On the origin of 4640-4650 A emission in X-ray stars

McClintock, J.E.; Canizares, C. R.; Tarter, C. Bruce

doi:10.1086/153642

Cited by 67 publications

(53 citation statements)

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“…The Doppler analysis of the Bowen blend is complicated by the merging of many C iii, N iii, and O ii transitions (see, e.g., McClintock, Canizares, & Tarter 1975). The most prominent component is N iii 4640.64, for which we have also computed a tomogram.…”

Section: No 2 2003 Bowen Fluorescence In X1822à371mentioning

confidence: 99%

Bowen Fluorescence from the Companion Star in X1822−371

Casares

Steeghs

Hynes

et al. 2003

ApJ

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We present clear evidence for the motion of the companion star in the low-mass X-ray binary (LMXB) X1822À371. We detect N iii 4640 emission moving in antiphase with the radial velocity curve of the neutron star and produced on the X-ray-heated hemisphere of the donor star. From the motion of this feature we derive a lower limit to the radial velocity semiamplitude of the companion star, K 2 ! 300 AE 8 km s À1 , which, combined with a previous determination of the inclination angle and the pulsar's radial velocity curve, yields M 2 ! 0:36 2 ð Þ M and M 1 ! 1:14 6 ð Þ M . The He i 4471 absorption line moves at lower velocities ('225 km s À1 ) and with a À0.05 phase shift, suggesting a likely origin on the gas stream near the L1 point. In addition, we detect an S-wave emission of O vi 3811 produced by illumination of the hot spot bulge by the central source. The Balmer lines are dominated by broad absorptions probably due to obscuration of the accretion disk by vertically extended cool material from the splash region and overflowing stream. We also derive a more accurate, and significantly different (compared to earlier work), systemic velocity of ¼ À44 AE 5 km s À1 , based on the motion of the He ii 4686 wings and Doppler tomography. This work confirms the power of imaging the companion stars in LMXBs and outbursting transients using the Bowen fluorescence transitions.

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Section: No 2 2003 Bowen Fluorescence In X1822à371mentioning

confidence: 99%

Bowen Fluorescence from the Companion Star in X1822−371

Casares

Steeghs

Hynes

et al. 2003

ApJ

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“…A common feature of the spectra of X-ray binaries is the Bowen blend, a mixture predominantly of N  and C  lines spanning ∼4635-4650 (McClintock et al 1975). This feature does also appear to be seen in CI Cam, but can only be discerned in the WHT/UES outburst spectra.…”

Section: The Bowen Blendmentioning

confidence: 99%

Spectroscopic observations of the candidate sgB[e]/X-ray binary CI Camelopardalis

Hynes

Clark

Barsukova

et al. 2002

A&A

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Abstract. We present a compilation of spectroscopic observations of the sgB[e] star CI Cam, the optical counterpart of XTE J0421+560. This includes data from before, during, and after its 1998 outburst, with quantitative results spanning 37 years. The object shows a rich emission line spectrum originating from circumstellar material, rendering it difficult to determine the nature of either star involved or the cause of the outburst. We collate all available pre-outburst data to determine the state of the system before this occurred and provide a baseline for comparison with outburst and post-outburst data. During the outburst all lines become stronger, and hydrogen and helium lines become significantly broader and asymmetric. After the outburst, spectral changes persist for at least three years, with Fe  and [N ] lines still a factor of ∼2 above the pre-outburst level and He , He , and N  lines suppressed by a factor of 2-10. We find that the spectral properties of CI Cam are similar to other sgB[e] stars and therefore suggest that the geometry of the circumstellar material is similar to that proposed for the other objects: a two component outflow, with a fast, hot, rarefied polar wind indistinguishable from that of a normal supergiant and a dense, cooler equatorial outflow with a much lower velocity. Based on a comparison of the properties of CI Cam with the other sgB[e] stars we suggest that CI Cam is among the hotter members of the class and is viewed nearly pole-on. The nature of the compact object and the mechanism for the outburst remain uncertain, although it is likely that the compact object is a black hole or neutron star, and that the outburst was precipitated by its passage through the equatorial material. We suggest that this prompted a burst of supercritical accretion resulting in ejection of much of the material, which was later seen as an expanding radio remnant. The enhanced outburst emission most likely originated either directly from this supercritical accretion, or from the interaction of the expanding remnant with the equatorial material, or from a combination of both mechanisms.

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“…HeII k4686, CIII/NIII kk4640-50, and their flux is well correlated with L X . Bowen fluorescence was proposed to explain the enhanced NIII emission (McClintock et al, 1975), a mechanism subsequently confirmed by the detection of OIII cascades in Her X-1 (Margon and Cohen, 1978) and Sco X-1 (Schachter et al, 1989; Fig. 1).…”

Section: Introductionmentioning

confidence: 86%

Fundamental parameters of low mass X-ray binaries II: X-ray persistent systems

Casares

Charles

2006

Advances in Space Research

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The determination of fundamental parameters in X-ray luminous (persistent) X-ray binaries has been classically hampered by the large optical luminosity of the accretion disc. New methods, based on irradiation of the donor star and burst oscillations, provide the opportunity to derive dynamical information and mass constraints in many persistent systems for the first time. These techniques are here reviewed and the latest results presented.

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On the origin of 4640-4650 A emission in X-ray stars

Cited by 67 publications

References 0 publications

Bowen Fluorescence from the Companion Star in X1822−371

Bowen Fluorescence from the Companion Star in X1822−371

Spectroscopic observations of the candidate sgB[e]/X-ray binary CI Camelopardalis

Fundamental parameters of low mass X-ray binaries II: X-ray persistent systems

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