S. Matz, D. Grabelsky, W. Purcell, M. Ulmer, W. Johnson, R. Kinzer, J. Kurfess, M. Strickman
The OSSE instrument on the Compton Gamma‐Ray Observatory (GRO) made 4 observations of Cygnus X–3 between May 1991 and December 1992. OSSE observed a substantial change in the average hard x‐ray flux, which has previously been observed to be stable (variations <20%). Over a 2–3 day period the flux above ∼50 keV decreased by roughly a factor of 3. This occurred about 15 days prior to a large radio flare from this source. OSSE detected by 4.8 hr period and observed significant orbital modulation of the hard x‐ray (≳50 keV) flux, in conflict with some extrapolations from lower energies. The spectrum in the high state is consistent with a power law, ∝E−3.0.
{"title":"Hard x‐ray variability of Cygnus X–3","authors":"S. Matz, D. Grabelsky, W. Purcell, M. Ulmer, W. Johnson, R. Kinzer, J. Kurfess, M. Strickman","doi":"10.1063/1.46020","DOIUrl":"https://doi.org/10.1063/1.46020","url":null,"abstract":"The OSSE instrument on the Compton Gamma‐Ray Observatory (GRO) made 4 observations of Cygnus X–3 between May 1991 and December 1992. OSSE observed a substantial change in the average hard x‐ray flux, which has previously been observed to be stable (variations <20%). Over a 2–3 day period the flux above ∼50 keV decreased by roughly a factor of 3. This occurred about 15 days prior to a large radio flare from this source. OSSE detected by 4.8 hr period and observed significant orbital modulation of the hard x‐ray (≳50 keV) flux, in conflict with some extrapolations from lower energies. The spectrum in the high state is consistent with a power law, ∝E−3.0.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126129980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Paciesas, Michael S. Briggs, G. Pendleton, B. A. Harmon, C. Wilson, Shuang-Nan Zhang, G. Fishman
The Compton Burst and Transient Source Experiment (BATSE) detected hard x‐ray flux from Nova Muscae 1991 (GS/GRS 1124–68) during an interval of ∼100 days beginning ∼130 days after the January 1991 main outburst. The light curve during this secondary outburst is roughly symmetric, reaching a maximum around mid‐July 1991 at an intensity of ∼15% of the peak intensity during the main outburst. The hard x‐ray spectrum displays a soft‐to‐hard evolution during the rise to maximum; the post‐maximum spectral evolution is less well determined. We compare our observations with those of the GRANAT/SIGMA experiment, which covered the initial outburst well but missed most of the secondary outburst.
{"title":"BATSE observations of Nova Muscae 1991","authors":"W. Paciesas, Michael S. Briggs, G. Pendleton, B. A. Harmon, C. Wilson, Shuang-Nan Zhang, G. Fishman","doi":"10.1063/1.46028","DOIUrl":"https://doi.org/10.1063/1.46028","url":null,"abstract":"The Compton Burst and Transient Source Experiment (BATSE) detected hard x‐ray flux from Nova Muscae 1991 (GS/GRS 1124–68) during an interval of ∼100 days beginning ∼130 days after the January 1991 main outburst. The light curve during this secondary outburst is roughly symmetric, reaching a maximum around mid‐July 1991 at an intensity of ∼15% of the peak intensity during the main outburst. The hard x‐ray spectrum displays a soft‐to‐hard evolution during the rise to maximum; the post‐maximum spectral evolution is less well determined. We compare our observations with those of the GRANAT/SIGMA experiment, which covered the initial outburst well but missed most of the secondary outburst.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129638373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The sign and magnitude of the orbital period derivative are perhaps the most critical diagnostics of the evolution of low mass x‐ray binaries (LMXBs). However ≲4 LMBXs have measured orbital period derivatives. One of these is the eclipsing x‐ray binary EXO0748‐676, whose sharp edged eclipse transitions provide a good fiducial marker. We have observed a single eclipse egress with ROSAT. We have combined our data with EXOSAT and Ginga timings to fit the ephemeris of EXO0748‐676. Assuming that the observed eclipse times are determined solely by a deterministic period plus measurement error, we confirm Asai et al.—a constant period and a constant period derivative are both ruled out. A constant second period derivative and a 12 yr sinusoidal variability provide equally good fits. The sinusoidal variation in orbital period is reminiscent of several cataclysmic variables. The period could be interpreted as evidence of a third body or of spin‐orbit coupling. However no CV has been observed for more than 1.5 long...
