JWST reveals star formation across a spiral arm in M33
JWST reveals star formation across a spiral arm in M33
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JWST 揭示了 M33 旋臂上的恒星形成过程
DOI：
10.1093/mnras/stad3879
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发表时间：
2023
影响因子：
4.8
通讯作者：
Leroy, Adam K
中科院分区：
文献类型：
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作者：
Peltonen, Joshua;Rosolowsky, Erik;Williams, Thomas G;Koch, Eric W;Dolphin, Andrew;Chastenet, Jérémy;Dalcanton, Julianne J;Ginsburg, Adam;Johnson, L Clifton;Leroy, Adam K
年轻恒星天体（YSO）是追踪星系中星星形成的黄金标准，但在银河系和麦哲伦云之外无法观测到。但当JWST发射时，这一切都改变了，我们用它来识别本星系群M33中的YSO，这标志着第一次在如此大的距离上识别出单个YSO。我们目前中红外仪器（MIRI）成像马赛克在5.6和21米，覆盖了M33的螺旋臂，现有的全色成像从theHubble空间望远镜和深阿塔卡马大型毫米/亚毫米阵列CO测量的一个重要部分。利用这些MIRI和哈勃空间望远镜的图像，我们使用新的dolphotMIRI模块识别点源。我们确定了793个候选YSO的切割颜色的基础上，接近巨大的分子云（GMCs），和目视检查。与银河系GMC相似，我们发现质量越高的GMC包含越多的YSO和YSO发射，这进一步表明YSO比大多数无法在云尺度上捕获这种关系的示踪剂更好地识别星星的形成。通过比较YSO和分子气体质量，我们发现南旋臂中星星形成效率提高的证据。
Young stellar objects (YSOs) are the gold standard for tracing star formation in galaxies but have been unobservable beyond the Milky Way and Magellanic Clouds. But that all changed when theJWSTwas launched, which we use to identify YSOs in the Local Group galaxy M33, marking the first time that individual YSOs have been identified at these large distances. We present Mid-Infrared Instrument (MIRI) imaging mosaics at 5.6 and 21m that cover a significant portion of one of M33’s spiral arms that has existing panchromatic imaging from theHubble Space Telescopeand deep Atacama Large Millimeter/submillimeter Array CO measurements. Using these MIRI andHubble Space Telescopeimages, we identify point sources using the newdolphotMIRI module. We identify 793 candidate YSOs from cuts based on colour, proximity to giant molecular clouds (GMCs), and visual inspection. Similar to Milky Way GMCs, we find that higher mass GMCs contain more YSOs and YSO emission, which further show YSOs identify star formation better than most tracers that cannot capture this relationship at cloud scales. We find evidence of enhanced star formation efficiency in the southern spiral arm by comparing the YSOs to the molecular gas mass.