Results 31 to 40 of about 37,389 (216)

The Nuclear Spectral Energy Distribution of NGC 4395, The Least Luminous Type 1 Seyfert Galaxy [PDF]

, 1999
We present X-ray (ROSAT), infrared, and radio observations of NGC 4395, which harbors the optically least luminous type 1 Seyfert nucleus discovered thus far.
Alexei V. Filippenko, Andrea Comastri, Casali M. M., Edward C. Moran, Hasinger G., Joseph C. Shields, Luis C. Ho, Padovani P., Pfeffermann E., Reynolds C. S., Richard A. Sramek, Steven L. Snowden, Tomaso Belloni, Walter R.   +13 more
core   +2 more sources

GIANT GAMMA-RAY BUBBLES FROMFERMI-LAT: ACTIVE GALACTIC NUCLEUS ACTIVITY OR BIPOLAR GALACTIC WIND? [PDF]

The Astrophysical Journal, 2010
Data from the Fermi-LAT reveal two large gamma-ray bubbles, extending 50° above and below the Galactic center (GC), with a width of about 40° in longitude. The gamma-ray emission associated with these bubbles has a significantly harder spectrum (dN/dE ~ E –2) than the inverse Compton emission from electrons in the Galactic disk, or the gamma rays ...
Su, Meng, Slatyer, Tracy R., Finkbeiner, Douglas P.   +2 more
openaire   +3 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

The parsec scale region of Active Galactic Nuclei in the IR [PDF]

, 2004
First results from the AGN-Heidelberg program aimed at spatially resolving the central pc region of the closest Active Galactic Nuclei are presented. The core region of prototype active nuclei are clearly unveiled at IR waves and at distances from the ...
Meisenheimer, Klaus, Prieto, M. Almudena
core   +2 more sources

Chandraunveils a binary active galactic nucleus in Mrk 463 [PDF]

Monthly Notices of the Royal Astronomical Society, 2008
We analyse Chandra, XMM-Newton and HST data of the double-nucleus Ultraluminous Infrared Galaxy (ULIRG), Mrk463. The Chandra detection of two luminous ($\mathrm{L}_\mathrm{2-10 keV}=1.5\times10^{43}$ and $3.8\times10^{42}$ erg cm$^{-2}$ s$^{-1}$), unresolved nuclei in Mrk~463 indicates that this galaxy hosts a binary AGN, with a projected separation of
BIANCHI, STEFANO, CHIABERGE MARCO, PICONCELLI ENRICO, GUAINAZZI MATTEO, MATT GIORGIO   +4 more
openaire   +2 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 ${\sim }6\times 10^8\, \mathrm{M}_\odot$.
G Cannizzaro, M Fraser, P G Jonker, J E Pringle, S Mattila, P C Hewett, T Wevers, E Kankare, Z Kostrzewa-Rutkowska, Ł Wyrzykowski, F Onori, J Harmanen, K E S Ford, B McKernan, C J Nixon   +14 more
openaire   +6 more sources

Decomposition of active galactic nucleus host galaxy images [PDF]

Monthly Notices of the Royal Astronomical Society, 2004
We describe an algorithm to decompose deep images of active galactic nuclei into host galaxy and nuclear components. Currently supported are three galaxy models: a de Vaucouleurs spheroidal; an exponential disc; and a two-component disc + bulge model. Key features of the method are: (semi-)analytic representation of a possibly spatially variable point ...
Kuhlbrodt, B., Wisotzki, Lutz (Prof. Dr.), Jahnke, Knud   +2 more
openaire   +2 more sources

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

Luminosity-dependent X-Ray Active Galactic Nucleus Clustering? [PDF]

The Astrophysical Journal, 2008
We have analyzed the angular clustering of X-ray-selected active galactic nuclei (AGNs) in different flux-limited subsamples of the Chandra Deep Field North (CDF-N) and South (CDF-S) surveys. We find a strong dependence of the clustering strength on the subsample flux limit, a fact that explains most of the disparate clustering results of different XMM
M. Plionis, M. Rovilos, S. Basilakos, I. Georgantopoulos, F. Bauer   +4 more
openaire   +2 more sources

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