搜索结果: 1-15 共查到“天文学 Variability”相关记录69条 . 查询时间(0.196 秒)
Near-Infrared Photometric Variability of Stars Toward the Orion A Molecular Cloud
YY Ori BM Ori
2014/12/26
We present an analysis of J, H, and Ks time series photometry obtained with the southern 2MASS telescope over a 0.84◦×6◦ region centered near the Trapezium region of the Orion Nebula Clust...
F-GAMMA: On the phenomenological classification of continuum radio spectra variability patterns of Fermi blazars
F-GAMMA phenomenological classification continuum radio spectra variability patterns Fermi blazars
2012/2/21
The F-GAMMA program is a coordinated effort to investigate the physics of Active Galactic Nuclei (AGNs) via multi-frequency monitoring of Fermi blazars. In the current study we show and discuss the ev...
Extreme Warm Absorber variability in the Seyfert Galaxy Mrk 704
Galaxies: active – X-rays: galaxies – X-rays: individual: Mrk 704
2011/9/28
In about half of Seyfert galaxies, the X-ray emission is absorbed by an optically thin, ionized medium, the so-called "Warm Absorber", whose origin and location is still a matter of debate. The aims o...
The Kepler characterization of the variability among A- and F-type stars. I. General overview
Asteroseismology - Stars: oscillations - Stars: variables: δ Scuti - Stars: fundamental parameters - binaries: general - Stars: statistics
2011/9/27
The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds of A-F type stars. We present a first general characterization of the pulsational behaviou...
Structure Function and Variability Mechanism of Quasars from SDSS Stripe 82
Structure Function Variability Mechanism Quasars
2011/10/13
Theoretical predictions for the ensemble quasar structure function are tested using multi-epoch observations of Stripe 82 collected by the Sloan Digital Sky Survey. We reanalyze the entire available v...
Variability in Blazars: Clues from PKS 2155-304
black hole physics – magnetic reconnection – relativistic processes – turbulence– galaxies: BL Lacertae objects: individual: PKS 2155-304 – galaxies: jets
2011/10/20
Rapid variability on a time scale much faster than the light-crossing time of the central supermassive black hole has been seen in TeV emission from the blazar PKS 2155-304. The most plausible explana...
Off-Axis Energy Variability of AGNs: a New Paradigm for Broad-Line- and Continuum-Emitting Regions
accretion, accretion disks—black hole physics—galaxies: active— galaxies: Seyfert — polarization — quasars: emission lines
2011/10/17
The general picture of how thermal AGNs work has become clearer in recent years but major observational puzzles threaten to undermine this picture. These puzzles include AGNs with extremely asymmetric...
The Nature and Cause of Spectral Variability in LMC X-1
Nature Cause Spectral Variability LMC X-1
2011/10/21
We present the results of a long-term observation campaign of the extragalactic wind-accreting black-hole X-ray binary LMC X-1, using the Proportional Counter Array on the Rossi X-Ray Timing Explorer ...
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...
Velocity Structure and Variability of [O III] Emission in Black Hole Host Globular Cluster RZ2109
Velocity Structure Variability Emission Globular Cluster
2011/10/12
We present a multi-facility study of the optical spectrum of the extragalactic globular cluster RZ2109, which hosts a bright black hole X-ray source. The optical spectrum of RZ2109 shows strong and ve...
The effects of X-ray absorption variability in NGC 4395
galaxies: active – galaxies: individual: NGC 4395 – X-rays: galaxies
2011/10/8
We present a new X-ray analysis of the dwarf Seyfert galaxy NGC 4395, based on two archival XMM-Newton and Suzaku observations. This source is well known for a series of remarkable properties: one of ...
Dual-Frequency Observations of 140 Compact, Flat-Spectrum Active Galactic Nuclei for Scintillation-Induced Variability
Flat-Spectrum Active Galactic Nuclei Variability
2011/10/8
The 4.9 GHz Micro-Arcsecond Scintillation-Induced Variability (MASIV) Survey detected a drop in Interstellar Scintillation (ISS) for sources at redshifts z > 2, indicating an apparent increase in angu...
Variability of the SiO thermal line emission toward the young L1448-mm outflow
Variability SiO emission L1448-mm outflow
2011/10/8
The detection of narrow SiO thermal emission toward young outflows has been proposed to be a signature of the magnetic precursor of C-shocks. Recent modeling of the SiO emission across C-shocks predic...
Variability of C III and Si III lines in the ultraviolet spectral region of the magnetic Bp star a Centauri
Variability ultraviolet spectral region magnetic Centauri
2011/9/30
The variability of twice ionized lines of carbon and silicon in the ultraviolet spectral region of the magnetic Bp star a Centauri is investigated. This study is based on the archival {\it Internation...
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...