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SIRTF at the AAS: June 2001 |
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The 198th meeting of the American Astronomical Society (AAS) was held in
Pasadena on June 3-7, 2001. SIRTF Project Scientist Dr. Michael W. Werner
presented an Invited Talk, "SIRTF's First Year: Science Plans and Science
Opportunities," on Monday, June 4 at 11:40 am. Dr. Werner presented an
overview of the SIRTF mission, and a preview of the investigations already
approved for execution in the first year of the mission. These include the
Legacy Science Program, the First-Look Survey , and a portion of the
Guaranteed Time Observer investigations. Between these programs, about
three-fourths of the observing time in the first year following the July
2002 launch has now been defined.Later that same day, a Special (Oral) Session was devoted to the Legacy Science projects selected in November 2000. During this 90-minute session starting at 2:00 pm, each of the six Legacy Science teams described the scientific goals of their project, and the databases and data products that will be developed and delivered to the community for archival research and for subsequent planning of follow-on SIRTF investigations.
AbstractsSIRTF's First Year: Science Plans and Science OpportunitiesM.W. WernerThe Space Infrared Telescope Facility (SIRTF) is a cryogenically-cooled observatory for infrared astronomy from space. SIRTF, scheduled for launch in 2002, will both complete NASA's family of Great Observatories and serve as a cornerstone of the Origins program. This talk will summarize the technical basis and status of SIRTF and review existing plans for the first year of SIRTF science, based on the programs defined by the SIRTF Science Working Group and by the recently-selected SIRTF Legacy Science investigations. In addition, the talk will review the schedule and opportunities for the international astronomical community to propose General Observer and Archival Research programs with SIRTF. About 25 and more than 75 observing time over the 2.5-to5 year SIRTF mission, will be made available to the community through these opportunities. The user community will interact with SIRTF through the SIRTF Science Center on the Caltech campus. Interested colleagues are invited to keep abreast of the status of SIRTF and the schedule for GO proposals via the SSC web site: http://sirtf.caltech.edu/
The Great Observatories Origins Deep Survey (GOODS)M. Dickinson (STScI), GOODS Legacy TeamGOODS is a SIRTF Legacy program to study galaxy evolution over the widest range of redshift and lookback time. It aims to trace the mass assembly history of galaxies, the evolution of their stellar populations, and their energetic output from star formation and active nuclei. SIRTF can observe rest-frame near- and mid-infrared light from objects at 1 < z < 6, but very deep exposures are needed to detect ``ordinary'' objects at such redshifts. GOODS will build on the deepest observations from NASA's other Great Observatories, Hubble and Chandra, and from ESA'S XMM-Newton, with extensive observing support from ESO and NOAO. We will survey ~300 arcmin2 in two fields, the Hubble Deep Field North and the Chandra Deep Field South. Dividing the survey provides insurance against clustering variance, and guarantees access for astronomers in both hemispheres.GOODS will observe for 25 hours/position with IRAC (3.6-8\mum). A smaller, ultradeep IRAC field (75-100 hours) is planned, contingent upon on-orbit tests of instrument performance. The IRAC observations can detect rest-frame near-infrared light from the progenitors of galaxies like the Milky Way out to z \approx 4. We also plan 10 hour MIPS exposures at 24\mum, pending on-orbit tests to establish the sensitivity gain relative to GTO observations of these fields. The MIPS data will be sensitive to emission from dust-obscured star formation in relatively ordinary galaxies (e.g., Lyman break objects) out to z=2.5, and, with X-ray data, will permit a census of supermassive black holes in obscured and unobscured AGN. GOODS data will also provide the best limits to the extragalactic background light at 3.6-24\mum. We will create a public archive of the deepest observations from X-ray through radio wavelengths. These data will offer a uniquely comprehensive history of galaxy evolution, and will serve as a bridge to future exploration in these wavelength and redshift regimes with NGST.
