New Light on Young Stars:
Spitzer's View of Circumstellar Disks

X-Ray Observations of Star Formation in Serpens

First Author:
Joanna Brown
Email: jbrown AT mpe.mpg.de
Max Planck Institut fur extraterrestrische Physik
Postfach 1312
Garching D85741 Germany

Abstract

We present XMM X-ray observations of Serpens with > 150 young stars detected in two EPIC fields. Spitzer infrared maps of this region revealed dense dust and numerous previously unknown pre-main sequence (PMS) stars, diverse in both mass and age. Comparison of the infrared disk and X-ray coronal properties allows detailed characterization of the individual stars and investigation of evolutionary trends in different regions. Young stars are strong X-ray emitters throughout their PMS evolution, from embedded protostars to older dust-free (and hence infrared-faint) PMS stars. X-ray emission provides an excellent method of tracing the entire PMS population and investigating the star formation histories of these regions and the processes controlling the fragmentation and formation of stars.