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相关论文: The Seyfert-Starburst Connection in X-rays. II. Re…

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We analyze X-ray spectra and images of a sample of Seyfert 2 galaxies that unambiguously contain starbursts, based on their optical and UV characteristics. Although all sample members contain active galactic nuclei (AGNs), supermassive…

天体物理学 · 物理学 2009-10-31 N. A. Levenson , K. A. Weaver , T. M. Heckman

We examine a representative sample of 35 Seyfert 2 nuclei. Previous work has shown that nearly 1/2 of these nuclei show the direct (but difficult-to-detect) spectroscopic signatures at optical-UV wavelengths of the hot massive stars that…

天体物理学 · 物理学 2009-11-06 R. Cid Fernandes , T. Heckman , H. Schmitt , R. Gonzalez Delgado , T. Storchi-Bergmann

It was once common to regard Seyfert and starburst galaxies as completely different types of object, but there is growing recognition that these classifications refer to the extremes of a continuous spectrum of galaxy types. In a previous…

天体物理学 · 物理学 2009-10-31 Tanya L. Hill , Charlene A. Heisler , Ray P. Norris , John E. Reynolds , Richard W. Hunstead

We present near-infrared spectra for a sample of galaxies with ambiguous optical emission line ratios. These galaxies fall between starbursts and Seyferts in the usual optical diagnostic diagrams. We find a similar result with the…

天体物理学 · 物理学 2009-10-31 Tanya L. Hill , Charlene A. Heisler , Ralph Sutherland , Richard W. Hunstead

We present optical spectra for new infrared Seyfert galaxies obtained with the 2.16m telescope at Beijing Astronomical Observatory (BAO). After wavelength and flux calibration, they are classified by the degree of nuclear activity: nine…

天体物理学 · 物理学 2007-05-23 Q. -S. Gu , J. -H. Huang , H. -J. Su , Z. -H. Shang

Obscured active galactic nuclei, which are classified optically as type 2 (narrow-line) Seyfert galaxies in the local universe, are by far the most promising candidates for the origin of the hard (2-10 keV) X-ray background radiation.…

天体物理学 · 物理学 2009-11-07 E. C. Moran , A. V. Filippenko , R. Chornock

High quality infrared spectra of active galaxies including the stellar absorption features of Si at 1.59 um, CO(6,3) at 1.62 um, and CO(2,0) at 2.29 um are used to measure the stellar mass to light ratio at 1.65 um (M_H/L) and investigate…

天体物理学 · 物理学 2007-05-23 E. Oliva , L. Origlia , R. Maiolino , A. F. M. Moorwood

The star formation (SF) can be regarded as an engine powering the light emission of spiral galaxies at several wavelengths. SF activity also plays a significant role in the evolution of galaxies. In this thesis we focus on the X-ray…

天体物理学 · 物理学 2009-09-29 Piero Ranalli

We present mid-infrared data of a sample of 57 AGNs obtained with the instrument ISOCAM on board the satellite ISO. The images were obtained through the LW2 (6.75 microns) and LW7 (9.62 microns) filters. This is a new analysis of Clavel et…

Far-infrared flux densities are newly extracted from the IRAS database for the RSA and CfA complete samples of Seyfert galaxies. These data are used to classify the Seyfert galaxies into those where the far-infrared continuum emission is…

天体物理学 · 物理学 2016-08-30 H. Mouri , Y. Taniguchi

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…

An analysis of archival mid-infrared (mid-IR) spectra of Seyfert galaxies from the Spitzer Space Telescope observations is presented. We characterize the nature of the mid-IR active nuclear continuum by subtracting a template starburst…

宇宙学与河外天体物理 · 物理学 2015-05-14 Rajesh. P. Deo , Gordon. T. Richards , D. M. Crenshaw , S. B. Kraemer

Starbursts are important because they can serve as local analogs of the processes that were important in the origin and early evolution of galaxies and in the heating and chemical enrichment of the inter-galactic medium. They may also play…

天体物理学 · 物理学 2007-05-23 Timothy M. Heckman

An enigmatic, small class of IR and X-ray luminous sources, named ``Composite'' starburst/Seyfert galaxies, has been defined from IRAS and RASS data. The objects have optical spectra dominated by the features of HII galaxies (plus, in some…

We present HST (WFPC2 and FOC) images and UV GHRS spectra plus ground-based optical spectra of four Luminous Infrared Galaxies (LIRGs) that have Seyfert 2 nuclei (Mrk 477, NGC 7130, NGC 5135 and IC 3639). The data provide direct evidence of…

天体物理学 · 物理学 2007-05-23 Rosa Gonzalez Delgado , Timothy Heckman

The relation between the X-ray, the coronal line and the infrared (IR) emissions in a sample of the brightest known Seyfert galaxies is analysed. A close relationship between the absorption-corrected soft X-ray emission and both the mid-IR…

天体物理学 · 物理学 2009-11-07 M. A. Prieto , A. M. Perez Garcia , J. M. Rodriguez Espinosa

We present NGC 6221 as a case study of ``X-ray loud composite galaxies,'' which appear similar to starbursts at optical wavelengths and resemble traditional active galactic nuclei in X-rays. The net optical spectrum of NGC 6221 is properly…

天体物理学 · 物理学 2012-08-27 N. A. Levenson , R. Cid Fernandes, , K. A. Weaver , T. M. Heckman , T. Storchi-Bergmann

We compare the arcsecond-scale circumnuclear radio continuum properties between five Seyfert and five starburst galaxies, concentrating on the search for any structures that could imply a spatial or causal connection between the nuclear…

天体物理学 · 物理学 2008-11-26 Seppo Laine , Jari K. Kotilainen , Juha Reunanen , Stuart D. Ryder , Rainer Beck

Aims. The synthesis of the cosmic X-ray background (CXB) requires a large population of Compton-thick active galactic nuclei that have not been detected so far. We probe whether bright infrared galaxies could harbor a population of…

高能天体物理现象 · 物理学 2009-11-13 R. Walter , N. Cabral

Active galaxies are often associated with starbursts, which are possible sources of fuelling for the nuclear black holes. By means of optical (3500-7500 A) spectroscopic and narrow-band photometric data (H_alpha+[NII]6548,6583 and…

天体物理学 · 物理学 2007-05-23 A. Romano , A. Rifatto , S. Ciroi , P. Rafanelli , M. Dopita
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