An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow
Due to observational challenges, our knowledge of low-level accretion flows around neutron stars is limited. We present NuSTAR, Swift and Chandra observations of the low-mass X-ray binary IGR J17062-6143, which has been persistently accreting at ≃0.1 per cent of the Eddington limit since 2006. Our s...
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| Format: | Article |
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Oxford University Press (OUP)
2019
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| Online Access: | http://hdl.handle.net/1721.1/120915 https://orcid.org/0000-0001-8804-8946 |
| _version_ | 1811068974061846528 |
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| author | Degenaar, N. Pinto, C. Miller, J. M. Wijnands, R. Altamirano, D. Paerels, F. Fabian, A. C. Chakrabarty, Deepto |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Degenaar, N. Pinto, C. Miller, J. M. Wijnands, R. Altamirano, D. Paerels, F. Fabian, A. C. Chakrabarty, Deepto |
| author_sort | Degenaar, N. |
| collection | MIT |
| description | Due to observational challenges, our knowledge of low-level accretion flows around neutron stars is limited. We present NuSTAR, Swift and Chandra observations of the low-mass X-ray binary IGR J17062-6143, which has been persistently accreting at ≃0.1 per cent of the Eddington limit since 2006. Our simultaneous NuSTAR/Swift observations show that the 0.5-79 keV spectrum can be described by a combination of a power law with a photon index of Γ ≃ 2, a blackbody with a temperature of kTbb ≃ 0.5 keV (presumably arising from the neutron star surface) and disc reflection. Modelling the reflection spectrum suggests that the inner accretion disc was located at Rin ≳ 100GM/c2 (≳225 km) from the neutron star. The apparent truncation may be due to evaporation of the inner disc into a radiatively-inefficient accretion flow, or due to the pressure of the neutron star magnetic field. Our Chandra gratings data reveal possible narrow emission lines near 1 keV that can be modelled as reflection or collisionally ionized gas, and possible low-energy absorption features that could point to the presence of an outflow. We consider a scenario in which this neutron star has been able to sustain its low accretion rate through magnetic inhibition of the accretion flow, which gives some constraints on its magnetic field strength and spin period. In this configuration, IGR J17062-6143 could exhibit a strong radio jet as well as a (propeller-driven) wind-like outflow. |
| first_indexed | 2024-09-23T08:03:41Z |
| format | Article |
| id | mit-1721.1/120915 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T08:03:41Z |
| publishDate | 2019 |
| publisher | Oxford University Press (OUP) |
| record_format | dspace |
| spelling | mit-1721.1/1209152022-09-30T07:14:44Z An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow Degenaar, N. Pinto, C. Miller, J. M. Wijnands, R. Altamirano, D. Paerels, F. Fabian, A. C. Chakrabarty, Deepto Massachusetts Institute of Technology. Department of Physics Chakrabarty, Deepto Due to observational challenges, our knowledge of low-level accretion flows around neutron stars is limited. We present NuSTAR, Swift and Chandra observations of the low-mass X-ray binary IGR J17062-6143, which has been persistently accreting at ≃0.1 per cent of the Eddington limit since 2006. Our simultaneous NuSTAR/Swift observations show that the 0.5-79 keV spectrum can be described by a combination of a power law with a photon index of Γ ≃ 2, a blackbody with a temperature of kTbb ≃ 0.5 keV (presumably arising from the neutron star surface) and disc reflection. Modelling the reflection spectrum suggests that the inner accretion disc was located at Rin ≳ 100GM/c2 (≳225 km) from the neutron star. The apparent truncation may be due to evaporation of the inner disc into a radiatively-inefficient accretion flow, or due to the pressure of the neutron star magnetic field. Our Chandra gratings data reveal possible narrow emission lines near 1 keV that can be modelled as reflection or collisionally ionized gas, and possible low-energy absorption features that could point to the presence of an outflow. We consider a scenario in which this neutron star has been able to sustain its low accretion rate through magnetic inhibition of the accretion flow, which gives some constraints on its magnetic field strength and spin period. In this configuration, IGR J17062-6143 could exhibit a strong radio jet as well as a (propeller-driven) wind-like outflow. 2019-03-12T13:46:22Z 2019-03-12T13:46:22Z 2016-09 2019-03-12T13:29:20Z Article http://purl.org/eprint/type/JournalArticle 0035-8711 1365-2966 http://hdl.handle.net/1721.1/120915 Degenaar, N., C. Pinto, J. M. Miller, R. Wijnands, D. Altamirano, F. Paerels, A. C. Fabian, and D. Chakrabarty. “An in-Depth Study of a Neutron Star Accreting at Low Eddington Rate: On the Possibility of a Truncated Disc and an Outflow.” Monthly Notices of the Royal Astronomical Society 464, no. 1 (September 15, 2016): 398–409. https://orcid.org/0000-0001-8804-8946 http://dx.doi.org/10.1093/MNRAS/STW2355 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv |
| spellingShingle | Degenaar, N. Pinto, C. Miller, J. M. Wijnands, R. Altamirano, D. Paerels, F. Fabian, A. C. Chakrabarty, Deepto An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow |
| title | An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow |
| title_full | An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow |
| title_fullStr | An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow |
| title_full_unstemmed | An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow |
| title_short | An in-depth study of a neutron star accreting at low Eddington rate: on the possibility of a truncated disc and an outflow |
| title_sort | in depth study of a neutron star accreting at low eddington rate on the possibility of a truncated disc and an outflow |
| url | http://hdl.handle.net/1721.1/120915 https://orcid.org/0000-0001-8804-8946 |
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