Multimission observations of the old nova GK Per during the 2015 outburst
GK Per, a classical nova of 1901, is thought to undergo variable mass accretion on to a magnetized white dwarf (WD) in an intermediate polar system. We organized a multimission observational campaign in the X-ray and ultraviolet energy ranges during its dwarf nova outburst in 2015 March-April. Compa...
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todo:paper_00358711_v469_n1_p476_Zemko2023-10-03T14:47:19Z Multimission observations of the old nova GK Per during the 2015 outburst Zemko, P. Orio, M. Luna, G.J.M. Mukai, K. Evans, P.A. Bianchini, A. Cataclysmic variables Novae Stars: individual: GK Per GK Per, a classical nova of 1901, is thought to undergo variable mass accretion on to a magnetized white dwarf (WD) in an intermediate polar system. We organized a multimission observational campaign in the X-ray and ultraviolet energy ranges during its dwarf nova outburst in 2015 March-April. Comparing data from quiescence and near outburst, we have found that the maximum plasma temperature decreased from about 26 to 16.2-0.4 +0.5 keV. This is consistent with the previously proposed scenario of increase in mass accretion rate while the inner radius of the magnetically disrupted accretion disc shrinks, thereby lowering the shock temperature. A NuSTAR observation also revealed a high-amplitude WD spin modulation of the very hard X-rays with a single-peaked profile, suggesting an obscuration of the lower accretion pole and an extended shock region on the WD surface. The X-ray spectrum of GK Per measured with the Swift X-Ray Telescope varied on time-scales of days and also showed a gradual increase of the soft X-ray flux below 2 keV, accompanied by a decrease of the hard flux above 2 keV. In the Chandra observation with the High Energy Transmission Gratings, we detected prominent emission lines, especially of Ne, Mg and Si, where the ratios of H-like to He-like transition for each element indicate a much lower temperature than the underlying continuum. We suggest that the X-ray emission in the 0.8-2 keV range originates from the magnetospheric boundary. © 2017 The Authors. Fil:Luna, G.J.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00358711_v469_n1_p476_Zemko |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Cataclysmic variables Novae Stars: individual: GK Per |
| spellingShingle |
Cataclysmic variables Novae Stars: individual: GK Per Zemko, P. Orio, M. Luna, G.J.M. Mukai, K. Evans, P.A. Bianchini, A. Multimission observations of the old nova GK Per during the 2015 outburst |
| topic_facet |
Cataclysmic variables Novae Stars: individual: GK Per |
| description |
GK Per, a classical nova of 1901, is thought to undergo variable mass accretion on to a magnetized white dwarf (WD) in an intermediate polar system. We organized a multimission observational campaign in the X-ray and ultraviolet energy ranges during its dwarf nova outburst in 2015 March-April. Comparing data from quiescence and near outburst, we have found that the maximum plasma temperature decreased from about 26 to 16.2-0.4 +0.5 keV. This is consistent with the previously proposed scenario of increase in mass accretion rate while the inner radius of the magnetically disrupted accretion disc shrinks, thereby lowering the shock temperature. A NuSTAR observation also revealed a high-amplitude WD spin modulation of the very hard X-rays with a single-peaked profile, suggesting an obscuration of the lower accretion pole and an extended shock region on the WD surface. The X-ray spectrum of GK Per measured with the Swift X-Ray Telescope varied on time-scales of days and also showed a gradual increase of the soft X-ray flux below 2 keV, accompanied by a decrease of the hard flux above 2 keV. In the Chandra observation with the High Energy Transmission Gratings, we detected prominent emission lines, especially of Ne, Mg and Si, where the ratios of H-like to He-like transition for each element indicate a much lower temperature than the underlying continuum. We suggest that the X-ray emission in the 0.8-2 keV range originates from the magnetospheric boundary. © 2017 The Authors. |
| format |
JOUR |
| author |
Zemko, P. Orio, M. Luna, G.J.M. Mukai, K. Evans, P.A. Bianchini, A. |
| author_facet |
Zemko, P. Orio, M. Luna, G.J.M. Mukai, K. Evans, P.A. Bianchini, A. |
| author_sort |
Zemko, P. |
| title |
Multimission observations of the old nova GK Per during the 2015 outburst |
| title_short |
Multimission observations of the old nova GK Per during the 2015 outburst |
| title_full |
Multimission observations of the old nova GK Per during the 2015 outburst |
| title_fullStr |
Multimission observations of the old nova GK Per during the 2015 outburst |
| title_full_unstemmed |
Multimission observations of the old nova GK Per during the 2015 outburst |
| title_sort |
multimission observations of the old nova gk per during the 2015 outburst |
| url |
http://hdl.handle.net/20.500.12110/paper_00358711_v469_n1_p476_Zemko |
| work_keys_str_mv |
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1807316759803330560 |