Results 201 to 210 of about 289,816 (297)

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

Timescales of Soft X‐Ray Variability and Physical Constraints in Active Galactic Nuclei [PDF]

, 2003
Wei‐Hao Bian, Yongheng Zhao
openalex   +1 more source

Late-time Radio Brightening and Emergence of a Radio Jet in the Changing-look AGN 1ES 1927+654

The Astrophysical Journal Letters
We present multifrequency (5–345 GHz) and multiresolution radio observations of 1ES 1927+654, widely considered one of the most unusual and extreme changing-look active galactic nuclei (CL-AGNs).
Eileen T. Meyer, Sibasish Laha, Onic I. Shuvo, Agniva Roychowdhury, David A. Green, Lauren Rhodes, Amelia M. Hankla, Alexander Philippov, Rostom Mbarek, Ari laor, Mitchell C. Begelman, Dev R. Sadaula, Ritesh Ghosh, Gabriele Bruni, Francesca Panessa, Matteo Guainazzi, Ehud Behar, Megan Masterson, Haocheng Zhang, Xiaolong Yang, Mark A. Gurwell, Garrett K. Keating, David Williams-Baldwin, Justin D. Bray, Emmanuel K. Bempong-Manful, Nicholas Wrigley, Stefano Bianchi, Federica Ricci, Fabio La Franca, Erin Kara, Markos Georganopoulos, Samantha Oates, Matt Nicholl, Main Pal, S. Bradley Cenko   +34 more
doaj   +1 more source

Low-ionization active galactic nuclei - X-ray or shock heated?

, 1983
J. P. Halpern, J. E. Steiner
openalex   +1 more source

VARIABILITY OF ACTIVE GALACTIC NUCLEI FROM THE OPTICAL TO X-RAY REGIONS [PDF]

, 2003
C. M. Gaskell, E. S. Klimek
openalex   +1 more source

An Active Galactic Nucleus Sample with High X‐Ray–to–Optical Flux Ratio from RASS. II. Optical Emission Line Properties of Seyfert 1–Type Active Galactic Nuclei [PDF]

, 2003
Da Xu, S. Komossa, Jian‐Yan Wei, Y. Qian, Xu-Chang Zheng   +4 more
openalex   +1 more source

Active galactic nuclei. 5: X-ray variability and the black hole cluster paradigm

, 1994
A. G. Pacholczyk, W. R. Stoeger
openalex   +1 more source

Black hole mass estimation from X-ray variability measurements in active galactic nuclei [PDF]

, 2004
M. Nikołajuk, I. E. Papadakis, B. Czerny   +2 more
openalex   +1 more source

The Fall of Active Galactic Nuclei and the Rise of Star-forming Galaxies: A Close Look at the Chandra Deep Field X-Ray Number Counts [PDF]

, 2004
F. E. Bauer, D. M. Alexander, W. N. Brandt, Donald P. Schneider, Ezequiel Treister, A. E. Hornschemeier, G. P. Garmire   +6 more
openalex   +1 more source

Powerful, obscured active galactic nuclei among X-ray hard, optically dim serendipitousChandrasources [PDF]

, 2004
P. Gandhi, C. S. Crawford, A. C. Fabian, R. M. Johnstone   +3 more
openalex   +1 more source