Results 101 to 110 of about 8,662 (194)

Compact objects in active galactic nuclei and X-ray binaries [PDF]

, 2007
In this thesis I study the inner-most regions of Active Galactic Nuclei (AGN) using the reverberation mapping technique, and neutron star low-mass X-ray binaries in quiescence using X-ray observations. Using the 13-year optical monitoring data for the
Cackett, Edward M.
core  

Interpreting Swift and NuSTAR Observations of the Low-luminosity Active Galactic Nucleus NGC 4278 with Radiatively Inefficient Accretion Flows and Implications for Neutrino Emission

The Astrophysical Journal
We report the first NuSTAR hard X-ray observations of the low-luminosity active galactic nucleus NGC 4278. The source is clearly detected beyond 10 keV with a hard X-ray spectrum consistent with a power law of photon index between 2.2 and 2.5 without ...
Abhishek Das, Qi Feng, Eleanor Young, Ashwani Pandey, Shigeo S. Kimura, Kohta Murase   +5 more
doaj   +1 more source

ReveaLLAGN 0: First Look at JWST MIRI Data of Sombrero and NGC 1052

The Astrophysical Journal
We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGNs. We focus on two observations with the Mid-Infrared Instrument (MIRI)’s Medium-Resolution Spectrometer of the ...
Kameron Goold, Anil Seth, Mallory Molina, David Ohlson, Jessie C. Runnoe, Torsten Böker, Timothy A. Davis, Antoine Dumont, Michael Eracleous, Juan Antonio Fernández-Ontiveros, Elena Gallo, Andy D. Goulding, Jenny E. Greene, Luis C. Ho, Sera B. Markoff, Nadine Neumayer, Richard M. Plotkin, Almudena Prieto, Shobita Satyapal, Glenn van de Ven, Jonelle L. Walsh, Feng Yuan, Anja Feldmeier-Krause, Kayhan Gültekin, Sebastian Hönig, Allison Kirkpatrick, Nora Lützgendorf, Amy E. Reines, Jay Strader, Jonathan R. Trump, Karina T. Voggel   +30 more
doaj   +1 more source

Seoul National University AGN Monitoring Project. V. Velocity-resolved Hβ Reverberation Mapping and Evidence of Kinematics Evolution

The Astrophysical Journal
We present velocity-resolved reverberation lags of H β for 20 active galactic nuclei (AGNs) from the Seoul National University AGN Monitoring Project.
Shu Wang, Jong-Hak Woo, Aaron J. Barth, Vardha N. Bennert, Elena Gallo, Edmund Hodges-Kluck, Minjin Kim, Suvendu Rakshit, Tommaso Treu, Hojin Cho, Kyle M. Kabasares, Matthew A. Malkan, Amit Kumar Mandal, Donghoon Son, Vivian U, Lizvette Villafana   +15 more
doaj   +1 more source

Optical polarimetry studies of Seyfert galaxies [PDF]

, 1999
Optical imaging polarimetry has been performed on seven nearby Seyfert galaxies, three with face-on and four with edge-on host galaxies of various morphological classifications.
Felton, Michelle Ann
core  

VERITAS Observations Contemporaneous with the LHAASO Detection of NGC 4278

The Astrophysical Journal
Significant gamma-ray emission between 1 TeV and 20 TeV from a point source, 1LHAASO J1219+2915, consistent with the location of the LINER/LLAGN galaxy NGC 4278 was recently reported by the Large High Altitude Air Shower Observatory (LHAASO ...
A. Archer, P. Bangale, J. T. Bartkoske, W. Benbow, J. H. Buckley, Y. Chen, J. L. Christiansen, A. J. Chromey, A. Duerr, M. Errando, M. Escobar Godoy, S. Feldman, Q. Feng, S. Filbert, L. Fortson, A. Furniss, W. Hanlon, O. Hervet, C. E. Hinrichs, J. Holder, Z. Hughes, T. B. Humensky, M. Iskakova, W. Jin, M. N. Johnson, M. Kertzman, M. Kherlakian, D. Kieda, T. K. Kleiner, N. Korzoun, S. Kumar, S. Kundu, M. J. Lang, M. Lundy, G. Maier, C. McSorley, P. Moriarty, R. Mukherjee, W. Ning, S. O’Brien, M. Ohishi, R. A. Ong, A. Pandey, C. Poggemann, M. Pohl, E. Pueschel, J. Quinn, P. L. Rabinowitz, K. Ragan, P. T. Reynolds, D. Ribeiro, L. Rizk, E. Roache, I. Sadeh, L. Saha, H. Salzmann, M. Santander, G. H. Sembroski, R. Shang, M. Splettstoesser, D. Tak, A. K. Talluri, I. Thoreson, J. V. Tucci, J. Valverde, D. A. Williams, S. L. Wong, T. Yoshikoshi, The VERITAS Collaboration   +68 more
doaj   +1 more source

The High-mass X-Ray Binary Luminosity Functions of Dwarf Galaxies

The Astrophysical Journal
Drawing from the Chandra archive and using a carefully selected set of nearby dwarf galaxies, we present a calibrated high-mass X-ray binary (HMXB) luminosity function in the low-mass galaxy regime and search for an already hinted at dependence on ...
Robel Geda, Andy D. Goulding, Bret D. Lehmer, Jenny E. Greene, Anish Kulkarni   +4 more
doaj   +1 more source

Nuclear Spectral Energy Distributions of Luminous Infrared Galaxies

The Astrophysical Journal
We present nuclear (100–150 pc) spectral energy distributions (SEDs) for a sample of 23 nearby luminous infrared galaxies hosting a total of 28 nuclei. We gather aperture photometry from high-resolution X-ray to submillimeter data for each nuclear region
Tianmu Gao, Vivian U, Connor W. Auge, Yiqing Song, Sean T. Linden, Kazushi Iwasawa, Alessandro Peca, George C. Privon, David B. Sanders, Núria Torres-Albà, Loreto Barcos-Muñoz, James Agostino, Anne M. Medling   +12 more
doaj   +1 more source

Evidence of the link between broad emission line regions and accretion disks in active Galactic nuclei [PDF]

, 2007
There is observational evidence that broad-line regions (BLRs) exist in most active galactic nuclei (AGNs), but their origin is still unclear. One scenario is that the BLRs originate from winds accelerated from the hot coronae of the disks, and the winds
Xu, Yun, Cao, Xin-Wu
core  

A Detailed Look at a Trio of Changing-look Quasars: Spectral Energy Distributions and the Dust Extinction Test

The Astrophysical Journal
Changing-look quasars (CLQs) exhibit dramatic variability in broad emission-line fluxes on short timescales. This behavior is challenging to many models of the quasar broad-line region, due in large part to the short transition times between high and low
Laura Duffy, Michael Eracleous, Jessie C. Runnoe, John J. Ruan, Scott F. Anderson, Sabrina Dimassimo, Paul Green, Stephanie LaMassa   +7 more
doaj   +1 more source