Herschel observations of B1-bS and B1-bN: two first hydrostatic core candidates in the Perseus star-forming cloud
Herschel observations of B1-bS and B1-bN: two first hydrostatic core candidates in the Perseus star-forming cloud
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DOI：
10.1051/0004-6361/201219501
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发表时间：
2012-09
影响因子：
6.5
通讯作者：
S. Pezzuto;D. Elia;E. Schisano;F. Strafella;J. Francesco;S. Sadavoy;P. Andre';M. Benedettini;J. Bernard;A. D. Giorgio;A. Facchini;M. Hennemann;T. Hill;V. Konyves;S. Molinari;F. Motte;Q. Nguyen-Luong;N. Peretto;M. Pestalozzi;D. Polychroni;K. Rygl;P. Saraceno;N. Schneider;L. Spinoglio;L. Testi;D. Ward-Thompson;G. White
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作者：
S. Pezzuto;D. Elia;E. Schisano;F. Strafella;J. Francesco;S. Sadavoy;P. Andre';M. Benedettini;J. Bernard;A. D. Giorgio;A. Facchini;M. Hennemann;T. Hill;V. Konyves;S. Molinari;F. Motte;Q. Nguyen-Luong;N. Peretto;M. Pestalozzi;D. Polychroni;K. Rygl;P. Saraceno;N. Schneider;L. Spinoglio;L. Testi;D. Ward-Thompson;G. White
本文报道了在英仙座恒星形成云B1区获得的两个恒星形成尘埃凝聚[HKM 99] B1-bS和[HKM 99] B1-bN在70 μm和500 μm之间的远红外赫歇尔观测结果。在英仙座云的西部，B1-bS是在所有六个PACS和SPIRE测光波段中唯一被探测到的源，但在斯皮策地图上24 μm处看不到。B1-bN在100 μm和250 μm之间清晰可见。我们已经拟合了这些源的光谱能量分布，推导出它们的物理性质，并发现一个简单的灰体模型无法再现所观察到的光谱能量分布。至少需要一个双组分模型，由一个被尘埃包层包围的中心源组成。但是，从拟合导出的特性表明中心源不是0类对象。然后，我们得出结论，虽然B1-bS和B1-bN似乎比前恒星核心更进化，但最佳拟合模型表明，它们的中心物体比0级源更年轻。因此，它们可能是第一流体静力学核心相的良好候选者。B1-bS和B1-bN之间的投影距离是几个牛仔裤长度。如果它们的物理距离接近这个值，这对恒星将允许研究两颗正在形成的恒星在演化的早期阶段之间的相互作用。
We report far-infrared Herschel observations obtained between 70 μm and 500 μm of two star-forming dusty condensations, [HKM99] B1-bS and [HKM99] B1-bN, in the B1 region of the Perseus star-forming cloud. In the western part of the Perseus cloud, B1-bS is the only source detected in all six PACS and SPIRE photometric bands, but it is not visible in the Spitzer map at 24 μm. B1-bN is clearly detected between 100 μm and 250 μm. We have fitted the spectral energy distributions of these sources to derive their physical properties, and find that a simple greybody model fails to reproduce the observed spectral energy distributions. At least a two-component model is required, consisting of a central source surrounded by a dusty envelope. The properties derived from the fit, however, suggest that the central source is not a Class 0 object. We then conclude that while B1-bS and B1-bN appear to be more evolved than a pre-stellar core, the best-fit models suggest that their central objects are younger than a Class 0 source. Hence, they may be good candidates to be examples of the first hydrostatic core phase. The projected distance between B1-bS and B1-bN is a few Jeans lengths. If their physical separation is close to this value, this pair would allow studying the mutual interactions between two forming stars at a very early stage of their evolution.