Nucleosynthesis in advection-dominated accretion flow （ADAF） onto a black hole is proposed to be an important role in chemical evolution around compact stars. We investigate the nucleosynthesis in ADAF relevant for ...Nucleosynthesis in advection-dominated accretion flow （ADAF） onto a black hole is proposed to be an important role in chemical evolution around compact stars. We investigate the nucleosynthesis in ADAF relevant for a black hole of low mass, different from that of the self-similar solution. In particular, the presence of supersolar metal mass fractions of some isotopes seems to be associated with the known black hole nucleosynthesis in ADAF, which offers further evidence of diversity of the chemical enrichment.展开更多
We have explored the structure of a hot flow bathed in a general large-scale magnetic field. The importance of outflow and thermal conduction on the self-similar structure of a hot accretion flow has been investigated...We have explored the structure of a hot flow bathed in a general large-scale magnetic field. The importance of outflow and thermal conduction on the self-similar structure of a hot accretion flow has been investigated. We consider the additional 2 2 2 magnetic parameters are the Alfv6n sound speeds in three directions of cylindrical coordinates. In comparison to the accretion disk without winds, our results show that the radial and rotational velocities of the disk become faster, but the disk becomes cooler because of the angular momentum and energy flux which are taken away by the winds. Moreover, thermal conduction opposes the effect of winds and not only decreases the rotational velocity but also in- creases the radial velocity as well as the sound speed of the disk. In addition, we study the effect of the global magnetic field on the structure of the disk. Our numerical re- suits show that all the components of a magnetic field can be important and they have a considerable effect on velocities and vertical structure of the disk.展开更多
The hot accretion flow model was re-discovered in 1994 by Narayan and collaborators.Intensive theoretical works have been conducted and significant progresses have been achieved.In this paper,we review several develop...The hot accretion flow model was re-discovered in 1994 by Narayan and collaborators.Intensive theoretical works have been conducted and significant progresses have been achieved.In this paper,we review several developments in the past ten years.This mainly includes the finding of outflow and convection and its dynamical effect on inflow;the direct electron heating by viscous dissipation;the effect of large scale toroidal magnetic fields in the inner region of the accretion flow;and the effect of global Compton scattering.Their observational applications are also introduced very briefly.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11547041,11403007,11673007,11643007,11333004,U1531130,11673059,11390374 and 11521303the Chinese Academy of Sciences under Grant Nos KJZD-EW-M06-01and QYZDB-SSW-SYS001
文摘Nucleosynthesis in advection-dominated accretion flow （ADAF） onto a black hole is proposed to be an important role in chemical evolution around compact stars. We investigate the nucleosynthesis in ADAF relevant for a black hole of low mass, different from that of the self-similar solution. In particular, the presence of supersolar metal mass fractions of some isotopes seems to be associated with the known black hole nucleosynthesis in ADAF, which offers further evidence of diversity of the chemical enrichment.
文摘We have explored the structure of a hot flow bathed in a general large-scale magnetic field. The importance of outflow and thermal conduction on the self-similar structure of a hot accretion flow has been investigated. We consider the additional 2 2 2 magnetic parameters are the Alfv6n sound speeds in three directions of cylindrical coordinates. In comparison to the accretion disk without winds, our results show that the radial and rotational velocities of the disk become faster, but the disk becomes cooler because of the angular momentum and energy flux which are taken away by the winds. Moreover, thermal conduction opposes the effect of winds and not only decreases the rotational velocity but also in- creases the radial velocity as well as the sound speed of the disk. In addition, we study the effect of the global magnetic field on the structure of the disk. Our numerical re- suits show that all the components of a magnetic field can be important and they have a considerable effect on velocities and vertical structure of the disk.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10773024, 10833002, 10821302, and 10825314)the Bairen Program of the Chinese Academy of Sciences,and the National Basic Research Program of China (Grant No. 2009CB824800)
文摘The hot accretion flow model was re-discovered in 1994 by Narayan and collaborators.Intensive theoretical works have been conducted and significant progresses have been achieved.In this paper,we review several developments in the past ten years.This mainly includes the finding of outflow and convection and its dynamical effect on inflow;the direct electron heating by viscous dissipation;the effect of large scale toroidal magnetic fields in the inner region of the accretion flow;and the effect of global Compton scattering.Their observational applications are also introduced very briefly.
