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相关论文: Polarized mm And sub-mm Emission From Sgr A* At Th…

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The mm to sub-mm spectrum of Sgr A* at the Galactic center, as well as its polarization characteristics, are consistent with the inner 10 Schwarzschild radii of a tight Keplerian emitting region of hot, magnetized, orbiting gas. This plasma…

天体物理学 · 物理学 2009-11-07 Siming Liu , Fulvio Melia

The radio source Sgr A* in the Galactic center emits a polarized spectrum at millimeter and sub-millimeter wavelengths that is strongly suggestive of relativistic disk accretion onto a massive black hole. We use the well-constrained mass of…

天体物理学 · 物理学 2009-11-06 Benjamin C. Bromley , Fulvio Melia , Siming Liu

PAPER WITHDRAWN. The recent detection of Sgr A* in the X-ray band, together with the radio polarization measurements conducted over the past few years, offer the best constraints yet for understanding the nature of the emitting gas within…

天体物理学 · 物理学 2007-05-23 Fulvio Melia , Siming Liu , Marco Fatuzzo

The recent detection of a three-hour X-ray flare from Sgr A* by Chandra provides very strong evidence for a compact emitting region near this supermassive black hole at the Galactic center. Sgr A*'s mm/sub-mm spectrum and polarimetric…

天体物理学 · 物理学 2009-11-07 Siming Liu , Fulvio Melia

The linearly polarized millimeter and sub-millimeter emission in Sagittarius A* is produced within 10 Schwarzschild radii of the supermassive black hole at the Galactic Center and may originate from a hot magnetized accretion disk, where…

天体物理学 · 物理学 2009-11-13 Siming Liu , Lei Qian , Xue-Bing Wu , Christopher L. Fryer , Hui Li

The sub-mm bump observed in the spectrum of Sgr A* appears to indicate the existence of a compact emitting component within several Schwarzschild radii, $r_S$, of the nucleus at the Galactic Center. This is interesting in view of the…

天体物理学 · 物理学 2009-10-31 Fulvio Melia , Siming Liu , Robert Coker

We report here the detection of circular polarization in the Galactic Center black hole candidate, Sagittarius A*. The detection was made at 4.8 GHz and 8.4 GHz with the Very Large Array. We find that the fractional circular polarization at…

天体物理学 · 物理学 2009-10-31 Geoffrey C. Bower , Heino Falcke , Donald C. Backer

The polarized mm/sub-mm radiation from Sgr A* is apparently produced by a Keplerian structure whose peak emission occurs within several Schwarzschild radii (r_S=2GM/c^2) of the black hole. The Chandra X-ray counterpart, if confirmed, is…

天体物理学 · 物理学 2009-11-06 Fulvio Melia , Benjamin C. Bromley , Siming Liu , Christopher , K. Walker

We have performed near-infrared monitoring observations of Sgr A*, the Galactic center radio source associated with a supermassive black hole, with the near-infrared camera CIAO and the 36-element adaptive optics system on the Subaru…

Context: The supermassive black hole at the Galactic center, SgrA*, shows frequent radiation outbursts, often called 'flares'. In the near-infrared some of these flares were reported as showing intrinsic quasi-periodicities. The flux peaks…

天体物理学 · 物理学 2009-11-11 L. Meyer , R. Schoedel , A. Eckart , V. Karas , M. Dovciak , W. J. Duschl

Sgr A* is a compact radio source at the Galactic Center, thought to be the radiative manifestation of a $2.6\times 10^6 M_\odot$ supermassive black hole. At least a portion of its spectrum--notably the mm/sub-mm ``bump''--appears to be…

天体物理学 · 物理学 2009-11-07 Siming Liu , Fulvio Melia

Sgr A* is thought to be the radiative manifestation of a ~3.6E6 Msun supermassive black hole at the Galactic center. Its mm/sub-mm spectrum and its flare emission at IR and X-ray wavelengths may be produced within the inner ten…

天体物理学 · 物理学 2009-11-13 M. Falanga , F. Melia , M. Prescher , G. Belanger , A. Goldwurm

We present a statistical analysis of polarized near-infrared (NIR) light from Sgr A*, the radio source associated with the supermassive black hole at the center of the Milky Way. The observations have been carried out using the adaptive…

The detection of a mm/Sub-mm ``bump'' in Sgr A*'s radio spectrum suggests that at least a portion of its overall emission is produced within a compact accretion torus. This inference is strengthened by observations of strong linear…

天体物理学 · 物理学 2009-11-10 Siming Liu , Fulvio Melia

In this article we summarise and discuss the infrared, radio, and X-ray emission from the supermassive black hole in the Galactic Centre, SgrA*. We include new results from near-infrared polarimetric imaging observations obtained on May…

天体物理学 · 物理学 2008-11-26 S. Trippe , T. Paumard , T. Ott , S. Gillessen , F. Eisenhauer , F. Martins , R. Genzel

We report results from a multiwavelength campaign to measure the simultaneous spectrum of the super-massive black hole candidate Sgr A* in the Galactic Center from cm to mm-wavelengths using the VLA, BIMA, the Nobeyama 45m, and the IRAM 30m…

天体物理学 · 物理学 2009-10-30 Heino Falcke , W. M. Goss , Hiroshi Matsuo , Peter Teuben , Jun-Hui Zhao , Robert Zylka

The near-infrared emission from the black hole at the Galactic center (Sgr A*) has unique properties. The most striking feature is a suggestive periodic sub-structure that has been observed in a couple of flares so far. Using near-infrared…

天体物理学 · 物理学 2009-11-13 L. Meyer , R. Schoedel , A. Eckart , W. J. Duschl , V. Karas , M. Dovciak

Recent measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a 3.6-million-solar-mass black hole. Sgr A* is remarkably faint in all wavebands other than the radio…

天体物理学 · 物理学 2009-11-10 R. Genzel , R. Schoedel , T. Ott , A. Eckart , T. Alexander , F. Lacombe , D. Rouan , B. Aschenbach

We summarize the current state of polarization observations of Sagittarius A*, the compact radio source and supermassive black hole candidate in the Galactic Center. These observations are providing new tools for understanding accretion…

天体物理学 · 物理学 2007-05-23 Geoffrey C. Bower

Images from the vicinity of the black hole horizon at the Galactic centre (Sgr A*) could be obtained in the near future with a Very Large Baseline Array of sub-millimetre telescopes. The recently observed short-term infrared and X-ray…

天体物理学 · 物理学 2009-11-13 Avery E. Broderick , Abraham Loeb
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