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Related papers: Seyfert 1 Composite Spectrum using SDSS Legacy Sur…

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We present modeling and interpretation of the continuum and emission lines for a sample of 51 unobscured Type 1 active galactic nuclei (AGN). All of these AGNs have high quality spectra from both XMM-Newton and Sloan Digital Sky Survey…

High Energy Astrophysical Phenomena · Physics 2015-05-30 C. Jin , M. Ward , C. Done , J. M. Gelbord

We present the first look at the spectral and timing analysis of Narrow-Line Seyfert 1 Galaxies (NLS1s) with the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Spectrum-Roentgen-Gamma (SRG) mission. The…

High Energy Astrophysical Phenomena · Physics 2023-01-04 G. Grünwald , Th. Boller , S. Rakshit , J. Buchner , T. Dauser , M. Freyberg , T. Liu , M. Salvato , A. Schichtel

Narrow Line Seyfert 1 galaxies (NLS1) are very interesting objects which display peculiar properties when compared to their broad line analogues (BLS1). Although well studied in many wavebands, their behaviour at >10 keV is poorly studied…

We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio…

The evolution of the universe together with the galaxies is one of the fundamental issues that we humans are most interested in. Both the observations of tidal streams from SDSS and the theory of $\Lambda$CDM support the hierarchical…

Astrophysics of Galaxies · Physics 2025-04-16 Yanhui Chen

Preliminary results are presented for a spectroscopic survey of the Groth Survey Strip (GSS), a 40 by 3.5 arcminute region of the sky imaged with HST, for which several hundred galaxy spectra have been obtained as part of the DEEP project…

Astrophysics · Physics 2007-05-23 Vicki Sarajedini

We calculate the angular power spectrum of galaxies selected from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) by using a quadratic estimation method with KL-compression. The primary data sample includes over 18 million galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-30 Brett Hayes , Robert Brunner , Ashley Ross

We present near-IR integral field spectroscopy of a sample of 31 Seyfert and LINER galaxies which were selected both to span a wide range of nuclear magnitudes and to possess roughly equal numbers of Seyfert type 1 and 2 nuclei. Moderate…

Astrophysics · Physics 2009-11-06 R. M. Sosa-Brito , L. E. Tacconi-Garman , M. D. Lehnert , J. F. Gallimore

We present the results from a detailed analysis of photometric and spectrophotometric data on five Seyfert 1 galaxies observed as a part of a recent reverberation mapping program. The data were collected at several observatories over a…

We combine SDSS and WISE photometry for the full SDSS spectroscopic galaxy sample, creating SEDs that cover lambda=0.4-22 micron for an unprecedented large and comprehensive sample of 858,365 present-epoch galaxies. Using MAGPHYS we then…

Astrophysics of Galaxies · Physics 2015-07-10 Yu-Yen Chang , Arjen van der Wel , Elisabete da Cunha , Hans-Walter Rix

According to the unified model, the differences observed in different classes of AGN are due to anisotropic obscuration. This implies that in the hard X-rays, at energies where the radiation can pierce the obscuring material, the average…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-31 C. Ricci , R. Walter , T. J. -L. Courvoisier

Sloan Digital Sky Survey (SDSS) repeat spectroscopic observations have resulted in multiple-epoch spectroscopy for roughly 2500 quasars observed more than 50 days apart. From this sample, we identify 315 quasars that have varied…

We present the first edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists of the 3814 objects (3000 discovered by the SDSS) in the initial SDSS public data release that have at least one emission line with a…

(Abridged) I present a comprehensive and uniform analysis of 25 {\it ASCA} observations from 23 Narrow-line Seyfert 1 galaxies. The spectral analysis and correlations are presented in this paper, Part 2; the reduction and time series…

Astrophysics · Physics 2008-11-26 Karen M. Leighly

We present a detailed characterization of the 849 broad-line quasars from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. Our quasar sample covers a redshift range of 0.1<z<4.5 and is flux-limited to i_PSF<21.7 without…

The Far Ultraviolet Spectroscopic Explorer (FUSE) has surveyed a large sample (> 100) of active galactic nuclei in the low redshift universe (z < 1). Its response at short wavelengths makes it possible to measure directly the EUV spectral…

Aims. We present low-frequency radio imaging and spectral properties of a well defined sample of Seyfert galaxies using GMRT 240/610 MHz dual frequency observations. Radio spectra of Seyfert galaxies over 240 MHz to 5.0 GHz are investigated…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-23 Veeresh Singh , Prajval Shastri , Ishwara-Chandra C. H. , Ramana Athreya

We present preliminary results of the analysis of optical spectra of two complementary samples of Seyfert galaxies. The first sample was extracted from a selection of the 4th Fermi Gamma-ray Large Area Telescope (4FGL) catalog, and consists…

Astrophysics of Galaxies · Physics 2023-11-06 Benedetta Dalla Barba , Marco Berton , Luigi Foschini , Giovanni La Mura , Amelia Vietri , Stefano Ciroi

Accurate relative spectrophotometry is critical for many science applications. Small wavelength scale residuals in the flux calibration can significantly impact the measurements of weak emission and absorption features in the spectra. Using…

Instrumentation and Methods for Astrophysics · Physics 2011-10-14 Renbin Yan

We present preliminary results of the spectral analysis of a large sample of Seyfert galaxies observed by BeppoSAX. The only selection criterium was a sufficiently large S/N ratio (>10) in the PDS band (12-200 keV) to allow good detection…

Astrophysics · Physics 2009-11-10 P. O. Petrucci , M. Dadina