A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933
We present coordinated multiwavelength observations of the high Galactic latitude (b = +50°) black hole X-ray binary (BHXB) Swift J1357.2−0933 in quiescence. Our broad-band spectrum includes strictly simultaneous radio and X-ray observations, and near-infrared, optical, and ultraviolet data taken 1–...
| 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/20.500.11937/10689 |
| _version_ | 1848747602213863424 |
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| author | Plotkin, Richard Gallo, E. Jonker, P. Miller-Jones, James Homan, J. Munoz-Darias, T. Markoff, S. Padilla, M. Fender, R. Rushton, A. Russell, D. Torres, M. |
| author_facet | Plotkin, Richard Gallo, E. Jonker, P. Miller-Jones, James Homan, J. Munoz-Darias, T. Markoff, S. Padilla, M. Fender, R. Rushton, A. Russell, D. Torres, M. |
| author_sort | Plotkin, Richard |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present coordinated multiwavelength observations of the high Galactic latitude (b = +50°) black hole X-ray binary (BHXB) Swift J1357.2−0933 in quiescence. Our broad-band spectrum includes strictly simultaneous radio and X-ray observations, and near-infrared, optical, and ultraviolet data taken 1–2 d later. We detect Swift J1357.2−0933 at all wavebands except for the radio (f5 GHz < 3.9 μJy beam−1; 3σrms). Given current constraints on the distance (2.3–6.3 kpc), its 0.5–10 keV X-ray flux corresponds to an Eddington ratio LX/LEdd = 4 × 10−9–3 × 10−8 (assuming a black hole mass of 10 M⊙). The broad-band spectrum is dominated by synchrotron radiation from a relativistic population of outflowing thermal electrons, which we argue to be a common signature of short-period quiescent BHXBs. Furthermore, we identify the frequency where the synchrotron radiation transitions from optically thick-to-thin (νb ≈ 2–5 × 1014 Hz), which is the most robust determination of a ‘jet break’ for a quiescent BHXB to date. Our interpretation relies on the presence of steep curvature in the ultraviolet spectrum, a frequency window made observable by the low amount of interstellar absorption along the line of sight. High Galactic latitude systems like Swift J1357.2−0933 with clean ultraviolet sightlines are crucial for understanding black hole accretion at low luminosities. |
| first_indexed | 2025-11-14T06:51:45Z |
| format | Journal Article |
| id | curtin-20.500.11937-10689 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:51:45Z |
| publishDate | 2016 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-106892022-11-28T04:09:31Z A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933 Plotkin, Richard Gallo, E. Jonker, P. Miller-Jones, James Homan, J. Munoz-Darias, T. Markoff, S. Padilla, M. Fender, R. Rushton, A. Russell, D. Torres, M. We present coordinated multiwavelength observations of the high Galactic latitude (b = +50°) black hole X-ray binary (BHXB) Swift J1357.2−0933 in quiescence. Our broad-band spectrum includes strictly simultaneous radio and X-ray observations, and near-infrared, optical, and ultraviolet data taken 1–2 d later. We detect Swift J1357.2−0933 at all wavebands except for the radio (f5 GHz < 3.9 μJy beam−1; 3σrms). Given current constraints on the distance (2.3–6.3 kpc), its 0.5–10 keV X-ray flux corresponds to an Eddington ratio LX/LEdd = 4 × 10−9–3 × 10−8 (assuming a black hole mass of 10 M⊙). The broad-band spectrum is dominated by synchrotron radiation from a relativistic population of outflowing thermal electrons, which we argue to be a common signature of short-period quiescent BHXBs. Furthermore, we identify the frequency where the synchrotron radiation transitions from optically thick-to-thin (νb ≈ 2–5 × 1014 Hz), which is the most robust determination of a ‘jet break’ for a quiescent BHXB to date. Our interpretation relies on the presence of steep curvature in the ultraviolet spectrum, a frequency window made observable by the low amount of interstellar absorption along the line of sight. High Galactic latitude systems like Swift J1357.2−0933 with clean ultraviolet sightlines are crucial for understanding black hole accretion at low luminosities. 2016 Journal Article http://hdl.handle.net/20.500.11937/10689 10.1093/mnras/stv2861 http://purl.org/au-research/grants/arc/FT140101082 Oxford University Press fulltext |
| spellingShingle | Plotkin, Richard Gallo, E. Jonker, P. Miller-Jones, James Homan, J. Munoz-Darias, T. Markoff, S. Padilla, M. Fender, R. Rushton, A. Russell, D. Torres, M. A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933 |
| title | A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933 |
| title_full | A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933 |
| title_fullStr | A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933 |
| title_full_unstemmed | A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933 |
| title_short | A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933 |
| title_sort | clean sightline to quiescence: multiwavelength observations of the high galactic latitude black hole x-ray binary swift j1357.2-0933 |
| url | http://purl.org/au-research/grants/arc/FT140101082 http://hdl.handle.net/20.500.11937/10689 |