THE JCMT GOULD BELT SURVEY: A FIRST LOOK AT DENSE CORES IN ORION B
THE JCMT GOULD BELT SURVEY: A FIRST LOOK AT DENSE CORES IN ORION B
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DOI：
10.3847/0004-637x/817/2/167
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发表时间：
2015-12
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通讯作者：
H. Kirk;J. Francesco;D. Johnstone;A. Duarte-Cabral;S. Sadavoy;J. Hatchell;J. Mottram;J. Mottram;J. Buckle;D. Berry;H. Broekhoven-Fiene;M. Currie;M. Fich;T. Jenness;D. Nutter;K. Pattle;J. Pineda;C. Quinn;C. Salji;S. Tisi;M. Hogerheijde;D. Ward-Thompson;P. Bastien;D. Bresnahan;H. Butner;M. C. Chen;A. Chrysostomou;S. Coudé;Christopher Davis;E. Drabek-Maunder;J. Fiege;P. Friberg;R. Friesen;G. Fuller;S. Graves;J. Greaves;J. Gregson;J. Gregson;W. Holland;W. Holland;G. Joncas;J. Kirk;L. Knee;S. Mairs;K. Marsh;B. Matthews;G. Moriarty-Schieven;C. Mowat;J. Rawlings;J. Richer;D. Robertson;E. Rosolowsky;D. Rumble;H. Thomas;N. Tothill;S. Viti;G. White;G. White;J. Wouterloot;Jeremy Yates;M. Zhu
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作者：
H. Kirk;J. Francesco;D. Johnstone;A. Duarte-Cabral;S. Sadavoy;J. Hatchell;J. Mottram;J. Mottram;J. Buckle;D. Berry;H. Broekhoven-Fiene;M. Currie;M. Fich;T. Jenness;D. Nutter;K. Pattle;J. Pineda;C. Quinn;C. Salji;S. Tisi;M. Hogerheijde;D. Ward-Thompson;P. Bastien;D. Bresnahan;H. Butner;M. C. Chen;A. Chrysostomou;S. Coudé;Christopher Davis;E. Drabek-Maunder;J. Fiege;P. Friberg;R. Friesen;G. Fuller;S. Graves;J. Greaves;J. Gregson;J. Gregson;W. Holland;W. Holland;G. Joncas;J. Kirk;L. Knee;S. Mairs;K. Marsh;B. Matthews;G. Moriarty-Schieven;C. Mowat;J. Rawlings;J. Richer;D. Robertson;E. Rosolowsky;D. Rumble;H. Thomas;N. Tothill;S. Viti;G. White;G. White;J. Wouterloot;Jeremy Yates;M. Zhu
我们首先介绍了SCUBA-2对猎户座B分子云的三个子区域的观测：LDN 1622，NGC 2023/2024和NGC 2068/2071，来自JCMT古尔德带遗产调查。利用SCUBA-2 850 μm图，我们在L1622、NGC 2023/2024和NGC 2068/2071中分别识别出29、564和322个致密芯，并利用FellWalker源提取算法，给出了它们的基本性质，包括峰值通量、总通量和大小，以及相应的450 μm峰值通量和总通量的估计。假设温度恒定为20 K，无星致密核心的质量函数与以前的致密核心分析中发现的类似，在高质量端具有Salpeter样的斜率。当只考虑热压力时，大多数核心对引力坍缩似乎是稳定的;事实上，大多数质量超过热金斯质量的核心已经与至少一颗原恒星有关。在云柱密度较高时（大于1-2 × 1023 cm−2），大部分质量都在致密的核心内，而在云柱密度较低时（小于1 × 1023 cm−2），这一比例下降到10%或更低。总的来说，与原恒星相关的致密核心的比例相当小（<8%），但对于致密核心和最集中的核心来说会变得更大。NGC 2023/2024和NGC 2068/2071似乎在未来形成大量恒星，而L1622在致密的核心中几乎没有额外的质量来形成许多新的恒星。
We present a first look at the SCUBA-2 observations of three sub-regions of the Orion B molecular cloud: LDN 1622, NGC 2023/2024, and NGC 2068/2071, from the JCMT Gould Belt Legacy Survey. We identify 29, 564, and 322 dense cores in L1622, NGC 2023/2024, and NGC 2068/2071 respectively, using the SCUBA-2 850 μm map, and present their basic properties, including their peak fluxes, total fluxes, and sizes, and an estimate of the corresponding 450 μm peak fluxes and total fluxes, using the FellWalker source extraction algorithm. Assuming a constant temperature of 20 K, the starless dense cores have a mass function similar to that found in previous dense core analyses, with a Salpeter-like slope at the high-mass end. The majority of cores appear stable to gravitational collapse when considering only thermal pressure; indeed, most of the cores which have masses above the thermal Jeans mass are already associated with at least one protostar. At higher cloud column densities, above 1–2 × 1023 cm−2, most of the mass is found within dense cores, while at lower cloud column densities, below 1 × 1023 cm−2, this fraction drops to 10% or lower. Overall, the fraction of dense cores associated with a protostar is quite small (<8%), but becomes larger for the densest and most centrally concentrated cores. NGC 2023/2024 and NGC 2068/2071 appear to be on the path to forming a significant number of stars in the future, while L1622 has little additional mass in dense cores to form many new stars.