J/A+A/574/A33 BVRI photometry of high-mass X-ray binaries (Reig+, 2015)
Long-term variability of high-mass X-ray binaries. I. Photometry.
Reig P., Fabregat J.
<Astron. Astrophys. 574, A33 (2015)>
=2015A&A...574A..33R 2015A&A...574A..33R
ADC_Keywords: Binaries, X-ray ; Photometry, UBVRI
Keywords: techniques: photometric - stars: emission line, Be -
stars: neutron - X-rays: binaries
Abstract:
We present photometric observations of the field around the optical
counterparts of high-mass X-ray binaries. Our aim is to study the
long-term photometric variability in correlation with their X-ray
activity and derive a set of secondary standard stars that can be used
for time series analysis. We find that the donors in Be/X-ray binaries
exhibit larger amplitude changes in the magnitudes and colours than
those hosting a supergiant companion. The amplitude of variability
increases with wavelength in Be/X-ray binaries and remains fairly
constant in supergiant systems. When time scales of years are
considered, a good correlation between the X-ray and optical
variability is observed. The X-rays cease when optical brightness
decreases. These results reflect the fact that the circumstellar disk
in Be/X-ray binaries is the main source of both optical and X-ray
variability. We also derive the colour excess, E(B-V), selecting
data at times when the contribution of the circumstellar disk was
supposed to be at minimum, and we revisit the distance estimates.
Description:
The data presented in this work were obtained from the Skinakas
Observatory, located in the island of Crete (Greece). The observations
cover the period 2001-2013. We analysed a total of 45 nights.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 112 20 List of targets
table2.dat 73 20 Average magnitudes and amplitude of variability
of the targets
tablea.dat 113 203 Secondary standards in the field of view of
high-mass X-ray binaries
images/* . 20 Individual finding charts images
--------------------------------------------------------------------------------
See also:
J/AZh/78/408 : Variability of Cyg X-1 in 1994-98 (Karitskaya+, 2001)
J/PAZh/26/27 : Variability of Cyg X-1 (V1357) in 1995-96 (Karitskaya+, 2000)
J/A+A/462/1081 : BVRIJHK light curves of 4U 0115+63/V635 Cas (Reig+, 2007)
J/ApJ/685/436 : X-ray variability in 4U 1636-53 (Altamirano+, 2008)
J/A+A/559/A87 : Hα observations of LSI+61 303 (Zamanov+, 2013)
J/AJ/146/60 : X-ray variability in 4U 1735-44 (Lei+, 2013)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Target X-ray name of the source
18- 29 A12 --- OName Optical name of the source
31- 32 I2 h RAh Right ascension (J2000)
34- 35 I2 min RAm Right ascension (J2000)
37- 40 F4.1 s RAs Right ascension (J2000)
42 A1 --- DE- Declination sign (J2000)
43- 44 I2 deg DEd Declination (J2000)
46- 47 I2 arcmin DEm Declination (J2000)
49- 50 I2 arcsec DEs Declination (J2000)
52- 63 A12 --- SpType Mk spectral type
65- 68 F4.2 mag E(B-V) B-V colour excess
70- 73 F4.2 mag e_E(B-V) rms uncertainty in E(B-V)
75- 78 F4.1 kpc Dist [1.6/10] Distance
80- 82 F3.1 kpc e_Dist [0.4/2.5] rms uncertainty on Dist
84- 86 A3 --- dloss [yes no] disk loss ?
88- 92 A5 --- XR X-ray outburst (I, II or flare)
94-112 A19 --- FileName Name of the file with the finding charts
image in subdirectory "images"
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Target X-ray name of the target
18- 22 F5.2 mag Bmag [9.7/22.2] Mean Johnson B magnitude
24- 28 F5.2 mag Vmag [9.2/19.5] Mean Johnson V magnitude
30- 34 F5.2 mag Rmag [8.7/17.4] Mean Cousins R magnitude
36- 40 F5.2 mag Imag [8.3/15.2] Mean Cousins I magnitude
42- 45 F4.2 mag Bamp [0/0.7] Amplitude of variation in B magnitude (1)
46 A1 --- u_Bamp [+] Uncertainty flag on Bamp (2)
48- 51 F4.2 mag Vamp [0/0.9] Amplitude of variation in V magnitude (1)
53- 56 F4.2 mag Ramp [0/1.1] Amplitude of variation in R magnitude (1)
58- 61 F4.2 mag Iamp [0/1.1] Amplitude of variation in I magnitude (1)
63- 64 I2 --- o_Bmag [6/28] Number of observations in B band
66- 67 I2 --- o_Vmag [6/28] Number of observations in V band
69- 70 I2 --- o_Rmag [6/28] Number of observations in R band
72- 73 I2 --- o_Imag [6/23] Number of observations in I band
--------------------------------------------------------------------------------
Note (1): Difference between the largest and smallest measured magnitudes
Note (2): +: Affected by a large uncertainty due to the faintness of the
source in this band.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Target Target X-ray name
18- 20 A3 --- Star Secondary star name (CNN, within the Target)
22- 24 I3 --- ID [2/228] Identification number within the Target
26- 27 I2 h RAh Right ascension (J2000)
29- 30 I2 min RAm Right ascension (J2000)
32- 35 F4.1 s RAs Right ascension (J2000)
37 A1 --- DE- Declination sign (J2000)
38- 39 I2 deg DEd Declination (J2000)
41- 42 I2 arcmin DEm Declination (J2000)
44- 45 I2 arcsec DEs Declination (J2000)
47- 49 F3.1 arcmin d [0/6.2] Angular distance between the star
and the target
51- 56 F6.3 mag Bmag [10.2/18.9] Mean Johnson B magnitude
58- 63 F6.3 mag Vmag [10.0/17.2] Mean Johnson V magnitude
65- 70 F6.3 mag Rmag [9.9/16.4] Mean Cousins R magnitude
72- 77 F6.3 mag Imag [9.8/15.7] Mean Cousins I magnitude
79- 83 F5.3 mag e_Bmag [0/0.03] Standard deviation on B magnitude (1)
85- 89 F5.3 mag e_Vmag [0/0.03] Standard deviation on V magnitude (1)
91- 95 F5.3 mag e_Rmag [0/0.03] Standard deviation on R magnitude (1)
97-101 F5.3 mag e_Imag [0/0.03] Standard deviation on I magnitude (1)
103-104 I2 --- o_Bmag [5/28] Number of observations in B band
106-107 I2 --- o_Vmag [5/28] Number of observations in V band
109-110 I2 --- o_Rmag [5/28] Number of observations in R band
112-113 I2 --- o_Imag [5/25] Number of observations in I band
--------------------------------------------------------------------------------
Note (1): calculated from Eq.(4) of the paper (σmean=σ/sqrt(N))
--------------------------------------------------------------------------------
Acknowledgements:
Pablo Reig, pau(at)physics.uoc.gr
(End) Patricia Vannier [CDS] 27-Nov-2014