{"title":"ROSAT measurement of the evolving orbital period in the LMXB EXO0748‐676","authors":"P. Hertz, Y. Ly, K. Wood, L. Cominsky","doi":"10.1063/1.45969","DOIUrl":"https://doi.org/10.1063/1.45969","url":null,"abstract":"The sign and magnitude of the orbital period derivative are perhaps the most critical diagnostics of the evolution of low mass x‐ray binaries (LMXBs). However ≲4 LMBXs have measured orbital period derivatives. One of these is the eclipsing x‐ray binary EXO0748‐676, whose sharp edged eclipse transitions provide a good fiducial marker. We have observed a single eclipse egress with ROSAT. We have combined our data with EXOSAT and Ginga timings to fit the ephemeris of EXO0748‐676. Assuming that the observed eclipse times are determined solely by a deterministic period plus measurement error, we confirm Asai et al.—a constant period and a constant period derivative are both ruled out. A constant second period derivative and a 12 yr sinusoidal variability provide equally good fits. The sinusoidal variation in orbital period is reminiscent of several cataclysmic variables. The period could be interpreted as evidence of a third body or of spin‐orbit coupling. However no CV has been observed for more than 1.5 long...","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127470076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Low‐mass stars in close orbits around supermassive black holes in active galactic nuclei (AGN) may provide an important signature for testing the existence of supermassive black holes. Here we discuss how such systems can form by being ‘‘ground down’’ by their interaction with an AGN accretion disk and discuss the peculiarities of such binaries with extreme mass ratios. In particular, we show that, in the case of a low‐mass main‐sequence companion, the orbit has to be circularized to avoid tidal disruption. If the companion is filling its Roche lobe, mass loss will occur through the outer Lagrangian point rather than the inner because of irradiation effects (this may also be important for some binary pulsars like PSR 1957+20). Finally, we discuss possible signatures of such systems.
{"title":"Supermassive black holes with stellar companions","authors":"P. Podsiadlowski, M. Rees","doi":"10.1063/1.45957","DOIUrl":"https://doi.org/10.1063/1.45957","url":null,"abstract":"Low‐mass stars in close orbits around supermassive black holes in active galactic nuclei (AGN) may provide an important signature for testing the existence of supermassive black holes. Here we discuss how such systems can form by being ‘‘ground down’’ by their interaction with an AGN accretion disk and discuss the peculiarities of such binaries with extreme mass ratios. In particular, we show that, in the case of a low‐mass main‐sequence companion, the orbit has to be circularized to avoid tidal disruption. If the companion is filling its Roche lobe, mass loss will occur through the outer Lagrangian point rather than the inner because of irradiation effects (this may also be important for some binary pulsars like PSR 1957+20). Finally, we discuss possible signatures of such systems.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129028513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study the disk‐instability and the effect of irradiation on accretion disks around black holes in x‐ray novae outbursts. The disk instability theory is proposed as the mechanism for the cause of outbursts in x‐ray novae. The mass flow rate into the black hole predicted by the disk instability theory is consistent with observations in both outburst and quiescence. Furthermore, a strong correlation between the optical and soft x‐rays in outburst can be naturally explained by the disk instability theory. We adopt a simple model for the direct irradiation of the whole disk by x‐rays from the innermost disk and examine its effects on the outburst in the context of the disk instability model. The effect of radiation influences both optical and soft x‐ray light curves and the disk evolution. In outburst, the disk becomes brighter and hotter in both optical and soft x‐ray bands, and both the duration of the outburst and the recurrence time are lengthened.
{"title":"The effect of irradiation on outbursts in x‐ray novae","authors":"Soon-Wook Kim, J. Wheeler, S. Mineshige","doi":"10.1063/1.46036","DOIUrl":"https://doi.org/10.1063/1.46036","url":null,"abstract":"We study the disk‐instability and the effect of irradiation on accretion disks around black holes in x‐ray novae outbursts. The disk instability theory is proposed as the mechanism for the cause of outbursts in x‐ray novae. The mass flow rate into the black hole predicted by the disk instability theory is consistent with observations in both outburst and quiescence. Furthermore, a strong correlation between the optical and soft x‐rays in outburst can be naturally explained by the disk instability theory. We adopt a simple model for the direct irradiation of the whole disk by x‐rays from the innermost disk and examine its effects on the outburst in the context of the disk instability model. The effect of radiation influences both optical and soft x‐ray light curves and the disk evolution. In outburst, the disk becomes brighter and hotter in both optical and soft x‐ray bands, and both the duration of the outburst and the recurrence time are lengthened.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132878061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hercules X‐1 was observed by the Large Area Counters (LAC) on the Ginga satellite during several periods in 1988 and 1989. The spectrum of Her X‐1 was measured on a timescale of several minutes, and the flux measured on a timescale of a few seconds. Large changes in flux and in spectral shape were observed, on short and on long timescales. The spectrum has been modeled consistently using a model with two continuum components plus iron emission line and absorption by cold matter. Spectral parameters are derived for pre‐eclipse absorption dips and for eclipse ingress. The changes in spectral parameters are given a physical interpretation in terms of the emission region around the neutron star and in terms of the absorbing matter in the system.
