Ups and downs in the X-ray emission of the colliding wind binaries HD 168112 and HD 167971

被引:2
作者
Rauw, G. [1 ]
Blomme, R. [2 ]
Naze, Y. [1 ]
Volpi, D. [2 ,3 ]
Fernandez-Vera, S. [1 ]
机构
[1] Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee 6 Aout, 19c, Bat B5c, B-4000 Liege, Belgium
[2] Royal Observ Belgium, Ringlaan 3, BE-1180 Brussels, Belgium
[3] Univ Libre Bruxelles, Fac Sci Motr, Campus Erasme,Route Lennik 808, B-1070 Anderlecht, Belgium
关键词
binaries: close; stars: early-type; stars: individual: HD 168112; stars: individual: HD 167971; radio continuum: stars; X-rays: stars; NONTHERMAL RADIO-EMISSION; EARLY-TYPE STARS; RESOLVED XMM-NEWTON; MAGNETIC-FIELDS; ETA-CARINAE; MODELS; SYSTEM; ACCELERATION; ABSORPTION; PHOTOMETRY;
D O I
10.1051/0004-6361/202450158
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Context. The long-period O-star binary system HD 168112 and the triple O-star system HD 167971 are well-known sources of non-thermal radio emission that arises from a colliding wind interaction. The wind-wind collisions in these systems should result in phase-dependent X-ray emissions. The presence of a population of relativistic electrons in the wind interaction zone could affect the properties of the X-ray emission and make it deviate from the behaviour expected for adiabatic shocks. Aims. We investigate the X-ray emission of these systems with the goals of quantifying the fraction of the X-ray flux arising from wind interactions and determining whether these emissions follow the predictions for adiabatic wind-wind collisions. Methods. Six X-ray observations were collected with XMM-Newton. Three observations were scheduled around the most recent peri-astron passage of HD 168112. Spectra and light curves were analysed and compared with simple predictions of model calculations for X-ray emission from colliding wind systems. Results. The X-ray emission of HD 168112 varies as the inverse of the orbital separation, as expected for an adiabatic wind interaction zone. The relative contribution of intrinsic X-ray emission from wind-embedded shocks varies between 38% at periastron to 81% at apastron. The wind-wind collision zone remains adiabatic even around periastron passage. The X-ray emission of HD 167971 displays variations on the orbital timescale of the inner eclipsing binary. The existing data of this system do not allow us to probe variations on the timescale of the outer orbit. Conclusions. Shock modification due to the action of relativistic electrons does not seem to be efficiently operating in the HD 168112 system. In the existing observations, a significant part of the emission of HD 167971 must arise in the inner eclipsing binary. The origin of this emission is as yet unclear.
引用
收藏
页数:10
相关论文
共 73 条
[1]   THE DETECTION OF VARIABLE, NONTHERMAL RADIO-EMISSION FROM 2 O-TYPE STARS [J].
ABBOTT, DC ;
BIEGING, JH ;
CHURCHWELL, E .
ASTROPHYSICAL JOURNAL, 1984, 280 (02) :671-678
[2]  
Arnaud KA, 1996, ASTR SOC P, V101, P17
[3]   The Chemical Composition of the Sun [J].
Asplund, Martin ;
Grevesse, Nicolas ;
Sauval, A. Jacques ;
Scott, Pat .
ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, VOL 47, 2009, 47 :481-522
[4]  
Berghfer T. W., 1995, WolfRayet Stars: Binaries, Colliding Winds, Evolution, V163, P382
[5]   The ROSAT all-sky survey catalogue of optically bright OB-type stars [J].
Berghofer, TW ;
Schmitt, JHMM ;
Cassinelli, JP .
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 1996, 118 (03) :481-494
[6]   A SURVEY OF RADIO-EMISSION FROM GALACTIC OB STARS [J].
BIEGING, JH ;
ABBOTT, DC ;
CHURCHWELL, EB .
ASTROPHYSICAL JOURNAL, 1989, 340 (01) :518-536
[7]   Non-thermal radio emission from O-type stars [J].
Blomme, R. ;
De Becker, M. ;
Runacres, M. C. ;
Van Loo, S. ;
Gunawan, D. Y. A. Setia .
ASTRONOMY & ASTROPHYSICS, 2007, 464 (02) :701-U148
[8]   Non-thermal radio emission from Otype stars [J].
Blomme, R ;
Van Loo, S ;
De Becker, M ;
Rauw, G ;
Runacres, MC ;
Gunawan, DYAS ;
Chapman, JM .
ASTRONOMY & ASTROPHYSICS, 2005, 436 (03) :1033-1040
[9]   The 2.35 year itch of Cygnus OB2 #9 II. Radio monitoring [J].
Blomme, R. ;
Naze, Y. ;
Volpi, D. ;
De Becker, M. ;
Prinja, R. K. ;
Pittard, J. M. ;
Parkin, E. R. ;
Absil, O. .
ASTRONOMY & ASTROPHYSICS, 2013, 550
[10]   SURVEY OF INTER-STELLAR H-I FROM L-ALPHA ABSORPTION-MEASUREMENTS .2. [J].
BOHLIN, RC ;
SAVAGE, BD ;
DRAKE, JF .
ASTROPHYSICAL JOURNAL, 1978, 224 (01) :132-142