搜索结果: 1-15 共查到“知识库 γ射线天文学”相关记录25条 . 查询时间(2.373 秒)
伽马射线暴及其余辉研究进展
辐射机制 伽玛射线暴 中子星 黑洞
2012/9/12
伽玛射线暴是一种来自宇宙空间随机方向的短时间内伽玛射线突然增亮的现象。伽玛射线暴虽然早在 1967 年就由 Vela 卫星观测到，但直到 1997 年人们才通过余辉观测确定其寄主星系，并通过寄主星系的红移最终确定了伽玛射线暴的宇宙学起源。对伽玛射线暴研究概况进行了评述：详细介绍了伽玛射线暴及其余辉的观测进展，特别是近期 Swift 卫星和 Fermi 卫星带来的新发现；系统描述了伽玛射线暴标准火球...
The optical/UV excess of isolated neutron stars in the RCS model
pulsars: individual RX J1308.6+2127 stars:neutron
2011/9/28
The X-ray dim isolated neutron stars (XDINSs) are peculiar pulsar-like objects, characterized by their very well Planck-like spectrum. In studying their spectral energy distributions, the optical/UV e...
A Search for Lyman Break Galaxies in the CDF-S Using Swift UVOT
Search Lyman Break Galaxies CDF-S Using Swift
2011/10/12
While the Swift satellite is primarily designed to study gamma-ray bursts, its ultraviolet and optical imaging and spectroscopy capabilities are also being used for a variety of scientific programs. I...
Identification of gamma-ray emission from 3C345 and NRAO512
Galaxies: active - quasars: individual (3C 345, NRAO512, B3 1640+396) - Gamma rays: galaxies
2011/10/9
For more than 15 years, since the days of the Energetic Gamma-Ray Experiment Telescope (EGRET) on board the Compton Gamma-Ray Observatory (CGRO; 1991-2000), it has remained an open question why the pr...
First observations of CN(2-1), HCO$^{+}$(3-2) and C$_{2}$H(3-2) emission lines in the Perseus cluster: constraints on heating mechanisms in the cluster gas
Astrochemistry - ISM:abundances - galaxies: intergalactic medium - Galaxies: clusters: individual:Perseus - galaxies: individual: NGC 1275 - Galaxies: cooling fl ows
2011/10/8
We present the first observations of emission lines of CN(2-1), HCO$^{+}$(3-2) and C$_{2}$H(3-2) in the Perseus cluster. We observed at two positions: directly at the central galaxy, NGC 1275 and also...
X-ray flare candidates in short gamma-ray bursts
gamma-ray: bursts – radiation mechanism: non-thermal –X-rays
2011/9/30
We present the first systematic study of X-ray flare candidates in short gamma-ray bursts (SGRBs) exploiting the large 6-year Swift database with the aim to constrain the physical nature of such fluct...
Periodic Radio Emission from the M7 Dwarf 2MASS J13142039+1320011: Implications for the Magnetic Field Topology
Periodic Radio Emission Implications Magnetic Field Topology
2011/9/29
We present multi-epoch radio and optical observations of the M7 dwarf 2MASS J13142039+1320011. We detect a ~1 mJy source at 1.43, 4.86, 8.46 and 22.5 GHz, making it the most luminous radio emission ov...
Fermi Large Area Telescope Observations of the Active Galaxy 4C +55.17: Steady, Hard Gamma-Ray Emission and its Implications
Steady Hard Gamma-Ray Emission Implications
2011/9/29
We report Fermi/LAT observations and broad-band spectral modeling of the radio-loud active galaxy 4C +55.17 (z=0.896), formally classified as a flat-spectrum radio quasar. Using 19 months of all-sky s...
Evidence for mild deviation from power-law distribution of electrons in relativistic shocks: GRB 090902B
radiation mechanisms: non-thermal - methods: analytical - methods: numerical- gamma-rays: bursts, theory - gamma-ray burst: individual: GRB090902B
2011/9/29
Many previous studies have determined that the long lasting emission at X-ray, optical and radio wavelengths from gamma-ray bursts (GRBs), called the afterglow, is likely produced by the external forw...
GRAVITAS : General Relativistic Astrophysics VIa Timing And Spectroscopy: An ESA M3 mission proposal
General Relativistic Astrophysics Spectroscopy mission proposal
2011/9/28
GRAVITAS is an X-ray observatory, designed and optimised to address the ESA Cosmic Vision theme of "Matter under extreme conditions". It was submitted as a response to the call for M3 mission proposal...
伽马射线暴的光度一光变复杂度关系
伽马射线暴 瞬时辐射 光变复杂度
2012/9/11
伽马射线暴的光变复杂度是描述其光变曲线复杂程度的物理量。由已知红移的伽马射线暴,Reichart等人发现其光变复杂度与各向同性光度之间有正相关性(L∝V~α,α在1.77～3.5之间),即光变越复杂,光度越高。此相关性类似于造父变星的周光关系,可用来估计伽马暴的距离和红移。调研、分析了各种光变复杂度的定义、算法和光变复杂度各向同性光度关系的拟合结果,最后对光变复杂度和光度之间的关系做了总结和展望。
Swift时代伽马射线暴的观测和理论
伽马射线暴 辐射机制 伽马射线
2012/9/12
伽马射线暴是宇宙中最剧烈的爆发现象之一。Swift卫星的快速定位和Fermi卫星的宽、高能段观测,使得伽马暴的观测可以全波段进行。通过Swift的观测可以对伽马暴现象的本质有进一步的理解,而Fermi卫星提供了一些暴高能光子的辐射数据,为进一步研究暴的辐射机制和伽马暴以及它的余辉提供了有力的依据。介绍了Swift和Fermi卫星发射后一些伽马暴的观测和理论研究进展。
3C 454.3 伽玛射线和近红外辐射延时分析
类星体 3C 454.3 延时
2012/9/11
2008 年秋天，3C 454.3 在° 射线能段和光学波段呈现出非常大的爆发，在这次爆发过程中Fermi/LAT 和SMARTS 都对其进行了观测。通过对° 射线能段与SMARTS J 及B 波段在这次大爆发期间获得的光变数据进行细致的DCF 分析发现：这段时期内3C 454.3 的J 波段光变落后° 射线光变大约2 d。在进行相关性分析过程中，对DCF 做了稍许改进，得到一种改进的DCF-时间...
Last Moments in the Life of a Compact Binary System：Gravitational Waves, Gamma-Ray Bursts and Magnetar Formation
Compact Binary System Gamma-Ray Bursts Gravitational Waves Magnetar Formation
2009/7/1
Last Moments in the Life of a Compact Binary System：Gravitational Waves, Gamma-Ray Bursts and Magnetar Formation。
Supernovae and Gamma Ray Bursts。