HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682
We present an analysis of a series of four consecutive Chandra high-resolution transmission gratings observations, amounting to a total of 150 ks, of the Be X-ray source HD 119682 (=1WGA J1346.5–6255), a member of the new class of γ Cas analogs. The Chandra light curve shows significant brightness v...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/93203 |
| _version_ | 1826197774245298176 |
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| author | Torrejón, J. M. Testa, P. Rodes, J. J. Nowak, Michael A. Schulz, Norbert S. |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Torrejón, J. M. Testa, P. Rodes, J. J. Nowak, Michael A. Schulz, Norbert S. |
| author_sort | Torrejón, J. M. |
| collection | MIT |
| description | We present an analysis of a series of four consecutive Chandra high-resolution transmission gratings observations, amounting to a total of 150 ks, of the Be X-ray source HD 119682 (=1WGA J1346.5–6255), a member of the new class of γ Cas analogs. The Chandra light curve shows significant brightness variations on timescales of hours. However, the spectral distribution appears rather stable within each observation and during the whole campaign. A detailed analysis is not able to detect any coherent pulsation up to a frequency of 0.05 Hz. The Chandra High Energy Transmission Gratings spectrum seems to be devoid of any strong emission line, including Fe Kα fluorescence. The continuum is well described with the addition of two collisionally ionized plasmas of temperatures kT ≈ 15 keV and 0.2 keV, respectively, by the apec model. Models using photoionized plasma components (mekal) or non-thermal components (powerlaw) give poorer fits, providing support for the pure thermal scenario. These two components are absorbed by a single column with N H = (0.20[superscript +0.15] –0.03) × 10[superscript 22] cm[superscript –2] compatible with the interstellar value. We conclude that HD 119682 can be regarded as a pole-on γ Cas analog. |
| first_indexed | 2024-09-23T10:52:56Z |
| format | Article |
| id | mit-1721.1/93203 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:52:56Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/932032022-09-27T15:40:29Z HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682 Torrejón, J. M. Testa, P. Rodes, J. J. Nowak, Michael A. Schulz, Norbert S. MIT Kavli Institute for Astrophysics and Space Research Nowak, Michael A. Schulz, Norbert S. We present an analysis of a series of four consecutive Chandra high-resolution transmission gratings observations, amounting to a total of 150 ks, of the Be X-ray source HD 119682 (=1WGA J1346.5–6255), a member of the new class of γ Cas analogs. The Chandra light curve shows significant brightness variations on timescales of hours. However, the spectral distribution appears rather stable within each observation and during the whole campaign. A detailed analysis is not able to detect any coherent pulsation up to a frequency of 0.05 Hz. The Chandra High Energy Transmission Gratings spectrum seems to be devoid of any strong emission line, including Fe Kα fluorescence. The continuum is well described with the addition of two collisionally ionized plasmas of temperatures kT ≈ 15 keV and 0.2 keV, respectively, by the apec model. Models using photoionized plasma components (mekal) or non-thermal components (powerlaw) give poorer fits, providing support for the pure thermal scenario. These two components are absorbed by a single column with N H = (0.20[superscript +0.15] –0.03) × 10[superscript 22] cm[superscript –2] compatible with the interstellar value. We conclude that HD 119682 can be regarded as a pole-on γ Cas analog. Spain. Ministerio de Ciencia e Innovación (Grant AYA2010-15431) Spain. Ministerio de Ciencia e Innovación (Grant AIB2010DE-00057) 2015-01-29T18:56:38Z 2015-01-29T18:56:38Z 2013-02 2012-07 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/93203 Torrejón, J. M., N. S. Schulz, M. A. Nowak, P. Testa, and J. J. Rodes. “HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682.” The Astrophysical Journal 765, no. 1 (February 11, 2013): 13. © 2013 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-637x/765/1/13 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 American Astronomical Society |
| spellingShingle | Torrejón, J. M. Testa, P. Rodes, J. J. Nowak, Michael A. Schulz, Norbert S. HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682 |
| title | HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682 |
| title_full | HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682 |
| title_fullStr | HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682 |
| title_full_unstemmed | HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682 |
| title_short | HOT THERMAL X-RAY EMISSION FROM THE Be STAR HD 119682 |
| title_sort | hot thermal x ray emission from the be star hd 119682 |
| url | http://hdl.handle.net/1721.1/93203 |
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