Coronae in the Coronet: a very deep X-ray look into a stellar nursery
- Author(s)
- J. Forbrich, T. Preibisch
- Abstract
Aims: To study the X-ray properties of young stellar objects (YSOs), we analyze an exceptionally sensitive Chandra dataset of the Coronet cluster in the CrA star-forming region, achieving a limiting luminosity of L_X,min ˜ 5× 1026 erg/s for lightly absorbed sources. This dataset represents one of the most sensitive X-ray observations ever obtained of a star-forming region. Methods:The X-ray data are used to investigate the membership status of tentative members of the region, to derive plasma temperatures and X-ray luminosities of the YSOs, and to investigate variability on the timescale of several years. Results: 46 of the 92 X-ray sources in the merged Chandra image can be identified with optical or near/mid-infrared counterparts. X-ray emission is detected from all of the previously known optically visible late-type (spectral types G to M)stellar cluster members, from five of the eight brown dwarf candidates,and from nine embedded objects (“protostars”) with class 0,class I, or flat-spectrum spectral-energy distributions (SEDs) in the field of view. While the Herbig Ae/Be stars TY CrA and R CrA, a close companion of the B9e star HD 176386, and the F0e star T CrA are detected, no X-ray emission is found from any of the Herbig-Haro (HH)objects or the protostellar cores without infrared source. We find indications for diffuse X-ray emission near R CrA / IRS 7. Conclusions: The observed X-ray properties of the Coronet YSOs are consistent with coronal activity; soft spectral components hinting towards X-ray emission from accretion shocks were not found. The X-ray emission of the Ae Be stars TY CrA and HD 176386 probably originates fromclose late-type companions. The Ae star R CrA shows a peculiar X-ray spectrum and an extremely hot plasma temperature. Finally, we discuss the differences of the X-ray properties of YSOs in different evolutionary stages. Appendix is only available in electronic form at www.aanda.org
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Max-Planck-Institut für Radioastronomie
- Journal
- Astronomy & Astrophysics
- Volume
- 475
- Pages
- 959-972
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361:20066342
- Publication date
- 12-2007
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103004 Astrophysics
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/89341a24-fef4-419c-971f-6c4f195e27ac