ALMA Deep Field in SSA22: Source Catalog and Number Counts
ALMA Deep Field in SSA22: Source Catalog and Number Counts
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DOI：
10.3847/1538-4357/835/1/98
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发表时间：
2016-11
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通讯作者：
H. Umehata;Y. Tamura;K. Kohno;R. Ivison;I. Smail;B. Hatsukade;K. Nakanishi;Y. Kato;S. Ikarashi;Y. Matsuda;S. Fujimoto;D. Iono;Minju M. Lee;C. Steidel;Tomoki Saito;D. Alexander;M. Yun;M. Kubo
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作者：
H. Umehata;Y. Tamura;K. Kohno;R. Ivison;I. Smail;B. Hatsukade;K. Nakanishi;Y. Kato;S. Ikarashi;Y. Matsuda;S. Fujimoto;D. Iono;Minju M. Lee;C. Steidel;Tomoki Saito;D. Alexander;M. Yun;M. Kubo
我们展示了在SSA22区域利用阿塔卡马大型毫米波/亚毫米波阵列（ALMA）进行的1.1毫米深度观测（在红移\(z = 3\)时，共动尺度为\(3.7\)百万秒差距\(\times5.5\)百万秒差距，面积为\(2'\times3'\)）的结果。我们观测到了一个红移\(z = 3.09\)的原星系团的核心区域，在\(0.″7\)的空间分辨率下，达到了\(60\)微焦耳每波束\(^{-1}\)的典型均方根灵敏度。我们探测到了18个信噪⽐（\(S/N\)）\(> 5\)的可靠的ALMA源。ALMA图与利用阿塔卡马亚毫米波望远镜实验（ASTE）上的AzTEC相机拍摄的1.1毫米图之间的比较表明，AzTEC/ASTE观测发现的三个亚毫米波源被ALMA分解为八个单独的亚毫米波星系（SMG）。我们的18个ALMA亚毫米波星系中至少有10个具有\(z\approx3.09\)的光谱红移，使它们位于原星系团中。这表明在原星系团的核心有许多尘埃星暴星系正在同时形成。9个信噪⽐\(> 10\)的最亮的ALMA亚毫米波星系的中值固有角大小为（在\(z = 3.09\)时为物理千秒差距），这与之前在其他区域对亚毫米波星系的大小测量结果一致。正如预期的那样，由于原星系团的存在，在\(S_{1.1mm}\geq1.0\)毫焦耳时，源计数与普通区域的计数相比可能有过量。我们连续的毫米波段测绘凸显了大尺度结构对尘埃星暴星系形成的重要性。
We present results from a deep 2′ × 3′ (comoving scale of 3.7 Mpc × 5.5 Mpc at z = 3) survey at 1.1 mm, taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in the SSA22 field. We observe the core region of a z = 3.09 protocluster, achieving a typical rms sensitivity of 60 μJy beam−1 at a spatial resolution of 0.″7. We detect 18 robust ALMA sources at a signal-to-noise ratio (S/N) > 5. Comparison between the ALMA map and a 1.1 mm map, taken with the AzTEC camera on the Atacama Submillimeter Telescope Experiment (ASTE), indicates that three submillimeter sources discovered by the AzTEC/ASTE survey are resolved into eight individual submillimeter galaxies (SMGs) by ALMA. At least 10 of our 18 ALMA SMGs have spectroscopic redshifts of z ≃ 3.09, placing them in the protocluster. This shows that a number of dusty starburst galaxies are forming simultaneously in the core of the protocluster. The nine brightest ALMA SMGs with S/N > 10 have a median intrinsic angular size of ( physical kpc at z = 3.09), which is consistent with previous size measurements of SMGs in other fields. As expected, the source counts show a possible excess compared to the counts in the general fields at S1.1mm ≥ 1.0 mJy, due to the protocluster. Our contiguous mm mapping highlights the importance of large-scale structures on the formation of dusty starburst galaxies.