English
Related papers

Related papers: Polarized Broad-Line Emission from Low-Luminosity …

200 papers

The first complete far-infrared spectrum (43-197um) of the Seyfert 2 galaxy NGC 1068 as observed with the LWS onboard ISO is reported. In addition to the expected ionic fine structure emission lines, the OH rotational lines at 79, 119 and…

We report on a study of forbidden emission-line spectrum of nearby Seyfert 1.5 galaxy NGC 4151 based on the high-resolution (R ~ 45,000) optical spectrum obtained by using the High Dispersion Spectrograph boarded on the Subaru Telescope.…

Astrophysics · Physics 2009-11-07 Tohru Nagao , Takashi Murayama , Yasuhiro Shioya , Yoshiaki Taniguchi

We present spatially resolved Chandra HETGS observations of the Seyfert 2 galaxy NGC 1068. X-ray imaging and high resolution spectroscopy are used to test the Seyfert unification theory. Fe K-alpha emission is concentrated in the nuclear…

Astrophysics · Physics 2009-11-07 P. M. Ogle , T. Brookings , C. R. Canizares , J. C. Lee , H. L. Marshall

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 report on sensitive dual-frequency (1.7 and 5 GHz) European VLBI Network observations of the central region of nine Seyfert galaxies. These sources are among the faintest and least luminous members of a complete sample of nearby (d<22…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 P. Bontempi , M. Giroletti , F. Panessa , M. Orienti , A. Doi

The detection of significant $\gamma$-ray emission from radio-loud narrow line Seyfert 1 (NLSy1s) galaxies enables us to study jets in environments different than those in blazars. However, due to the small number of known $\gamma$-ray…

High Energy Astrophysical Phenomena · Physics 2018-01-23 Vaidehi S. Paliya , M. Ajello , S. Rakshit , A. Mandal , C. S. Stalin , A. Kaur , D. Hartmann

We present spectral and timing results from a long (130 ks) XMM-NEWTON EPIC observation of the nucleus of the Seyfert/LINER galaxy M 81. During the observation the X-ray flux varied by 20%, but there was no significant change in spectral…

Astrophysics · Physics 2009-11-10 M. J. Page , R. Soria , S. Zane , K. Wu , R. Starling

We investigate spatially-resolved emission-line ratios in a sample of 219 galaxies ($0.6<z<1.3$) detected using the G102 grism on the \emph{Hubble Space Telescope} Wide Field Camera 3, taken as part of the CANDELS Ly$\alpha$ Emission at…

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…

New spectra of NGC 2992 from the Cerro Tololo Inter-American Observatory show that this nearby AGN has changed its type classification to a Seyfert 2 in 2006. It was originally classified as a Seyfert 1.9, and has been previously seen as a…

Astrophysics · Physics 2014-10-01 M. L. Trippe , D. M. Crenshaw , R. Deo , M. Dietrich

We focus on determining the underlying physical cause of a Seyfert galaxy's appearance as type a 1.8 or 1.9. Are these "intermediate" Seyfert types typical Seyfert 1 nuclei with reddened broad-line regions? Or are they objects with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 M. L. Trippe , D. M. Crenshaw , R. P. Deo , M. Dietrich , S. B. Kraemer , S. E. Rafter , T. J. Turner

We explore the properties of ionized gas in the nuclear and circumnuclear environment of the narrow-line Seyfert 1 galaxy NGC 4051 using spectroscopic and imaging observations from the Hubble Space Telescope (HST) and Apache Point…

Active Galactic Nuclei (AGN) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight. However, except for a few special cases, the specific inclinations…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 T. C. Fischer , D. M. Crenshaw , S. B. Kraemer , H. R. Schmitt

The nearby Seyfert 2 Galaxy NGC 1068 was observed with speckle imaging techniques in the near-infrared H-band (1.6 microns) at the Hale 200-inch Telescope and K-band (2.2 microns) at the 10 m Keck I Telescope. Images with diffraction…

Astrophysics · Physics 2009-10-31 A. J. Weinberger , G. Neugebauer , K. Matthews

Seyfert galaxies have traditionally been classified as radio-quiet active galactic nuclei. A proper consideration of the nuclear optical emission however proves that a majority of Seyferts are radio-loud. Kpc-scale radio lobes/bubbles are…

Astrophysics of Galaxies · Physics 2014-03-13 P. Kharb , V. Singh , J. F. Gallimore , C. H. Ishwara-Chandra

The origin of the unification model for Active Galactic Nuclei (AGN) was the detection of broad hydrogen recombination lines in the optical polarized spectrum of the Seyfert 2 galaxy (Sy2) NGC 1068. Since then, a search for the hidden…

We use X-ray observations of three galaxies hosting LINERs (NGC 404, NGC 4736, NGC 4579) with Chandra to study their power sources. We find very diverse properties within this small group: NGC 404 has an X-ray-faint nucleus with a soft,…

Astrophysics · Physics 2009-11-07 M. Eracleous , J. C. Shields , G. Chartas , E. C. Moran

We are now exploring the inner region of Type 1 active galactic nuclei (AGNs) with the Keck interferometer in the near-infrared. Adding to the four targets previously studied, we report measurements of the K-band (2.2 um) visibilities for…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Makoto Kishimoto , Sebastian F. Hoenig , Robert Antonucci , Richard Barvainis , Takayuki Kotani , Konrad R. W. Tristram , Gerd Weigelt , Ken Levin

We discuss the polarization of broad emission lines in the type 1 active galactic nuclei (AGNs). The polarization depends on the geometry of the broad line region (BLR), and also on the polarization mechanism, or distribution of the…

Astrophysics of Galaxies · Physics 2021-11-12 L. C. Popović , E. Shablovinskaya , Dj. Savić