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Quasi-stellar objects (QSOs) occur in galaxies in which supermassive black holes (SMBHs) are growing substantially through rapid accretion of gas. Many popular models of the co-evolutionary growth of galaxies and SMBHs predict that QSOs are…

In every proposed unification scheme for Active Galactic Nuclei (AGN), an integral element is the presence of circumnuclear dust arranged in torus-like structures. A crucial model parameter in this context is the covering factor (CF),…

Astrophysics of Galaxies · Physics 2023-11-02 Mateusz Rałowski , Krzysztof Hryniewicz , Agnieszka Pollo , Łukasz Stawarz

Contamination-free assessments of the interstellar medium and star formation in quasar host galaxies, particularly based on the far-infrared, offer insights into the role of supermassive black holes in galaxy evolution. Motivated by…

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…

Astrophysics · Physics 2007-05-23 E. Oliva , L. Origlia , R. Maiolino , A. F. M. Moorwood

We have constructed a sample of radio-loud and radio-quiet quasars from the Faint Im- ages Radio Sky at Twenty-one centimetres (FIRST) and the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), over the H-ATLAS Phase 1 Area (9h, 12h and…

We present MEGARA (Multi-Espectr\'ografo en GTC de Alta Resoluci\'on para Astronom\'ia) Integral Field Unit (IFU) observations of 5 local type-2 quasars (QSO2s, z $\sim 0.1$) from the Quasar Feedback (QSOFEED) sample. These active galactic…

We fit the near-infrared to radio spectral energy distributions of 30 luminous and ultra-luminous infrared galaxies with pure starburst models or models that include both starburst and AGN components to determine important physical…

Astrophysics · Physics 2009-11-13 O. Vega , M. S. Clemens , A. Bressan , G. L. Granato , L. Silva , P. Panuzzo , --

Recently, Zakamska et al. (2003) selected 291 high-ionization narrow emission-line AGN in the redshift range 0.3-0.83 from the Sloan Digital Sky Survey spectroscopic data. The sample includes both Seyfert II galaxies and their higher…

Astrophysics · Physics 2009-11-10 C. Vignali , D. M. Alexander , A. Comastri

Type 2 quasars are luminous active galactic nuclei (AGN) whose central regions are obscured by large amounts of gas and dust. In this paper, we present a catalog of type 2 quasars from the Sloan Digital Sky Survey (SDSS), selected based on…

We use ultradeep SCUBA-2 850um observations (~0.37 mJy rms) of the 2 Ms Chandra Deep Field-North (CDF-N) and 4 Ms Chandra Deep Field-South (CDF-S) X-ray fields to examine the amount of dusty star formation taking place in the host galaxies…

Astrophysics of Galaxies · Physics 2020-01-16 A. J. Barger , L. L. Cowie , F. N. Owen , C. -C. Chen , G. Hasinger , L. -Y. Hsu , Y. Li

Many recent estimates of the star formation rate density at high redshift rely on rest-frame ultraviolet (UV) data. These are highly sensitive to dust absorption. Applying a correlation between the far-infrared (FIR) to UV flux ratio and UV…

The stellar properties of about 800 galaxies hosting optically luminous, unobscured quasars at z < 0.6 are analyzed. Deep co-added Sloan Digital Sky Survey (SDSS) images of the quasars on Stripe 82 are decomposed into nucleus and host…

Astrophysics of Galaxies · Physics 2015-06-18 Yoshiki Matsuoka , Michael A. Strauss , Ted N. Price , Matthew S. DiDonato

We combine submm photometric data of z>4 quasars, to obtain a mean far-infrared (FIR) (rest-frame) spectral energy distribution (SED) of thermal emission from dust, parameterised by a single temperature (T) and power-law emissivity index…

Astrophysics · Physics 2015-06-24 Robert S. Priddey , Richard G. McMahon

We have derived star formation rates (SFRs), gas-phase oxygen abundances and effective dust absorption optical depths for a sample of galaxies drawn from the Stromlo-APM redshift survey using the new Charlot and Longhetti (2001; CL01)…

Astrophysics · Physics 2009-11-07 S. Charlot , G. Kauffmann , M. Longhetti , L. Tresse , S. D. M. White , S. J. Maddox , S. M. Fall

We combine near-to-mid-IR Spitzer data with shorter wavelength observations (optical to X-rays) to get insights on the properties of a sample of luminous, obscured Active Galactic Nuclei (AGN). We aim at modeling their broad-band Spectral…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Pozzi , C. Vignali , A. Comastri , E. Bellocchi , J. Fritz , C. Gruppioni , M. Mignoli , R. Maiolino , L. Pozzetti , M. Brusa , F. Fiore , G. Zamorani

Type II quasars are the long-sought luminous analogs of type II (narrow emission line) Seyfert galaxies, suggested by unification models of active galactic nuclei (AGN) and postulated to account for an appreciable fraction of the cosmic…

Results are presented for [CII] 158 micron line fluxes observed with the Herschel PACS instrument in 112 sources with both starburst and AGN classifications, of which 102 sources have confident detections. Results are compared with…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 L. Sargsyan , V. Lebouteiller , D. Weedman , H. Spoon , J. Bernard-Salas , D. Engels , G. Stacey , J. Houck , D. Barry , J. Miles , A. Samsonyan

Large-scale cosmological simulations suggest that feedback from active galactic nuclei (AGN) plays a crucial role in galaxy evolution. In this study, we directly test this hypothesis utilising SDSS spectra of a sample of 48 low redshift…

Astrophysics of Galaxies · Physics 2024-09-25 Patricia S. Bessiere , Cristina Ramos Almeida , Luke R. Holden , Clive N. Tadhunter , Gabriela Canalizo

The total star formation budget of galaxies consists of the sum of the unobscured star formation, as observed in the rest-frame ultraviolet (UV), together with the obscured component that is absorbed and re-radiated by dust grains in the…

Astrophysics of Galaxies · Physics 2017-12-20 Katherine E. Whitaker , Alexandra Pope , Ryan Cybulski , Caitlin M. Casey , Gergö Popping , Min S. Yun

We present results of near-infrared photometry (J, H, K_S) for a sample of active galactic nuclei (AGNs) obtained from hard X-ray surveys with ASCA. The sample covers the AGNs at z=0.1-1 with L(2-10keV)=10^42-10^46 erg/s with very high…

Astrophysics · Physics 2009-11-10 Chisato Watanabe , Kouji Ohta , Masayuki Akiyama , Yoshihiro Ueda
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