ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR
We present an analysis of a 78 ks Chandra high-energy transmission gratings observation of the B0I star QV Nor, the massive donor of the wind-accreting pulsar 4U1538−52. The neutron star (NS) orbits its companion in a very close orbit (r < 1.4R[subscript *], in units of the stellar radii), thereb...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/100044 |
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| author | Oskinova, Lidia M. Rodes-Roca, J. J. Shenar, T. Wilms, J. Torrejon, J. M. Schulz, Norbert S. Nowak, Michael A. |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Oskinova, Lidia M. Rodes-Roca, J. J. Shenar, T. Wilms, J. Torrejon, J. M. Schulz, Norbert S. Nowak, Michael A. |
| author_sort | Oskinova, Lidia M. |
| collection | MIT |
| description | We present an analysis of a 78 ks Chandra high-energy transmission gratings observation of the B0I star QV Nor, the massive donor of the wind-accreting pulsar 4U1538−52. The neutron star (NS) orbits its companion in a very close orbit (r < 1.4R[subscript *], in units of the stellar radii), thereby allowing probing of the innermost wind regions. The flux of the Fe Kα line during eclipse reduces to only ~30% of the flux measured out of eclipse. This indicates that the majority of Fe fluorescence must be produced in regions close to the NS, at distances smaller than 1R[subscript *] from its surface. The fact that the flux of the continuum decreases to only ~3% during eclipse allows for a high contrast of the Fe Kα line fluorescence during eclipse. The line is not resolved and centered at λ = 1.9368 [+0.0032 over -0.0018] Å. From the inferred plasma speed limit of v < c[∆λ over λ] < 800 km s[superscript −1] and range of ionization parameters of log ξ = [-1, 2], together with the stellar density profile, we constrain the location of the cold, dense material in the stellar wind of QV Nor using simple geometrical considerations. We then use the Fe Kα line fluorescence as a tracer of wind clumps and determine that these clumps in the stellar wind of QV Nor (B0I) must already be present at radii r < 1.25R[subscript *], close to the photosphere of the star. |
| first_indexed | 2024-09-23T16:14:57Z |
| format | Article |
| id | mit-1721.1/100044 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:14:57Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1000442022-09-29T19:07:10Z ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR Oskinova, Lidia M. Rodes-Roca, J. J. Shenar, T. Wilms, J. Torrejon, J. M. Schulz, Norbert S. Nowak, Michael A. MIT Kavli Institute for Astrophysics and Space Research Schulz, Norbert S. Nowak, Michael A. We present an analysis of a 78 ks Chandra high-energy transmission gratings observation of the B0I star QV Nor, the massive donor of the wind-accreting pulsar 4U1538−52. The neutron star (NS) orbits its companion in a very close orbit (r < 1.4R[subscript *], in units of the stellar radii), thereby allowing probing of the innermost wind regions. The flux of the Fe Kα line during eclipse reduces to only ~30% of the flux measured out of eclipse. This indicates that the majority of Fe fluorescence must be produced in regions close to the NS, at distances smaller than 1R[subscript *] from its surface. The fact that the flux of the continuum decreases to only ~3% during eclipse allows for a high contrast of the Fe Kα line fluorescence during eclipse. The line is not resolved and centered at λ = 1.9368 [+0.0032 over -0.0018] Å. From the inferred plasma speed limit of v < c[∆λ over λ] < 800 km s[superscript −1] and range of ionization parameters of log ξ = [-1, 2], together with the stellar density profile, we constrain the location of the cold, dense material in the stellar wind of QV Nor using simple geometrical considerations. We then use the Fe Kα line fluorescence as a tracer of wind clumps and determine that these clumps in the stellar wind of QV Nor (B0I) must already be present at radii r < 1.25R[subscript *], close to the photosphere of the star. Spain. Ministerio de Economia y Competitividad (Grant ESP2013-48637-C2-2P) Spain. Ministerio de Economia y Competitividad (Grant ESP2014-53672-C3-3-P) 2015-11-24T19:57:09Z 2015-11-24T19:57:09Z 2015-09 2015-05 Article http://purl.org/eprint/type/JournalArticle 1538-4357 0004-637X http://hdl.handle.net/1721.1/100044 Torrejón, J. M., N. S. Schulz, M. A. Nowak, L. Oskinova, J. J. Rodes-Roca, T. Shenar, and J. Wilms. “ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR.” The Astrophysical Journal 810, no. 2 (September 3, 2015): 102. © 2015 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-637x/810/2/102 The Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Oskinova, Lidia M. Rodes-Roca, J. J. Shenar, T. Wilms, J. Torrejon, J. M. Schulz, Norbert S. Nowak, Michael A. ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR |
| title | ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR |
| title_full | ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR |
| title_fullStr | ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR |
| title_full_unstemmed | ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR |
| title_short | ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR |
| title_sort | on the radial onset of clumping in the wind of the b0i massive star qv nor |
| url | http://hdl.handle.net/1721.1/100044 |
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