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J.L. Linsky, A. Krishnamurthi (JILA/Univ. Colorado & NIST)
The high sensitivity, exquisite angular resolution, 16 by 16 arcmin field of view, low background, and modest energy resolution of the ACIS-I detector make Chandra a powerful new resource for the study of young stellar clusters and associations. In the first 8 months of operation, Chandra has observed a number of young clusters ranging in age from 1\times 106 to 1\times 108 years, including the Pleiades, NGC 2516, Trapezium, and \rho Ophiucus.
These rich images containing hundreds of detected sources provide the information needed to address a number of important questions in star formation and evolution including the shape of the initial mass function, the presence or absence of hot X-ray emitting coronae in brown dwarfs and hot stars with shallow convective zones, coronal variability and flaring as a function of stellar mass, the dependence of X-ray luminosity on age and rotation and the presence of disks, and
The 60 ks ACIS-I image of the Pleiades, for example, provides 3.5\sigma detections down to Lx = 5\times 1027 ergs, about a factor of 10 deeper than the ROSAT surveys. This low threshold permits the detection of coronae down to the end of the M dwarf sequence and beyond into the brown dwarfs. This work is supported by NASA through grant H-04630D to the University of Colorado and NIST.
The author(s) of this abstract have provided an email address for comments about the abstract: jlinsky@jila.colorado.edu