Effect of pulse profile variations on measurement of eccentricity in orbits of Cen X-3 and SMC X-1

Raichur, Harsha; Paul, Biswajit

doi:10.1111/j.1365-2966.2009.15778.x

Cited by 40 publications

(61 citation statements)

References 33 publications

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“…All ephemerides seem to describe the data well, except for the MAXI observations. Our updated model is consistent with the ephemeris proposed by Raichur & Paul (2010) at a 1σ level but deviates from that proposed by Wojdowski et al (1998) and Falanga et al (2015).…”

Section: Refinement Of the Orbital Ephemerissupporting

confidence: 78%

Monitoring the Superorbital Period Variation and Spin Period Evolution of SMC X-1

Mihara

Sugizaki

et al. 2019

ApJ

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The X-ray pulsar SMC X-1 shows a superorbital modulation with an unstable cycle length in the Xray band. We present its timing behaviors, including the spin, orbital, and superorbital modulations, beyond the end of the Rossi X-ray Timing Explorer mission. The time-frequency maps derived by the wavelet Z-transform and the Hilbert-Huang transform suggest that a new superorbital period excursion event occurred in ∼MJD 57100 (2015 March). This indicates the excursion is recurrent and probably (quasi)periodic. The hardness ratio obtained with the Monitor of All-sky X-ray Image (MAXI) suggests increased absorption during the transition from the high to the low state in the superorbital cycle. Compared to the regular epochs, the superorbital profile during the excursion epochs has a shallower and narrower valley, likely caused by a flatter warp. By tracking the spin period evolution with the MAXI Gas Slit Camera in 2-20 keV, we derive an averaged spin-up rate oḟ ν = 2.515(3) × 10 −11 s −2 during the period between MJD 55141 (2009 November) and 58526 (2019 February). We obtain no positive correlation between the spin frequency residual and the superorbital frequency, but a torque change accompanying the superorbital period excursion is possible. We suggest that the accretion torque on the neutron star could be changed by various mechanisms, including the change of mass accretion rate and the warp angle. We update the value of the orbital decay aṡ P orb /P orb = −3.380(6) × 10 −6 yr −1 . Finally, we reconfirm the detection of the superorbital modulation in the optical band and its coherence in phase with the X-ray modulation.

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Section: Refinement Of the Orbital Ephemerissupporting

confidence: 78%

Monitoring the Superorbital Period Variation and Spin Period Evolution of SMC X-1

Mihara

Sugizaki

et al. 2019

ApJ

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“…(2003); 25 Galloway, Morgan & Levine (2004); 26 Wilson, Finger & Camero‐Arranz (2008); 27 Baykal et al. (2007); 28 Raichur & Paul (2010a); 29 Grundstrom et al. (2007); 30 Levine (1991), van der Meer et al.…”

Section: Discussionmentioning

confidence: 99%

“…(2007); 31 Kreykenbohm et al. (2008); 32 Raichur & Paul (2010a); 33 Ray & Chakrabarty (2002); 34 Koh et al. (1997); 35 Clark (2000); 36 Thompson et al.…”

Section: Discussionmentioning

confidence: 99%

On the orbital parameters of Be/X-ray binaries in the Small Magellanic Cloud

Townsend¹,

Coe²,

Corbet³

et al. 2011

Monthly Notices of the Royal Astronomical Society

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The orbital motion of a neutron star about its optical companion presents a window through which we can study the orbital parameters of that binary system. This has been used extensively in the Milky Way to calculate these parameters for several high‐mass X‐ray binaries. Using several years of Rossi X‐ray Timing Explorer Proportional Counter Array data, we derive the orbital parameters of four Be/X‐ray binary systems in the Small Magellanic Cloud (SMC), increasing the number of systems with orbital solutions by a factor of 3. We find one new orbital period, confirm a second and discuss the parameters with comparison to the Galactic systems. Despite the low metallicity in the SMC, these binary systems sit amongst the Galactic distribution of orbital periods and eccentricities, suggesting that metallicity may not play an important role in the evolution of high‐mass X‐ray binary systems. A plot of orbital period against eccentricity shows that the supergiant, Be and low‐eccentricity OB transient systems occupy separate regions of the parameter space; akin to the separated regions on the Corbet diagram. Using a Spearman’s rank correlation test, we also find a possible correlation between the two parameters. The mass functions, inclinations and orbital semimajor axes are derived for the SMC systems based on the binary parameters and the spectral classification of the optical counterpart. As a by‐product of our work, we present a catalogue of the orbital parameters for every high‐mass X‐ray binary in the Galaxy and Magellanic Clouds for which they are known.

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“…(a) Levine et al (2000), Bildsten et al (1997) but see also Naik & Paul (2004); (b) Bildsten et al (1997), Raichur & Paul (2010b); (c) Rubin et al (1996), Hammerschlag-Hensberge et al (2003); (d) Mukherjee et al (2006), Clark (2000); (e) Inam et al (2010), Raichur & Paul (2010b); ( f ) (a.k.a. IGR J18027-2016) Hill et al (2005); (g) Corbet & Mukai (2002); (h) (a.k.a.…”

Section: Introductionmentioning

confidence: 99%

Ephemeris, orbital decay, and masses of ten eclipsing high-mass X-ray binaries

Falanga

Bozzo

Lutovinov

et al. 2015

A&A

188

265

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We update the ephemeris of the eclipsing high-mass X-ray binary (HMXB) systems LMC X-4, Cen X-3, 4U 1700-377, 4U 1538-522, SMC X-1, IGR J18027-2016, Vela X-1,IGR J17252-3616, XTE J1855-026, and OAO 1657-415 with the help of more than ten years of monitoring these sources with the All Sky Monitor onboard RXTE and with the Integral Soft Gamma-Ray Imager onboard INTEGRAL. These results are used to refine previous measurements of the orbital period decay of all sources (where available) and provide the first accurate values of the apsidal advance in Vela X-1 and 4U 1538-522. Updated values for the masses of the neutron stars hosted in the ten HMXBs are also provided, as well as the long-term light curves folded on the best determined orbital parameters of the sources. These light curves reveal complex eclipse ingresses and egresses that are understood mostly as being caused by accretion wakes. Our results constitute a database to be used for population and evolutionary studies of HMXBs and for theoretical modeling of long-term accretion in wind-fed X-ray binaries.

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Effect of pulse profile variations on measurement of eccentricity in orbits of Cen X-3 and SMC X-1

Cited by 40 publications

References 33 publications

Monitoring the Superorbital Period Variation and Spin Period Evolution of SMC X-1

Monitoring the Superorbital Period Variation and Spin Period Evolution of SMC X-1

On the orbital parameters of Be/X-ray binaries in the Small Magellanic Cloud

Ephemeris, orbital decay, and masses of ten eclipsing high-mass X-ray binaries

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