Radio Variability from a Quiescent Stellar-mass Black Hole Jet
© 2019 The American Astronomical Society. All rights reserved. Relativistic outflows are believed to be a common feature of black hole X-ray binaries (BHXBs) at the lowest accretion rates, when they are in their "quiescent" spectral state. However, we still lack a detailed understanding o...
| Main Authors: | , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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IOP PUBLISHING LTD
2019
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| Subjects: | |
| Online Access: | http://purl.org/au-research/grants/arc/FT140101082 http://hdl.handle.net/20.500.11937/80173 |
| _version_ | 1848764171925061632 |
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| author | Plotkin, Richard Miller-Jones, James Chomiuk, L. Strader, J. Bruzewski, S. Bundas, A. Smith, K.R. Ruan, J.J. |
| author_facet | Plotkin, Richard Miller-Jones, James Chomiuk, L. Strader, J. Bruzewski, S. Bundas, A. Smith, K.R. Ruan, J.J. |
| author_sort | Plotkin, Richard |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © 2019 The American Astronomical Society. All rights reserved. Relativistic outflows are believed to be a common feature of black hole X-ray binaries (BHXBs) at the lowest accretion rates, when they are in their "quiescent" spectral state. However, we still lack a detailed understanding of how quiescent jet emission varies with time. Here we present 24 yr of archival radio observations (from the Very Large Array and the Very Long Baseline Array) of the BHXB V404 Cygni in quiescence (totaling 150 observations from 1.4 to 22 GHz). The observed flux densities follow lognormal distributions with means and standard deviations of (logf v ,σ log f v ) = (-0.53, 0.19) and (-0.53, 0.30) at 4.9 and 8.4 GHz, respectively (where f v is the flux density in units of mJy). As expected, the average radio spectrum is flat with a mean and standard deviation of (α r σ αr ) (0.02, 0.65), where f v ∝ v αr . We find that radio flares that increase the flux density by factors of 2-4 over timescales as short as <10 minutes are commonplace, and that long-term variations (over 10-4000 day timescales) are consistent with shot-noise impulses that decay to stochastic variations on timescales ∼10 days (and perhaps as short as tens of minutes to several hr). We briefly compare the variability characteristics of V404 Cygni to jetted active galactic nuclei, and we conclude with recommendations on how to account for variability when placing quiescent BHXB candidates with radio luminosities comparable to V404 Cygni (LR ≈ 10 28 erg s -1 ) onto the radio/X-ray luminosity plane. |
| first_indexed | 2025-11-14T11:15:07Z |
| format | Journal Article |
| id | curtin-20.500.11937-80173 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:15:07Z |
| publishDate | 2019 |
| publisher | IOP PUBLISHING LTD |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-801732020-07-29T09:39:01Z Radio Variability from a Quiescent Stellar-mass Black Hole Jet Plotkin, Richard Miller-Jones, James Chomiuk, L. Strader, J. Bruzewski, S. Bundas, A. Smith, K.R. Ruan, J.J. Science & Technology Physical Sciences Astronomy & Astrophysics accretion, accretion disks stars: black holes stars: individual (V404 Cygni) X-rays: binaries X-RAY BINARIES ACTIVE GALACTIC NUCLEI NOVA V404 CYGNI NEUTRON-STAR LIGHT CURVES RELATIVISTIC JETS FLUX CORRELATION ACCRETION FLOWS COMPLETE SAMPLE XTE J1550-564 © 2019 The American Astronomical Society. All rights reserved. Relativistic outflows are believed to be a common feature of black hole X-ray binaries (BHXBs) at the lowest accretion rates, when they are in their "quiescent" spectral state. However, we still lack a detailed understanding of how quiescent jet emission varies with time. Here we present 24 yr of archival radio observations (from the Very Large Array and the Very Long Baseline Array) of the BHXB V404 Cygni in quiescence (totaling 150 observations from 1.4 to 22 GHz). The observed flux densities follow lognormal distributions with means and standard deviations of (logf v ,σ log f v ) = (-0.53, 0.19) and (-0.53, 0.30) at 4.9 and 8.4 GHz, respectively (where f v is the flux density in units of mJy). As expected, the average radio spectrum is flat with a mean and standard deviation of (α r σ αr ) (0.02, 0.65), where f v ∝ v αr . We find that radio flares that increase the flux density by factors of 2-4 over timescales as short as <10 minutes are commonplace, and that long-term variations (over 10-4000 day timescales) are consistent with shot-noise impulses that decay to stochastic variations on timescales ∼10 days (and perhaps as short as tens of minutes to several hr). We briefly compare the variability characteristics of V404 Cygni to jetted active galactic nuclei, and we conclude with recommendations on how to account for variability when placing quiescent BHXB candidates with radio luminosities comparable to V404 Cygni (LR ≈ 10 28 erg s -1 ) onto the radio/X-ray luminosity plane. 2019 Journal Article http://hdl.handle.net/20.500.11937/80173 10.3847/1538-4357/ab01cc English http://purl.org/au-research/grants/arc/FT140101082 IOP PUBLISHING LTD fulltext |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics accretion, accretion disks stars: black holes stars: individual (V404 Cygni) X-rays: binaries X-RAY BINARIES ACTIVE GALACTIC NUCLEI NOVA V404 CYGNI NEUTRON-STAR LIGHT CURVES RELATIVISTIC JETS FLUX CORRELATION ACCRETION FLOWS COMPLETE SAMPLE XTE J1550-564 Plotkin, Richard Miller-Jones, James Chomiuk, L. Strader, J. Bruzewski, S. Bundas, A. Smith, K.R. Ruan, J.J. Radio Variability from a Quiescent Stellar-mass Black Hole Jet |
| title | Radio Variability from a Quiescent Stellar-mass Black Hole Jet |
| title_full | Radio Variability from a Quiescent Stellar-mass Black Hole Jet |
| title_fullStr | Radio Variability from a Quiescent Stellar-mass Black Hole Jet |
| title_full_unstemmed | Radio Variability from a Quiescent Stellar-mass Black Hole Jet |
| title_short | Radio Variability from a Quiescent Stellar-mass Black Hole Jet |
| title_sort | radio variability from a quiescent stellar-mass black hole jet |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics accretion, accretion disks stars: black holes stars: individual (V404 Cygni) X-rays: binaries X-RAY BINARIES ACTIVE GALACTIC NUCLEI NOVA V404 CYGNI NEUTRON-STAR LIGHT CURVES RELATIVISTIC JETS FLUX CORRELATION ACCRETION FLOWS COMPLETE SAMPLE XTE J1550-564 |
| url | http://purl.org/au-research/grants/arc/FT140101082 http://hdl.handle.net/20.500.11937/80173 |