Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs

Owing to their quiet evolutionary histories, nearby dwarf galaxies (stellar masses M∗ ≲ 3 × 109 M⊙) have the potential to teach us about the mechanism(s) that 'seeded' the growth of supermassive black holes, and also how the first stellar mass black holes formed and interacted with their e...

Full description

Bibliographic Details
Main Authors: Thygesen, E., Plotkin, R.M., Soria, R., Reines, A.E., Greene, J.E., Anderson, Gemma, Baldassare, V.F., Owens, M.G., Urquhart, R.T., Gallo, E., Miller-Jones, James, Paul, J.D., Rollings, A.P.
Format: Journal Article
Language:English
Published: OXFORD UNIV PRESS 2023
Subjects:
Online Access:http://purl.org/au-research/grants/arc/DE180100346
http://hdl.handle.net/20.500.11937/96439
_version_ 1848766152342241280
author Thygesen, E.
Plotkin, R.M.
Soria, R.
Reines, A.E.
Greene, J.E.
Anderson, Gemma
Baldassare, V.F.
Owens, M.G.
Urquhart, R.T.
Gallo, E.
Miller-Jones, James
Paul, J.D.
Rollings, A.P.
author_facet Thygesen, E.
Plotkin, R.M.
Soria, R.
Reines, A.E.
Greene, J.E.
Anderson, Gemma
Baldassare, V.F.
Owens, M.G.
Urquhart, R.T.
Gallo, E.
Miller-Jones, James
Paul, J.D.
Rollings, A.P.
author_sort Thygesen, E.
building Curtin Institutional Repository
collection Online Access
description Owing to their quiet evolutionary histories, nearby dwarf galaxies (stellar masses M∗ ≲ 3 × 109 M⊙) have the potential to teach us about the mechanism(s) that 'seeded' the growth of supermassive black holes, and also how the first stellar mass black holes formed and interacted with their environments. Here, we present high spatial resolution observations of three dwarf galaxies in the X-ray (Chandra), the optical/near-infrared (Hubble Space Telescope), and the radio (Karl G. Jansky Very Large Array). These three galaxies were previously identified as hosting candidate active galactic nuclei on the basis of lower resolution X-ray imaging. With our new observations, we find that X-ray sources in two galaxies (SDSS J121326.01+543631.6 and SDSS J122111.29+173819.1) are off-nuclear and lack corresponding radio emission, implying they are likely luminous X-ray binaries. The third galaxy (Mrk 1434) contains two X-ray sources (each with LX ≈ 1040 erg s-1) separated by 2.8 arcsec, has a low metallicity [12 + log(O/H) = 7.8], and emits nebular He ii λ4686 line emission. The northern source has spatially coincident point-like radio emission at 9.0 GHz and extended radio emission at 5.5 GHz. We discuss X-ray binary interpretations (where an ultraluminous X-ray source blows a 'radio bubble') and active galactic nucleus interpretations (where an ≈ 4 × 105 M⊙ black hole launches a jet). In either case, we find that the He ii emission cannot be photoionized by the X-ray source, unless the source was ≈30-90 times more luminous several hundred years ago.
first_indexed 2025-11-14T11:46:36Z
format Journal Article
id curtin-20.500.11937-96439
institution Curtin University Malaysia
institution_category Local University
language English
last_indexed 2025-11-14T11:46:36Z
publishDate 2023
publisher OXFORD UNIV PRESS
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-964392024-12-17T07:44:30Z Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs Thygesen, E. Plotkin, R.M. Soria, R. Reines, A.E. Greene, J.E. Anderson, Gemma Baldassare, V.F. Owens, M.G. Urquhart, R.T. Gallo, E. Miller-Jones, James Paul, J.D. Rollings, A.P. Science & Technology Physical Sciences Astronomy & Astrophysics stars: black holes galaxies: dwarf radio continuum: galaxies X-rays: galaxies STAR-FORMATION RATE QUASAR LUMINOSITY FUNCTION ACTIVE GALACTIC NUCLEI DIGITAL-SKY-SURVEY LOW-MASS GALAXIES BLACK-HOLE STELLAR MASS FUNDAMENTAL PLANE SEYFERT-1 GALAXY FORMING GALAXIES Owing to their quiet evolutionary histories, nearby dwarf galaxies (stellar masses M∗ ≲ 3 × 109 M⊙) have the potential to teach us about the mechanism(s) that 'seeded' the growth of supermassive black holes, and also how the first stellar mass black holes formed and interacted with their environments. Here, we present high spatial resolution observations of three dwarf galaxies in the X-ray (Chandra), the optical/near-infrared (Hubble Space Telescope), and the radio (Karl G. Jansky Very Large Array). These three galaxies were previously identified as hosting candidate active galactic nuclei on the basis of lower resolution X-ray imaging. With our new observations, we find that X-ray sources in two galaxies (SDSS J121326.01+543631.6 and SDSS J122111.29+173819.1) are off-nuclear and lack corresponding radio emission, implying they are likely luminous X-ray binaries. The third galaxy (Mrk 1434) contains two X-ray sources (each with LX ≈ 1040 erg s-1) separated by 2.8 arcsec, has a low metallicity [12 + log(O/H) = 7.8], and emits nebular He ii λ4686 line emission. The northern source has spatially coincident point-like radio emission at 9.0 GHz and extended radio emission at 5.5 GHz. We discuss X-ray binary interpretations (where an ultraluminous X-ray source blows a 'radio bubble') and active galactic nucleus interpretations (where an ≈ 4 × 105 M⊙ black hole launches a jet). In either case, we find that the He ii emission cannot be photoionized by the X-ray source, unless the source was ≈30-90 times more luminous several hundred years ago. 2023 Journal Article http://hdl.handle.net/20.500.11937/96439 10.1093/mnras/stad002 English http://purl.org/au-research/grants/arc/DE180100346 OXFORD UNIV PRESS fulltext
spellingShingle Science & Technology
Physical Sciences
Astronomy & Astrophysics
stars: black holes
galaxies: dwarf
radio continuum: galaxies
X-rays: galaxies
STAR-FORMATION RATE
QUASAR LUMINOSITY FUNCTION
ACTIVE GALACTIC NUCLEI
DIGITAL-SKY-SURVEY
LOW-MASS GALAXIES
BLACK-HOLE
STELLAR MASS
FUNDAMENTAL PLANE
SEYFERT-1 GALAXY
FORMING GALAXIES
Thygesen, E.
Plotkin, R.M.
Soria, R.
Reines, A.E.
Greene, J.E.
Anderson, Gemma
Baldassare, V.F.
Owens, M.G.
Urquhart, R.T.
Gallo, E.
Miller-Jones, James
Paul, J.D.
Rollings, A.P.
Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
title Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
title_full Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
title_fullStr Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
title_full_unstemmed Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
title_short Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
title_sort multiwavelength scrutiny of x-ray sources in dwarf galaxies: ulxs versus agns
topic Science & Technology
Physical Sciences
Astronomy & Astrophysics
stars: black holes
galaxies: dwarf
radio continuum: galaxies
X-rays: galaxies
STAR-FORMATION RATE
QUASAR LUMINOSITY FUNCTION
ACTIVE GALACTIC NUCLEI
DIGITAL-SKY-SURVEY
LOW-MASS GALAXIES
BLACK-HOLE
STELLAR MASS
FUNDAMENTAL PLANE
SEYFERT-1 GALAXY
FORMING GALAXIES
url http://purl.org/au-research/grants/arc/DE180100346
http://hdl.handle.net/20.500.11937/96439