THE ALMA SPECTROSCOPIC SURVEY IN THE HUBBLE ULTRA DEEP FIELD: CONTINUUM NUMBER COUNTS, RESOLVED 1.2 mm EXTRAGALACTIC BACKGROUND, AND PROPERTIES OF THE FAINTEST DUSTY STAR-FORMING GALAXIES
THE ALMA SPECTROSCOPIC SURVEY IN THE HUBBLE ULTRA DEEP FIELD: CONTINUUM NUMBER COUNTS, RESOLVED 1.2 mm EXTRAGALACTIC BACKGROUND, AND PROPERTIES OF THE FAINTEST DUSTY STAR-FORMING GALAXIES
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DOI：
10.3847/1538-4357/833/1/68
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发表时间：
2016-12-10
影响因子：
4.9
通讯作者：
Wagg, J.
中科院分区：
文献类型：
--
作者：
Aravena, M.;Decarli, R.;Wagg, J.
我们提出了一个深（1西格玛= 13 μ焦耳）宇宙学1.2毫米连续谱图的基础上ASPECS，在哈勃超深场的阿尔马光谱调查的分析。在ASPECS覆盖的1弧分（2）中，我们在1.2 mm处检测到9个大于3.5 sigma显著性的源。我们的ALMA选择的样本具有z = 1.6 +/- 0.4的中值红移，在调查区域内仅检测到一个z > 2的星系。该值明显低于在较高通量密度截止和类似频率下选择的毫米样品中发现的值。大多数星系的比星星形成率与主序星相同，恒星质量和星星形成率的中值分别为4.0 × 10（10）M圆点和40 M圆点yr（-1）。使用的灰尘排放作为示踪剂的ISM质量，我们得出的耗尽时间，通常长于3亿年，我们发现分子气体分数范围从类似的0.1至1.0。正如以前的研究所指出的，这些值比使用基于CO的ISM估计值低2倍。1 mm的计数（校正保真度和完整性）与以前的研究，通常限于较亮的来源是一致的。仅通过我们的单独探测，我们恢复了普朗克卫星测量的1.2 mm处的河外背景光（EBL）的55% +/- 4%，如果我们包括数量计数的亮端和来自叠加的额外探测，我们恢复了该EBL的80% +/- 7%。堆积的贡献主要由z接近1-2的星系组成，恒星质量为（1-3）x 10（10）M圆点。这是第一次，我们能够描述在1.2毫米的EBL中占主导地位的星系群。
We present an analysis of a deep (1 sigma = 13 mu Jy) cosmological 1.2 mm continuum map based on ASPECS, the ALMA Spectroscopic Survey in the Hubble Ultra Deep Field. In the 1 arcmin(2) covered by ASPECS we detect nine sources at >3.5 sigma significance at 1.2 mm. Our ALMA-selected sample has a median redshift of z = 1.6 +/- 0.4, with only one galaxy detected at z > 2 within the survey area. This value is significantly lower than that found in millimeter samples selected at a higher flux density cut-off and similar frequencies. Most galaxies have specific star formation rates similar to that of main sequence galaxies at the same epoch, and we find median values of stellar mass and star formation rates of 4.0 x 10(10) M circle dot and similar to 40 M circle dot yr(-1), respectively. Using the dust emission as a tracer for the ISM mass, we derive depletion times that are typically longer than 300 Myr, and we find molecular gas fractions ranging from similar to 0.1 to 1.0. As noted by previous studies, these values are lower than using CO-based ISM estimates by a factor similar to 2. The 1\,mm number counts (corrected for fidelity and completeness) are in agreement with previous studies that were typically restricted to brighter sources. With our individual detections only, we recover 55% +/- 4% of the extragalactic background light (EBL) at 1.2 mm measured by the Planck satellite, and we recover 80% +/- 7% of this EBL if we include the bright end of the number counts and additional detections from stacking. The stacked contribution is dominated by galaxies at z similar to 1-2, with stellar masses of (1-3) x 10(10) M circle dot. For the first time, we are able to characterize the population of galaxies that dominate the EBL at 1.2 mm.