搜索结果: 46-60 共查到“知识库 天体力学”相关记录128条 . 查询时间(4.359 秒)
A brief introduction to theories of the gravitational field with a Lagrangian that is a function of the scalar curvature is given. The emphasis will be placed in formal developments, while comparison ...
Very Long Baseline Array Imaging of Parsec-scale Jet Structures in Radio-loud Narrow-line Seyfert 1 Galaxies
Long Baseline Array Imaging Radio-loud Narrow-line Seyfert
2011/10/21
We conducted very long baseline interferometry (VLBI) observations of five radio-loud narrow-line Seyfert 1 (NLS1) galaxies in milliarcsecond resolutions at 1.7 GHz (18 cm) using the Very Long Baselin...
Luminosities of recycled radio pulsars in globular clusters
stars: neutron — pulsars: general — methods:general — globular clusters: individual
2011/10/13
Using Monte Carlo simulations, we model the luminosity distribution of recycled pulsars in globular clusters as the brighter, observable part of an intrinsic distribution and find that the observed lu...
Revision of the 15N(p,γ)16O reaction rate and oxygen abundance in H-burning zones
physical data processes: nuclear reactions abundances
2011/10/13
The NO cycle takes place in the deepest layer of a H-burning core or shell, when the temperature exceeds T {\simeq} 30 {\cdot} 106 K. The O depletion observed in some globular cluster giant stars, alw...
The Orbital Period and Variability of the Dwarf Nova ES Draconis
stars: individual: ES Dra (PG 1524+622) – novae: cataclysmic variables – binaries: spectroscopic – AAVSO
2011/10/12
A radial velocity study of the cataclysmic variable ES Dra (PG 1524+622) is presented. ES Dra is found to have an orbital period of 0.17660 \pm 0.00006 d (4.2384 \pm 0.0014 h). The mass-losing seconda...
Can an astrophysical black hole have a topologically non-trivial event horizon?
astrophysical black hole topologically non-trivial horizon
2011/10/17
In 4-dimensional General Relativity, there are several theorems restricting the topology of the event horizon of a black hole. In the stationary case, black holes must have a spherical horizon, while ...
Next-to-next-to-leading order post-Newtonian spin(1)-spin(2) Hamiltonian for self-gravitating binaries
Next-to-next-to-leading order post-Newtonian spin(1)-spin(2) Hamiltonian for self-gravitating binaries
2011/10/17
We present the next-to-next-to-leading order post-Newtonian (PN) spin(1)-spin(2) Hamiltonian for two self-gravitating spinning compact objects. If both objects are rapidly rotating, then the correspon...
Shapes and gravitational fields of rotating two-layer Maclaurin ellipsoids: Application to planets and satellites
two-layer Maclaurin ellipsoids: Application to planets and satellites
2011/10/12
The exact solution for the shape and gravitational field of a rotating two-layer Maclaurin ellipsoid of revolution is compared with predictions of the theory of figures up to third order in the small ...
The impact of a stochastic gravitational-wave background on pulsar timing parameters
impact stochastic gravitational-wave background timing parameters
2011/10/12
Gravitational waves are predicted by Einstein's theory of general relativity as well as other theories of gravity. The rotational stability of the fastest pulsars means that timing of an array of thes...
Dynamical chaos in the problem of magnetic jet collimation
galaxies: jets – magnetic fi elds – MHD – ISM: jets and outfl ows – ISM:kinematics and dynamics
2011/10/12
We investigate dynamics of a jet collimated by magneto-torsional oscillations. The problem is reduced to an ordinary differential equation containing a singularity and depending on a parameter. We fin...
Radio Imaging of the NGC 1333 IRAS 4A Region: Envelope, Disks, and Outflows of a Protostellar Binary System
ISM: individual (NGC 1333 IRAS 4A) — ISM: jets outfl ows — ISM: binaries: general— stars: formation
2011/10/12
The NGC 1333 IRAS 4A protobinary was observed in the 1.3 cm and 6.9 mm continuum and the ammonia and SiO lines, with an angular resolution of about 0.4 arcseconds. The continuum maps show the circumst...
Pulsar state switching, timing noise and free precession
dense matter – stars: neutron – stars: oscillations – stars: pulsars –stars: rotation
2011/10/10
Recent radio pulsar observations have shown that a number of pulsars display interesting long term periodicities in their spin-down rates. At least some of these pulsars also undergo sharp changes in ...
The energy source of intermediate luminosity optical transients
energy source intermediate luminosity optical transients
2011/10/10
We argue that transient systems with luminosity between novae and supernovae (SNe) are powered by gravitational energy of mass accreted onto, or a companion merges with, a main-sequence star. These tr...
Quantum gravity stability of isotropy in homogeneous cosmology
quantum stability cosmological isotropy cosmological
2011/10/17
It has been shown that anisotropy of homogeneous spacetime described by the general Kasner metric can be damped by quantum fluctuations coming from perturbative quantum gravity in one-loop approximati...
Weak-field limit of Kaluza-Klein models with spherical compactification I: problematic aspects
Weak-field limit Kaluza-Klein models spherical compactification problematic aspects
2011/10/17
We investigate classical gravitational tests for the Kaluza-Klein model with spherical compactification of the internal two-dimensional space. In the case of the absence of a multidimensional bare cos...