تقرير
Local Active Galactic Nuclei with Large Broad-H{\alpha} Variability Reside in Red Galaxies
| العنوان: | Local Active Galactic Nuclei with Large Broad-H{\alpha} Variability Reside in Red Galaxies |
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| المؤلفون: | Liu, Wen-Juan, Lira, Paulina, Yao, Su, Xu, Dawei, Wang, Jing, Dong, Xiao-Bo, Martínez-Palomera, Jorge |
| سنة النشر: | 2021 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | Inspired by our serendipitous discovery of six AGNs with varying broad-Halpha fluxes over years out of our searching for intermediate-mass black holes (IMBHs), we conduct a systematic investigation of changing-look (CL) and large-variability AGNs. We collect all the CL AGNs at z<0.15 and the reverberation mapped AGNs with strongly variable broad Halpha, and perform careful decomposition fittings to both their images and spectra. We find two observational facts: (1) The host galaxies of local CL and large-variability AGNs, mainly being Seyferts, are in the red (gas-poor) tail of the general Seyfert galaxy population. (2) In contrast, there is a significant trend that their more luminous counterparts namely CL and extremely variable quasars (CLQs and EVQs) are different: CLQs are generally in blue galaxies; in terms of the diagram of SFR and M* local CL Seyfert galaxies are located in the green valley, whereas CLQ hosts are in the star-forming main sequence. We propose explanations for those strongly variable Seyferts and quasars, respectively, under the thought that accretion disks broadly depend on nuclear fueling modes. Local large-variability and CL Seyferts are in nuclear famine mode, where cold-gas clumps can be formed stochastically in the fueling flow, and their episodic infall produces sharp peaks in the accretion-rate curve. CLQs and EVQs are in feast fueling mode, which may account for both their preference to blue galaxies and their variability pattern (high-amplitude tail of the continuous distribution). Lastly, we propose a new thinking: to search for IMBHs by optical variability in red galaxies. Comment: 37 pages(incl. Appendix), 10 figures, and 5 tables. Published in ApJ. (v2)Text changed to match the published version |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.3847/1538-4357/abf82c |
| URL الوصول: | http://arxiv.org/abs/2103.11935 |
| رقم الأكسشن: | edsarx.2103.11935 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.3847/1538-4357/abf82c |
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