COMAP Early Science. VI. A First Look at the COMAP Galactic Plane Survey-猫眼课题宝

DOI：

10.3847/1538-4357/ac63c8

发表时间：

2021-11

期刊：

The Astrophysical Journal

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

Thomas J. Rennie;S. Harper;C. Dickinson;Liju Philip;K. Cleary;R. Bond;J. Borowska;P. Breysse;M. Catha;R. Cepeda-Arroita;D. Chung;S. Church;Delaney A. Dunne;H. Eriksen;M. K. Foss;T. Gaier;J. Gundersen;A. Harris;B. Hensley;Richard Hobbs;H. Ihle;J. Lamb;C. Lawrence;J. Lunde;R. Paladini;T. Pearson;M. Rasmussen;A. Readhead;N. Stutzer;D. Watts;I. Wehus;D. Woody

我们介绍了2019年6月至2021年4月期间进行的CO映射阵列项目（COMAP）银河平面巡天的早期结果，银河经度范围为20° <θ < 40°，银河纬度范围为B θ < 1.°5，角分辨率为4.′5。我们目前的初步结果，从第一部分的调查，包括扩散发射和光谱能量分布的H II地区和超新星遗迹（SNRs）。使用低频和高频调查来限制自由尘埃和热尘埃发射的贡献，我们在六个区域发现了30 GHz处过剩通量密度的证据，我们将其解释为异常微波发射。此外，我们模型超紧凑H II的贡献，使用5 GHz的康沃尔语目录的数据，并拒绝这些30 GHz的过剩的原因。六个已知的信噪比检测在30 GHz，我们测量的光谱指数与文献一致或显示的陡峭的证据。SNR W 44在30 GHz的通量密度与从较低频率的幂律外推一致，与撒丁岛射电望远镜最近的结果相比，没有迹象表明光谱变陡。我们还提取了五个氢无线电复合线（RRL）映射温暖的电离气体，它可以用来估计电子温度或约束连续自由发射。完整的COMAP银河平面巡天将于2023/2024年发布，跨度为20°-220°，将是第一个大规模的射电连续谱和RRL巡天，分辨率为4.5。

We present early results from the CO Mapping Array Project (COMAP) Galactic Plane Survey conducted between 2019 June and 2021 April, spanning 20° < ℓ < 40° in Galactic longitude and ∣b∣ < 1.°5 in Galactic latitude with an angular resolution of 4.′5. We present initial results from the first part of the survey, including the diffuse emission and spectral energy distributions of H ii regions and supernova remnants (SNRs). Using low- and high-frequency surveys to constrain free–free and thermal dust emission contributions, we find evidence of excess flux density at 30 GHz in six regions, which we interpret as anomalous microwave emission. Furthermore we model ultracompact H ii contributions using data from the 5 GHz CORNISH catalog and reject these as the cause of the 30 GHz excess. Six known SNRs are detected at 30 GHz, and we measure spectral indices consistent with the literature or show evidence of steepening. The flux density of the SNR W44 at 30 GHz is consistent with a power-law extrapolation from lower frequencies with no indication of spectral steepening in contrast with recent results from the Sardinia Radio Telescope. We also extract five hydrogen radio recombination lines (RRLs) to map the warm ionized gas, which can be used to estimate electron temperatures or to constrain continuum free–free emission. The full COMAP Galactic Plane Survey, to be released in 2023/2024, will span ℓ ∼ 20°–220° and will be the first large-scale radio continuum and RRL survey at 30 GHz with 4.′5 resolution.

COMAP Early Science. VI. A First Look at the COMAP Galactic Plane Survey

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