SWIRE: The SIRTF Wide-area InfraRed Extragalactic SurveyC.J. Lonsdale (IPAC/Caltech)SWIRE is a wide-area, high latitude, imaging survey to trace the evolution of dusty, star-forming galaxies, evolved stellar populations, and AGN, as a function of environment from z~2.5 to the current epoch. SWIRE will survey 7 high latitude fields, covering about 70 sq. degrees in total, in all 7 SIRTF imaging bands, producing highly uniform source catalogs and images, providing an unprecedented view of the evolution of galaxies, structure, and AGN. Extensive modeling suggests that the Legacy Extragalactic Catalog may contain in excess of 2 million IR-selected galaxies dominated by (1) luminous infrared galaxies (log L(fir)>11 solar luminosities), up to 40,000 of them with z>2; (2) ~1 million early-type galaxies (~400,000 with z>2); and (3) ~30,000 classical AGN and as many as 250,000 dust-obscured QSO/AGN. An extensive ground-based Legacy follow-up program is being designed to provide optical identifications to R = 25 for the entire survey area and multi-color optical/near-infrared imaging (g', r', i', K') and photometric redshift information for smaller areas (~30 sq deg; Smith et al. poster at this meeting).
SINGS: The SIRTF Nearby Galaxies SurveyR. Kennicutt (U. Arizona), SINGS TeamThe SINGS Legacy project is a comprehensive imaging and spectroscopic survey of 75 nearby galaxies. Its primary goal is to characterize the infrared emission of galaxies and their principle IR-emitting components, across the entire range of galaxy properties and star formation environments, including regions that until now have been inaccessible at infrared wavelengths. SINGS will provide new insights into the physical processes connecting star formation to the ISM properties of galaxies, and provide a vital foundation of of data, diagnostic tools, and astrophysical inputs for understanding infrared observations of ultraluminous galaxies and the distant universe. The combination of the SIRTF data with ancillary UV, visible, near-IR, and radio observations will make it possible to integrate visible/UV and IR/submillimeter diagnostics of star formation and the ISM into a coherent, self-consistent framework, and apply them across the full range of interstellar environments found in the local universe.The SINGS galaxy sample and observing strategy are designed to maximize the scientific and archival value of the data set for the SIRTF user community at large. Observations will include full imaging of each galaxy at 3.5--160 \mum, low-resolution spectral mapping across each galaxy at 14--99 \mum, and high-resolution spectroscopy at 5--37 \mum of their centers and a representative set of IR-emitting extra-nuclear regions. The images and spectra, combined with the ancillary data into a multi-wavelength archive, will enable scores of archival investigations of problems in galactic structure and evolution, star formation, stellar populations, interstellar dust, and ISM physics. This talk will highlight the main astrophysical issues to be addressed by SINGS, and describe the observing program, the data products, and opportunities for archival research and follow-up GO observations.
The Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE)E. Churchwell (U. Wisconsin), GLIMPSE TeamThe GLIMPSE team will image the inner galaxy in all IRAC bands from 10 to 70 degrees on either side of the Galactic center and one degree above and below the plane (240 square degrees). The survey will be fully sampled and will reach the confusion limit in all IRAC bands at longitudes \leq 50 deg. At longitudes> 50 deg, the 5.8 and 8.0 \mum bands may be flux limited. GLIMPSE will: 1) produce a complete census of star formation in the inner galaxy; 2) measure the stellar disk scale length; 3) delineate the stellar structure of the molecular ring, inner spiral arms and bar as traced by the distributions of stars and star formation regions; 4) determine the luminosity and initial mass functions of all nearby star formation regions and clusters down to the stellar limit or below (for the nearest regions); 5) detect all young O and B stars still embedded in their natal clouds; 6) detect and identify young stellar objects (surrounded by circumstellar disks) in nearby star forming regions; 7) determine the mid-IR interstellar extinction law in dense regions; and, 8) detect a host of other types of stars and nebulae such as supernovae, planetary nebulae, hidden galaxies, OH/IR stars, LBVs, etc. that will be of interest to a large fraction of the astronomical community. An additional value of a large, unbiased Galactic plane survey is its potential for new discoveries that might otherwise be missed by piecemeal imaging of selected regions. We expect to detect and catalog ~ 108 sources. This program is funded by NASA through the SIRTF Science Center (SSC).
