Delving deep: A population of extremely dusty dwarfs observed by JWST
Delving deep: A population of extremely dusty dwarfs observed by JWST
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深入探索：JWST 观测到的一群尘土飞扬的矮星
DOI：
10.1051/0004-6361/202346219
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发表时间：
2023
影响因子：
6.5
通讯作者：
Bisigello L
中科院分区：
文献类型：
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作者：
Bisigello L
我们利用近红外相机测光观测作为宇宙演化早期释放科学巡天（CEERS）的一部分，识别和分析非常红的源，努力发现非常尘埃的星星形成星系。方法我们选择红色星系作为对象，在4.4 μm处的所有JWST和HST滤波器中，在λ≤ 2 μm处，对应于[F200 W]−[F444 W]> 1.2。 这种选择是理想的，以确定非常多尘（AV> 1等）星系的恒星质量之间的106和1010 M赫兹<5，更大质量的尘埃星系赫兹= 5 − 18和星系赫兹> 18由于莱曼吸收，独立于他们的尘埃extinction.ResultsOur样本ofF 200 W-dropouts包含没有强有力的候选人赫兹> 6.5，而是它几乎完全由（约81%）OFZ<2低质量星系，与恒星质量中位数为107.3 M赫兹。 这些星系显示出异常的尘埃消光，平均值为AV = 4.9等，考虑到它们的低恒星质量，这是完全出乎意料的。 其余的星系，atz<6.5，也有类似的大尘埃消光（AV> 1），但它们的质量一般都大于107.5 M <$。
AimsWe take advantage of the NIRCam photometric observations available as part of the Cosmic Evolution Early Release Science survey (CEERS) to identify and analyse very red sources in an effort to discover very dusty star forming galaxies.MethodsWe select red galaxies as objects with aS/N> 3 at 4.4 μm and aS/N< 2 in all JWST and HST filters atλ≤ 2 μm, which corresponds to [F200W]−[F444W]> 1.2 considering CEERS depths. This selection is ideal to identify very dusty (AV> 1 mag) galaxies with stellar masses between 106and 1010M⊙atz< 5, more massive dusty galaxies atz= 5 − 18 and galaxies atz> 18 due to the Lyman absorption, independently of their dust extinction.ResultsOur sample ofF200W-dropouts contains no strong candidates atz> 6.5, instead it consists almost completely (∼81%) ofz< 2 low-mass galaxies, with a median stellar mass of 107.3M⊙. These galaxies show an exceptional dust extinction with median value ofAV= 4.9 mag, completely unexpected given their low stellar mass. The remaining galaxies, which are atz< 6.5, show similar large dust extinction (AV> 1), but they are generally more massive > 107.5M⊙.