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We present Chandra X-ray observations of the nearby Seyfert 1.5 galaxy NGC 4151. The images show the extended soft X-ray emission on the several hundreds of pc scale with better sensitivity than previously obtained. The spectrum of the…

Astrophysics · Physics 2009-11-07 Y. Yang , A. S. Wilson , P. Ferruit

We present an analysis of the time-averaged spectrum of the Seyfert-2 active galaxy NGC 4388, obtained by NICER. The intrinsic strength of the reflection spectrum in NGC 4388, the large collecting area and favorable pass band of NICER, and…

High Energy Astrophysical Phenomena · Physics 2019-11-06 J. M. Miller , E. Kammoun , R. M. Ludlam , K. Gendreau , Z. Arzoumanian , E. Cackett , F. Tombesi

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Rajesh. P. Deo , Gordon. T. Richards , D. M. Crenshaw , S. B. Kraemer

We discuss implications of a stellar-dominated UV background at high redshifts. The composite spectrum of 29 LBGs evaluated by Steidel etal (2000) at <z>=3.4 can be well fit by a stellar population with ongoing star formation, a Salpeter…

Astrophysics · Physics 2009-10-31 Martin G. Haehnelt , Piero Madau , Rolf P. Kudritzki , Francesco Haardt

We present observations of the O VI system at z_abs = 0.495096 toward PKS 0405-123 (z_em = 0.5726) obtained with FUSE and STIS. In addition to strong O VI, with log N(O VI) = 14.47+/-0.02, and moderate H I this absorber shows C III, N IV, O…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-25 J. Christopher Howk , Joseph S. Ribaudo , Nicolas Lehner , J. Xavier Prochaska , Hsiao-Wen Chen

The correlation between the soft X-ray and near infrared emission from AGN is analysed using composite models by the code SUMA. We find new evidences for differences in ranges of parameters which characterize the NLR of Seyfert galaxies and…

Astrophysics · Physics 2009-11-10 M. Contini , S. M. Viegas , P. E. Campos

The most important cooling lines of the neutral interstellar medium (ISM) lie in the far-infrared (FIR). We present measurements by the Infrared Space Observatory Long Wavelength Spectrometer of seven lines from neutral and ionized ISM of…

JHKL'M (1-5 micron) imaging of a sample of Seyfert (Sy) 2 galaxies is presented. We confirm that the 1-2.2 micron nuclear continuum of some Sy 2s is dominated by stellar emission, whereas the continuum emission at longer wavelengths (3-5…

Astrophysics · Physics 2009-10-31 A. Alonso-Herrero , A. C. Quillen , C. Simpson , A. Efstathiou , M. J. Ward

We present Infrared Space Observatory (ISO) observations of fine structure lines toward the Radio Arc region, close to Sgr A, in the Galactic center region (GCR). The ionization at large scale is dominated by the clusters of massive stars…

Astrophysics · Physics 2009-11-07 N. J. Rodriguez-Fernandez , J. Martin-Pintado , P. de Vicente

This paper is the second in a series, studying the optical properties of a sample of mid-IR Warm Seyfert galaxies and a control sample of mid-IR Cold galaxies. The present paper is devoted to aperture photometry. We discuss nuclear (within…

Astrophysics · Physics 2009-10-31 Eleni T. Chatzichristou

The X-ray and mid-IR emission from active galactic nuclei (AGN) are strongly correlated. However, while various published parameterizations of this correlation are consistent with the low-redshift, local Seyfert galaxy population,…

Astrophysics of Galaxies · Physics 2015-07-15 Daniel Stern

Broad-band polarimetry and spectropolarimetry of a complete sample of 18 luminous AGNs (Lbol > 10^11.5 Lsun), selected in an orientation-independent way by warm infrared flux, shows that an orientation-dust-covering Unified Scheme like that…

Astrophysics · Physics 2007-05-23 Beverley J. Wills , Dean C. Hines

Correlated variability between coronal X-rays and disc optical/UV photons provides a very useful diagnostic of the interplay between the different regions around an active galactic nucleus (AGN) and how they interact. AGN that reveal strong…

High Energy Astrophysical Phenomena · Physics 2023-12-13 Samuzal Barua , Oluwashina K. Adegoke , Ranjeev Misra , Pramod Pawar , V. Jithesh , Biman J. Medhi

We report the results of a spectropolarimetric survey of a complete far infrared selected sample of Seyfert 2 galaxies. We have found polarized broad Halpha emission in one new source, NGC5995. In the sample as a whole, there is a clear…

Astrophysics · Physics 2009-11-06 S. L. Lumsden , C. A. Heisler , J. A. Bailey , J. H. Hough , S. Young

We report the discovery of a strong CIV 1548,1550 absorption system at z_abs = 5.7238 in the near-infrared spectrum (J-band) of the z_em = 6.28 QSO SDSS J1030+0524. These observations, obtained with the Infrared Spectrometer And Array…

Astrophysics · Physics 2009-11-11 Emma V. Ryan-Weber , Max Pettini , Piero Madau

We present the second extensive study of the coronal line variability in an active galaxy. Our data set for the well-studied Seyfert galaxy NGC 5548 consists of five epochs of quasi-simultaneous optical and near-infrared spectroscopy…

Astrophysics of Galaxies · Physics 2015-10-28 Hermine Landt , Martin J. Ward , Katrien C. Steenbrugge , Gary J. Ferland

We report the spectral analysis of a long XMM-Newton observation of the well-studied, moderate luminosity Broad Line Seyfert 1 galaxy NGC 5548. The source was at an historically average brightness and we find the hard (3-10 keV) spectrum…

Astrophysics · Physics 2011-07-19 K. A. Pounds , J. N. Reeves , K. L. Page , R. Edelson , G. Matt , G. C. Perola

We use hard X-ray data for an "optimal" sample of Seyfert 2 galaxies to derive the distribution of the gaseous absorbing column densities among obscured active nuclei in the local Universe. Of all Seyfert 2 galaxies in the sample, 75% are…

Astrophysics · Physics 2009-10-31 G. Risaliti , R. Maiolino , M. Salvati

We report spectro-imaging observations of the bright western ridge of the supernova remnant IC 443 obtained with the ISOCAM circular variable filter (CVF) on board the Infrared Space Observatory (ISO). This ridge corresponds to a location…

We investigate the properties of the ionized gas irradiated by an active galactic nucleus (AGN) based on our "radiation-driven fountain" model for the nearest type-2 Seyfert galaxy, the Circinus galaxy (Wada et al. 2016). We conducted…

Astrophysics of Galaxies · Physics 2018-11-07 Keiichi Wada , Kensuke Yonekura , Tohru Nagao
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