2001A&A...376..476C


Query : 2001A&A...376..476C

2001A&A...376..476C - Astronomy and Astrophysics, volume 376, 476-483 (2001/9-3)

On the radio emitting high mass X-ray binary LS 5039.

CLARK J.S., REIG P., GOODWIN S.P., LARIONOV V.M., BLAY P., COE M.J., FABREGAT J., NEGUERUELA I., PAPADAKIS I. and STEELE I.A.

Abstract (from CDS):

We present new optical - near-IR spectroscopic and photometric observations of the newly discovered galactic microquasar LS 5039, which indicate a classification for the mass donor in the system of O6.5V((f)). Optical spectroscopy and photometry shows no variability over a timescale of years, and we find no evidence of modulation by, or emission from the compact companion in these data. However significant photometric variability (∼0.4mag) is present in the H and K bands between 1995-2000. Such variability has been observed in other radio bright X-ray binaries where it has been attributed to synchrotron emission from the jet. However, given the non-thermal spectral index of the radio emission in LS 5039 this explanation appears unlikely, predicting a near-IR flux ∼3 orders of magnitude too small to contribute significantly at such wavelengths. Nightly optical photometry over a 21 day period between 2000 May-June reveals variability at a level of a few hundredths of a magnitude, with no periodicity or long term trend visible. Likewise, while the radio lightcurves show moderate variability (∼20 per cent of the mean flux density) we find no evidence of periodic modulation - Monte Carlo simulations constrain any such periodic variability to <4 per cent modulation at 2.25GHz. The differences in behaviour between LS 5039 and Cygnus X-1 - the most closely related radio emitting High Mass X-ray Binary - are likely to be a result of the weaker stellar wind and probable greater orbital separation of LS 5039 compared to Cyg X-1.

Abstract Copyright:

Journal keyword(s): stars: early-type - stars: individual: LS 5039 - X-rays: stars, binaries

Simbad objects: 9

goto Full paper

goto View the references in ADS

Number of rows : 9
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 LS I +61 303 HXB 02 40 31.6641883136 +61 13 45.591138110 11.27 11.61 10.75 10.19 9.55 B0Ve 781 2
2 V* CI Cam HXB 04 19 42.1353986687 +55 59 57.708146070 12.13 12.41 11.77 10.79 9.99 B0/2I[e] 228 0
3 * 15 Mon Be* 06 40 58.65963 +09 53 44.7229 3.360 4.400 4.640   4.88 O7V+B1.5/2V 761 0
4 HD 101190 ** 11 38 09.9112605648 -63 11 48.613340265 6.58 7.37 7.33 8.48   O6IV((f)) 156 0
5 V* V479 Sct HXB 18 26 15.0561532140 -14 50 54.249464136 12.02 12.23 11.27 11.04   ON6V((f))z 510 2
6 * lam Aql PM* 19 06 14.9397099975 -04 52 57.231496924 3.07 3.34 3.43 3.46 3.55 B8.5V 213 0
7 SS 433 HXB 19 11 49.5645897700 +04 58 57.824087535   16.3 13.0     A7Ib: 1979 4
8 HD 226868 HXB 19 58 21.6758193269 +35 12 05.782512305 9.38 9.72 8.91 8.42   O9.7Iabpvar 4022 0
9 V* V1521 Cyg HXB 20 32 25.78 +40 57 27.9           WN4/5-6/7 1820 2

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2001A&A...376..476C and select 'bookmark this link' or equivalent in the popup menu


2021.07.30-03:34:51

© Université de Strasbourg/CNRS

    • Contact