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Related papers: ASCA Observations of the Sgr B2 Cloud: An X-Ray Re…

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We present an ASCA discovery of diffuse hard X-ray emission from the Sgr C complex with its peak in the vicinity of the molecular cloud core. The X-ray spectrum is characterized by a strong 6.4-keV line and large absorption. These…

Astrophysics · Physics 2009-10-31 H. Murakami , K. Koyama , M. Tsujimoto , Y. Maeda , M. Sakano

We present the first Chandra results of the giant molecular cloud Sagittarius B2 (Sgr B2), located about 100 pc away from the Galactic center. Diffuse X-rays are clearly separated from one-and-a-half dozen resolved point sources. The X-ray…

Astrophysics · Physics 2009-11-06 H. Murakami , K. Koyama , Y. Maeda

Galactic Center (GC) molecular cloud Sgr B2 is the best manifestation of an X-ray reflection nebula (XRN) reprocessing a past giant outburst from the supermassive black hole Sgr A*. Alternatively, Sgr B2 could be illuminated by low-energy…

The Sagittarius B2 (Sgr B2) molecular cloud complex is an X-ray reflection nebula whose total emissions have continued to decrease since 2001 as it reprocesses one or more past energetic outbursts from the supermassive black hole…

High Energy Astrophysical Phenomena · Physics 2022-10-27 Field Rogers , Shuo Zhang , Kerstin Perez , Maïca Clavel , Afura Taylor

Strong iron fluorescence at 6.4 keV and hard-X-ray emissions from giant molecular clouds in the Galactic center region have been interpreted as reflections of a past outburst of the Sgr A* supermassive black hole. Careful treatment of…

Astrophysics of Galaxies · Physics 2011-10-11 Hirokazu Odaka , Felix Aharonian , Shin Watanabe , Yasuyuki Tanaka , Dmitry Khangulyan , Tadayuki Takahashi

The Sgr B2 giant molecular cloud is claimed to be an "X-ray reflection nebula" - the reprocessing site of a powerful flare of the Sgr A* source, occurred few hundred years ago. The shape of the X-ray spectrum and the strength of the iron…

Astrophysics · Physics 2009-11-07 E. Churazov , R. Sunyaev , S. Sazonov

The centre of our Galaxy harbours a 4 million solar mass black hole that is unusually quiet: its present X-ray luminosity is more than 10 orders of magnitude less than its Eddington luminosity. The observation of iron fluorescence and hard…

High Energy Astrophysical Phenomena · Physics 2015-05-19 R. Terrier , G. Ponti , G. Belanger , A. Decourchelle , V. Tatischeff , A. Goldwurm , G. Trap , M. R. Morris , R. Warwick

Observations of the diffuse emission in the 8--22 keV energy range, elongated parallel to the Galactic plane (Sunyaev et al. 1993) and detection of the strong 6.4 keV fluorescent line with $\sim$ 1 keV equivalent width from some giant…

Astrophysics · Physics 2009-10-30 R. Sunyaev , E. Churazov

We report the association of the recently discovered hard X-ray source IGR J17475-2822 with the giant molecular cloud Sgr B2 in the Galactic Center region. The broad band (3-200 keV) spectrum of the source constructed from data of different…

Molecular cloud Sgr B2 is a natural Compton mirror in the Central Molecular Zone. An observed fading of the Sgr B2 X-ray emission in continuum and Fe K$\alpha$ 6.4 keV line indicates, as believed, a past X-ray flare activity of the…

High Energy Astrophysical Phenomena · Physics 2021-11-24 Ekaterina Kuznetsova , Roman Krivonos , Alexander Lutovinov , Maïca Clavel

This paper reports on the early Chandra view of the Galactic center (GC) activities. The massive black hole Sgr A* is extremely faint, while more bright diffuse X-ray emission is prevailing in the circumnuclear disk. Another high…

Astrophysics · Physics 2007-05-23 Katsuji Koyama

The Galactic Center Region has been surveyed in 1997-1998 with the Narrow Field Instruments on-board the BeppoSAX satellite (2-10keV energy range). The X-ray emission from SgrA*, the putative supermassive black hole at the center of our…

Astrophysics · Physics 2007-05-23 L. Sidoli

We present the result of a study of the X-ray emission from the Galactic Centre Molecular Clouds (MC), within 15 arcmin from Sgr A*. We use XMM-Newton data spanning about 8 years. We observe an apparent super-luminal motion of a light front…

High Energy Astrophysical Phenomena · Physics 2010-04-12 Gabriele Ponti , Regis Terrier , Andrea Goldwurm , Guillaume Belanger , Guillaume Trap

We present the result of a study of the X-ray emission from the Galactic Centre (GC) Molecular Clouds (MC) within 15 arcmin from Sgr A*. We use XMM-Newton data (about 1.2 Ms of observation time) spanning about 8 years. The MC spectra show…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Gabriele Ponti , Regis Terrier , Andrea Goldwurm , Guillaume Belanger , Guillaume Trap

We report the results of X-ray (2-10 keV) observations of the giant molecular clouds SgrB, SgrC and SgrD in the Galactic Center region, together with the discovery of the point-like source SAXJ1748.2-2808. The data have been obtained with…

Astrophysics · Physics 2009-11-06 L. Sidoli , S. Mereghetti , A. Treves , A. N. Parmar , R. Turolla , F. Favata

We investigated the emission of K$\alpha$ iron line from the massive molecular clouds in the Galactic center (GC). We assume that at present the total flux of this emission consists of time variable component generated by primary X-ray…

Astrophysics of Galaxies · Physics 2015-05-27 Vladimir Dogiel , Dmitrii Chernyshov , Katsuji Koyama , Masayoshi Nobukawa , Kwong-Sang Cheng

The relatively rapid spatial and temporal variability of the X-ray radiation from some molecular clouds near the Galactic center shows that this emission component is due to the reflection of X-rays generated by a source that was luminous…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Maïca Clavel , R. Terrier , A. Goldwurm , M. R. Morris , G. Ponti , S. Soldi , G. Trap

In the centre of our galaxy lies a super-massive black hole, identified with the radio source Sagittarius A*. This black hole has an estimated mass of around 4 million solar masses. Although Sagittarius A* is quite dim in terms of total…

High Energy Astrophysical Phenomena · Physics 2016-09-02 Michael Walls , Maria Chernyakova , Regis Terrier , Andrea Goldwurm

The diffuse X-ray background (DXB) emission near the Galactic plane ($l,b \sim 25.6^{\circ},0.78^{\circ}$) has been observed with $ASCA$. The observed region is toward a Galactic molecular cloud which was recently reported to cast a deep…

Astrophysics · Physics 2009-10-31 Sangwook Park , Ken Ebisawa

Using the Mopra telescope, we have undertaken a 3-mm spectral-line imaging survey of a 5 x 5 arcmin^2 area around Sgr B2. We covered almost the complete spectral the range from 81.7 to 113.5 GHz, with 2.2 MHz wide spectral channels or ~ 6…

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