Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058
RXS J180408.9–342058 is a transient neutron star low-mass X-ray binary that exhibited a bright accretion outburst in 2015. We present NuSTAR , Swift , and Chandra observations obtained around the peak brightness of this outburst. The source was in a soft X-ray spectral state and displayed an X-ray l...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Journal Article |
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Oxford University Press
2016
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| Online Access: | http://purl.org/au-research/grants/arc/FT140101082 http://hdl.handle.net/20.500.11937/33719 |
| _version_ | 1848754025177022464 |
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| author | Degenaar, N. Altamirano, D. Parker, M. Miller-Jones, James Miller, J. Heinke, C. Wijnands, R. Ludlam, R. Parikh, A. Hessels, J. Gusinskaia, N. Deller, A. Fabian, A. |
| author_facet | Degenaar, N. Altamirano, D. Parker, M. Miller-Jones, James Miller, J. Heinke, C. Wijnands, R. Ludlam, R. Parikh, A. Hessels, J. Gusinskaia, N. Deller, A. Fabian, A. |
| author_sort | Degenaar, N. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | RXS J180408.9–342058 is a transient neutron star low-mass X-ray binary that exhibited a bright accretion outburst in 2015. We present NuSTAR , Swift , and Chandra observations obtained around the peak brightness of this outburst. The source was in a soft X-ray spectral state and displayed an X-ray luminosity of L X _~(2–3) × 10 37 ( D / 5.8kpc) 2 ergs − 1 (0.5– 10 keV). The NuSTAR data reveal a broad Fe–K emission line that we model as relativistically broadened reflection to constrain the accretion geometry. We found that the accretion disc is viewed at an inclination of i _~27 ◦ –35 ◦ and extended close to the neutron star, down to R in _~5–7.5 gravitational radii (_~11–17 km). This inner disc radius suggests that the neutron star magnetic field strength is B ~<2 × 10 8 G. We find a narrow absorption line in the Chandra /HEG data at an energy of _~7.64 keV with a significance of _~4.8 σ. This feature could correspond to blueshifted Fe XXVI and arise from an accretion disc wind, which would imply an outflow velocity of v out _~0.086 c (_~25 800kms − 1 ). However, this would be extreme for an X-ray binary and it is unclear if a disc wind should be visible at the low inclination angle that we infer from our reflection analysis. Finally, we discuss how the X-ray and optical properties of 1RXS J180408.9–342058 are consistent with a relatively small ( P orb ~<3h) binary orbit |
| first_indexed | 2025-11-14T08:33:51Z |
| format | Journal Article |
| id | curtin-20.500.11937-33719 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:33:51Z |
| publishDate | 2016 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-337192022-11-23T06:47:53Z Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058 Degenaar, N. Altamirano, D. Parker, M. Miller-Jones, James Miller, J. Heinke, C. Wijnands, R. Ludlam, R. Parikh, A. Hessels, J. Gusinskaia, N. Deller, A. Fabian, A. RXS J180408.9–342058 is a transient neutron star low-mass X-ray binary that exhibited a bright accretion outburst in 2015. We present NuSTAR , Swift , and Chandra observations obtained around the peak brightness of this outburst. The source was in a soft X-ray spectral state and displayed an X-ray luminosity of L X _~(2–3) × 10 37 ( D / 5.8kpc) 2 ergs − 1 (0.5– 10 keV). The NuSTAR data reveal a broad Fe–K emission line that we model as relativistically broadened reflection to constrain the accretion geometry. We found that the accretion disc is viewed at an inclination of i _~27 ◦ –35 ◦ and extended close to the neutron star, down to R in _~5–7.5 gravitational radii (_~11–17 km). This inner disc radius suggests that the neutron star magnetic field strength is B ~<2 × 10 8 G. We find a narrow absorption line in the Chandra /HEG data at an energy of _~7.64 keV with a significance of _~4.8 σ. This feature could correspond to blueshifted Fe XXVI and arise from an accretion disc wind, which would imply an outflow velocity of v out _~0.086 c (_~25 800kms − 1 ). However, this would be extreme for an X-ray binary and it is unclear if a disc wind should be visible at the low inclination angle that we infer from our reflection analysis. Finally, we discuss how the X-ray and optical properties of 1RXS J180408.9–342058 are consistent with a relatively small ( P orb ~<3h) binary orbit 2016 Journal Article http://hdl.handle.net/20.500.11937/33719 10.1093/mnras/stw1593 http://purl.org/au-research/grants/arc/FT140101082 Oxford University Press fulltext |
| spellingShingle | Degenaar, N. Altamirano, D. Parker, M. Miller-Jones, James Miller, J. Heinke, C. Wijnands, R. Ludlam, R. Parikh, A. Hessels, J. Gusinskaia, N. Deller, A. Fabian, A. Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058 |
| title | Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058 |
| title_full | Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058 |
| title_fullStr | Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058 |
| title_full_unstemmed | Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058 |
| title_short | Disc reflection and a possible disc wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058 |
| title_sort | disc reflection and a possible disc wind during a soft x-ray state in the neutron star low-mass x-ray binary 1rxs j180408.9-342058 |
| url | http://purl.org/au-research/grants/arc/FT140101082 http://hdl.handle.net/20.500.11937/33719 |