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相关论文: The Diagnostics and Possible Evolution in Active G…

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A survey for H2O megamaser emission from 354 active galaxies has resulted in the detection of 10 new sources, making 16 known altogether. The galaxies surveyed include a distance-limited sample (covering Seyferts and LINERs with recession…

天体物理学 · 物理学 2009-10-30 J. A. Braatz , A. S. Wilson , C. Henkel

We present oxygen abundances relative to hydrogen (O/H) in the narrow line regions (NLRs) gas phases of Seyferts 1 (Sy 1s) and Seyferts 2 (Sy 2s) Active Galactic Nuclei (AGNs). We used fluxes of the optical narrow emission line intensities…

Starbursts are episodes of intense star-formation in the central regions of galaxies, and are the sites of roughly 25% of the high-mass star-formation in the local universe. In this contribution I review the role starbursts play in the…

天体物理学 · 物理学 2009-10-31 Timothy M. Heckman

Far-Infrared (FIR) photometry from the the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory is presented for 313 nearby, hard X-ray selected galaxies from the 58-month Swift Burst Alert Telescope (BAT)…

星系天体物理 · 物理学 2015-06-22 M. Meléndez , R. F. Mushotzky , T. T. Shimizu , A. J. Barger , L. L. Cowie

We present a three-dimensional study of the local (<100 h^-1} kpc) and the large scale (<1 h^{-1} Mpc) environment of the two main types of Seyfert AGN galaxies. For this purpose we use 48 Sy1 galaxies (with redshifts in the range…

天体物理学 · 物理学 2009-11-13 E. Koulouridis , M. Plionis , V. Chavushyan , D. Dultzin-Hacyan , Y. Krongold , C. Goudis

To investigate the dependence of the occurrence of active galactic nuclei (AGNs) on local galaxy density, we study the nuclear properties of ~5000 galaxies in the Coma Supercluster whose density spans 2 orders of magnitude from the sparse…

宇宙学与河外天体物理 · 物理学 2015-05-28 Giuseppe Gavazzi , Giulia Savorgnan , Mattia Fumagalli

We present archival Hubble Space Telescope images of the nuclear regions of 43 of the 46 Seyfert galaxies found in the volume-limited, spectroscopically-complete CfA Redshift Survey sample. Using an improved method of image contrast…

天体物理学 · 物理学 2009-11-07 Richard W. Pogge , Paul Martini

We have studied the relationship between the high- and low-ionization [O IV] lambda 25.89 micron, [Ne III] lambda 15.56 micron and [Ne II] lambda 12.81 micron emission lines with the aim of constraining the active galactic nuclei (AGN) and…

No. Due to their apparently extreme optical to X-ray properties, Narrow Line Seyfert 1s (NLSy1s) have been considered a special class of active galactic nuclei (AGN). Here, we summarize observational results from different groups to…

The galaxies M82, NGC 253, NGC 1068, and NGC 4945 have been detected in gamma-rays by Fermi. Previously, we developed and tested a model for cosmic ray interactions in the starburst galaxy M82. Now, we aim to explore the differences between…

高能天体物理现象 · 物理学 2015-06-18 Tova M. Yoast-Hull , J. S. Gallagher , Ellen G. Zweibel , John E. Everett

We present an analysis of the host properties of 85224 emission-line galaxies from the Sloan Digital Sky Survey. We show that Seyferts and LINERs form clearly separated branches on the standard optical diagnostic diagrams. We derive a new…

天体物理学 · 物理学 2009-07-09 Lisa J. Kewley , Brent Groves , Guinevere Kauffmann , Tim Heckman

The revision of the fourth Fermi Large Area Telescope (LAT) catalog of gamma-ray point sources (rev4FGL) revealed that the gamma-ray sky is populated by emerging populations of jetted active galactic nuclei (AGN) other than blazars and…

高能天体物理现象 · 物理学 2026-01-27 Luigi Foschini

We report R~3000 VLT ISAAC K-band spectroscopy of the nuclei (i.e. central 100-300pc) of 9 galaxies hosting an active galactic nucleus. For 5 of these we also present spectra of the circumnuclear region out to 1kpc. We have measured a…

天体物理学 · 物理学 2009-11-13 R. I. Davies , A. Sternberg , M. D. Lehnert , L. E. Tacconi-Garman

We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…

星系天体物理 · 物理学 2010-01-15 G. D. Thompson , N. A. Levenson , S. A. Uddin , M. M. Sirocky

We present an analysis of 10 ks snapshot Chandra observations of 12 shocked post-starburst galaxies, which provide a window into the unresolved question of active galactic nuclei (AGN) activity in post-starburst galaxies and its role in the…

In this paper we report the discovery of a new class of active galactic nucleus in which although the nucleus is viewed directly, no broad emission lines are present. The results are based on a survey for AGN in which a sample of about 800…

天体物理学 · 物理学 2009-11-10 M. R. S. Hawkins

We present the results of IRS low-resolution spectroscopy of 51 Seyfert galaxies, part of a large Spitzer observing program to determine the mid-to-far infrared spectral energy distributions of a well-defined sample of 87 nearby, 12…

We investigated the 65$\mu$m, 71$\mu$m, 79$\mu$m, 84$\mu$m, 119$\mu$m, and 163$\mu$m OH doublets of 178 local (0 < $z$ < 0.35) galaxies. They were observed using the $Herschel$/PACS spectrometer, including Seyfert galaxies, LINERs, and…

We present the first AGN census in a sample of 61 galaxies selected at 70microns, a wavelength which should strongly favour the detection of star-forming systems. For the purpose of this study we take advantage of deep Chandra X-ray and…

宇宙学与河外天体物理 · 物理学 2015-05-14 M. Symeonidis , D. Rosario , A. Georgakakis , J. Harker , E. S. Laird , M. J. Page

Post-StarBurst (PSB) galaxies are galaxies that have undergone a large burst of star formation followed by rapid quenching. Understanding their properties as a population can help us better understand how galaxies evolve to quiescence. This…