{"title":"Flux and spectrum variability in Her X‐1","authors":"D. Leahy","doi":"10.1063/1.45989","DOIUrl":"https://doi.org/10.1063/1.45989","url":null,"abstract":"Hercules X‐1 was observed by the Large Area Counters (LAC) on the Ginga satellite during several periods in 1988 and 1989. The spectrum of Her X‐1 was measured on a timescale of several minutes, and the flux measured on a timescale of a few seconds. Large changes in flux and in spectral shape were observed, on short and on long timescales. The spectrum has been modeled consistently using a model with two continuum components plus iron emission line and absorption by cold matter. Spectral parameters are derived for pre‐eclipse absorption dips and for eclipse ingress. The changes in spectral parameters are given a physical interpretation in terms of the emission region around the neutron star and in terms of the absorbing matter in the system.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130281045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. E. Wilson and D. Terrell Citation: AIP Conference Proceedings 308, 483 (1994); doi: 10.1063/1.45925 View online: http://dx.doi.org/10.1063/1.45925 View Table of Contents:http://scitation.aip.org/content/aip/proceeding/aipcp/308?ver=pdfcov Published by the AIP Publishing Articles you may be interested in The periodicities of AQL X‐1 in quiescence AIP Conf. Proc. 308, 127 (1994); 10.1063/1.46030 Hard x‐ray variability of Cygnus X–3 AIP Conf. Proc. 308, 263 (1994); 10.1063/1.46020 Optical observations of the x‐ray nova J0422+32 AIP Conf. Proc. 308, 99 (1994); 10.1063/1.45997 Spin evolution of neutron stars in accretion powered pulsars AIP Conf. Proc. 308, 439 (1994); 10.1063/1.45984 The properties of accreting x‐ray pulsars AIP Conf. Proc. 308, 415 (1994); 10.1063/1.45982
R. E. Wilson and D. Terrell引文:AIP会议论文集308,483 (1994);doi: 10.1063/1.45925在线查看:http://dx.doi.org/10.1063/1.45925查看目录:http://scitation.aip.org/content/aip/proceeding/aipcp/308?ver=pdfcov由AIP出版，您可能对AQL X‐1在静态中的周期性感兴趣AIP Conf. Proc. 308, 127 (1994);10.1063/1.46030 Cygnus x - 3的硬x射线变异性，AIP学报，308,263 (1994);10.1063/1.46020 x射线新星J0422+32的光学观测[j] .天文学报，2003,19 (1994);10.1063/1.45997中子星在吸积动力脉冲星中的自旋演化[j] .地球物理学报，2000,29 (1);吸积x -射线脉冲星的性质[j] .天文学报，2000,19 (4);10.1063/1.45982
{"title":"Sub-synchronous rotation and tidal lag in HD 77581/Vela X-1","authors":"R. Wilson, D. Terrell","doi":"10.1063/1.45925","DOIUrl":"https://doi.org/10.1063/1.45925","url":null,"abstract":"R. E. Wilson and D. Terrell Citation: AIP Conference Proceedings 308, 483 (1994); doi: 10.1063/1.45925 View online: http://dx.doi.org/10.1063/1.45925 View Table of Contents:http://scitation.aip.org/content/aip/proceeding/aipcp/308?ver=pdfcov Published by the AIP Publishing Articles you may be interested in The periodicities of AQL X‐1 in quiescence AIP Conf. Proc. 308, 127 (1994); 10.1063/1.46030 Hard x‐ray variability of Cygnus X–3 AIP Conf. Proc. 308, 263 (1994); 10.1063/1.46020 Optical observations of the x‐ray nova J0422+32 AIP Conf. Proc. 308, 99 (1994); 10.1063/1.45997 Spin evolution of neutron stars in accretion powered pulsars AIP Conf. Proc. 308, 439 (1994); 10.1063/1.45984 The properties of accreting x‐ray pulsars AIP Conf. Proc. 308, 415 (1994); 10.1063/1.45982","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129279901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In light of recent observations of PSR 1957+20, we suggest a mechanism in which the mass loss by the secondary carries away varying degrees of specific angular momentum. We present a model which incorporates Roche‐lobe overflow and wind driven mass loss. In our model, Roche‐lobe overflow of the companion produces an evaporating disk or ring. An external disk around the binary may also be created by the mass loss. Changes in the structure of the accretion disk and external disk produce variations in the specific angular momentum carried away by the mass loss. These variations are likely to occur over a viscous timescale. This mechanism could account for the dramatic changes of Pb observed and predicts alternating cycles of expansion and contraction of the binary orbit.
