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arXiv 2408.04774astro-ph.GA
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原初星系的本地类似体:利用 JWST NIRSpec 搜寻中等质量黑洞

Local Analogs of Primordial Galaxies: In Search of Intermediate Mass Black Holes with JWST NIRSpec

Sara Doan, Shobita Satyapal, William Matzko, Nicholas P. Abel, Torsten Böker, Thomas Bohn, Gabriela Canalizo, Jenna M. Cann, Jacqueline Fischer, Stephanie LaMas… 展开作者

Sara Doan, Shobita Satyapal, William Matzko, Nicholas P. Abel, Torsten Böker, Thomas Bohn, Gabriela Canalizo, Jenna M. Cann, Jacqueline Fischer, Stephanie LaMassa, Suzanne C. Madden, Jeffrey D. McKaig, D. Schaerer, Nathan J. Secrest, Anil Seth, Laura Blecha, Mallory Molina, Barry Rothberg

AI总结:

本文利用 JWST NIRSpec 对极贫金属矮星系 SDSS J120122.30+021108.3 进行观测,发现其红色中红外源来自中央未分解源,提出可用年轻核星团与深埋 AGN 解释,并据此估算黑洞质量约为 1450 M⊙。

摘要:

具有可能吸积活动特征的本地低金属丰度星系,是搜寻最低质量黑洞并研究其对宿主星系影响的理想实验室。本文首次展示了 SDSS J120122.30+021108.3 的 JWST NIRSpec IFS 观测结果。该天体是一个邻近(z=0.00354)的极贫金属矮星系,没有吸积活动的光学特征,但被 WISE 识别为具有与活动星系核(AGN)一致的极红中红外颜色。我们在约 1.7–5.2 微米之间识别出一百多条谱线,一个未分解的核连续谱源,其极陡的光谱斜率与来自 AGN 的热尘埃一致(Fν≈ν^{-1.5}),以及大量的 H I、He I 和 H2 谱线,但没有来自较重元素的谱线、CO 或冰吸收特征,也没有多环芳烃(PAHs)。我们的观测揭示,红色的 WISE 源完全来自一个明亮的中央未分解源(<3 pc),暗示存在 AGN,但光谱中未识别出 He II 线或冕线,并且重要的是,没有证据表明核源的辐射场比周围区域更硬。这些观测可以用一个年轻的(<5 Myr)核星团(恒星质量约 3×10^4 M⊙)和一个深埋的 AGN(热光度约 2×10^41 erg s^{-1})来解释。根据爱丁顿极限,隐含的黑洞质量约为 1450 M⊙,这与基于更大质量黑洞推导的黑洞-星系标度关系外推所预期的结果大致一致。更长波长的观测对于确认这一图景至关重要。

英文摘要:

Local low metallicity galaxies with signatures of possible accretion activity are ideal laboratories in which to search for the lowest mass black holes and study their impact on the host galaxy. Here we present the first JWST NIRSpec IFS observations of SDSS J120122.30+021108.3, a nearby ($z=0.00354$) extremely metal poor dwarf galaxy with no optical signatures of accretion activity but identified by WISE to have extremely red mid-infrared colors consistent with AGNs. We identify over one hundred lines between $\sim$ 1.7-5.2 microns, an unresolved nuclear continuum source with an extremely steep spectral slope consistent with hot dust from an AGN ($F_ν\approxν^{-1.5}$), and a plethora of H I, He I, and H$_2$ lines, with no lines from heavier elements, CO or ice absorption features, or PAHs.Our observations reveal that the red WISE source arises exclusively from a bright central unresolved source ($<$ 3pc) suggestive of an AGN, yet there are no He II lines or coronal lines identified in the spectrum, and, importantly, there is no evidence that the radiation field is harder in the nuclear source compared with surrounding regions. These observations can be explained with a young ($<$ 5 Myr) nuclear star cluster with stellar mass $\sim3\times 10^4$ M$_\odot$ and a deeply embedded AGN with bolometric luminosity $\sim$ $2\times10^{41}$ ergs $^{-1}$. The implied black hole mass is $\sim$ 1450 M$_\odot$, based on the Eddington limit, roughly consistent with that expected based on extrapolations of black hole galaxy scaling relations derived for more massive black holes. Longer wavelength observations are crucial to confirm this scenario.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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