Results 21 to 30 of about 1,302 (205)

Asymmetric jet production in the active galactic nucleus of NGC 1052 [PDF]

Astronomy & Astrophysics, 2019
Context. Few active galactic nuclei (AGN) reveal double-sided jet systems. However, these systems are crucial to understand basic physical properties of extragalactic jets. Aims. We address the questions whether jets in AGN are symmetric in nature, how well they are collimated on small scales, and how they evolve with time. Methods.
A.-K. Baczko, R. Schulz, M. Kadler, E. Ros, M. Perucho, C. M. Fromm, J. Wilms   +6 more
openaire   +3 more sources

3C 273 WITHNuSTAR: UNVEILING THE ACTIVE GALACTIC NUCLEUS [PDF]

The Astrophysical Journal, 2015
We present results from a 244 ks NuSTAR observation of 3C 273 obtained during a cross-calibration campaign with the Chandra, INTEGRAL, Suzaku, Swift, and XMM-Newton observatories. We show that the spectrum, when fit with a power-law model using data from all observatories except INTEGRAL over the 1–78 keV band, leaves significant residuals in the ...
Kristin K. Madsen, Felix Fürst, Dominic J. Walton, Fiona A. Harrison, Krzysztof Nalewajko, David R. Ballantyne, Steve E. Boggs, Laura W. Brenneman, Finn E. Christensen, William W. Craig, Andrew C. Fabian, Karl Forster, Brian W. Grefenstette, Matteo Guainazzi, Charles J. Hailey, Greg M. Madejski, Giorgio Matt, Daniel Stern, Roland Walter, William W. Zhang   +19 more
openaire   +3 more sources

Discovery of a dual active galactic nucleus with ∼8 kpc separation [PDF]

Monthly Notices of the Royal Astronomical Society: Letters, 2017
Abstract Targeted searches for dual active galactic nuclei (AGNs), with separations 1–10 kpc, have yielded relatively few successes. A recent pilot survey by Satyapal et al. has demonstrated that mid-infrared (mid-IR) pre-selection has the potential to significantly improve the success rate for dual AGN confirmation in late stage galaxy ...
Ellison, S., Secrest, N., Mendel, J., Satyapal, S., Simard, L.   +4 more
openaire   +3 more sources

Extreme variability in an active galactic nucleus: Gaia16aax [PDF]

Monthly Notices of the Royal Astronomical Society, 2020
ABSTRACT We present the results of a multiwavelength follow-up campaign for the luminous nuclear transient Gaia16aax, which was first identified in 2016 January. The transient is spatially consistent with the nucleus of an active galaxy at z = 0.25, hosting a black hole of mass ${\sim }6\times 10^8\, \mathrm{M}_\odot$.
Cannizzaro, G., Fraser, M., Jonker, P.G., Pringle, J.E., Mattila, S., Hewett, P.C., Wevers, T., Kankare, E., Kostrzewa-Rutkowska, Z., Wyrzykowski, Ł, Onori, F., Harmanen, J., Ford, K.E.S., McKernan, B., Nixon, C.J.   +14 more
openaire   +8 more sources

Active galactic nucleus feedback in NGC 3982

Astronomy & Astrophysics, 2022
The energetic feedback from supermassive black holes can influence star formation at the centres of galaxies. Observational evidence for active galactic nucleus (AGN) impact on star formation can be searched for in galaxies by combining ultraviolet imaging and optical integral field unit data. The ultraviolet flux directly traces recent star formation,
P. Joseph, K. George, K. T. Paul
openaire   +2 more sources

FRAMEx. IV. Mechanical Feedback from the Active Galactic Nucleus in NGC 3079

The Astrophysical Journal, 2023
Using the Very Long Baseline Array, we observed the active galactic nucleus (AGN) in NGC 3079 over a span of six months to test for variability in the two main parsec-scale radio components, A and B , which lie on either side of the AGN.
Luis C. Fernandez, Nathan J. Secrest, Megan C. Johnson, Travis C. Fischer   +3 more
doaj   +1 more source

2MASX J00423991 + 3017515: an offset active galactic nucleus in an interacting system [PDF]

Monthly Notices of the Royal Astronomical Society, 2021
ABSTRACT We present a spectroscopic and imaging study of an abnormal active galactic nucleus (AGN), 2MASX J00423991 + 3017515. This AGN is newly identified in the hard X-rays by the Swift BAT All-Sky survey and found in an edge-on disc galaxy interacting with a nearby companion.
Hogg, J Drew, Blecha, Laura, Reynolds, Christopher S, Smith, Krista Lynne, Winter, Lisa M   +4 more
openaire   +2 more sources

NGC 1808: active galactic nucleus or starburst? [PDF]

Monthly Notices of the Royal Astronomical Society, 1992
We present optical and near-infrared images, together with long-slit spectra at red wavelengths, of NGC 1808. The complex morphology of hotspots seen at short wavelengths may be the result of dust obscuration. Our data (namely the equivalent width of the Ca II triplet and broad-band colours) suggest the presence of red supergiants, associated with a ...
D. A. Forbes, C. Boisson, M. J. Ward
openaire   +1 more source

New Conformally Invariant Born–Infeld Models and Geometrical Currents

Physics
A new conformally invariant gravitational generalization of the Born–Infeld (BI) model is proposed and analyzed from the point of view of symmetries. Taking a geometric identity involving the determinant functions detfBμν, Fμν with the Bach Bμν and the ...
Diego Julio Cirilo-Lombardo
doaj   +1 more source

Coherent State Description of Astrophysical Gamma-Ray Amplification from a Para-Positronium Condensate

Particles
The para-positronium system S01Ps is described by means of specially constructed coherent states (CSs) in the Klauder–Perelomov sense. It is analyzed from the physical point of view and from the geometry underlying the relevant symmetry group ...
Diego Julio Cirilo-Lombardo
doaj   +1 more source