A Ringed Dwarf LINER 1 Galaxy Hosting an Intermediate-mass Black Hole with Large-scale Rotation-like Hα Emission

Journal Article · Fri Mar 10 04:00:00 EST 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA5EB6· OSTI ID:22869241

Liu, Wen-Juan; Dong, Xiao-Bo ^[1]; Qian, Lei ^[2]; Jiang, Ning ^[3]; Lira, Paulina ^[4]; Cai, Zheng ^[5]; Wang, Feige; Yang, Jinyi ^[6]; Xiao, Ting ^[7]; Kim, Minjin ^[8]

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1. Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)
2. Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012 (China)
3. Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China)
4. Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile)
5. UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)
6. Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China)
7. Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)
8. Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)

We report the discovery of a 20 kpc sized Hα emission in SDSS J083803.68+540642.0, a ringed dwarf galaxy (M{sub V}=−17.89 mag) hosting an accreting intermediate-mass black hole at z = 0.02957. Analysis of the Hubble Space Telescope images indicates that it is an early-type galaxy with a featureless low-surface brightness disk (μ{sub 0}=20.39 mag arcsec{sup −2} in the V band) and a prominent, relatively red bulge (V − I = 2.03, R{sub e}=0.28 kpc or 0.″48) that accounts for ≈81% of the total light in the I band. A circumgalactic ring of a diameter 16 kpc is also detected, with a disperse shape on its south side. The optical emission lines reveal the nucleus to be a broad-line LINER. Our MMT longslit observation indicates that the kinematics of the extended Hα emission is consistent with a rotational gaseous disk, with a mean blueshifted velocity of 162 km s{sup −1} and mean redshifted velocity of 86 km s{sup −1}. According to our photoionization calculations, the large-scale Hα emission is unlikely to be powered by the central nucleus or by hot evolved (post-AGB) stars interspersed in the old stellar populations, but by in situ star formation; this is vindicated by the line-ratio diagnostic of the extended emission. We propose that both the ring and large-scale Hα-emitting gas are created by the tidal accretion in a collision—and then merger—with a gas-rich galaxy of a comparable mass.

• OSTI ID: 22869241
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 837; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BLACK HOLES
BRIGHTNESS
COLLISIONS
COMPARATIVE EVALUATIONS
DWARF STARS
EMISSION
GALAXIES
GALAXY NUCLEI
MASS
PHOTOIONIZATION
RED SHIFT
ROTATION
SEYFERT GALAXIES
SPACE
SURFACES
TELESCOPES
VELOCITY