我们提出了一个样本的40个活动星系在矮星系的红移$z \lesssim$ 2.4。这些星系是从\textit{Chandra} COSMOS-Legacy巡天中得出的,其恒星质量为$10^{7}\leq M_{*}\leq3 \times 10^{9}$ M $_{\odot}$。大多数矮星系都在形成恒星。除去恒星形成对X射线辐射的贡献后,这40个矮星系的活动星系核光度都在$L_\mathrm{0.5-10 keV} \sim10^{39} - 10^{44}$ erg s $^{-1}$范围内。在$z > 0.5$的12个源中,我们的样本构成了矮星系中活动星系核最高红移的发现。记录保持者是$z = 2.39$和$L_\mathrm{0.5-10 keV} \sim 10^{44}$ erg s $^{-1}$的1192。其中一个矮星系有$M_\mathrm{*} = 6.6 \times 10^{7}$ M $_{\odot}$,是迄今为止发现的最小质量的活动星系核。所有的活动星系核都属于2型,与中等质量黑洞(BH)的宿主一致,其质量为$\sim 10^{4} - 10^{5}$ M $_{\odot}$和典型的爱丁顿比$> 1\%$。我们还研究了演化,修正的完整性,AGN分数与恒星质量,X射线光度,和红移的矮星系$z$ = 0.7。我们发现$10^{9}< M_{*}\leq3 \times 10^{9}$ M $_{\odot}$和$L_\mathrm{X} \sim 10^{41}-10^{42}$ erg s $^{-1}$的活动星系核分数为$\sim$ 0 4%,$z \leq$ 0 3,它随X射线光度和恒星质量的减小而减小。与大质量星系不同的是,活动星系核的分数似乎随着红移而减少,这表明矮星系中活动星系核的演化与高质量星系不同。考虑到潜在的警告,结果似乎有利于早期宇宙中种子黑洞的直接坍缩形成机制。
英文摘要:
We present a sample of 40 AGN in dwarf galaxies at redshifts $z \lesssim$ 2.4. The galaxies are drawn from the \textit{Chandra} COSMOS-Legacy survey as having stellar masses $10^{7}\leq M_{*}\leq3 \times 10^{9}$ M$_{\odot}$. Most of the dwarf galaxies are star-forming. After removing the contribution from star formation to the X-ray emission, the AGN luminosities of the 40 dwarf galaxies are in the range $L_\mathrm{0.5-10 keV} \sim10^{39} - 10^{44}$ erg s$^{-1}$. With 12 sources at $z > 0.5$, our sample constitutes the highest-redshift discovery of AGN in dwarf galaxies. The record-holder is cid\_1192, at $z = 2.39$ and with $L_\mathrm{0.5-10 keV} \sim 10^{44}$ erg s$^{-1}$. One of the dwarf galaxies has $M_\mathrm{*} = 6.6 \times 10^{7}$ M$_{\odot}$ and is the least massive galaxy found so far to host an AGN. All the AGN are of type 2 and consistent with hosting intermediate-mass black holes (BHs) with masses $\sim 10^{4} - 10^{5}$ M$_{\odot}$ and typical Eddington ratios $> 1\%$. We also study the evolution, corrected for completeness, of AGN fraction with stellar mass, X-ray luminosity, and redshift in dwarf galaxies out to $z$ = 0.7. We find that the AGN fraction for $10^{9}< M_{*}\leq3 \times 10^{9}$ M$_{\odot}$ and $L_\mathrm{X} \sim 10^{41}-10^{42}$ erg s$^{-1}$ is $\sim$0.4\% for $z \leq$ 0.3 and that it decreases with X-ray luminosity and decreasing stellar mass. Unlike massive galaxies, the AGN fraction seems to decrease with redshift, suggesting that AGN in dwarf galaxies evolve differently than those in high-mass galaxies. Mindful of potential caveats, the results seem to favor a direct collapse formation mechanism for the seed BHs in the early Universe.
