The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst

We report on quasi-simultaneous observations from radio to X-ray frequencies of the neutron star X-ray binary Aql X-1 over accretion state transitions during its 2016 outburst. All the observations show radio to millimetre spectra consistent with emission from a jet, with a spectral break from optic...

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Main Authors: Díaz Trigo, M., Altamirano, D., Dinçer, T., Miller-Jones, James, Russell, D., Sanna, A., Bailyn, C., Lewis, F., Migliari, S., Rahoui, F.
Format: Journal Article
Published: EDP Sciences 2018
Online Access:http://purl.org/au-research/grants/arc/FT140101082
http://hdl.handle.net/20.500.11937/71018
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author Díaz Trigo, M.
Altamirano, D.
Dinçer, T.
Miller-Jones, James
Russell, D.
Sanna, A.
Bailyn, C.
Lewis, F.
Migliari, S.
Rahoui, F.
author_facet Díaz Trigo, M.
Altamirano, D.
Dinçer, T.
Miller-Jones, James
Russell, D.
Sanna, A.
Bailyn, C.
Lewis, F.
Migliari, S.
Rahoui, F.
author_sort Díaz Trigo, M.
building Curtin Institutional Repository
collection Online Access
description We report on quasi-simultaneous observations from radio to X-ray frequencies of the neutron star X-ray binary Aql X-1 over accretion state transitions during its 2016 outburst. All the observations show radio to millimetre spectra consistent with emission from a jet, with a spectral break from optically thick to optically thin synchrotron emission that decreases from ~100 GHz to <5.5 GHz during the transition from a hard to a soft accretion state. The 5.5 GHz radio flux density as the source reaches the soft state, 0.82 ± 0.03 mJy, is the highest recorded to date for this source. During the decay of the outburst, the jet spectral break is detected again at a frequency of ~30-100 GHz. The flux density is 0.75 ± 0.03 mJy at 97.5 GHz at this stage. This is the first time that a change in the frequency of the jet break of a neutron star X-ray binary has been measured, indicating that the processes at play in black holes are also present in neutron stars, supporting the idea that the internal properties of the jet rely most critically on the conditions of the accretion disc and corona around the compact object, rather than the black hole mass or spin or the neutron star surface or magnetic field.
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institution Curtin University Malaysia
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publishDate 2018
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spelling curtin-20.500.11937-710182022-11-23T06:23:04Z The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst Díaz Trigo, M. Altamirano, D. Dinçer, T. Miller-Jones, James Russell, D. Sanna, A. Bailyn, C. Lewis, F. Migliari, S. Rahoui, F. We report on quasi-simultaneous observations from radio to X-ray frequencies of the neutron star X-ray binary Aql X-1 over accretion state transitions during its 2016 outburst. All the observations show radio to millimetre spectra consistent with emission from a jet, with a spectral break from optically thick to optically thin synchrotron emission that decreases from ~100 GHz to <5.5 GHz during the transition from a hard to a soft accretion state. The 5.5 GHz radio flux density as the source reaches the soft state, 0.82 ± 0.03 mJy, is the highest recorded to date for this source. During the decay of the outburst, the jet spectral break is detected again at a frequency of ~30-100 GHz. The flux density is 0.75 ± 0.03 mJy at 97.5 GHz at this stage. This is the first time that a change in the frequency of the jet break of a neutron star X-ray binary has been measured, indicating that the processes at play in black holes are also present in neutron stars, supporting the idea that the internal properties of the jet rely most critically on the conditions of the accretion disc and corona around the compact object, rather than the black hole mass or spin or the neutron star surface or magnetic field. 2018 Journal Article http://hdl.handle.net/20.500.11937/71018 10.1051/0004-6361/201832693 http://purl.org/au-research/grants/arc/FT140101082 EDP Sciences fulltext
spellingShingle Díaz Trigo, M.
Altamirano, D.
Dinçer, T.
Miller-Jones, James
Russell, D.
Sanna, A.
Bailyn, C.
Lewis, F.
Migliari, S.
Rahoui, F.
The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst
title The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst
title_full The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst
title_fullStr The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst
title_full_unstemmed The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst
title_short The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional states during its 2016 outburst
title_sort evolving jet spectrum of the neutron star x-ray binary aql x-1 in transitional states during its 2016 outburst
url http://purl.org/au-research/grants/arc/FT140101082
http://hdl.handle.net/20.500.11937/71018