论文标题
巨大的星形团块？
Giant star-forming clumps?
论文作者
论文摘要
随着Atacama大毫米阵列（ALMA）的空间分辨率，遥远的宇宙中的尘土灰星系通常是单一的，紧凑的灰尘发射斑点，中间半光线半径为$ \ $ \ $ 1 kpc。有时，前景星系或星系簇的强烈重力镜头探测了空间尺度的1-2个数量级，通常会显示后期的合并，有时会带有诱人的子结构提示。尤其是一个镜头的星系，$ z = $ 2.3的宇宙睫毛已被广泛引用为一个示例，其中星际介质在$ \ $ \ $ \ $ 100的空间尺度上表现出明显，明显的团块。七个数量级比本地宇宙中的巨大分子云更发光，这些特征被视为间接证据，表明在许多$ z \ sim $ 2-3的星系中观察到的蓝色团块是正在进行的恒星形成的重要地点，具有大量的气体和恒星。 Here, we present data from ALMA which reveal that the dust continuum of the Cosmic Eyelash is in fact smooth and can be reproduced using two Sérsic profiles with effective radii, 1.2 and 4.4 kpc, with no evidence of significant star-forming clumps down to a spatial scale of $\approx$ 80 pc and a star-formation rate of $<$ 3 M$_\odot$ yr$^{-1}$.
With the spatial resolution of the Atacama Large Millimetre Array (ALMA), dusty galaxies in the distant Universe typically appear as single, compact blobs of dust emission, with a median half-light radius, $\approx$ 1 kpc. Occasionally, strong gravitational lensing by foreground galaxies or galaxy clusters has probed spatial scales 1-2 orders of magnitude smaller, often revealing late-stage mergers, sometimes with tantalising hints of sub-structure. One lensed galaxy in particular, the Cosmic Eyelash at $z=$ 2.3, has been cited extensively as an example of where the interstellar medium exhibits obvious, pronounced clumps, on a spatial scale of $\approx$ 100 pc. Seven orders of magnitude more luminous than giant molecular clouds in the local Universe, these features are presented as circumstantial evidence that the blue clumps observed in many $z\sim$ 2-3 galaxies are important sites of ongoing star formation, with significant masses of gas and stars. Here, we present data from ALMA which reveal that the dust continuum of the Cosmic Eyelash is in fact smooth and can be reproduced using two Sérsic profiles with effective radii, 1.2 and 4.4 kpc, with no evidence of significant star-forming clumps down to a spatial scale of $\approx$ 80 pc and a star-formation rate of $<$ 3 M$_\odot$ yr$^{-1}$.
