Nothing to Hide: An X-ray Survey for Young Stellar Objects in the Pipe Nebula

Author(s)
Jan Forbrich, Bettina Posselt, Kevin R. Covey, Charles J. Lada
Abstract

We have previously analyzed sensitive mid-infrared observations to establish that the Pipe Nebula (PiN) has a very low star formation efficiency. That study focused on young stellar objects (YSOs) with excess infrared emission (i.e., protostars and pre-main-sequence stars with disks), however, and could have missed a population of more evolved pre-main-sequence stars or Class III objects (i.e., young stars with dissipated disks that no longer show excess infrared emission). Evolved pre-main-sequence stars are X-ray bright, so we have used ROSAT All-SkySurvey data to search for diskless pre-main-sequence stars throughout the PiN. We have also analyzed archival XMM-Newton observations of three prominent areas within the Pipe: Barnard 59 (B 59), containing a known cluster of YSOs; Barnard 68, a dense core that has yet to form stars;and the Pipe molecular ring, a high-extinction region in the bowl of the Pipe. We also characterize the X-ray properties of YSOs in B 59. TheROSAT and XMM-Newton data provide no indication of a significant population of more evolved pre-main-sequence stars within the Pipe,reinforcing our previous measurement of the Pipe's very low star formation efficiency.

Organisation(s)
Department of Astrophysics
External organisation(s)
Harvard-Smithsonian Center for Astrophysics, Cornell University
Journal
The Astrophysical Journal: an international review of astronomy and astronomical physics
Volume
719
Pages
691-699
ISSN
0004-637X
DOI
https://doi.org/10.1088/0004-637X/719/1/691
Publication date
08-2010
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/a84add5d-1d43-4d4d-b303-148e2f61e135