dr. Catala as "a fixed spectrograph with a fixed configuration, (which) will necessitate only very minor operations from the CFHT staff." While not proven, the spectrograph design suggests that this will indeed be the case.
Over the last several years GECKO has proven "costly" for three reasons:
a) maintenance of the coude mirror train alignment and coatings
b) detector setups and allignments
c) maintenance of the alignment of the mosaic grating.
CFHT plans to implement a fiber-feed from the f/8 Cassegrain focus to the coude
focus in 1999 (and CFHT is also carrying out a feasibility study of the possibility
of mounting the f/8 secondary in such a way as to permit quick switching between
the prime focus and the f/8 focus). This fact, and the commissioning of the
EEV device as a dedicated GECKO detector, eliminates two of the three GECKO
operation concerns. We completely agree with CFHT's concern about the current
level of maintenance required to keep the GECKO gratings aligned - in its current
state it is clearly impractical to attempt to maintain GECKO in the round-the-clock
state of readiness needed for queue observing. However, rather than making the
scientifically unjustified decision to simply decommission a $US450K instrument
(the cost of GECKO was actually substantially higher since HIA charged CFHT
for only 50% of their true manpower costs because it was a collaborative CFHT/HIA
effort) which has only now reached its design goals and full scientific capabilities,
we strongly urge CFHT to invest a modest amount of manpower and cash to investigate
replacment options for the current GECKO grating mosaic. At least three possibilities
exist:
a) simply redesign the overly-complex, electronically controlled mosaic with a much simpler mechanical mount. There is little need to control the alignment of the individual gratings remotely as can now be done
with GECKO, especially if a stable assembly can be constructed. For example, the decommissioned CFHT coude f/8.2 grating assembly was much more stable than the Gecko mosaic (when mosaics were not changed) and the identical mosaic for the DAO 1.2-m telescope's coude spectrograph has its alignment checked perhaps only once every 2-3 months. CFHT has an extremely competent mechanical group who should have no problem with such a project (ignoring time constraints of course), especially when existing designs would seem to exist. The cost and manpower impact of this work would then appear to be minimal.
b) replace the current GECKO mosaic with a mosaic similar to that of Keck's HIRES. This is likely the most uncertain option and perhaps the most costly.
c) consider a modification of GECKO such as that proposed by Paul Felenbok (see http://www.astro.ubc.ca/E-Cass/1997-DS/gecko.html). Felenbok's design would enable observations of several orders simultaneously by using a small (30mm) cross-dispersing prism and replacing the current
GECKO gratings with a monolithic echelle. With this modification, GECKO would give continuous spectral coverage from 470 to 720 nm with R > 100,000 when fed by a fiber from the f/20 output focus of the AOB.
We feel that two low-maintenance fiber-fed spectrographs with complementary
features (ESPADONS: complete wavelength coverage and spectropolarimetric capabilities
at moderate resolution of R=50,000; GECKO: high-resolution of R=120,000 with
excellent photometric precision) when combined with queue-scheduled wide-field
imaging (optical and IR) and high-spatial resolution AOB programs will provide
the highest possible scientific output of the CFHT for the foreseeable future.
For example, recent CFHT statistics indicate that seeing on Mauna Kea is >1
arcsec on approximately 20% of the clear nights. In other words, on the order
of 60 usable nights per year are
unsuitable for obtaining high quality imagery in the optical or near infrared
but are perfectly suited for high resolution optical spectroscopy! We also feel
that such queue scheduling will generate a substantial increase in the
demand for high resolution spectroscopy at CFHT since there are many long-term
monitoring programs of fundamental scientific interest which have been, for
the most part, impractical to carry out with classical scheduling. Given the
lack of planned spectrographs with R > 100,000 on 4m and 8m class telescopes,
there would also seem to be an indication of a longer term future and need for
high resolution spectroscopy - i.e. CFHT can provide unique capabilities for
considerably longer than the 3-4 year niche other planned and proposed instruments
may offer, whether or not the telescope is upgraded in the future.
In summary, we urge CFHT and SAC NOT to decommission GECKO when a simple redesign (or replacement) of the spectrograph's grating assembly promises to remove the last of the instrument's operational concerns for a very minor cost.
David Bohlender (HIA)
Marie-Christine Artru (ENS-Lyon)
Pierre Bergeron (U. Montreal)
Tom Bolton (U. Toronto)
Pierre Brassard (U. Montreal)
Claude Catala (OMP)
Paul Felenbok (OPM)
Gilles Fontaine (U. Montreal)
Alex Fullerton (UVic/JHU)
Jean-Francois Gonzalez (ENS-Lyon)
David Gray (UWO)
Austin Gulliver (Brandon U.)
Grant Hill (HET)
David Holmgren (Brandon U.)
Swetlana Hubrig (U. Potsdam)
John Lester (U. Toronto)
Jaymie Matthews (UBC)
John Rice (Brandon U.)
