Discovery of X-Rays from Class 0 Protostar Candidates in OMC-3-猫眼课题宝

发现 OMC-3 中 0 级原恒星候选者的 X 射线

DOI：

10.1086/321392

发表时间：

2001

期刊：

The Astrophysical Journal

影响因子：

通讯作者：

中科院分区：

文献类型：

作者：

Y. Tsuboi;K. Koyama;K. Hamaguchi;K. Tatematsu;Y. Sekimoto;J. Bally;B. Reipurth

We have observed the Orion Molecular Clouds 2 and 3 (OMC-2 and OMC-3) with the Chandra X-Ray Observatory (CXO). The northern part of OMC-3 is found to be particularly rich in new X-ray features; four hard X-ray sources are located in and along the filament of cloud cores. Two sources coincide positionally with the submillimeter-millimeter dust condensations of MMS 2 and 3 or an outflow radio source VLA 1, which are in a very early phase of star formation. The X-ray spectra of these sources show an absorption column of (1-3) × 1023 H cm-2. Assuming a moderate temperature plasma, the X-ray luminosity in the 0.5-10 keV band is estimated to be ~1030 ergs s-1 at a distance of 450 pc. From the large absorption, positional coincidence, and moderate luminosity, we infer that the hard X-rays are coming from very young stellar objects embedded in the molecular cloud cores.We found another hard X-ray source near the edge of the dust filament. The extremely high absorption of 3 × 1023 H cm-2 indicates that the source must be surrounded by dense gas, suggesting that it is either a young stellar object in an early accretion phase or a Type II AGN (e.g., a Seyfert 2), although no counterpart is found at any other wavelength. In contrast to the hard X-ray sources, soft X-ray sources are found spread around the dust filaments, most of which are identified with IR sources in the T Tauri phase.