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Related papers: The Galactic Center: Not an Active Galactic Nucleu…

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We present direct measures of the ionization fractions of several sulfur ions in the Galactic warm ionized medium (WIM). We obtained high resolution ultraviolet absorption line spectroscopy of post-asymptotic giant branch stars in the the…

Astrophysics of Galaxies · Physics 2015-06-11 J. Christopher Howk , S. Michelle Consiglio

We report ALMA observations with resolution $\approx0.5$" at 3 mm of the extended Sgr B2 cloud in the Central Molecular Zone (CMZ). We detect 271 compact sources, most of which are smaller than 5000 AU. By ruling out alternative…

We present the first systematic investigation of the [NeV] (14um/24um) and [SIII] (18um/33um) infrared line flux ratios, traditionally used to estimate the density of the ionized gas, in a sample of 41 Type 1 and Type 2 active galactic…

Astrophysics · Physics 2009-06-23 R. P. Dudik , J. C. Weingartner , S. Satyapal , J. Fischer , C. C. Dudley , B. O'Halloran

The Galactic centre - as the closest galactic nucleus - holds both intrinsic interest and possibly represents a useful analogue to star-burst nuclei which we can observe with orders of magnitude finer detail than these external systems. The…

Astrophysics of Galaxies · Physics 2015-06-03 Roland M. Crocker

To better characterize the upper end of the galaxy stellar mass range, the MUSE Most Massive Galaxies (M3G) Survey targeted the most massive galaxies (M$>10^{12}$ M$_{\odot}$) found in the densest known clusters of galaxies at $z\sim0.046$.…

Astrophysics of Galaxies · Physics 2021-05-12 I. Pagotto , D. Krajnović , M. den Brok , E. Emsellem , J. Brinchmann , P. M. Weilbacher , W. Kollatschny , M. Steinmetz

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

Diffuse 511 keV line emission, from the annihilation of cold positrons, has been observed in the direction of the Galactic Centre for more than 30 years. The latest high-resolution maps of this emission produced by the SPI instrument on…

Astrophysics · Physics 2009-11-13 Reba M. Bandyopadhyay , Joseph Silk , James E. Taylor , Thomas J. Maccarone

The nucleus of M87 displays a LINER spectrum at optical wavelengths, with a nuclear disk of nebulosity that is resolved by the Hubble Space Telescope. We present new results from optical and ultraviolet spectra of the central ~40pc as…

Astrophysics · Physics 2009-11-07 B. M. Sabra , J. C. Shields , L. C. Ho , A. J. Barth , A. V. Filippenko

We present the first interferometric molecular line and dust emission maps for the Galactic Center (GC) cloud G0.253+0.016, observed using the Combined Array for Research in Millimeter--wave Astronomy (CARMA) and the Submillimeter Array…

Astrophysics of Galaxies · Physics 2015-06-12 Jens Kauffmann , Thushara Pillai , Qizhou Zhang

The massive infrared dark cloud G0.253+0.016 projected 45pc from the Galactic centre contains ~10^5Msun of dense gas whilst being mostly devoid of observed star-formation tracers. To scrutinise the physical properties, dynamics and…

Astrophysics of Galaxies · Physics 2014-11-12 K. G. Johnston , H. Beuther , H. Linz , A. Schmiedeke , S. E. Ragan , Th. Henning

We present Hubble Space Telescope Wide Field Camera 3 slitless grism spectroscopy of 28 emission-line galaxies at z~2, in the GOODS-S region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). The high…

Mid-infrared molecular hydrogen (H$_2$) emission is a powerful cooling agent in galaxy mergers and in radio galaxies; it is a potential key tracer of gas evolution and energy dissipation associated with mergers, star formation, and…

This {\it supplement} paper presents the maps of HCN $J$=4-3, HNC $J$=1-0, $\mathrm{H^{13}CN}$ $J$=1-0, and HC$_3$N $J$=10-9 for the Galactic central molecular zone (CMZ), which have been obtained using the Atacama Submillimeter Telescope…

Astrophysics of Galaxies · Physics 2018-06-13 Kunihiko Tanaka , Makoto Nagai , Kazuhisa Kamegai , Takahiro Iino. , Takeshi Sakai

We investigate the X-ray emission from the Galactic Centre (GC) region, focusing on the 6.4 keV fluorescent line of neutral or weakly ionised iron, which is commonly attributed to X-ray reflection from dense molecular clouds. Our goal is to…

High Energy Astrophysical Phenomena · Physics 2025-05-16 K. Anastasopoulou , I. Khabibullin , E. Churazov , G. Ponti , M. C. Sormani , R. A. Sunyaev , C. Maitra , S. Piscitelli

We showed that if the non-thermal emission from the Galactic center in the range 14-40 keV is due to inverse bremsstrahlung emission of subrelativistic protons, their interactions with hot and cold fractions of the interstellar medium are…

We model gas and dust emission from regions 0.3-20 AU from a central low mass star in intermediate-aged(~10Myr) disks with optically thin dust. The models treat thermal balance and chemistry self-consistently and calculate the vertical…

Astrophysics · Physics 2009-11-10 Uma Gorti , David Hollenbach

Using the 20-pixel camera SHARC, we have surveyed the 350 micron emission from a 60 arcminute by 12 arcminute region in the Galactic center. A comparable region has been observed at 800 microns by Lis & Carlstrom (1994); the SHARC map has…

Astrophysics · Physics 2007-05-23 C. D. Dowell , D. C. Lis , E. Serabyn , M. Gardner , A. Kovacs , S. Yamashita

The H3O+ molecule probes the oxygen chemistry and the ionization rate of dense circumnuclear gas in galaxies. In particular, recent H3O+ observations show variations in the cosmic-ray ionization rate by factors of $>$10 within our Galaxy.…

Astrophysics · Physics 2009-11-13 Floris van der Tak , Susanne Aalto , Rowin Meijerink

The emission-line intensity ratios are used to distinguish the main sources of gas ionization to study the state of galactic interstellar medium (ISM). In intermediate cases, when the contributions of radiation from some sources mix, the…

Astrophysics of Galaxies · Physics 2022-07-26 Behjat Zarei Jalalabadi , Abbas Abedi , Alexei V. Moiseev