Results 121 to 130 of about 39,820 (206)

Physics Insights from Recent MAGIC AGN Observations

, 2009
The total set of the 14 active galactic nuclei detected by MAGIC so far includes well-studied bright blazars like Mkn 501, the giant radio galaxy M 87, but also the distant flat-spectrum radio quasar 3C 279, and an intriguing gamma-ray source in the 3C ...
Wagner, Robert
core   +1 more source

Constraining Star Formation in M87 Using Deep Hubble Space Telescope UV Data

The Astrophysical Journal
We analyzed the deepest Hubble Space Telescope F275W ultraviolet (UV) imaging of M87 to obtain the most robust constraints on its star formation rate (SFR) and star formation history (SFH).
Prathamesh Tamhane, William Waldron, Ming Sun, Silvia Martocchia, Claudia Maraston, Alessandro Boselli, William Forman, Massimo Gaspari, Juhi Tiwari, Megan Donahue, G. Mark Voit, Tim Edge, Grant Tremblay, Daniel Thomas   +13 more
doaj   +1 more source

X-ray properties of coronal emission in radio quiet active galactic nuclei

Frontiers in Astronomy and Space Sciences
Active galactic nuclei (AGN) are powerful sources of panchromatic radiation. All AGN emit in X-rays, contributing around 5%–10% of the AGN bolometric luminosity.
Sibasish Laha, Sibasish Laha, Sibasish Laha, Claudio Ricci, Claudio Ricci, John C. Mather, Ehud Behar, Luigi Gallo, Frederic Marin, Rostom Mbarek, Rostom Mbarek, Amelia Hankla   +11 more
doaj   +1 more source

Revisiting Radio Variability of the Blazar 3C 454.3

The Astrophysical Journal
We examine lengthy radio light curves of the flat spectrum radio galaxy 3C 454.3 for possible quasiperiodic oscillations (QPOs). The data used in this work were collected at five radio frequencies, 4.8, 8.0, 14.5, 22.0, and 37.0 GHz between 1979 and 2013
Ashutosh Tripathi, Alok C. Gupta, Krista Lynne Smith, Paul J. Wiita, Margo F. Aller, Alexandr E. Volvach, Anne Lähteenmäki, Hugh D. Aller, Merja Tornikoski, Larisa N. Volvach   +9 more
doaj   +1 more source

Cosmic ray feedback in galaxies and galaxy clusters: A pedagogical introduction and a topical review of the acceleration, transport, observables, and dynamical impact of cosmic rays. [PDF]

Astron Astrophys Rev, 2023
Ruszkowski M, Pfrommer C.
europepmc   +1 more source

Powerful Radio-loud Quasars Are Triggered by Galaxy Mergers in the Cosmic Bright Ages

The Astrophysical Journal
While supermassive black holes are ubiquitous features of galactic nuclei, only a small minority are observed during episodes of luminous accretion. The physical mechanism(s) driving the onset of fueling and ignition in these active galactic nuclei (AGN)
Peter Breiding, Marco Chiaberge, Erini Lambrides, Eileen T. Meyer, S. P. Willner, Bryan Hilbert, Martin Haas, George Miley, Eric S. Perlman, Peter Barthel, Christopher P. O’Dea, Alessandro Capetti, Belinda Wilkes, Stefi A. Baum, Duccio F. Macchetto, William Sparks, Grant Tremblay, Colin Norman   +17 more
doaj   +1 more source

Analysis of Jet Dynamics and Collimation Characteristics of 0241+622 on Parsec Scales

The Astrophysical Journal
We conducted a detailed analysis of the jet structure and dynamics of the source 0241+622 on milliarcsecond scales. We stacked images from multiple epochs to better recover the cross section of the jet. By analyzing the relationship between jet width and
Haitian Shang, Wei Zhao, Xiaoyu Hong, Xu-zhi Hu   +3 more
doaj   +1 more source

No Galaxy-scale [C ii] Fast Outflow in the z = 6.72 Red Quasar HSC J1205–0000

The Astrophysical Journal
HSC 120505.09-000027.9 (J1205–0000) is one of the highest redshift ( z = 6.72) dust-reddened quasars (red quasars) known to date. We present an improved analysis of Atacama Large Millimeter/submillimeter Array data of the [C  ii ] 158 μ m line and the ...
Mahoshi Sawamura, Takuma Izumi, Kouichiro Nakanishi, Takeshi Okuda, Michael A. Strauss, Masatoshi Imanishi, Yoshiki Matsuoka, Yoshiki Toba, Hideki Umehata, Takuya Hashimoto, Shunsuke Baba, Tomotsugu Goto, Toshihiro Kawaguchi, Kotaro Kohno, Dragan Salak, Taiki Kawamuro, Kazushi Iwasawa, Masafusa Onoue, Chien-Hsiu Lee, Kianhong Lee   +19 more
doaj   +1 more source

Circular Mystery: Exploring Diffuse Emission Surrounding a Radio Galaxy with uGMRT and VLA Multiwavelength Observations

The Astrophysical Journal
We report the discovery of J1218+1813, a circular diffuse radio source detected in the Very Large Array (VLA) FIRST survey at 1400 MHz. The source has an angular diameter of approximately one arcminute, corresponding to a physical size of ∼180 kpc, and ...
Shobha Kumari, Sabyasachi Pal, Souvik Manik   +2 more
doaj   +1 more source

FRAMEx. V. Radio Spectral Shape at Central Subparsec Region of Active Galactic Nuclei

The Astrophysical Journal
We present results from the Very Long Baseline Array multifrequency (1.6, 4.4, 8.6, and 22 GHz), high-sensitivity (∼25 μ Jy beam ^−1 ), subparsec-scale (
Onic I. Shuvo, Megan C. Johnson, Nathan J. Secrest, Mario Gliozzi, Phillip J. Cigan, Travis C. Fischer, Alexander J. Van Der Horst   +6 more
doaj   +1 more source