Evelyne Roueff (OPM)
Slavek Rucinski (U. Toronto)
Aaron Sigut (UWO)
Greg Wade (U. Toronto)
Gordon Walker (UBC)
(several other names added later)
Summary of the experimental setup:
We propose to provide the CFHT community with a capability of integral field and long-slit spectroscopy at the diffraction limit in the near IR. This goal is achieved by installing two selectable optical devices in the KIR dewar (a small cooled grism on the filter-wheel and a cold aperture on an entrance focal plane wheel) and a room-temperature Fabry-Perot etalon (FPE) in front of KIR, the IR camera dedicated to PUEO. No elements of the optics will alter the image formation and sampling.
At each exposure, several (8-10) monochromatic images of a rectangular field of 36" x 3.5" are simultaneously acquired, providing a multiplex advantage, accurate deconvolution and allowing a precise substraction of continuum and background. The cooled grism guarantees a sky-limited background, thus an excellent sensitivity at K giving access to extragalactic programs. The good spectral resolution (2000-3400) fits to many programs and represents a considerable improvement on imaging with narrow-band filters. The classical operation mode of KIR is not compromised, and even a long-slit spectroscopy mode becomes available, simply by selecting the grism and a slit and removing the FPE from the beam.
Science case
The spectroscopic diagnostic is an essential one to derive constraints and a quantitative information on the physical processes at work in the variety of objects studied by astronomers. Imaging is on the other hand mandatory to discriminate structures and morphology. Integral-field spectroscopy which combines both types of information is thus a powerful tool to study compact objects, especially when associated to adaptive optics. GriF will provide this capability with the major advantage to be limited in sensitivity by the sky only, being in fact a cooled spectrograph. None of the 8 meter telescopes will offer such a capability in the coming years and GriF will be a unique instrument with a well defined niche.
The near-infrared range is rich in spectroscopic signatures of molecules, atoms,
ions, and solids that give direct physical information on the stellar population,
on the interstellar medium or on planets atmospheres or ground. For instance,
in the case of the interstellar medium, important features are the quadrupolar
lines of molecular hydrogen (H2 v=1-0 s(1)...) tracing shocks or UV, Br gamma
and Paschen alpha (redshifted) lines tracing ionized hydrogen.
Regarding the stellar population, the lines of Fe II (1.64 mic), a good indicator
of supernova rate, CO bandhead (2.3-2.4 mic) indicative of Giantsand Supergiants,
and the Helium line at 2.05 mic, are among the most important
ones. Atmospheres and mineral surface of objects in the solar system can also
be probed in lines or bands such as those of methane (1.28, 1.6, 2.0 mic) or
broad organic bands. The infrared range has the additional advantage of being
much less absorbed by the interstellar dust than in the visible where opacity
can be a very limiting factor, precisely in compact objects where dust is often
highly concentrated (protostars, YSOs, circumstellar envelopes around AGB and
post-AGB stars, Starbursters, AGN, etc.).
The -now completed- system study of GriF leads to the following performances:
- spectral domain : H+K = 1.49 - 2.53 mic
- FOV : 3.3 - 3.6 arcsec x 36 arcsec
- number of simultaneous monochromatic images : 8-10
- spectral resolution : 2000-2600 in K, 2800-3400 in H (i.e. 90 - 150 km/s)
- estimated sensitivity : mK = 16-17, mH = 17-18 in 5 minutes (S/N = 5)
The spectral resolution is well adapted to a wide set of programs, including
velocity measurements in the field of extragalactic astrophysics, a key issue
to study the nuclear region of active or normal galaxies. Regarding this last
field, one notes that a characteristic that makes Pueo/Kir practically unique
is the good sensitivity of the wavefront sensor which authorizes to observe
external galaxies, using the nucleus as the reference source.
A non-exhaustive list of astrophysical programs that will benefit directly from GriF is given below; many of them will be the object of proposals by astronomers within the GriF team.
- Solar system: atmosphere and ground of satellite (e.g. structure of the atmosphere of Titan), Mineralogy of asteroids and Kuiper objects, structures in the atmosphere of giant planets (e.g., aurorae in polar regions of Jupiter)
- Multiple stellar systems and crowded clusters : gas and stellar clusters towards the Galactic Center; accurate HR diagram of stellar clusters; accurate spectral classification of tight binary systems among young stellar objects (Herbig and T Tau stars); clues for the formation of stellar and planetary systems, stellar mass function; dynamics of stellar clusters; study of the momentum distribution by systematic measurements of spectroscopically multiple systems.
- Exoplanets and browndwarfs : direct imaging of exo-planets by substraction of two simultaneous images, one of which at the wavelength of a feature of giant planet, such as methane (Racine et al.); search and accurate classification of brown dwarf stars, thanks to improved separation and/or relative radial velocities measurements.
