搜索结果: 1-12 共查到“空间天文学 Variability”相关记录12条 . 查询时间(0.126 秒)
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...
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...
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...
Multiwavelength campaign on Mrk 509. IV. Optical-UV-X-ray variability and the nature of the soft X-ray excess
galaxies: active – galaxies: nuclei – galaxies: Seyfert – quasars: individual: Mrk 509 – X-rays: galaxies
2011/9/27
We present the analysis of XMM-Newton and Swift optical-UV and X-ray observations of the Seyfert-1/QSO Mrk 509, part of an unprecedented multi-wavelength campaign, investigating the nuclear environmen...
Discovering the missing 2.2ars by combining optical variability and optical/near-IR colors
Discovering missing quasars combining variability optical/near-IR colors
2011/9/27
The identifications of quasars in the redshift range 2.2are known to be very inefficient as their optical colors are indistinguishable from those of stars. Recent studies have proposed to use opt...
AGN Surveys via Optical Variability, X-ray, and mid-IR Detection in HST Fields
X-ray HST Fields mid-IR Detection
2009/7/9
AGN Surveys via Optical Variability, X-ray, and mid-IR Detection in HST Fields。
Optical variability of infrared power law-selected galaxies & X-ray sources in the goods-south field
X-ray sources infrared power
2009/7/1
Optical variability of infrared power law-selected galaxies & X-ray sources in the goods-south field。
Long-term variability in the quiescent x-ray transient v404 cyg
Long-term variability quiescent x-ray transient v404 cyg
2009/6/17
Long-term variability in the quiescent x-ray transient v404 cyg。
Hidden blazars and emission line variability of high redshift quasars
emission line high redshift quasars
2009/6/8
Hidden blazars and emission line variability of high redshift quasars。
Soft X-ray Variability of the Bright Quasar 3C273
individual (3C273) quasar—X-rays galaxies
2009/5/20
We present the results from ROSAT observations of 3C273
in the soft X-ray band. The light variation of 3C273 was investigated for
three different energy bands of soft, medium, and hard. The maximum
...
Photometric Variability of Four Coronally Active Stars
Stars variable optical photometry X-rays source
2009/5/19
We present photometric observations of four stars that are
optical counterparts of soft X-ray/EUV sources, namely 1ES 0829+15.9,
1ES0920-13.6, 2RE J110159+223509 and 1ES 1737+61.2. We have discovere...
Spectral Variability in Hard X-rays and the Evidence for a 13.5 Years Period in the Bright Quasar 3C273
Galaxies individual 3C273—X-rays
2009/5/19
We report the observation of nearest quasar 3C273 made
with LASE instrument on November 20th, 1998 as a part of our continuing
programme of balloon borne hard X-ray observations in the 20–200 keV
b...