搜索结果: 1-15 共查到“天文学 Discs”相关记录21条 . 查询时间(0.181 秒)
Multi-wavelength observations of the young binary system Haro 6-10: The case of misaligned discs
Binary stars - Star Formation - Haro 6-10
2011/10/17
Context. We present a multi-wavelength, high-resolution observational survey of the young binary system Haro 6-10 (GV Tau, IRAS 04263+2426), which is harbouring one of the few known infrared companion...
Gas density and star formation in the rarified regions of discs of normal and LSB galaxies
Gas density star formation rarified regions discs normal
2011/10/11
We calculated the radial profiles of the azimuthally averaged midplane gas volume density $\rho_g$ for 11 high surface brightness (HSB) spiral galaxies, 7 low surface brightness (LSB) galaxies and 3 S...
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.
High-resolution simulations of planetesimal formation in turbulent protoplanetary discs
High-resolution simulations turbulent protoplanetary discs
2011/1/10
We present high-resolution computer simulations of dust dynamics and planetesimal formation in turbulence generated by the magnetorotational instability. We show that the turbulent viscosity associate...
Non-convergence of the critical cooling timescale for fragmentation of self-gravitating discs
accretion accretion discs protoplanetary discs planets and satellites
2010/11/10
We carry out a resolution study on the fragmentation boundary of self-gravitating discs. We perform three-dimensional Smoothed Particle Hydrodynamics simulations of discs to determine whether the crit...
Accretion Discs with an Inner Spiral Density Wave
accretion accretion discs - binaries general - binaries close - stars dwarf novae - novae
2010/11/16
In Montgomery (2009a), we show that accretion discs in binary systems could retrogradely precess by the same physics that causes the Earth to retrogradely precess [i.e., tidal torques by the Moon and ...
Thin accretion discs around millisecond X-ray pulsars
accretion accretion discs – magnetic fields – MHD –stars magnetic fields –stars
2010/11/15
Millisecond x-ray pulsars have weak magnetic dipole moments of ∼ 1016 Tm3 compared to ordinaryX-ray pulsars with dipolemoments of 1020 Tm3. For this reason a surrounding accretion
disc can exte...
Debris discs in the 27 Myr old open cluster IC4665
Solar and Stellar Astrophysics (astro-ph.SR)
2010/12/28
We present Spitzer IRAC and MIPS 24um imaging of members of the 27+/-5Myr old open cluster IC 4665. Models for the assembly of terrestrial planets through planetesimal collisions and mergers predict e...
Variability of black-hole accretion discs: a theoretical study
Solar and Stellar Astrophysics (astro-ph.SR) Galaxy Astrophysics (astro-ph.GA)
2010/12/29
This thesis investigates phenomena occurring in black-hole accretion discs which are likely to induce high-frequency quasi-periodic variability. Two classes of pseudo-relativistic theoretical models a...
Resonant radii of kHz quasi-periodic oscillations in Keplerian discs orbiting neutron stars
High Energy Astrophysical Phenomena (astro-ph.HE)
2010/12/28
Exchange of dominance between twin kHz quasi-periodic oscillations (QPOs) observed in some low-mass-X-ray-binaries (LMXB) suggests the possibility of a resonance between two oscillatory modes.
Quantifying the Imprecision of Accretion Theory and Implications for Multi-Epoch Observations of Protoplanetary Discs
Solar and Stellar Astrophysics (astro-ph.SR) Earth and Planetary Astrophysics (astro-ph.EP) High Energy Astrophysical Phenomena (astro-ph.HE)
2010/12/27
If accretion disc emission results from turbulent dissipation, then axisymmetric accretion theory must be used as a mean field theory: turbulent flows are at most axisymmetric only when suitably avera...
The imprint of photoevaporation on edge-on discs
Solar and Stellar Astrophysics (astro-ph.SR) Earth and Planetary Astrophysics (astro-ph.EP)
2010/12/24
We have performed hydrodynamic and radiative transfer calculations of a photoevaporating disc around a Herbig Ae/Be star to determine the evolution and observational impact of dust entrained in the wi...
Lindblad resonance torques in relativistic discs: II. Computation of resonance strengths
High Energy Astrophysical Phenomena (astro-ph.HE) General Relativity and Quantum Cosmology (gr-qc)
2010/12/24
We present a fully relativistic computation of the torques due to Lindblad resonances from perturbers on circular, equatorial orbits on discs around Schwarzschild and Kerr black holes. The computation...
Lindblad resonance torques in relativistic discs: I. Basic equations
High Energy Astrophysical Phenomena (astro-ph.HE) General Relativity and Quantum Cosmology (gr-qc)
2010/12/24
Lindblad resonances have been suggested as an important mechanism for angular momentum transport and heating in discs in binary black hole systems.