- Circumstellar environnement and star formation regions : embedded very young stellar or protostellar sources; flows and jets around young stellar objects (T Tau and Ae/Be Herbig stars); morphology of inflow and outflow, jets, disks, winds; circumstellar envelope s and flows around evolved stars (post-AGB, LBVs, Planetary nebulae) ; novae (studies of ejecta in diffraction-limited images in spectral lines); supernovae remnants in nearby galaxies.
- Interstellar medium: small scale structure of the ISM.
- Extragalactic astrophysics : ; gas kinematics in the nuclear region of nearby and distant galaxies (the redshift/Kmag histogram shows that most of objects at z=0.2-0.3 are within GriF/KIR sensitivity); starbursters,ultra-luminous galaxies; dusty/gaseous torus in AGNs, micro-spiral structures; detection/study of quasar fuzz, distant ellipticals, primeval galaxies; detailed analysis of distant radio/interacting galaxies
Project progress and schedule
Most of the design studies are completed (documents are available on request):
- Optical design and grism specification
- Fabry-Perot specification
- mechanical design of the entrance wheel
The remaining study to complete concerns the mechanical interface with the bonnette;
a satisfactory setup has already been discussed with CFHT.
Orders can already be placed on FPE and grism and in fact should occur withinthe coming weeks in order to keep the schedule on track.
The sharing of software development tasks between CFHT and institutes is now clear :
- LAOG will provide data reduction software directly derived from the one developed for the GraF instrument (on Adonis at the 3m6 ESO).
- DESPA will design the medium-level software (high-level routines for the specific control of the FP etalon, such as alignment/parallelism, proper spacing, scanning etc.)
- CFHT will have to design the low-level routines to interface the new controller, if any, and the high-level routines within DETI and/or PEGASUS to synchronize controls of the camera (wheels, exposure, etc.) and of the FPE.
The current schedule is as follows:
M J J A S O N D
- Mechanical interface design --------
- Mechanical manufacturing : -----------------
- Grism procurement -----------------
- Fabry-Perot procurement --------------------
- Control software development -----------------------
- Shipment ----
- Integration and test ----
- Test on telescope ----
The CFHT archive has been part of the operations mandate of the CADC since 1992.
CADC catalogues and distributes data from as far back as September 1989. With
10 years of superb, high-resolution imagery complemented by an equally rich
catalogue of low- and high-resolution spectra, the CFHT Archive is currently
one of the most significant archive resources available to the Canadian, French,
and worldwide astronomical communities.
CADC is faced with three problems related to the CFHT archive. First, CFHT
had the foresight (extraordinary for its time) of saving all data to optical
media with basic exposure information but this foresight was not accompanied
by the other necessary commitments (e.g., electronic logging, complete header
information) that would have made an effective science archive viable. The result
is a permanent reduction in the scientific potential of the CFHT data.
Second, CFHT is now storing and distributing data on unreliable media (tape)
which fails to ensure the security of the data themselves. Third, the huge increase
in data volume presented by the CFH12K mosaic camera cannot be accommodated
at CADC with existing storage capability and upgrading that capability is not
taking place due to HIA budget restrictions.
The CFH12K camera represents a great scientific opportunity for CFHT. The
impact can be multiplied if a serious commitment is made that CFHT renew and
extend its commitment to scientific data archiving beginning with this
instrument and setting the stage for MEGAPRIME. We propose that CFHT resolve
to do take following actions before the beginning of the next semester of observing.
1) The scientific value of CFH12K data must be preserved. This includes storage on secure media, developing mandatory minimum calibration sequences, providing reliable and complete header information, and recording all necessary auxiliary information such as weather conditions and observing logs reliably and making this information accessible to all users.
2) Pipeline processing of CFH12K data must be implemented at CFHT and those data should be provided to the proposer immediately for assessment and verification of the pipeline procedures.
3) CFHT should commit itself to the existence of an online archive of calibrated CFH12K data. This will be facilitated by the above two resolutions.
The required budget to archive ONE copy of the CFHT12K data is around $68K per annum if only calibrated data is put on-line and $76K if the raw data only is put on-line. Another copy could be considered as a emergency backup and could be located in France for convenience. Putting both raw and calibrated data on-line will cost $87K per annum due essentially to the cost of the juke boxes.
The CADC has the expertise (built up over 12 years) to contribute to a successful
archive for CFH12K. We propose that CADC take delivery of CFH12K data on tape
and be responsible for writing all data to permanent media. Calibrated data
would be catalogued and provided to users online and raw data would be stored
offline. We propose that CFHT provide us with the hardware and media that we
need to do this.
This proposal would result in a valuable scientific archive for CFH12K data and would lay the groundwork for a MEGAPRIME archive. But support for an archive at CADC must be coupled to resolutions 1 and 2 (above). If the actions implied by those resolutions are not taken then the opportunity for the wider community to benefit scientifically from CFHT and thus to multiply the science impact of the CFHT wide-field imaging program will be irretrievably lost.