Results 161 to 170 of about 77,605 (280)

BASS. XLIX. Characterization of Highly Luminous and Obscured AGNs: Local X-Ray and [Ne V]λ3426 Emission in Comparison with the High-redshift Universe

The Astrophysical Journal
We present a detailed analysis of the most luminous and obscured active galactic nuclei (AGNs) detected in the ultra-hard X-ray band (14–195 kev) by the Swift/Burst Alert Telescope. Our sample comprises 21 X-ray luminous ( ${\mathrm{log}}\,{L}_{{\rm{X}}}/
Alessandro Peca, Michael J. Koss, Kyuseok Oh, Claudio Ricci, Benny Trakhtenbrot, Richard Mushotzky, Ezequiel Treister, C. Megan Urry, Andrealuna Pizzetti, Kohei Ichikawa, Alessia Tortosa, Federica Ricci, Matilde Signorini, Darshan Kakkad, Chin-Shin Chang, Giovanni Mazzolari, Turgay Caglar, Macon Magno, Ignacio del Moral-Castro, Peter G. Boorman, Tonima T. Ananna, Fiona Harrison, Daniel Stern, David Sanders   +23 more
doaj   +1 more source

Broad emission features in QSOs and active galactic nuclei. I - New calculations of Fe II line strengths

, 1983
H. Netzer, Beverley J. Wills
openalex   +1 more source

Compact Radio Sources, Quasars and Active Galactic Nuclei [PDF]

, 1994
K. L. Kellermann
openalex   +1 more source

First Observational Evidence for an Interconnected Evolution between Time Lag and QPO Frequency among AGNs

The Astrophysical Journal Letters
Quasiperiodic oscillations (QPOs) have been widely observed in black hole X-ray binaries (BHBs), which often exhibit significant X-ray variations. Extensive research has explored the long-term evolution of the properties of QPOs in BHBs.
Ruisong Xia, Hao Liu, Yongquan Xue
doaj   +1 more source

Infrared-ultraviolet spectra of active galactic nuclei [PDF]

Data from IRAS and IUE were combined with ground based optical and infrared spectrophotometry to derive emission line free spectral energy distributions (SEDs) for 29 active galactic nuclei (AGNs) between 0.1 and 100 microns.
Malkan, M. A., These corrected SEDs are shown.   +1 more
core   +1 more source

Accretion disks and periodic outbursts of active galactic nuclei

, 1986
D. N. C. Lin, G. A. Shields
openalex   +1 more source

Thick tori around active galactic nuclei: a comparison of model predictions with observations of the infrared continuum and silicate features [PDF]

, 1994
G. L. Granato, L. Danese
openalex   +1 more source

Strong Amplitude Modulation of Hard-band X-Ray Quasiperiodic Oscillation with Soft-band Flux in RE J1034+396

The Astrophysical Journal
The X-ray quasiperiodic oscillation (QPO) is a remarkable form of variability in systems of compact object accretion. RE J1034+396, harboring the most significant X-ray QPO in active galactic nuclei (AGNs), is the most noteworthy source for in-depth ...
Ruisong Xia, Hao Liu, Yongquan Xue
doaj   +1 more source

Hard X-ray variability of three active galactic nuclei

, 1984
P. Ubertini, A. Bazzano, C. La Padula, V. F. Polcaro, R. Manchanda   +4 more
openalex   +1 more source

Implications of particle acceleration in active galactic nuclei for cosmic rays and high energy neutrino astronomy [PDF]

, 1994
Á. Szabó, R. J. Protheroe
openalex   +1 more source