A Caltech Library Service

The Host Galaxy of the Recoiling Black Hole Candidate in 3C 186: An Old Major Merger Remnant at the Center of a z = 1 Cluster

Morishita, T. and Chiaberge, M. and Hilbert, B. and Lambrides, E. and Blecha, L. and Baum, S. and Bianchi, S. and Capetti, A. and Castignani, G. and Macchetto, F. D. and Miley, G. K. and O’Dea, C. P. and Norman, C. A. (2022) The Host Galaxy of the Recoiling Black Hole Candidate in 3C 186: An Old Major Merger Remnant at the Center of a z = 1 Cluster. Astrophysical Journal, 931 (2). Art. No. 165. ISSN 0004-637X. doi:10.3847/1538-4357/ac6a58.

[img] PDF - Published Version
Creative Commons Attribution.

[img] PDF - Accepted Version
Creative Commons Attribution.


Use this Persistent URL to link to this item:


3C 186, a radio-loud quasar at z = 1.0685, was previously reported to have both velocity and spatial offsets from its host galaxy, and has been considered as a promising candidate for a gravitational wave recoiling black hole triggered by a black hole merger. Another possible scenario is that 3C 186 is in an ongoing galaxy merger, exhibiting a temporary displacement. In this study, we present analyses of new deep images from the Hubble Space Telescope WFC3-IR and Advanced Camera for Surveys, aiming to characterize the host galaxy and test this alternative scenario. We carefully measure the light-weighted center of the host and reveal a significant spatial offset from the quasar core (11.1 ± 0.1 kpc). The direction of the confirmed offset aligns almost perpendicularly to the radio jet. We do not find evidence of a recent merger, such as a young starburst in disturbed outskirts, but only marginal light concentration in F160W at ∼30 kpc. The host consists of mature (≳200 Myr) stellar populations and one compact star-forming region. We compare with hydrodynamical simulations and find that those observed features are consistently seen in late-stage merger remnants. Taken together, those pieces of evidence indicate that the system is not an ongoing/young merger remnant, suggesting that the recoiling black hole scenario is still a plausible explanation for the puzzling nature of 3C 186.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Morishita, T.0000-0002-8512-1404
Chiaberge, M.0000-0003-1564-3802
Hilbert, B.0000-0002-6875-1543
Lambrides, E.0000-0003-3216-7190
Blecha, L.0000-0002-2183-1087
Baum, S.0000-0002-4735-8224
Bianchi, S.0000-0002-4622-4240
Capetti, A.0000-0003-3684-4275
Castignani, G.0000-0001-6831-0687
Macchetto, F. D.0000-0002-5793-7828
Miley, G. K.0000-0003-2884-7214
O’Dea, C. P.0000-0001-6421-054X
Norman, C. A.0000-0002-5222-5717
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 December 13; revised 2022 April 20; accepted 2022 April 23; published 2022 June 7. We thank the anonymous referee for the constructive comments. We thank Emanuele Berti and Davide Gerosa for fruitful discussion on the physical interpretation of our findings, and Markos Georganopoulos, Andrea Marinucci, Eileen Meyer, Eric S. Perlman, William B. Sparks, and Grant R. Tremblay for their contribution to the HST observing program GO-15254. M.C. thanks Marta Volonteri for providing constructive comments on our study. Support for this study was provided by NASA through a grant HST-GO-15254.005-A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. This work is based in part on observations taken by the VLA, operated by the U.S. National Radio Astronomy Observatory, which is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. L.B. acknowledges support from NSF award AST-1909933. S.B. and C.O. acknowledge support from the Natural Sciences and Engineering Research Council (NSERC) of Canada. G.C. acknowledges the support from the grant ASI n.2018-23-HH.0. Software: Astropy (Astropy Collaboration et al. 2013, 2018), Astrodrizzle (Hack et al. 2012), FAST (Kriek et al. 2009), GALFIT (Peng et al. 2002, 2010), gsf (Morishita et al. 2019), LACOSMIC (van Dokkum et al. 2001), numpy (Oliphant 2006; Van Der Walt et al. 2011), Pypher (Boucaud et al. 2016), SExtractor (Bertin & Arnouts 1996).
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NASANAS 5-26555
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Agenzia Spaziale Italiana (ASI)2018-23-HH.0
Subject Keywords:Active galaxies; Gravitational waves
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Active galaxies (17); Gravitational waves (678)
Record Number:CaltechAUTHORS:20220608-849502000
Persistent URL:
Official Citation:T. Morishita et al 2022 ApJ 931 165
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115089
Deposited By: George Porter
Deposited On:08 Jun 2022 22:33
Last Modified:08 Jun 2022 22:33

Repository Staff Only: item control page