English
Related papers

Related papers: Black-Hole Mass and Growth Rate at High Redshift

200 papers

We present new Gemini-North/NIRI and VLT/SINFONI H-band spectroscopy for a flux limited sample of 40 z~4.8 active galactic nuclei, selected from the Sloan Digital Sky Survey. The sample probably contains the most massive active black holes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Benny Trakhtenbrot , Hagai Netzer , Paulina Lira , Ohad Shemmer

We study the distribution of Eddington luminosity ratios, L_bol/L_edd, of active galactic nuclei (AGNs) discovered in the AGN and Galaxy Evolution Survey (AGES). We combine H-beta, MgII, and CIV line widths with continuum luminosities to…

We present the results from performing spectral energy distribution (SED) fitting on 121 variable active galactic nuclei (AGN) candidates in the Hubble Ultra Deep Field (HUDF) using photometry from both the Hubble Space Telescope (HST) and…

There is general consensus that active galactic nuclei (AGNs) derive their radiating power from a supermassive black hole (SMBH) that accretes matter. Yet, their precise powering mechanisms and the resulting growth of the SMBH are poorly…

Astrophysics of Galaxies · Physics 2025-05-21 Jose Maria Sanchez Zaballa , Eugenio Bottacini , Andrea Tramacere

The James Webb Space Telescope (JWST) has revealed low-luminosity active galactic nuclei (AGNs) at redshifts of $z\gtrsim 4-7$, many of which host accreting massive black holes (BHs) with BH-to-galaxy mass ($M_{\rm BH}/M_{\star}$) ratios…

Astrophysics of Galaxies · Physics 2025-03-07 Haojie Hu , Kohei Inayoshi , Zoltan Haiman , Luis C. Ho , Ken Ohsuga

We study the hard-X-ray spectral properties of ten highly luminous radio-quiet (RQ) active galactic nuclei (AGNs) at z=1.3-3.2, including new XMM-Newton observations of four of these sources. We find a significant correlation between the…

Astrophysics · Physics 2009-11-13 Ohad Shemmer , W. N. Brandt , Hagai Netzer , Roberto Maiolino , Shai Kaspi

We present a sample of 930 intermediate-mass black hole (IMBH) active galactic nuclei (AGNs) with black hole masses of $M_\mathrm{BH} \leqslant 2 \times 10^{6}$ M$_{\odot}$, uniformly selected from the Seventeenth Data Release of the Sloan…

Astrophysics of Galaxies · Physics 2026-05-12 Wen-Juan Liu , Luis C. Ho , Xiao-Bo Dong , Su Yao , Paulina Lira , Yicheng Guo

We present near-infrared spectra of ten luminous, intermediate redshift quasars observed with SofI at the NTT of ESO/La Silla. With these rest-frame optical spectra we probe the Hb -[OIII] emission line region. Using the standard scaling…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Matthias Dietrich , Smita Mathur , Dirk Grupe , S. Komossa

We investigated a sample of 15 luminous high-redshift quasars (3.3 < z < 5.1) to measure the mass of their super-massive black holes (SMBH) and compare, for the first time, results based on CIV, MgII, and Hbeta emission lines at…

Astrophysics · Physics 2009-11-10 Matthias Dietrich , Fred Hamann

This is the second in a series of papers reporting on a large reverberation mapping (RM) campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). The goal is to identify super-Eddington accreting…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Jian-Min Wang , Pu Du , Chen Hu , Hagai Netzer , Jin-Ming Bai , Kai-Xing Lu , Shai Kaspi , Jie Qiu , Yan-Rong Li , Fang Wang

We present line and continuum measurements for 9818 SDSS type-I active galactic nuclei (AGNs) with z le 0.75. The data are used to study the four dimensional space of black hole mass, normalized accretion rate (Ledd), metalicity and…

Astrophysics · Physics 2008-11-26 Hagai Netzer , Benny Trakhtenbrot

Recent observations have identified an abundance of high-redshift active galactic nuclei (AGN) with supermassive black holes (BHs) that are over-massive compared to the local BH mass$-$total stellar mass ($M_{\mathrm{BH}}-M_\star$)…

Astrophysics of Galaxies · Physics 2025-04-02 Jonathan H. Cohn , Emmanuel Durodola , Quinn O. Casey , Erini Lambrides , Ryan C. Hickox

We study the distribution of accretion rates onto supermassive black holes (SMBH) in AGNs of the local Universe ($z<0.15$) based on near-infrared and hard X-ray surveys (2MASS and Swift/BAT). Using sufficiently accurate black hole mass…

High Energy Astrophysical Phenomena · Physics 2021-11-16 Sergey Prokhorenko , Sergey Sazonov

We search for high-redshift (z>4.5) X-ray AGNs in the deep central (off-axis angle <5.7') region of the 7 Ms Chandra Deep Field-South X-ray image. We compile an initial candidate sample from direct X-ray detections. We then probe more…

Astrophysics of Galaxies · Physics 2020-03-11 L. L. Cowie , A. J. Barger , F. E. Bauer , J. Gonzalez-Lopez

We report first results from a large project to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). Such objects may be different from other AGNs in being powered by slim accretion disks and showing saturated…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 P. Du , C. Hu , K. -X. Lu , F. Wang , J. Qiu , Y. -R. Li , J. -M. Bai , S. Kaspi , H. Netzer , J. -M. Wang

We have measured the stellar velocity dispersions (\sigma_*) and estimated the central black hole (BH) masses for over 900 broad-line active galactic nuclei (AGNs) observed with the Sloan Digital Sky Survey. The sample includes objects…

Astrophysics · Physics 2009-06-23 J. Shen , D. E. Vanden Berk , D. P. Schneider , P. B. Hall

We investigate the local supermassive black hole (SMBH) density function and relative mass accretion rates of all active galactic nuclei (AGNs) identified in a volume-limited sample of infrared (IR) bright galaxies (L_IR > 3 x 10^9 L_sun)…

Astrophysics of Galaxies · Physics 2015-05-18 Andy D. Goulding , David M. Alexander , Bret D. Lehmer , James R. Mullaney
‹ Prev 1 2 3 10 Next ›