The Chandra COSMOS-Legacy survey: Source X-ray spectral properties
本文介绍了钱德拉宇宙遗产巡天目录中1855个河外源的X射线谱分析,这些源在0.5-7 keV波段有30多个净计数。38%的源是光学分类的1型活动星系核(AGN),60%是2型活动星系核,2%是被动的低红移星系。我们研究了活动星系核的光子指数和内禀吸收N(H,z)的分布,并基于源的光学分类:第一类活动星系核的平均光子指数比第二类活动星系核稍陡,而第二类活动星系核的平均内禀吸收比第一类活动星系核高约3倍。我们发现,约15%的1型活动星系核的N(H,z)> 1 E22 cm^(-2),即,根据X射线光谱拟合,这些源中的绝大多数具有L(2- 10 keV)> $1E44 erg/s. The existence of these objects suggests that optical and X-ray obscuration can be caused by different phenomena, the X-ray obscuration being for example caused by dust-free material surrounding the inner part of the nuclei. ~18% of Type 2 AGN have N(H,z)<1E22 cm^(-2), and most of these sources have low X-ra…
The Chandra COSMOS legacy survey: Energy Spectrum of the Cosmic X-ray Background and constraints on undetected populations
使用{ \em钱德拉}观测在2.15度$^{2}$ COSMOS遗产领域,我们提出了一个最准确的测量宇宙X射线背景(CXB)光谱的日期在[0.3-7] keV的能量带。CXB有三个不同的组成部分:来自两个银河系碰撞热等离子体在kT $\sim$ 0.27和0.07千电子伏和河外幂律与光子光谱指数$Γ$ =1.45 $\pm{0.02}$的贡献。河外分量的1 keV标准化为10.91 $\pm{0.16}$ keV cm $^{-2}$ s $^{-1}$ sr $^{-1}$ keV $^{-1}$。去除所有X射线探测源,剩余的未分辨CXB通过幂律最佳拟合,归一化为4.18 $\pm{0.26}$ keV cm $^{-2}$ s $^{-1}$ sr $^{-1}$ keV $^{-1}$,光子谱指数$Γ$ =1.57 $\pm{0.10}$。去除暗星系到i $_{AB}\sim$ 27-28留下了硬光谱,$Γ\sim$为1.25,$\sim$为1.37 keV cm $^{-2}$ s $^{-1}$ sr $^{-1}$ keV $^{-1}$。这意味着观测到的CXB的$\sim$ 91%被分解为探测到的X射线源和未探测到的星系。贡献总CXB的$\sim 8-9\%$的未解析来源显示出比解析来源更难且可能更模糊的边缘证据。CXB的另一个$\sim$ 1可以归因于尚未被发现的恒…
Star formation in galaxies hosting AGN: A flat trend of star-formation rate with X-ray luminosity of galaxies hosting AGN in the SCUBA-2 Cosmology Legacy Survey
Deep Extragalactic VIsible Legacy Survey (DEVILS): SED Fitting in the D10-COSMOS Field and the Evolution of the Stellar Mass Function and SFR-$M_\star$ relation
The NIKA2 Cosmological Legacy Survey in COSMOS: Final 1.2mm and 2mm source catalogs and redshift distribution of dusty star-forming galaxies
Aix Marseille Univ, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille)(艾克斯-马赛大学);Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange(蔚蓝海岸大学);School of Physics and Astronomy, Cardiff University(卡迪夫大学);Université Paris Cité, Université Paris-Saclay, CEA, CNRS, AIM(巴黎西岱大学、巴黎萨克雷大学);Institut de Radioastronomie Millimétrique (IRAM)(毫米波射电天文研究所);Instituto de Astrofísica e Ciências do Espaço, Universidade de Lisboa, OAL(里斯本大学);Departamento de Física, Faculdade de Ciências, Universidade de Lisboa(里斯本大学);Instituto de Estudios Astrofícos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales(迭戈·波特莱斯大学)
An ALMA Survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS Field: The Far-infrared/Radio correlation for High-redshift Dusty Star-forming Galaxies
The Far-Ultraviolet Extragalactic Legacy (FUEL) Survey: Hubble Far-UV Images and Catalogs of the Extragalactic Legacy Fields
University of California, Riverside(加州大学河滨分校);California Institute of Technology(加州理工学院);Universidad Complutense de Madrid(马德里康普顿斯大学);University of Western Australia(西澳大学);Stockholm University(斯德哥尔摩大学);University of California at Santa Cruz(加州大学圣克鲁兹分校);Clemson University(克莱姆森大学)
Cold Dust Emission from X-ray AGN in the SCUBA-2 Cosmology Legacy Survey: Dependence on Luminosity, Obscuration & AGN Activity
