Simultaneous X-Ray and Radio Observations of Young Stellar Objects in NGC 1333 and IC 348
- Author(s)
- Jan Forbrich, Rachel A. Osten, Scott J. Wolk
- Abstract
Young stellar objects (YSOs) and in particular protostars are known to show a variety of high-energy processes. Observations in the X-ray and centimetric radio wavelength ranges are thought to constrain some ofthese processes, e.g., coronal-type magnetic activity. There is awell-known empirical correlation of radio and X-ray luminosities inactive stars, the so-called Güdel-Benz (GB) relation. Previous evidence of whether YSOs are compatible with this relation remains inconclusive for the earliest evolutionary stages. The main difficulty is that due to the extreme variability of these sources, simultaneous observations are essential. Until now, only a few YSOs and only a handful of protostars have been observed simultaneously in the X-ray and radio range. To expand the sample, we have obtained such observations of two young clusters rich in protostars, NGC 1333 and IC 348. While the absolute sensitivity is lower for these regions than for more nearby clusters like CrA, we find that even in deep continuum observations carried out with the NRAO Very Large Array (VLA), the radio detection fraction for protostars in these clusters is much lower than the X-ray detection fraction. Very few YSOs are detected in both bands, and we find the radio and X-ray populations among YSOs to be largely distinct. We combine these new results with previous simultaneous Chandra and VLA observations of star-forming regions and find that YSOs with detectionsin both bands appear to be offset toward higher radio luminosities forgiven X-ray luminosities when compared with the GB relation, although even in this sensitive data set most sources are too weak for the radio detections to provide information on the emission processes. The considerably improved sensitivity of the Expanded VLA will provide abetter census of the YSO radio population as well as better constraintson the emission mechanisms.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Harvard-Smithsonian Center for Astrophysics, Space Telescope Science Institute
- Journal
- The Astrophysical Journal: an international review of astronomy and astronomical physics
- Volume
- 736
- No. of pages
- 11
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.1088/0004-637X/736/1/25
- Publication date
- 07-2011
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103004 Astrophysics
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/b05bdd4b-a7f2-4598-b056-d719ea7354ec