Astronomy and Astrophysics – Astrophysics
Scientific paper
Jan 2012
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012aas...21940701h&link_type=abstract
American Astronomical Society, AAS Meeting #219, #407.01
Astronomy and Astrophysics
Astrophysics
Scientific paper
The Spitzer Space Telescope archive provides a means for studying mid-infrared variability in large numbers of young stellar objects (YSOs) in different star-forming regions. We are conducting such a study, as part of NASA's Astrophysics Data Analysis Program (ADAP), to identify those YSOs exhibiting variability and to characterize the frequency, magnitude, and color of this variability. Our results for isolated core regions, for example, demonstrate that (70 +/- 20)% of Class I and Flat-spectrum YSOs exhibit variability over timescales of 1-2 years, while only (24 +/- 8)% of Class II and III YSOs appear to be variable over these times, suggestive of a dependence on evolutionary class. In contrast, we find no such dependence in the IC 5146 cluster forming region or the Perseus or Serpens regions, where 35-45% of the YSOs exhibit variability. In general, the variable YSOs brighten or dim consistently across the IRAC 3.6-8.0 micron bands; the mid-infrared color changes are typically inconsistent with variable line-of-sight extinction. The magnitude of maximum IRAC variability for many YSOs is inconsistent with starspots as the dominant cause. Instead, intermittent heating and cooling by episodic accretion is the favored mechanism. In some cases, YSO observations were repeated over shorter timescales, from 0.2 to 2 days. We analyzed these observations to determine whether YSOs exhibited variability over these timescales and, if so, whether it was consistent with the longterm variations that we observed. Results from this study and implications for accretion will be presented.
Huard Tracy L.
Mundy Lee G.
Storm Shaye
No associations
LandOfFree
Survey of Infrared Variability of Young Stellar Objects in Nearby Molecular Clouds does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Survey of Infrared Variability of Young Stellar Objects in Nearby Molecular Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Survey of Infrared Variability of Young Stellar Objects in Nearby Molecular Clouds will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1582497