搜索结果: 16-30 共查到“理学 accretion”相关记录129条 . 查询时间(0.013 秒)
PRIMUS: The dependence of AGN accretion on host stellar mass and color
PRIMUS:dependence accretion stellar mass color
2011/10/13
We present evidence that the incidence of active galactic nuclei (AGN) and the distribution of their accretion rates do not depend on the stellar masses of their host galaxies, contrary to previous st...
Accretion in the detached post-common-envelope binary LTT 560
binaries: close – Stars: late-type – white dwarfs – Stars: individual: LTT 560 – cataclysmic variables
2011/10/11
In a previous study, we found that the detached post-common-envelope binary LTT 560 displays an Halpha emission line consisting of two anti-phased components. While one of them was clearly caused by s...
The Role of Tiny Grains on the Accretion Process in Protoplanetary Disks
Tiny Grains Accretion Process Protoplanetary Disks
2011/10/9
Tiny grains such as PAHs have been thought to dramatically reduce the coupling between gas and magnetic fields in weakly ionized gas such as in protoplanetary disks (PPDs) because they provide tremend...
Magnetorotational Instability Driven Accretion in Protoplanetary Disks
Instability Driven Accretion Protoplanetary
2011/10/9
The gas dynamics in protoplanetary disks (PPDs) is strongly affected by non-ideal MHD effects. Using a complex chemical reaction network with standard prescriptions for X-ray and cosmic-ray ionization...
Nonradial and nonpolytropic astrophysical outflows IX. Modeling T Tauri jets with a low mass-accretion rate
MHD, Stars: pre-main sequence, Stars: winds, outfl ows, Stars: mass-loss, Stars: rotation, ISM
2011/10/8
Context: A large sample of T Tauri stars exhibits optical jets, approximately half of which rotate slowly, only at ten per cent of their breakup velocity. The disk-locking mechanism has been shown to ...
Short Gamma-ray Bursts: the mass of the accretion disk and the initial radius of the outflow
Short Gamma-ray Bursts:accretion disk initial radius outflow
2011/10/9
In this work we estimate the accretion-disk mass in the specific scenario of binary-neutron-star-merger with current observational data. Assuming that the outflows of short Gamma-ray Bursts (GRBs) are...
Considerations on the accretion of Uranus and Neptune by mutual collisions of planetary embryos in the vicinity of Jupiter and Saturn
planetary systems – planets and satellites: formation – planets and satellites: individual: Uranus, Neptune – protoplanetary disks
2011/10/8
Modeling the formation of Uranus and Neptune is a long-lasting problem in planetary science. Due to the gas-drag, collisional damping, and resonant shepherding, the planetary embryos repel the planete...
Pulse-amplitude-resolved spectroscopy of bright accreting pulsars: indication of two accretion regimes
X-ray binaries – neutron stars – accretion
2011/10/8
Context: In addition to coherent pulsation, many accreting neutron stars exhibit flaring activity and strong aperiodic variability on time scales comparable to or shorter than their pulsation period. ...
Analytic solutions to the accretion of a rotating finite cloud towards a central object - II. Schwarzschild spacetime
accretion, accretion discs, black hole physics, hydrodynamics, relativistic processes
2011/9/30
We construct a general relativistic model for the accretion flow of a rotating finite cloud of non-interacting particles infalling onto a Schwarzschild black hole. The streamlines start at a spherical...
Accretion disks around kicked black holes: Post-kick Dynamics
Accretion disks kicked black holes: Post-kick Dynamics
2011/9/29
Numerical calculations of merging black hole binaries indicate that asymmetric emission of gravitational radiation can kick the merged black hole at up to thousands of km/s, and a number of systems ha...
Can Self Organized Critical Accretion Disks Generate a Log-normal Emission Variability in AGN?
Accretion accretion disks
2011/9/29
Active Galactic Nuclei (AGN), such as Seyfert galaxies, quasars, etc., show light variations in all wavelength bands, with various amplitude and in many time scales. The variations usually look errati...
General-relativistic model of hot accretion flows with global Compton cooling
accretion, accretion discs – black hole physics – X-rays: binaries – X-rays:general
2011/9/28
We present a model of optically thin, two-temperature, accretion flows using an exact Monte Carlo treatment of global Comptonization, with seed photons from synchrotron and bremsstrahlung emission, as...
3C390.3: More Stable Evidence for Origination of Double-Peaked Broad Balmer Lines from Accretion Disk Near Central Black Hole
Galaxies:Active – Galaxies:nuclei – Galaxies:Seyfert – quasars:Emission lines – Galaxies:individual: 3C390.3
2011/9/27
In this manuscript, the structure of broad emission line regions (BLRs) of well-mapping double-peaked emitter (AGN with broad double-peaked low-ionization emission lines) 3C390.3 is studied. Besides t...
Optical and Near-IR long-term monitoring of NGC3783 and MR2251-178: evidence for variable near-IR emission from thin accretion discs
Seyfert galaxies:general — Seyfert galaxies:individual(NGC 3783,MR 2251-178)
2011/9/26
We present long term near-IR light curves for two nearby AGN: NGC3783 and MR2251-178. The near-IR data are complemented with optical photometry obtained over the same period of time. The light curves ...
Optical and Near-IR long-term monitoring of NGC3783 and MR2251-178: evidence for variable near-IR emission from thin accretion discs
Seyfert galaxies:general ?Seyfert galaxies:individual
2011/8/24
We present long term near-IR light curves for two nearby AGN: NGC3783 and MR2251-178. The near-IR data are complemented with optical photometry obtained over the same period of time.