{"title":"The orbital period derivative of PSR 1957+20","authors":"P. Mccormick, J. Frank, A. King, A. Rajasekhar","doi":"10.1063/1.45973","DOIUrl":"https://doi.org/10.1063/1.45973","url":null,"abstract":"In light of recent observations of PSR 1957+20, we suggest a mechanism in which the mass loss by the secondary carries away varying degrees of specific angular momentum. We present a model which incorporates Roche‐lobe overflow and wind driven mass loss. In our model, Roche‐lobe overflow of the companion produces an evaporating disk or ring. An external disk around the binary may also be created by the mass loss. Changes in the structure of the accretion disk and external disk produce variations in the specific angular momentum carried away by the mass loss. These variations are likely to occur over a viscous timescale. This mechanism could account for the dramatic changes of Pb observed and predicts alternating cycles of expansion and contraction of the binary orbit.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"43 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120994124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emission lines are valuable probes of the conditions in the accretion flows associated with binary x‐ray sources. In this review I describe examples of emission lines in different spectral bands, review the observations, and discuss what they indicate about the conditions in binary x‐ray sources. These lines are interpreted using an x‐ray illuminated accretion disk model; the structure and dynamics of the heated disk, its spectral signatures, and the major unsolved theoretical issues surrounding them are discussed.
{"title":"Spectral diagnostics and accretion disk corona reprocessing in x‐ray binaries","authors":"T. Kallman","doi":"10.1063/1.46001","DOIUrl":"https://doi.org/10.1063/1.46001","url":null,"abstract":"Emission lines are valuable probes of the conditions in the accretion flows associated with binary x‐ray sources. In this review I describe examples of emission lines in different spectral bands, review the observations, and discuss what they indicate about the conditions in binary x‐ray sources. These lines are interpreted using an x‐ray illuminated accretion disk model; the structure and dynamics of the heated disk, its spectral signatures, and the major unsolved theoretical issues surrounding them are discussed.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121601836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The HEAO‐2 Einstein solid state spectrometer (SSS; 0.5–4.5 keV) and monitor proportional counter (MPC; 1.2–20.0 keV) carried out an extensive survey of 50 low mass x‐ray binaries (LMXB). Simultaneous SSS plus MPC spectra, selected on the basis of their intensity, were fit with a set of simple and complex spectral models. For all the sources, including Eddington‐limited bulge sources, bursters, dippers, the soft spectrum black hole candidates, and a few transients in decline, the spectra could be fit acceptably with combinations of thermal bremsstrahlung and blackbody spectra or a Comptonized spectrum and a blackbody. The results rule out optically thick disk models for the bright (Z) sources and for the bursters power law models are unacceptable. The SSS can confirm only the strongest of previously reported low energy emission lines due to OVIII or Fe L transitions. The data does not support a unique physical interpretation.
{"title":"The Einstein Solid State Spectrometer and Monitor Proportional Counter Survey of Low Mass X-ray Binaries","authors":"D. Christian","doi":"10.1063/1.46007","DOIUrl":"https://doi.org/10.1063/1.46007","url":null,"abstract":"The HEAO‐2 Einstein solid state spectrometer (SSS; 0.5–4.5 keV) and monitor proportional counter (MPC; 1.2–20.0 keV) carried out an extensive survey of 50 low mass x‐ray binaries (LMXB). Simultaneous SSS plus MPC spectra, selected on the basis of their intensity, were fit with a set of simple and complex spectral models. For all the sources, including Eddington‐limited bulge sources, bursters, dippers, the soft spectrum black hole candidates, and a few transients in decline, the spectra could be fit acceptably with combinations of thermal bremsstrahlung and blackbody spectra or a Comptonized spectrum and a blackbody. The results rule out optically thick disk models for the bright (Z) sources and for the bursters power law models are unacceptable. The SSS can confirm only the strongest of previously reported low energy emission lines due to OVIII or Fe L transitions. The data does not support a unique physical interpretation.","PeriodicalId":101857,"journal":{"name":"The evolution of X‐ray binaries","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133784424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：