Nothing to Hide -- An X-ray Survey of Star Formation Activity in the Pipe Nebula
- Author(s)
- Jan Forbrich, Bettina Posselt, Charles J. Lada, Kevin Covey
- Abstract
The Pipe Nebula, a large nearby molecular cloud, lacks obvious signposts of star formation in all but one of more than 130 dust extinction cores that have been identified within it. In a recent mid-infrared survey using Spitzer-MIPS to cover 13 square degrees, we have established that the star formation efficiency for the entire cloud is only ˜0.06%.The mid-infrared data are most sensitive for the earliest evolutionary stages of Young Stellar Objects (YSOs), covering class I protostars and typical class II sources (classical T Tauri stars). X-ray observations allow us to extend our survey to constrain any population of classical and weak-line T Tauri stars. In a first step, we use the ROSAT All-Sky Survey to constrain any overall T Tauri star population of the Pipe Nebula. Due to the fact that the Pipe Nebula is at a distance of only130 pc, the ROSAT survey is already quite sensitive. Assuming a typical level of extinction, the completeness for G- and K-type stars is estimated to be about 50%. Subsequently, we use XMM-Newton observations pointed at three high-extinction regions within the Pipe Nebula to analyze these areas at higher sensitivity. These three regions are Barnard 59, the only core with ongoing star formation, the ``ring''(i.e., the highest extinction region in the ``bowl'' of the Pipe), and Barnard 68. We additionally analyze the YSOs of Barnard 59 in the radio continuum to constrain high-energy processes. Overall, our results corroborate our previous Spitzer result that the star formation efficiency of the Pipe Nebula is very low.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Harvard-Smithsonian Center for Astrophysics, Cornell University
- Pages
- 99
- Publication date
- 09-2009
- Austrian Fields of Science 2012
- 103004 Astrophysics
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/264c3ce5-9e30-4192-b1d3-2e52d94536b6