我们利用SCUBA-2宇宙学遗产巡天的新数据研究了2平方度宇宙场中X射线选择活动星系核的850 μ m辐射。我们发现了19 850 μ m的明亮X射线活动星系核,其高灵敏度区面积为0.89平方度,通量密度为S850=4-10 mJy。19个活动星系核的红移和硬X射线光度范围都涵盖在样品范围内-- 0.7<z<3.5和43.2<log 10(LX)<45. We report a highly significant stacked 850um detection of a hard X-ray flux-limited population of 699 z>1 X射线活动星系核--S 850 =0.71+/-0.08 mJy。我们探讨的趋势,在堆叠的850微米的流量密度与红移,发现没有演变的平均冷尘埃排放的红移范围内探测。对于1型活动星系核,850 μ m的叠加通量与硬X射线光度之间没有明显的相关性。然而,在2型活动星系核中,在高光度时,叠加的亚毫米通量是2倍。当对所有X射线光度进行平均时,1型和2型活动星系核以及根据X射线硬度比和光学-红外颜色分离的活动星系核的叠加亚毫米通量没有显著差异。然而,在log 10(LX)>44.4时,平均亚毫米通量对光学到红外颜色的依赖性变得更加明显。我们认为,这些高光度活动星系核代表了一个过渡,从一个长期的合并驱动的演化阶…
The SCUBA-2 Cosmology Legacy Survey: The EGS deep field - II. Morphological transformation and multi-wavelength properties of faint submillimetre galaxies
The SCUBA-2 Cosmology Legacy Survey: The EGS deep field I - Deep number counts and the redshift distribution of the recovered Cosmic Infrared Background at 450 and 850 um
Deep Extragalactic VIsible Legacy Survey (DEVILS): First Data Release Covering The D10 (COSMOS) Region
ICRAR, The University of Western Australia(西澳大利亚大学);Department of Physics & Astronomy, McMaster University(麦克马斯特大学);Jodrell Bank Centre for Astrophysics, University of Manchester(曼彻斯特大学);Australian Astronomical Optics, Macquarie University(麦考瑞大学);School of Physics & Astronomy, Monash University(莫纳什大学);Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney(悉尼大学);Astrophysics Group, School of Physics, University of Bristol(布里斯托大学);Instituto de Astrofísica de Canarias(加那利天体物理研究所);Departamento de Astrofísica, Universidad de La Laguna (ULL)(拉帕尔马大学);Research School of Astronomy and Astrophysics, Australian National University(澳大利亚国立大学)
Spectral Energy Distributions in Three Deep-Drilling Fields of the Vera C. Rubin Observatory Legacy Survey of Space and Time: Source Classification and Galaxy Properties
W-CDF-S、ELAIS-S1和XMM-LSS将是Vera C. Rubin Observatory Legacy Survey of Space and Time(LSST),但其广泛的多波长数据尚未像另一个LSST DDF COSMOS领域那样得到充分利用。为了为未来的科学做准备,我们在这三个领域中拟合了从X射线到远红外的源光谱能量分布(SED),主要用于推导星系恒星质量和恒星形成率。我们使用CIGALE v2022.0,这是一个定期开发和评估的代码,用于SED拟合。我们的目录包括覆盖W-CDF-S中的$4.9~\mathrm{deg^2}$的80万个源、覆盖ELAIS-S1中的$3.4~\mathrm{deg^2}$的80万个源和覆盖XMM-LSS中的$4.9~\mathrm{deg^2}$的120万个源。除了拟合正常星系外,我们还选择可能拥有活动星系核(AGN)或正在经历最近恒星形成变化的候选者,并使用专门为这些来源设计的模型来拟合它们的SED;这增加了我们的目录在未来各种项目中的实用性。我们校准我们的测量结果与那些在研究较小的区域进行比较,并简要讨论了我们的研究结果的影响。我们还进行了详细的测试的完整性和纯度的SED选择活动星系核。我们的数据可以从公共网站检索。
The NIKA2 cosmological legacy survey at 2 mm: catalogs, colors, redshift distributions, and implications for deep surveys
Aix Marseille Univ, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille)(艾克斯-马赛大学);Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange(蔚蓝海岸大学);School of Physics and Astronomy, Cardiff University(卡迪夫大学);Université Paris Cité, Université Paris-Saclay, CEA, CNRS, AIM(巴黎西岱大学、萨克雷大学);Institut de Radioastronomie Millimétrique (IRAM)(毫米波射电天文研究所);Institut Néel, CNRS, Université Grenoble Alpes(格勒诺布尔阿尔卑斯大学);Astronomy Centre, Department of Physics and Astronomy, University of Sussex(苏塞克斯大学)
From the Intergalactic to the Interstellar Scales -- EQUALS: a High-resolution Legacy Survey of Gas in the Distant Universe Using ESPRESSO
Camosun College(卡莫森学院);INAF–Trieste Astronomical Observatory(意大利国家天体物理研究所的里雅斯特天文台);University of Chile(智利大学);University of Trieste(的里雅斯特大学);INAF–Padua Astronomical Observatory(意大利国家天体物理研究所帕多瓦天文台);Hamburg University(汉堡大学);University of Hertfordshire(赫特福德大学);IAP, Paris(巴黎天体物理研究所);ESO(欧洲南方天文台);SISSA(国际高等研究学院);Durham University(杜伦大学)