From Molecular Cores to Planet-forming DisksN. J. Evans II (University of Texas at Austin), L. E. Allen (Smithsonian Astrophysical Observatory), G. A. Blake (California Institute of Technology), P. M. Harvey (University of Texas at Austin), D. W. Koerner (University of Pennsylvania), L. G. Mundy (University of Maryland), P. C. Myers (Smithsonian Astrophysical Observatory), D. L. Padgett (SIRTF Science Center), A. I. Sargent (California Institute of Technology), K. Stapelfeldt (Jet Propulsion Laboratory), E. F. van Dishoeck (University of Leiden)Crucial steps in the formation of stars and planets can be studied only at mid-infrared to far-infrared wavelengths, where SIRTF provides an unprecedented improvement in sensitivity. We will use all three SIRTF instruments (IRAC, MIPS, and IRS) to observe sources that span the evolutionary sequence from molecular cores to protoplanetary disks, encompassing a wide range of cloud masses, stellar masses, and star-forming environments. In addition to targeting 120 known compact cores, we will survey the entire areas of at least four of the nearest large molecular clouds for new candidate protostars and substellar objects as faint as 0.001 solar luminosities. We will also observe about 130 systems likely to be in the early stages of planetary system formation, probing the evolution of the circumstellar dust and gas, the raw materials for planetary cores and atmospheres. Candidate planet-forming disks as small as 0.1 lunar masses will be detectable. Spectroscopy of new objects found in the surveys and of a select group of known objects will add vital complementary information on the changing chemical and physical conditions in the disks. The resulting data products will include catalogs of thousands of previously unknown sources, multiwavelength maps of about 20 square degrees of molecular clouds, photometry of 130 known young stars, spectra of at least 130 sources, ancillary data from ground-based telescopes, and new tools for analysis and modeling. These products will constitute the foundations for many follow-up studies with ground-based telescopes, as well as with SIRTF and other space missions like SIM, NGST, and TPF.
The Formation and Evolution of Planetary Systems: Placing Our Solar System in Context with SIRTFM.R. Meyer (Steward Observatory, The University of Arizona), Formation and Evolution of Planetary Systems SIRTF Legacy Science TeamWe propose to trace the evolution of planetary systems at all ages ranging from: (1) 3-10 Myr when stellar accretion from the disk terminates; to (2) 10-100 Myr when planets achieve their final masses via coalescence of solids and accretion of remnant molecular gas; to (3) 100-1000 Myr when the final architecture of solar systems takes form and frequent collisions between remnant planetesimals produce copious quantities of dust; and finally to (4) mature systems of age comparable to the Sun in which planet-driven activity of planetesimals continues to generate detectable dust. Our strategy is to use carefully calibrated spectral energy distributions and high-resolution spectra to infer the radial distribution of dust and the molecular hydrogen content of disks surrounding a sample of 300 solar-like stars distributed uniformly in log-age over 3 Myr to 3 Gyr.The high precision and fine sampling of SIRTF spectral energy distributions can reveal both the existence of planets and their approximate masses and radial distributions through modeling of the dynamical effects of planets in sculpting planetesimal distributions and orchestrating their collision frequency. The size of our target list will enable us to characterize the diversity of planetary system architectures, providing a deeper appreciation of the range of possible outcomes of the planet formation process - thus placing our own solar system in context. Our proposed Legacy program promises to provide: (1) new insight into problems of fundamental scientific and philosophical interest; (2) calibration with precision 2-3 times that of standard SIRTF data products, to the benefit of all SIRTF observers; (3) new numerical tools for simulating the dynamical history of forming solar systems; and (4) a rich database to stimulate follow-up observations with SIRTF, with existing and future ground-based facilities, and later with SIM, NGST, and TPF.
More Than Your Eyes Can See: Outreach at the Space Infrared Telescope FacilityM. ThallerCommunicating the world of infrared astronomy to the public comes with a unique set of pleasures and challenges. How do you begin to visualize the universe in a kind of light that is totally invisible to the human eye? At the SIRTF Science Center, we're answering that question with a wide variety of educational projects and products. We've produced a suite of award-winning websites (all of which can be accessed at sirtf.caltech.edu) that speak to audiences as varied as kindegarteners to amateur astronomers. We've also filmed and distributed a short video about infrared light that has become a favorite with NASA education specialists as well as classroom teachers. In the coming year, we will be collaborating with SOFIA to develop an internet-based astronomy course that will be part of an online master's degree in education.
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