Massive Star Formation in the Tarantula Nebula
Massive Star Formation in the Tarantula Nebula
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DOI：
10.3847/1538-4357/acac8b
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
O. Nayak;Alex Green;A. Hirschauer;R. Indebetouw;M. Meixner;T. Wong;M. Chevance;G. de Marchi;V. Lebouteiller;Min-Young Lee;L. Looney;S. Madden;J. Roman-Duval;Y. Fukui;Á. Hacar;K. Jameson;V. Kalari;L. Oudshoorn;M. Rubio;E. Sabbi
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作者：
O. Nayak;Alex Green;A. Hirschauer;R. Indebetouw;M. Meixner;T. Wong;M. Chevance;G. de Marchi;V. Lebouteiller;Min-Young Lee;L. Looney;S. Madden;J. Roman-Duval;Y. Fukui;Á. Hacar;K. Jameson;V. Kalari;L. Oudshoorn;M. Rubio;E. Sabbi
在这项工作中，我们展示了利用斯皮策和赫歇尔点源星表在剑鱼座30中发现的299个候选年轻恒星天体（YSOs），其中276个是新的。我们利用最近发表的阿塔卡马大毫米/亚毫米阵列（ALMA）第7周期对12CO和13CO的观测数据，研究了这些YSO候选者形成的母体巨大分子云。根据基于lte的质量表面密度推断，剑鱼座30的恒星形成阈值为178 M⊙pc−2，比银河系的恒星形成阈值高40%。与银河系相比，恒星形成阈值的增加，以及距离R136超级星团11pc的团块与距离R136超级星团45pc的团块相比，线宽的增加，可能是由于注入的湍流能量，星际介质压力的增加，和/或当地磁场强度的增加。在本研究的299个YSO候选者中，62%与12CO分子气体无关。这个大比例可以用75%-97%的H2气体没有被CO追踪到这一事实来解释。我们对YSO候选人进行了Kroupa初始质量函数拟合，发现总恒星质量为18,000 M⊙，该区域的恒星形成率（SFR）为0.18 M⊙yr−1。这里确定的初始质量函数适用于ALMA观测到的4个150″× 150″（37.5 pc × 37.5 pc）子场和1个150″× 75″（37.5 pc × 18.8 pc）子场。在过去的几百万年里，30 Doradus的SFR增加了。
In this work, we present 299 candidate young stellar objects (YSOs) in 30 Doradus discovered using Spitzer and Herschel point-source catalogs, 276 of which are new. We study the parental giant molecular clouds in which these YSO candidates form using recently published Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 7 observations of 12CO and 13CO. The threshold for star formation in 30 Doradus inferred by the LTE-based mass surface density is 178 M ⊙ pc−2, 40% higher than the threshold for star formation in the Milky Way. This increase in star formation threshold in comparison to the Milky Way and increase in line width seen in clumps 11 pc away in comparison to clumps 45 pc away from the R136 super star cluster could be due to injected turbulent energy, increase in interstellar medium pressure, and/or local magnetic field strength. Of the 299 YSO candidates in this work, 62% are not associated with 12CO molecular gas. This large fraction can be explained by the fact that 75%–97% of the H2 gas is not traced by CO. We fit a Kroupa initial mass function to the YSO candidates and find that the total integrated stellar mass is 18,000 M ⊙ and that the region has a star formation rate (SFR) of 0.18 M ⊙ yr−1. The initial mass function determined here applies to the four 150″ × 150″ (37.5 pc × 37.5 pc) subfields and one 150″ × 75″ (37.5 pc × 18.8 pc) subfield observed with ALMA. The SFR in 30 Doradus has increased in the past few million years.