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相关论文: Non-thermal Emission in Sagittarius B?

200 篇论文

We present new Very Large Array observations at five frequencies, from 1.4 to 22GHz, of the extremely low-metallicity blue compact dwarf SBS0335-052. The radio spectrum shows considerable absorption at 1.49GHz, and a composite…

天体物理学 · 物理学 2009-11-10 Leslie K. Hunt , Kristy K. Dyer , Trinh X. Thuan , James S. Ulvestad

We present 168 arcmin^2 spectral images of the Sgr B2 complex taken with Herschel/SPIRE-FTS. We detect ubiquitous emission from CO (up to J=12-11), H2O, [CI]492, 809 GHz, and [NII] 205 um lines. We also present maps of the SiO, N2H+, HCN,…

星系天体物理 · 物理学 2021-05-12 M. G. Santa-Maria , J. R. Goicoechea , M. Etxaluze , J. Cernicharo , S. Cuadrado

Together, the Fermi-LAT and HESS have revealed the presence of an unusual GeV-TeV source coincident with Sgr A* at the Galactic center. Its high-energy emission appears to be bimodal, hinting at an energizing process more sophisticated than…

星系天体物理 · 物理学 2015-06-11 Marco Fatuzzo , Fulvio Melia

We use data from the Large Area Telescope onboard the Fermi gamma-ray space telescope (Fermi-LAT) to analyze the faint gamma-ray source located at the center of the Sagittarius (Sgr) dwarf spheroidal galaxy. In the 4FGL-DR3 catalog, this…

Resolved maps of the thermal and nonthermal radio continuum (RC) emission of distant galaxies are a powerful tool for understanding the role of the interstellar medium (ISM) in the evolution of galaxies. We simulate the RC surface…

Recent Chandra and XMM-{\it Newton} observations reported evidence of two X-ray filaments G359.88-0.08 (SgrA-E) and G359.54+0.18 (the ripple filament) near the Galactic center. The X-ray emission from these filaments has a nonthermal…

天体物理学 · 物理学 2009-05-29 F. Yusef-Zadeh , M. Wardle , M. Muno , C. Law , M. Pound

Cyg OB2 #5 is a contact binary system (O6.5-7+O5.5-6) with associated radio continuum emission. Two compact ($\leq 0\rlap.{"}3$) radio continuum components have been reported previously: the primary one is associated with the contact binary…

太阳与恒星天体物理 · 物理学 2011-11-29 G. N. Ortiz-Leon , L. F. Rodriguez , M. Tapia

We present submm images of Sgr A* and its surroundings obtained at 800, 600 and 450 $\mu$m with the JCMT and derive flux densities of Sgr A* at all three wave- lengths. Combined with upper limits by Gezari and associates at MIR wavelengths…

天体物理学 · 物理学 2007-05-23 R. Zylka , P. G. Mezger , D. Ward-Thompson , W. J. Duschl , H. Lesch

We calculate the radiative properties of Sagittarius A* -- spectral energy distribution, variability, and radio-infrared images -- using the first 3D, physically motivated black hole accretion models that directly evolve the electron…

高能天体物理现象 · 物理学 2017-03-22 Sean M. Ressler , Alexander Tchekhovskoy , Eliot Quataert , Charles F. Gammie

We attempt to determine the nature of the high energy emission of the radio galaxy 3C 111, by distinguishing between the effects of the thermal and non-thermal processes. We study the X-ray spectrum of 3C 111 between 0.4 keV and 200 keV,…

高能天体物理现象 · 物理学 2015-06-05 S. de Jong , V. Beckmann , F. Mattana

Observations with the RXTE and SAX satellites have recently led to the measurement of a second component in the spectra of several clusters of galaxies which are known to have regions of extended radio emission. This new component is quite…

天体物理学 · 物理学 2009-11-06 Yoel Rephaeli

The IRDC G14.225-0.506 is associated with a network of filaments, which result in two different dense hubs, as well as with several signposts of star formation activity. The aim of this work is to study the cm continuum emission to…

In a recent analysis of the radio emission from the planetary nebula A30, Dgani, Evans & White (1998) claim that the emission, located in the inner region, is probably dominated by nonthermal emission. We propose a model to explain this. We…

天体物理学 · 物理学 2009-10-30 Ruth Dgani , Noam Soker

We have observed the central 45' region of the Galaxy at 620 MHz band of the Giant Metrewave Radio Telescope (GMRT) in radio continuum, and measured the polarisation properties of 64 small diameter background extragalactic sources seen…

天体物理学 · 物理学 2007-05-23 Subhashis Roy

We report the X-ray population study in the giant molecular cloud Sagittarius B2 (SgrB2). More than a dozen of X-ray cloud members (and candidates) are discovered with Chandra. Two bright X-ray sources are located near Sgr B2 Main, the most…

天体物理学 · 物理学 2009-11-07 S. Takagi , H. Murakami , K. Koyama

We have initiated a spectral line survey, at a wavelength of 3 millimeters, toward the hot molecular core Sagittarius B2(N-LMH). This is the first spectral line survey of the Sgr B2(N) region utilizing data from both an interferometer (BIMA…

天体物理学 · 物理学 2009-11-10 D. N. Friedel , L. E. Snyder , B. E. Turner , A. Remijan

We present values of temperature and spectral index of the galactic diffuse radiation measured at 600 and 820 MHz along a 24 hours right ascension circle at declination $\delta = +42^{\circ}$. They have been obtained from a subset of…

天体物理学 · 物理学 2009-11-13 A. Tartari , M. Zannoni , M. Gervasi , G. Boella , G. Sironi

We study the hard X-ray (20-100 keV) variability of the Galactic Center (GC) and of the nearby sources on the time scale of 1000 s. We find that 3 of the 6 hard X-ray sources detected by INTEGRAL within the central 1 degree of the Galaxy…

天体物理学 · 物理学 2007-05-23 A. Neronov , M. Chernyakova , T. J. -L. Courvoisier , R. Walter

We have performed monitoring observations of the flux density toward the Galactic center compact radio source, Sagittarius A* (Sgr A*), which is a supermassive black hole, from 1996 to 2005 using the Nobeyama Millimeter Array of the…

天体物理学 · 物理学 2007-05-23 Atsushi Miyazaki , Takahiro Tsutsumi , Makoto Miyoshi , Masato Tsuboi , Zhi-Qiang Shen

The X-ray spectrum in a $1^{\circ}\times1^{\circ}$ region of the Galactic center observed with the ASCA satellite is examined in detail, following the first report by Koyama et al. (1996, AAA 65.155.208). The observed spectrum contains…

天体物理学 · 物理学 2015-06-24 Y. Tanaka , K. Koyama , Y. Maeda , T. Sonobe