J/ApJ/871/244 Times of X-ray minima & orbit numbers of Cyg X-3 (Antokhin+, 2019)
The period change of Cyg X-3.
Antokhin I.I., Cherepashchuk A.M.
<Astrophys. J., 871, 244 (2019)>
=2019ApJ...871..244A 2019ApJ...871..244A
ADC_Keywords: Binaries, X-ray; References
Keywords: accretion, accretion disks; binaries: close;
stars: individual (Cyg X-3) ; X-rays: binaries
Abstract:
By using available archival X-ray data, we significantly extended the
list of times of X-ray minima. The new list includes 65 data points
obtained by critically reanalyzing RXTE ASM data, 88 data points based
on observations by MAXI, and 2 data points based on observations by
SUZAKU and AstroSat. Analyzing the data along with times of X-ray
minima available from the literature, we provide the most accurate
estimate of the rate of period change to date. We do not confirm the
existence of a second derivative of the orbital period suggested by
some authors earlier. Instead, we find that the changes in the period
can be fit by a sum of quadratic and sinusoidal functions. The period
of sinusoidal variations is 15.79yr. They can be related either to
apsidal motion in the close binary with eccentricity e∼0.03 or to the
presence of a third body with a mass of about 0.7M☉ located at a
distance ∼16 au from the close binary.
Description:
The RXTE/ASM (Rossi X-Ray Timing Explorer/All-Sky Monitor) light curve
in the total energy range 1.3-12keV was downloaded from the RXTE Guest
Observer Facility provided by HEASARC. The total number of data points
was 97996, covering the period from 1996 January to 2011 December.
Cyg X-3 was also observed by SUZAKU in 2006 November for about 50hr.
Three XIS (X-ray Imaging Spectrometers) instruments (XI0, XI1, and
XI3) covering the energy range 0.2-12keV were combined to obtain the
light curve data (621 measurements).
We downloaded GSC (Gas Slit Camera) SCAN data for Cyg X-3 from the
MAXI (Monitor of All-sky X-ray Image) website. The data cover the
period from 2009 August 15 to 2018 March 24, with 25042 measurements
in total. To study the period change and long-term variability, we
used the data for the total band 2-20keV.
Cyg X-3 was observed by AstroSat for 1.5 days in 2015 November. The
useful data were obtained by the SXT instrument, the energy range is
0.3-8keV for 192 measurements.
Objects:
-------------------------------------------------------------------
RA (ICRS) DE Designation(s) (Period)
-------------------------------------------------------------------
20 32 25.78 +40 57 27.9 Cyg X-3 = V* V1521 Cyg (P=0.19968)
-------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 26 270 Times of X-ray minima and orbit numbers
--------------------------------------------------------------------------------
See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
IX/28 : ROSAT HRI Pointed Observations (1RXH) (ROSAT Team, 2000)
VI/117 : Observation Log from ASCA (PLAIN Center, 2001)
V/106 : Catalogue of X-ray binaries (Liu+ 2001)
J/ApJS/96/303 : Calibrating Broad Band X-ray Telescope (Weaver+ 1995)
J/ApJS/151/299 : Spectra classification from ISO PHT-S database (Hodge+, 2004)
J/ApJ/649/L9 : INTEGRAL IBIS census of the sky >100keV (Bazzano+, 2006)
J/A+A/467/585 : Sources detected by ISGRI (Bodaghee+, 2007)
J/A+A/480/611 : XMM-Newton Slew Survey catalogue, XMMSL1 (Saxton+, 2008)
J/MNRAS/406/307 : Radio variations of Cygnus X-3 (Koljonen+, 2010)
J/A+A/522/A68 : Variable sources detected by INTEGRAL (Telezhinsky+, 2010)
J/BaltA/24/395 : X-ray and radio sources in binaries (Malkov+, 2015)
J/ApJS/222/15 : WATCHDOG all-sky database of Gal. BHXBs (Tetarenko+, 2016)
J/ApJS/223/15 : 8yr INTEGRAL/IBIS soft gamma-ray source obs. (Bird+, 2016)
J/ApJS/235/4 : The 105-month Swift-BAT all-sky hard X-ray survey (Oh+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.4 d MJD [40949.42/58179.4] Modified Julian Date (1)
12- 17 F6.4 d e_MJD [0.0005/0.02] Error in MJD
19- 23 I5 --- Num [0/86284] Orbit number
25- 26 I2 --- Ref [1/13] Reference number (2)
--------------------------------------------------------------------------------
Note (1): The original paper contained typographic errors in the
MJD values of lines 1, 5 in this table. It was corrected by
Elsner+ (1980ApJ...239..335E 1980ApJ...239..335E).
Note (2): Reference as follows:
1 = Leach et al. (1975ApJ...199..184L 1975ApJ...199..184L);
2 = Mason & Sanford (1979MNRAS.189....9M 1979MNRAS.189....9M);
3 = Parsignault et al. (1976ApJ...209L..73P 1976ApJ...209L..73P);
4 = Manzo, Molteni, & Robba (1978A&A....70..317M 1978A&A....70..317M);
5 = Lamb, Dower, & Fickle (1979ApJ...229L..19L 1979ApJ...229L..19L);
6 = Elsner et al. (1980ApJ...239..335E 1980ApJ...239..335E);
7 = van der Klis & Bonnet-Bidaud (1981A&A....95L...5V 1981A&A....95L...5V);
8 = van der Klis & Bonnet-Bidaud (1989A&A...214..203V 1989A&A...214..203V);
9 = Kitamoto et al. (1987PASJ...39..259K 1987PASJ...39..259K);
10 = Kitamoto et al. (1992ApJ...384..263K 1992ApJ...384..263K);
11 = Kitamoto et al. (1995PASJ...47..233K 1995PASJ...47..233K);
12 = Singh et al. (2002A&A...392..161S 2002A&A...392..161S);
13 = Current study.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Jul-2020