We present optical spectroscopic observations of SS 433 during different precessional and orbital phases.Our 2004,2007 and 2008 data provide us a good chance to study the variability of the Hαline at different orbita...We present optical spectroscopic observations of SS 433 during different precessional and orbital phases.Our 2004,2007 and 2008 data provide us a good chance to study the variability of the Hαline at different orbital phases for nearly the same disk inclination.The data show that the Hαof SS 433 usually had a symmetric profile between orbital phases 0.25-0.75,while an asymmetric structure with a strong red peak was observed for other orbital phases.We suggest that the orbital variability of Hαemission is connected with accretion flow from the donor star to the accretion disk.In addition,we attribute the dramatic increase of Hαemission during our 2007 observational run,which had a time scale of one day,to the emergence of strong jets.展开更多
In this paper we give a brief review of the astrophysics of active galactic nuclei （AGNs）. After a general introduction motivating the study of AGNs, we discuss our present understanding of the inner workings of the...In this paper we give a brief review of the astrophysics of active galactic nuclei （AGNs）. After a general introduction motivating the study of AGNs, we discuss our present understanding of the inner workings of the central engines, most likely accreting black holes with masses between 106 and 10^10M. We highlight recent results concerning the jets （collimated outflows） of AGNs derived from X-ray observations （Chandra） of kpc-scale jets and ~/-ray observations of AGNs （Fermi, Cherenkov telescopes） with jets closely aligned with the lines of sight （blazars）, and discuss tile interpretation of these observations. Subsequently, we summarize our knowledge about the cosmic history of AGN formation and evolution. We conclude with a description of upcoming observational opportunities.展开更多
基金supported by the National Basic Research Program of China(Grant No.2009CB824800)the Natural Science Foundation of China(Grant Nos.10873036 and 10673032)
文摘We present optical spectroscopic observations of SS 433 during different precessional and orbital phases.Our 2004,2007 and 2008 data provide us a good chance to study the variability of the Hαline at different orbital phases for nearly the same disk inclination.The data show that the Hαof SS 433 usually had a symmetric profile between orbital phases 0.25-0.75,while an asymmetric structure with a strong red peak was observed for other orbital phases.We suggest that the orbital variability of Hαemission is connected with accretion flow from the donor star to the accretion disk.In addition,we attribute the dramatic increase of Hαemission during our 2007 observational run,which had a time scale of one day,to the emergence of strong jets.
文摘In this paper we give a brief review of the astrophysics of active galactic nuclei （AGNs）. After a general introduction motivating the study of AGNs, we discuss our present understanding of the inner workings of the central engines, most likely accreting black holes with masses between 106 and 10^10M. We highlight recent results concerning the jets （collimated outflows） of AGNs derived from X-ray observations （Chandra） of kpc-scale jets and ~/-ray observations of AGNs （Fermi, Cherenkov telescopes） with jets closely aligned with the lines of sight （blazars）, and discuss tile interpretation of these observations. Subsequently, we summarize our knowledge about the cosmic history of AGN formation and evolution. We conclude with a description of upcoming observational opportunities.
