Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
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矮星系中 X 射线源的多波长研究：ULX 与 AGN
DOI：
10.1093/mnras/stad002
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发表时间：
2023
影响因子：
4.8
通讯作者：
Gallo, Elena
中科院分区：
文献类型：
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作者：
Thygesen, Erica;Plotkin, Richard M.;Soria, Roberto;Reines, Amy E.;Greene, Jenny E.;Anderson, Gemma E.;Baldassare, Vivienne F.;Owens, Milo G.;Urquhart, Ryan T.;Gallo, Elena
由于它们安静的进化史，附近的矮小星系(恒星质量)有可能告诉我们‘播种’超大质量黑洞生长的机制(S)，以及第一批恒星质量黑洞是如何形成并与环境相互作用的。在这里，我们介绍了三个矮星系的高空间分辨率观测：X射线(钱德拉)、光学/近红外(哈勃太空望远镜)和射电(卡尔·G·詹斯基甚大阵列)。根据较低分辨率的X射线成像，这三个星系此前被确定为拥有候选活动星系核。根据我们的新观测，我们发现两个星系(SDSS J121326.01+543631.6和SDSS J122111.29+173819.1)中的X射线源是非核的，没有相应的射电发射，这意味着它们很可能是发光X射线双星。第三个星系(MRK1434)包含两个X射线源(每个源的LX≈1040erg S−1)，相距2.8log弧秒，具有低金属丰度[12+ (O/H)=77.8]，并发出星云Heiiλ4686线发射。北方源在9.0 GHz处有空间重合点状射电发射，在5.5 GHz处有扩展射电发射。我们讨论了X射线的二元解释(超高亮度X射线源吹出‘射电气泡’)和活动星系核的解释(黑洞发射喷流)。在任何一种情况下，我们都发现，除非X射线源是几百年前亮度高30-90倍的≈，否则HII发射不能被X射线源光致电离。
Owing to their quiet evolutionary histories, nearby dwarf galaxies (stellar masses) have the potential to teach us about the mechanism(s) that ‘seeded’ the growth of supermassive black holes, and also how the first stellar mass black holes formed and interacted with their environments. Here, we present high spatial resolution observations of three dwarf galaxies in the X-ray (Chandra), the optical/near-infrared (Hubble Space Telescope), and the radio (Karl G. Jansky Very Large Array). These three galaxies were previously identified as hosting candidate active galactic nuclei on the basis of lower resolution X-ray imaging. With our new observations, we find that X-ray sources in two galaxies (SDSS J121326.01+543631.6 and SDSS J122111.29+173819.1) are off-nuclear and lack corresponding radio emission, implying they are likely luminous X-ray binaries. The third galaxy (Mrk 1434) contains two X-ray sources (each withLX≈ 1040erg s−1) separated by 2.8 arcsec, has a low metallicity [12 + log(O/H) = 7.8], and emits nebular Heiiλ4686 line emission. The northern source has spatially coincident point-like radio emission at 9.0 GHz and extended radio emission at 5.5 GHz. We discuss X-ray binary interpretations (where an ultraluminous X-ray source blows a ‘radio bubble’) and active galactic nucleus interpretations (where anblack hole launches a jet). In either case, we find that the Heiiemission cannot be photoionized by the X-ray source, unless the source was ≈30–90 times more luminous several hundred years ago.