The most luminous heavily obscured quasars have a high merger fraction: morphological study of wise -selected hot dust-obscured galaxies

Journal Article · Tue May 10 00:00:00 EDT 2016 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8205/822/2/L32· OSTI ID:22654329

Fan, Lulu; Gao, Ying; Zhang, Dandan; Jiang, Xiaoming; Wu, Qiaoqian; Yang, Jun; Li, Zhao ^[1]; Han, Yunkun ^[2]; Fang, Guanwen ^[3]

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1. Shandong Provincial Key Lab of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Science, Shandong University, Weihai 264209 (China)
2. Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China)
3. Institute for Astronomy and History of Science and Technology, Dali University, Dali 671003 (China)

Previous studies have shown that Wide-field Infrared Survey Explorer -selected hyperluminous, hot dust-obscured galaxies (Hot DOGs) are powered by highly dust-obscured, possibly Compton-thick active galactic nuclei (AGNs). High obscuration provides us a good chance to study the host morphology of the most luminous AGNs directly. We analyze the host morphology of 18 Hot DOGs at z ∼ 3 using Hubble Space Telescope /WFC3 imaging. We find that Hot DOGs have a high merger fraction (62 ± 14%). By fitting the surface brightness profiles, we find that the distribution of Sérsic indices in our Hot DOG sample peaks around 2, which suggests that most Hot DOGs have transforming morphologies. We also derive the AGN bolometric luminosity (∼10{sup 14} L {sub ⊙}) of our Hot DOG sample by using IR spectral energy distributions decomposition. The derived merger fraction and AGN bolometric luminosity relation is well consistent with the variability-based model prediction. Both the high merger fraction in an IR-luminous AGN sample and relatively low merger fraction in a UV/optical-selected, unobscured AGN sample can be expected in the merger-driven evolutionary model. Finally, we conclude that Hot DOGs are merger-driven and may represent a transit phase during the evolution of massive galaxies, transforming from the dusty starburst-dominated phase to the unobscured QSO phase.

• OSTI ID: 22654329
• Journal Information: Astrophysical Journal Letters, Vol. 822, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BOLOMETERS
BRIGHTNESS
DISTRIBUTION
DUSTS
ENERGY SPECTRA
EVOLUTION
FORECASTING
GALAXIES
GALAXY NUCLEI
INFRARED SURVEYS
INTERACTIONS
LUMINOSITY
QUASARS
RED SHIFT
SPACE
SURFACES
TELESCOPES