Analysis of<i>RXTE</i>-PCA Observations of SMC X-1

İnam, S. Ç.; Baykal, A.; Beklen, E.

doi:10.1111/j.1365-2966.2009.16121.x

Cited by 16 publications

(17 citation statements)

References 31 publications

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“…We find that a sin i/c, e, and Ω are not well constrained compared to several pointed observations (see, e.g., Raichur & Paul 2010). Moreover, their values are not consistent with each other from different measurements (İnam et al 2010;Raichur & Paul 2010). This could be caused by the variability of the pulse profile (Raichur & Paul 2010).…”

Section: Spin-superorbital Connectioncontrasting

confidence: 79%

“…It is interpreted as the reprocessing of X-rays from the accretion disk (Hickox & Vrtilek 2005). Since 1997, SMC X-1 has been well monitored with several X-ray instruments, and the most frequent monitoring was carried out with RXTE between 1996 and 2000 (Henry & Schreier 1977;Inam et al 2010). The full history of the pulse frequency evolution of SMC X-1 up to MJD 52987 (2003 December 14) is reported byİnam et al (2010).…”

Section: Introductionmentioning

confidence: 89%

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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: Spin-superorbital Connectioncontrasting

confidence: 79%

Section: Introductionmentioning

confidence: 89%

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

Mihara

Sugizaki

et al. 2019

ApJ

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“…The variation of the n H value may be due to the partial obscuration of the neutron star by the precessing accretion disk or X-ray eclipses. Another possibility for the variation may be an artifact of simple POWERLAW model or the tails of the soft excess components affecting our result (Inam et al 2010). The photoelectric absorption by the interstellar matter is dominated in lower energy range but as we can't go below 3 keV energy due to the limitation of our instrument, its not possible to constraint the n H value precisely.…”

Section: Pulse Profile Hardness Ratio and The Energy Spectramentioning

confidence: 93%

A report on Type II X-ray bursts from SMC X-1

Rai

Pradhan

Paul

2018

Res. Astron. Astrophys.

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We study RXTE PCA data for the high mass X-ray binary source SMC X-1 between 2003-10 and 2003-12 when the source was in high states. The source is found to be frequently bursting which can be seen as flares in lightcurves on an average of one in every 800 s, with an average of 4-5 X-ray burst per hour of type II. We note that typically burst was short lasting for few tens of seconds in addition few long bursts of more than hundred seconds were also observed. The flares apparently occupied 2.5% of the total observing time of 225.5 ks. We note a total of 272 flares with mean FWHM of the flare ∽21 s. The rms variability and the aperiodic variability are independent of flares. As observed the pulse profiles of the lightcurves do not change its shape implying that there is no change in the geometry of accretion disk due to burst. The hardness ratio and the rms variability of lightcurves show no correlation with the flares. The flare-fraction shows a positive correlation with the peak-topeak ratio of the primary and secondary peaks of the pulse profile. The observed hardening or the softening of the spectrum cannot be correlated with the flaring rate but may be due to the interstellar absorption of X-rays as evident from the change in the hydrogen column density (n H ). It is found that the luminosity of the source increases with the flaring rate. Considering the viscous timescale equal to mean recurrence time of flares we fixed the viscosity parameter α ∽ 0.16.

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“…All these systems show evidence for alternate spin-up and spin-down phases. In some cases the average spin evolution led to an effective long-term increase or decrease of the NS spin rate (see e.g., Bildsten et al 1997;Inam et al 2010, for more details), and thus the spin periods reported in Table 1 should only be considered as indicative. The spin period of the NS (possibly) hosted in 4U1700-377 is currently unknown.…”

Section: Ten Eclipsing Hmxbsmentioning

confidence: 99%

“…(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

179

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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Analysis ofRXTE-PCA Observations of SMC X-1

Cited by 16 publications

References 31 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

A report on Type II X-ray bursts from SMC X-1

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

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