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相关论文: Intermediate Inclinations of Type 2 Coronal-Line F…

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We explore host galaxy properties and environment of a sample of Type 1 and 2 active galactic nuclei (AGN) taken from the COSMOS2015 catalog, within 0.3 $\leq z \leq$ 1.1 selected for their emission in X-rays, optical spectra and SED…

星系天体物理 · 物理学 2018-07-11 Carlos Guillermo Bornancini , Diego García Lambas

Extended narrow-line regions (NLRs) around active galactic nuclei (AGN) are shaped by the distribution of gas in the host galaxy and by the geometry of the circumnuclear obscuration, and thus they can be used to test the AGN unification…

We have conducted a series of investigations on the geometry of the reddening material in AGNs, which have important implications to the AGN unification and SMBH demography. According to our statistics of partially obscured quasars, we…

星系天体物理 · 物理学 2009-03-25 Kai Zhang , Tinggui Wang , Xiaobo Dong , Hongyan Zhou , Honglin Lu

We present spectroscopic observations of the type 2 quasar SDSS J11311.05+162739.5 (Q1131+16 hereafter; z=0.1732), which has the richest spectrum of forbidden high ionisation lines (FHIL, e.g. [Fe \textsc{vii}], [Fe \textsc{x}], [Fe…

宇宙学与河外天体物理 · 物理学 2015-05-27 Marvin Rose , Clive Tadhunter , Joanna Holt , Cristina Ramos Almeida , Stuart Littlefair

Emission-line studies in the active galactic nuclei (AGNs), particularly those utilizing high spatial resolution, provide the most accurate method to determine critical quantities of the central engine and of the gas a few tens of parsecs…

The Wide-field Infrared Survey Explorer (WISE) has scanned the entire sky with unprecedented sensitivity in four infrared bands, at 3.4, 4.6, 12, and 22 micron. The WISE Point Source Catalog contains more than 560 million objects, among…

星系天体物理 · 物理学 2015-06-18 Robert Nikutta , Maia Nenkova , Zeljko Ivezic , Nicholas Hunt-Walker , Moshe Elitzur

We report spectroscopic observations in the wavelength region 0.8-2.4 microns aimed at detecting near-infrared coronal lines in a sample of 5 narrow-line and 1 broad-line Seyfert 1 galaxies. Our measurements show that [SiVI] 1.963mu, [SIX]…

天体物理学 · 物理学 2009-11-07 Alberto Rodriguez-Ardila , Sueli M. Viegas , Miriani G. Pastoriza , Lisa Prato

Mid-resolution spectra are used to deduce the size and kinematics of the coronal gas in a sample of Seyfert galaxies by means of observations of the [FeXI], [FeX], [FeVII], [SiVI] and [SiVII] lines. These coronal lines (CL) extend from the…

天体物理学 · 物理学 2008-11-26 Alberto Rodriguez-Ardila , M. A. Prieto , S. Viegas , R. Gruenwald

Context: We investigate mid-infrared and X-ray properties of the dusty torus invoked in the unification scenario for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain the geometry and…

天体物理学 · 物理学 2009-11-13 Hannes Horst , Poshak Gandhi , Alain Smette , Wolfgang J. Duschl

In this paper, we present a semi-empirical calibration between the oxygen abundance and the $N2$ emission-line ratio for Low Ionization Nuclear Emission Regions (LINERs). This relation was derived by comparing the optical spectroscopic data…

A cornerstone of AGN unification schemes is the presence of an optically and geometrically thick dust torus. It provides the obscuration to explain the difference between type 1 and type 2 AGN. We investigate the influence of the dust…

天体物理学 · 物理学 2007-09-24 Sebastian F. Hoenig , Thomas Beckert

We investigate the physical cause of the great range in the ionization level seen in the spectra of narrow lined active galactic nuclei (AGN). Mean field independent component analysis identifies examples of individual SDSS galaxies whose…

宇宙学与河外天体物理 · 物理学 2015-06-17 Chris T. Richardson , James T. Allen , Jack A. Baldwin , Paul C. Hewett , Gary J. Ferland

The presence of an obscuring torus at pc-scale distances from the central black hole is the main ingredient for the Unified Model of Active Galactic Nuclei (AGN), as obscured sources are thought to be seen through this structure. However,…

We study the narrow emission line properties and stellar populations of a sample of 1385 AGN selected to have strong excess emission at mid-infrared wavelengths based on comparing Wide-field Infrared Survey Explorer W1-W2 band colours with…

星系天体物理 · 物理学 2018-08-15 Guinevere Kauffmann

We present optical imaging and long slit spectroscopic observations of 9 luminous type 2 AGNs within the redshift range 0.3<z<0.6 based on VLT-FORS2 data. Most objects (6/9) are high luminosity Seyfert 2, and three are type 2 quasars…

We study the properties of a sample of 211 heavily-obscured Active Galactic Nucleus (AGN) candidates in the Extended Chandra Deep Field-South selecting objects with f_24/f_R>1000 and R-K>4.5. Of these, 18 were detected in X-rays and found…

VLT and NTT spectra are used to examine the nuclear and extended coronal line emission in a sample of well-known Seyfert 1 and 2 galaxies. The excellent spatial resolution obtained with VLT allowed us to map [SiVI] 1.963 $\mu$m and [SiVII]…

天体物理学 · 物理学 2009-11-10 A. Rodriguez-Ardila , A. Prieto , S. M. Viegas

The motivation of the "unified model" is to explain the main properties of the large zoo of active galactic nuclei with a single physical object. The discovery of broad permitted lines in the polarized spectrum of type 2 Seyfert galaxies in…

星系天体物理 · 物理学 2021-02-03 Luigi Spinoglio , Juan Antonio Fernández-Ontiveros

Spectra of extranuclear clouds within the ionization cone of Circinus galaxy are presented and modelled assuming photoionization by the Seyfert 2 nucleus but no preconceived assumption concerning the spectral shape of the ionizing AGN…

天体物理学 · 物理学 2007-05-23 E. Oliva , A. Marconi , A. F. M. Moorwood

We report the discovery of six active galactic nuclei (AGN) caught "turning on" during the first nine months of the Zwicky Transient Facility (ZTF) survey. The host galaxies were classified as LINERs by weak narrow forbidden line emission…