A Caltech Library Service

Variability-selected intermediate mass black hole candidates in dwarf galaxies from ZTF and WISE

Ward, Charlotte and Gezari, Suvi and Nugent, Peter and Bellm, Eric C. and Dekany, Richard and Drake, Andrew and Duev, Dmitry A. and Graham, Matthew J. and Kasliwal, Mansi M. and Kool, Erik C. and Masci, Frank J. and Riddle, Reed L. (2021) Variability-selected intermediate mass black hole candidates in dwarf galaxies from ZTF and WISE. . (Unpublished)

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


In this paper we present a sample of variability-selected AGN from a parent sample of dwarf galaxies using optical photometry from the Zwicky Transient Facility (ZTF) and forward-modeled mid-IR photometry of time-resolved Wide-field Infrared Survey Explorer (WISE) coadded images. We found that 44 out of 25,714 dwarf galaxies had optically variable AGN candidates, and 158 out of 79,879 dwarf galaxies had mid-IR variable AGN candidates, corresponding to active fractions of 0.17±0.03% and 0.20±0.02% respectively. Only two objects, NSA164884 and NSA451469, broad line AGN with virial masses M_(BH) = 10^(6.9) M_⊙ and M_(BH) = 10^(6.3) M_⊙ respectively, were found in both optical and mid-IR searches. We find that spectroscopic approaches to AGN identification would have missed 81% of our ZTF IMBH candidates and 69% of our WISE IMBH candidates. Only 9 candidates have been detected previously in radio, X-ray, and variability searches for dwarf galaxy AGN. The IMBHs with broad Balmer lines have virial masses of 10⁵ M_⊙ < M_(BH) < 10⁷ M_⊙ but for the rest of the sample, BH masses predicted from host galaxy mass range between 10^(4.8) M_⊙ < M_(BH) < 10⁷ M_⊙. We found that only 5 of 152 previously reported variability-selected AGN candidates from the Palomar Transient Factory in common with our parent sample were variable in ZTF. We also determined a nuclear supernova fraction of 0.05±0.01% year⁻¹ for dwarf galaxies in ZTF. Our ZTF and WISE IMBH candidates show the promise of variability searches for discovery of otherwise hidden low mass AGN in preparation for the Legacy Survey of Space and Time (LSST) at Vera C. Rubin Observatory.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Ward, Charlotte0000-0002-4557-6682
Gezari, Suvi0000-0003-3703-5154
Nugent, Peter0000-0002-3389-0586
Bellm, Eric C.0000-0001-8018-5348
Dekany, Richard0000-0002-5884-7867
Duev, Dmitry A.0000-0001-5060-8733
Graham, Matthew J.0000-0002-3168-0139
Kasliwal, Mansi M.0000-0002-5619-4938
Kool, Erik C.0000-0002-7252-3877
Masci, Frank J.0000-0002-8532-9395
Riddle, Reed L.0000-0002-0387-370X
Additional Information:Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, and IN2P3, France. Operations are conducted by COO, IPAC, and UW. The ZTF forced-photometry service was funded under the Heising-Simons Foundation grant 12540303 (PI: Graham). ECK acknowledges support from the G.R.E.A.T research environment funded by Vetenskapsrådet, the Swedish Research Council, under project number 2016-06012, and support from The Wenner-Gren Foundations. MMK acknowledges generous support from the David and Lucille Packard Foundation. This work was supported by the GROWTH project funded by the National Science Foundation under Grant No 1545949. The author would like to thank Yuhan Yao for her useful comments. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. P.E.N. acknowledges support from the DOE under grant DE-AC02-05CH11231, Analytical Modeling for Extreme-Scale Computing Environments. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaboration. Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and the Ministerio da Ciencia, Tecnologia e Inovacao, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenossische Technische Hochschule (ETH) Zurich, Fermi National Accelerator Laboratory, the University of Illinois at Urbana-Champaign, the Institut de Ciencies de l'Espai (IEEC/CSIC), the Institut de Fisica d'Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universitat Munchen and the associated Excellence Cluster Universe, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, the Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, and Texas A&M University. Software: Ampel (Nordin et al. 2019), Astromatic (, Astropy (Robitaille et al. 2013; Price-Whelan et al. 2018), catsHTM (Soumagnac & Ofek 2018), extcats (, GROWTH Marshal (Kasliwal et al. 2019), Hotpants (, The Tractor (Lang et al. 2016a).
Group:Astronomy Department, Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility
Funding AgencyGrant Number
ZTF partner institutionsUNSPECIFIED
Heising-Simons Foundation12540303
Swedish Research Council2016-06012
Wenner-Gren FoundationUNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Department of Energy (DOE)DE-AC02-05CH11231
Dark Energy Survey (DES) collaborationUNSPECIFIED
Record Number:CaltechAUTHORS:20211130-215733950
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112109
Deposited By: George Porter
Deposited On:01 Dec 2021 20:05
Last Modified:01 Dec 2021 20:05

Repository Staff Only: item control page