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Related papers: The Sgr A* Stellar Cluster: New NIR Imaging and Sp…

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We present radio and mm continuum observations of the Galactic center taken with the VLA and ALMA at 44 and 226 GHz, respectively. We detect radio and mm emission from IRS 3, lying ~4.5" NW of Sgr A*, with a spectrum that is consistent with…

Astrophysics of Galaxies · Physics 2017-03-15 F. Yusef-Zadeh , M. Wardle , W. Cotton , R. Schödel , M. J. Royster , D. A. Roberts , D. Kunneriath

The goal of the present paper is to investigate the circumstellar material around the brightest dust-enshrouded sources in the central stellar cluster of the Milky Way. Observations have been carried out at the European Southern…

Astrophysics of Galaxies · Physics 2009-10-02 J. Moultaka , A. Eckart , R. Schödel

Integral field spectroscopy of the central parsec of the Galactic Center was obtained at 2.06 microns using BEAR, an imaging Fourier Transform Spectrometer, at a spectral resolution of 74 km/s. Sixteen stars were confirmed as helium stars…

Astrophysics · Physics 2016-08-30 T. Paumard , J. P. Maillard , M. Morris , F. Rigaut

We present the results of a deep (1.1 Ms) observation of the Coma cluster of galaxies in the 18-30 keV band with the IBIS/ISGRI imager on board the INTEGRAL satellite. We show that the source extension in the North-East to South-West (SW)…

Astrophysics · Physics 2007-10-25 D. Eckert , N. Produit , A. Neronov , T. J. -L. Courvoisier

We have observed the Galactic Center (GC) region at 0.154 and 0.255 GHz with the GMRT. A total of 62 compact likely extragalactic sources are detected. Their scattering sizes go down linearly with increasing angular distance from the GC up…

Astrophysics of Galaxies · Physics 2015-06-16 Subhashis Roy

We present three dimensional spectroscopy of eleven E+A galaxies, selected for their strong H-delta absorption but weak (or non-existent) [OII]3727 and H-alpha emission. This selection suggests that a recent burst of star-formation was…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 Mark Swinbank , Michael Balogh , Richard Bower , Ann Zabludoff , John Lucey , Sean McGee , Chris Miller , Robert Nichol

We report the detection of strong absorption and weak emission features in the 4--27 micron Spitzer-IRS spectrum of the distant ultraluminous infrared galaxy (ULIRG) IRAS F00183--7111 (z=0.327). The absorption features of CO2 and CO gas,…

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…

Astrophysics · Physics 2009-11-13 Avery E. Broderick , Abraham Loeb

We aim at modelling small groups of young stars such as IRS 13N, 0.1 pc away from Sgr A*, which is suggested to contain a few embedded massive young stellar objects. We perform hydrodynamical simulations to follow the evolution of molecular…

Astrophysics of Galaxies · Physics 2015-06-17 B. Jalali , I. Pelupessy , A. Eckart , S. Portegies Zwart , N. Sabha , A. Borkar , J. Moultaka , K. Muzic , L. Moser

The Bolocam Galactic Plane Survey (BGPS) data for a six square degree region of the Galactic plane containing the Galactic center is analyzed and compared to infrared and radio continuum data. The BGPS 1.1 mm emission consists of clumps…

We performed a systematic analysis of the 4.67 $\mu$m CO ro-vibrational absorption band toward nearby active galactic nuclei (AGNs) and analyzed the absorption profiles of ten nearby galaxies collected from the AKARI and Spitzer…

Astrophysics of Galaxies · Physics 2018-01-24 S. Baba , T. Nakagawa , N. Isobe , M. Shirahata

Most galactic nuclei are now believed to harbour supermassive black holes. Studies of stellar motions in the central few light-years of our Milky Way Galaxy indicate the presence of a dark object with a mass of about 2.6 million solar…

A CO(1-0) on-source spectrum of the well-known carbon star IRC+10216 taken with the IRAM 30m telescope in June 1996 shows excess emission between -18.3 and -14.3 km/s at the red wing of the underlying profile. The excess emission is…

Astrophysics · Physics 2009-09-25 M. A. T. Groenewegen , H. -G. Ludwig

Context. In the near- to mid-infrared wavelength domain, bright continuum sources in the central parsec of the Galactic center (GC) are subject to foreground absorption. These sources therefore represent ideal probes of the intervening…

Astrophysics of Galaxies · Physics 2019-06-12 Jihane Moultaka , Andreas Eckart , Kiran Tikare , Armelle Bajat

An attempt is made to reconcile the large wind-loss rates of stars in the Galactic Centre (GC) with the predicted low accretion rate for Sgr A*, the putative blackhole at the heart of the Milky Way. It is found that, independent of the…

Astrophysics · Physics 2016-08-30 R. F. Coker

We present high-resolution multiwavelength radio continuum images of the region within 150$"$ of Sgr A*, revealing a number of new extended features and stellar sources in this region. First, we detect a continuous 2" east-west ridge of…

Astrophysics of Galaxies · Physics 2016-03-16 F. Yusef-Zadeh , M. Wardle , R. Schödel , D. A. Roberts , W. Cotton , H. Bushouse , R. Arendt , M. Royster

The super-massive 4 million solar mass black hole Sagittarius~A* (SgrA*) shows flare emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light curves allows us to address the accretion phenomenon in a…

We present a spectrum of Sgr A* observed simultaneously on June 17, 2003 at wavelengths from 90 to 0.7 cm with the VLA. In the spectrum, we also include the measurements of Sgr A* observed on the same day with the GMRT at 49 cm, the SMA at…

Astrophysics · Physics 2007-05-23 T. An , J. -H. Zhao , X. -Y. Hong , Z. -Q. Shen , W. M. Goss , S. Roy , A. P. Rao

We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5--11 campaign. The observations were carried…

High Energy Astrophysical Phenomena · Physics 2023-11-16 The Event Horizon Telescope Collaboration

Diffuse X-rays from the Galactic center (GC) region were found to exhibit many K-shell lines from iron and nickel atoms in the 6--9 keV band. The strong emission lines seen in the spectrum are neutral iron K$\alpha$ at 6.4~keV, He-like iron…

High Energy Astrophysical Phenomena · Physics 2010-07-29 T. G. Tsuru , H. Uchiyama , M. Nobukawa , M. Sawada , S. G. Ryu , R. Fukuoka , K. Koyama