MEETING REPORT: Astrophysics Working Group

1997 March, Infrared/Submillimeter Subgroup

LABORATORY ASTROPHYSICS WORKSHOP

It was announced that Harvard University would host a lab astro workshop in November, with the goal of bringing together the various constituencies that produce and utilize lab astro data. The AWG/ISR endorsed the idea that NASA consider that theoretical work of direct relevance also be considered part of a broadly-defined concept of laboratory astrophysics. Moreover, the AWG/ISR hopes that by inviting the astrophysics and planetary communities, one of the byproducts of the Harvard workshop will be motivation for an intelligent consolidation of the disparate NASA/OSS R&A lab astro programs currently scattered throughout the old astrophysics and solar system programs. Moreover, the AWG/ISR suggests that the community ensure that the solar physics community be integrated into the workshop.

MIDCOURSE SPACE EXPERIMENT (MSX)

The AWG/ISR heard a presentation from Ed Tedesco (Mission Research Corporation) on early science results from the Midcourse Space Experiment (MSX), a BMDO payload. The mission includes three instruments, covering UV to mid-IR wavelengths. The infrared instrument SPIRIT-III ceased operations following the depletion of its cryogen after 10 months of mapping about one-fifth of the celestial sky (the UV experiment is still collecting data).

MSX was originally conceived as a characterization and monitoring device for rocket plumes associated with ballistic missiles. The original intention was to spend roughly 10% of its time looking outwards (i.e. capable of astronomical observations), and some 90% looking towards the Earth's limb. According to Tedesco, the actual ratio in practice was reversed! A video tape scanning the Galactic plane from +90 to -90 deg (one degree wide strip) played throughout Tedesco's presentation, and the oohs and ahs from the assembled masses were audible. NASA's position has always been that MSX had to prove it could yield astronomically useful data before it would consider any support for data analysis. The AWG/ISR was favorably impressed with the qualitative aspect of the SPIRIT-III data, and supports the submission of a proposal seeking NASA data analysis support (and subsequent peer review). As it currently stands, MSX data is not expected to be publicly available until late 1999.

The AWG/ISR went on record as insisting that astronomers would need to have greater insight into the calibration procedures before ascertaining the astronomical utility of the SPIRIT-III dataset. For example, BMDO is primarily interested in looking for S/N>10 events, whereas much of the astronomical interest is likely to lie at S/N<10. These concerns would naturally be addressed in a future ad hoc peer review of any submitted proposal.

Bicay also indicated that SPIRIT-III data might be useful in providing mid-IR finding charts in confused regions of the sky for SIRTF/IRS observations. This may be important because the ability of the SIRTF/IRS peak-up array to provide useful images that permit correct positional offsets to the spectrometer slits is going to depend on source density and our knowledge of the 10 micron sky. If the probability of successfully acquiring an IRS target is improved to something approaching 100% (rather than, say, 90%), it has dramatic implications on the development of costly workaround solutions in the event of IRS acquisition failures. The MSX data at 6-11 microns has a pixel size of 18 arcsec, at least 5 times better angular resolution than IRAS. Adding to the potential utility of the SPIRIT-III dataset is the fact that the areas mapped by MSX -- such as the Galactic plane, Orion, Rho Oph, LMC, SMC -- are also likely to be some of the most popular and crowded regions for SIRTF spectroscopy. For this purpose, photometric calibration is not particularly important; the astrometric data is sufficient. The MSX/SPIRIT-III team and representatives will be encouraged to explore the potential utility of using MSX data to reduce SIRTF development/operations costs. And if NASA support for data analysis is provided by NASDA, the AWG/ISR representatives would hope to see some pressure exerted to provide an earlier public release of MSX data.

SOFIA

Eric Becklin (UCLA), the Chief Scientist for SOFIA, provided a status report on the next-generation airborne observatory. The development/operations contracts for SOFIA were awarded late last year to Universities Space Research Association (USRA), a private, nonprofit corporation organized in 1969 by the National Academy of Sciences at the request of NASA. Becklin described the organizational responsibilities and indicated that the SOFIA Science center will eventually have a staff of 80 (including 12 scientists) and be situated at Moffett Field, California. In addition to Becklin, the other staff scientist already on board is Jackie Davidson, the Facility Scientist.

SOFIA will be a true national-class observatory, with some user-friendly facility instruments in addition to the "PI instruments" that characterized the Kuiper Airborne Observatory. The idea of facility instruments would be to provide black boxes and documentation that would permit members of the general community to successfully carry out observing programs without the need for the instrument builder to accompany the flight.

The initial complement of instruments will be selected via peer review in late 1997. The governing Call for Proposals is scheduled for release by USRA about 4/1/97. Three members of the AWG/ISR are also members of the recently constituted SOFIA Science Steering Committee (Lester, Stacey, Greenhouse.

SIRTF

Michael Bicay (JPL/Caltech) reported on the status of SIRTF, with emphasis on activities of the SIRTF Community Task Force (CTF). The CTF is a 3-year old body drawn from the community at large, and charged with providing advice to the SIRTF Science Working Group and SIRTF project Office, while helping to organize the annual Community Workshops at the winter AAS meetings.

SIRTF entered Phase B last October, and is in the President's FY1998 budget as the sole "New Start" candidate for NASA/OSS. To the extent that the NASA budget is approved with little change (deemed likely by the NASA/OSS Board of Directors), SIRTF's launch date will move forward from July 2002 to December 2001. Moreover, the recent HQ decision to launch SIRTF on a Delta 7920-H launch vehicle provides 200 kg of additional mass capability. It is likely that some of this added capability will significantly enhance the prospects of achieving the desired goal of a 5-year lifetime (2.5 years is the requirement).

Bicay summarized the SIRTF Science Activity Timeline for the next decade, with emphasis on 1998. That is the year when the SIRTF Project Office and the community need to seriously pursue a rational course of activities in advance of the 1999 release of the Legacy Science solicitation for proposals. Various formats of workshops have been discussed for many months, and the AWG/ISR endorsed the idea of holding a "handful" (number left undetermined) of science-focused workshops at sites around the country. The format would be to survey the "state-of-the-field" in a particular subject area(s) for perhaps 1.5 days, and then to spend a couple of hours discussing the best ways of using SIRTF Legacy Science as a tool for advancing knowledge in that area. The goal would be to encourage community members to begin discussing the detailed methods for attacking the science goals, and to perhaps start the coalescence of proto-teams in advance of the actual call for proposals.

ISR RESEARCH AND ANALYSIS PROGRAM

Harley Thronson (NASA HQ) summarized the state of NASA's Infrared/Submm/Radio R&A programs for FY1997. This is the first year of a 3-year cycle of funding that resulted from a peer review of all relevant programs in the summer of 1996. Thronson reported that external funding from Origins technology initiatives would be pursued to help alleviate some of the severe pressure on available R&A resources, especially in the area of detector development.


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Updated 22 July 1997
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