X‐Ray and Ultraviolet Orbital Phase Dependence in LMC X‐3

Boyd, Patricia T.; Smale, A. P.; Dolan, J. F.

doi:10.1086/321511

Cited by 12 publications

(11 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The orbital X-ray flux changes are smaller (Boyd, Smale, & Dolan 2001). Thus, the indicated large flux range reported here in the far-FUV has not been seen at other wavelengths.…”

Section: Discussioncontrasting

confidence: 51%

Far Ultraviolet Spectroscopic ExplorerSpectra of the Black Hole Binary LMC X-3

et al. 2003

View full text Add to dashboard Cite

Far-ultraviolet spectra of LMC X-3 were taken covering photometric phases 0.47-0.74 in the 1.7 day orbital period of the black hole binary (phase zero being superior conjunction of the X-ray source). The continuum is faint and flat but appears to vary significantly during the observations. Concurrent RXTE/ASM observations show the system was in its most luminous X-ray state during the Far Ultraviolet Spectroscopic Explorer (FUSE) observations. The far-UV spectrum contains strong terrestrial airglow emission lines, while the only stellar lines clearly present are emissions from the O vi resonance doublet. Their flux does not change significantly during the FUSE observations. These lines are modeled as two asymmetric profiles, including the local ISM absorptions due to C ii and possibly O vi. Velocity variations of O vi emission are consistent with the orbital velocity of the black hole and provide a new constraint on its mass.

show abstract

“…The orbital X-ray flux changes are smaller (Boyd, Smale, & Dolan 2001). Thus, the indicated large flux range reported here in the far-FUV has not been seen at other wavelengths.…”

Section: Discussioncontrasting

confidence: 51%

Far Ultraviolet Spectroscopic ExplorerSpectra of the Black Hole Binary LMC X-3

et al. 2003

View full text Add to dashboard Cite

show abstract

“…Patterson et al (2005, and references therein) reports that cataclysmic binaries exhibit superhumps with periodicity a few percent higher than the orbital period provided the mass ratio q = M 2 /M 1 < 0.3 (where, M 2 and M 1 are the companion mass and the compact mass respectively). Boyd, Smale and Dolan (2001) find X-ray modulation in LMC X-3 at the known orbital period of 1.7 days. Brocksopp et al (1999a) find a similar modulation in Cyg X-1.…”

mentioning

confidence: 71%

Smearing of mass accretion rate variation by viscous processes in accretion disks in compact binary systems

Ghosh

Chakrabarti

2016

Astrophys Space Sci

View full text Add to dashboard Cite

Variation of mass supply rate from the companion can be smeared out by viscous processes inside an accretion disk. Hence, by the time the flow reaches the inner edge, the variation in X-rays need not reflect the true variation of the mass supply rate at the outer edge. However, if the viscosity fluctuates around a mean value, one would expect the viscous time scale t visc also to spread around a mean value. In high mass X-ray binaries, which are thought to be primarily windfed, the size of the viscous Keplerian disk is smaller and thus such a spread could be lower as compared to the low mass X-ray binaries which are primarily fed by Roche lobe overflow. If there is an increasing or decreasing trend in viscosity, the interval between enhanced emission would be modified systematically. In the absence of a detailed knowledge about the variation of mass supply rates at the outer edge, we study ideal circumstances where modulation must take place exactly in orbital time scales, such as when there is an ellipticity in the orbit. We study a few compact binaries using long term All Sky monitor (ASM) data (1.5-12 keV) of Rossi X-ray Timing Explorer (RXTE) and all sky survey data (15-50 keV) of Swift satellites by different methods to look for such smearing effects and to infer what these results can tell us about the viscous processes inside the respective disks. We employ three different methods to seek imprints of periodicity on the X-ray variation and found that in all the cases, the location of the peak in the power density spectra is consistent with the orbital frequencies. Interestingly, in high mass X-ray binaries the peaks are sharp with high rms values, consistent with a small Keplerian disk in a wind fed system. However, in low mass X-ray binaries with larger Keplerian disk component, the peaks are spreaded out with much lower rms values. X-ray reflections, or superhump phenomena which may also cause such X-ray modulations would not be affected by the size of the Keplerian disk component. Our result thus confirms different sizes of Keplerian disks in these two important classes of binaries. If the orbital period of any binary system is not known, it may be obtained with reasonable accuracy for HMXBs and with lesser accuracy for LMXBs by our method.

show abstract

“…If the observed variability of Source 2 really reflects an orbital effect, the phase-dependent spectral changes may be caused, e.g., by an orbital modulation in the mass accreting rate, or eclipses of the inner disk. Actually, based on a 6.4-day observation with RXTE, Boyd et al (2001) report on a clear high-energy X-ray modulation in LMC X-3 synchronized with its 1.7-day orbital period.…”

Section: Discussionmentioning

confidence: 99%

A Possible X-Ray Periodicity at Several Tens of Hours of an Ultraluminous Compact X-Ray Source in IC 342

Sugiho

Kotoku

Makishima

et al. 2001

The Astrophysical Journal

View full text Add to dashboard Cite

A long (155 hours) ASCA observation was performed of two ultra luminous compact X-ray sources, Source 1 and Source 2, in the spiral galaxy IC 342. While Source 1 that was in a hard spectral state varied little, Source 2 that was in its soft spectral state varied significantly on a time scale of about one day. The rms variation amplitude amounts to 5% in the 2-10 keV band, but is less than 4% in 0.7-2 keV. The variation involves statistically significant changes in the parameters describing multi-color disk blackbody emission from this source. The variation is possibly periodic, with a period of either 31 ± 2 hours or 41 ± 3 hours. Both are consistent with the orbital period of a semi-detached binary formed by a black hole and a main-sequence star of several tens solar masses. These results reinforce the interpretation of these X-ray objects in terms of accreting massive stellar black holes.

show abstract

X‐Ray and Ultraviolet Orbital Phase Dependence in LMC X‐3

Cited by 12 publications

References 22 publications

Far Ultraviolet Spectroscopic ExplorerSpectra of the Black Hole Binary LMC X-3

Far Ultraviolet Spectroscopic ExplorerSpectra of the Black Hole Binary LMC X-3

Smearing of mass accretion rate variation by viscous processes in accretion disks in compact binary systems

A Possible X-Ray Periodicity at Several Tens of Hours of an Ultraluminous Compact X-Ray Source in IC 342

Contact Info

Product

Resources

About