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SIRTF at the AAS: June 2002 |
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SIRTF at AAS - Albuquerque, NM, June 2-6, 2002The 200th meeting of the American Astronomical Society (AAS) was held in Albuquerque, NM on June 2-6, 2002. The following posters featured SIRTF or the research of SIRTF team members:
The Reddest Quasars -- Further Observations of the "Red Menace"M. Lacy (SSC), M.D. Gregg, R.H. Becker (IGPP/LLNL, UC Davis), R.L. White (STScI), E. Glickman, D. Helfand (Columbia)We present the latest results of our program to find luminous, dust-reddened quasars through matching the FIRST radio survey with the 2MASS near-infrared survey. We show Keck/ESI optical and IRTF/SpeX spectra of our objects, and briefly discuss new Chandra data on a few of our sources. 2/13 of our red quasars are lensed (including the first known lensed FeLoBAL quasar). Simple calculations suggest that these objects may consistute a significant population impossible to find in optical bands at high redshifts. We use these findings to briefly discuss the nature and numbers of red quasars in the context of the general quasar population.
Identifying Moderate Redshift Damped Lyman-alpha GalaxiesL. J. Storrie-Lombardi (SSC), M. Lacy (SSC), R.H. Becker (IGPP/LLNL, U.C. Davis)We present here preliminary results from a survey of quasar fields with damped Lyman-alpha absorption systems (DLA) in the redshift range 0.6 < z < 2. This is a program to identify new DLA absorbers with z < 2 and understand the nature of the galaxies responsible for the absorption and their contribution to the comoving mass density in neutral gas at moderate redshifts. NIRC K' imaging is combined with LRIS spectroscopy of the candidate galaxies detected in the field and an HST program to identify the Lyman-alpha absorption based on the strength of MgII seen in the optical quasar spectra.
On the Relationship Between Stellar Rotation and Radius in Young ClustersL. M. Rebull (SSC), S. C. Wolff (NOAO), S. E. Strom (NOAO), R. B. Makidon (STScI)We have compiled data on rotational velocities for more than 1000 K & M stars in 12 young clusters ranging in age from Orion to the Hyades. These data enable a search for systematic changes in stellar rotational velocity vs. age. Taken together, these data show that most PMS stars spanning ages ~0.1-~10 Myr do not appear to spin up in response to contraction down their convective tracks, and further suggest that any spin up between 10 Myr and the ZAMS is modest (<2x) at best.These results extend and reinforce our earlier study (Rebull et al. 2002), based on observations of several hundred stars in the Orion Flanking Fields, NGC 2264, and the Orion Nebula Cluster (ONC), which showed that the majority of PMS stars in these three groups apparently do not conserve stellar angular momentum as they contract, but instead evolve at nearly constant angular velocity. This result applies both to stars with and without near-IR (I-K) excesses indicative of disks.
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