Results 31 to 40 of about 264,425 (308)

First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole [PDF]

Astrophysical Journal, 2019
We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ~40 μas, consistent with the size and shape of the lensed photon orbit ...
K. Akiyama, A. Alberdi, W. Alef, K. Asada, R. Azulay, A. Baczko, D. Ball, M. Baloković, J. Barrett, D. Bintley, L. Blackburn, W. Boland, K. Bouman, G. Bower, M. Bremer, C. Brinkerink, R. Brissenden, S. Britzen, A. Broderick, D. Broguiere, T. Bronzwaer, D. Byun, J. Carlstrom, A. Chael, Chi-kwan Chan, S. Chatterjee, K. Chatterjee, Ming-Tang Chen, Y. Chen 陈, I. Cho, P. Christian, J. Conway, J. Cordes, G. Crew, Yuzhu Cui, J. Davelaar, M. De Laurentis, R. Deane, J. Dempsey, G. Desvignes, J. Dexter, S. Doeleman, R. Eatough, H. Falcke, V. Fish, E. Fomalont, R. Fraga-Encinas, W. T. Freeman, P. Friberg, C. Fromm, J. Gómez, P. Galison, C. Gammie, R. García, O. Gentaz, B. Georgiev, C. Goddi, R. Gold, M. Gu 顾, M. Gurwell, K. Hada, M. Hecht, R. Hesper, Luis C. 子山 Ho 何, P. Ho, M. Honma, Chih-Wei L. Huang, L. Huang 黄, David H. Hughes, Shiro Ikeda, M. Inoue, S. Issaoun, D. James, B. Jannuzi, M. Janssen, B. Jeter, Wu 悟 Jiang 江, Michael D. Johnson, S. Jorstad, T. Jung, M. Karami, R. Karuppusamy, T. Kawashima, G. Keating, M. Kettenis, Jae-Young Kim, Junhan Kim, Jongsoo Kim, M. Kino, J. Koay, P. Koch, S. Koyama, M. Kramer, C. Kramer, T. Krichbaum, C. Kuo, T. Lauer, Sang-Sung Lee, Y. Li 李, Z. Li 李, M. Lindqvist, Kuo Liu, E. Liuzzo, Wen-Ping Lo, A. Lobanov, L. Loinard, C. Lonsdale, Ru-Sen 如森 Lu 路, N. MacDonald, J. Mao 毛, S. Markoff, D. Marrone, A. Marscher, I. Martí-Vidal, S. Matsushita, L. Matthews, L. Medeiros, K. Menten, Y. Mizuno, I. Mizuno, J. Moran, K. Moriyama, M. Mościbrodzka, C. Müller, H. Nagai, N. Nagar, M. Nakamura, R. Narayan, G. Narayanan, I. Natarajan, R. Neri, C. Ni, A. Noutsos, H. Okino, H. Olivares, T. Oyama, F. Özel, D. Palumbo, N. Patel, U. Pen, D. Pesce, V. Piétu, R. Plambeck, A. PopStefanija, O. Porth, B. Prather, J. A. Preciado-López, D. Psaltis, Hung-Yi Pu, V. Ramakrishnan, R. Rao, M. Rawlings, A. Raymond, L. Rezzolla, B. Ripperda, F. Roelofs, A. Rogers, E. Ros, M. Rose, A. Roshanineshat, H. Rottmann, A. Roy, C. Ruszczyk, B. Ryan, K. Rygl, S. Sánchez, D. Sánchez-Arguelles, M. Sasada, T. Savolainen, F. Schloerb, K. Schuster, Lijing Shao, Z. Shen 沈, D. Small, B. Sohn, J. SooHoo, F. Tazaki, P. Tiede, R. Tilanus, M. Titus, K. Toma, P. Torne, T. Trent, S. Trippe, S. Tsuda, I. van Bemmel, H. V. van Langevelde, D. V. van Rossum, J. Wagner, J. Wardle, J. Weintroub, N. Wex, R. Wharton, M. Wielgus, G. Wong, Q. Wu 吴, A. Young, K. Young, Z. Younsi, F. Yuan 袁, Y. Yuan 袁, J. Zensus, Guangyao Zhao, Shan-Shan Zhao, Ziyan Zhu, J. Farah, Z. Meyer-Zhao, D. Michalik, A. Nadolski, H. Nishioka, N. Pradel, R. Primiani, K. Souccar, L. Vertatschitsch, P. Yamaguchi   +214 more
semanticscholar   +1 more source

PAWS and POCO: NIR Astrophotonic Instruments for Astronomy

Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract For near‐infrared ground and space‐based astronomy, compact photonic devices can replace the large bulk optical components in spectrographs, frequency combs, beam combiners, and sky subtraction filters, thus saving cost, reducing volume, weight, and power requirements.
Kalaga Madhav, Alan Günther, Eloy Hernandez, Stella Vjes̆nica, Daniel Bodenmüller, Andreas Stoll, Christer Sandin, Haydar Altuğ Yıldırım, Martin M. Roth   +8 more
wiley   +1 more source

Characterization of a C‐RED One camera for astrophotonical applications

Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract To better understand the impact of the avalanche gain applied in the detector technology and apply this technology in our in‐house astrophotonic projects, we have characterized a C‐RED One camera and produced a stable and reliable method for calculating the system gain at any desired avalanche gain setting.
Stella Vješnica, Eloy Hernandez, Kalaga Madhav, Martin M. Roth   +3 more
wiley   +1 more source

Perturbative Solution of the Einstein Constraints with Spin and Momentum Far Away From a Binary Source in the Bowen‐York Formalism

Fortschritte der Physik, Volume 71, Issue 8-9, September 2023., 2023
Abstract The momentum and Hamiltonian constraints of vacuum Einstein equations, within the Bowen‐York formalism, for two interacting black holes in close separation, with anti‐parallel spins and anti‐parallel linear momenta is studied. An analytical solution using perturbation theory is given.
Emel Altas, Emine Ertugrul, Bayram Tekin
wiley   +1 more source

Relativistic redshift of the star S0-2 orbiting the Galactic Center supermassive black hole [PDF]

Science, 2019
Gravitational redshift in the Galactic Center General relativity predicts that light emitted by an object in a strong gravitational field—for example, close to a black hole—should be shifted to longer wavelengths.
T. Do, A. Hees, A. Ghez, G. Martinez, D. Chu, S. Jia, S. Sakai, Jessica R. Lu, A. Gautam, K. K. O’neil, E. Becklin, M. Morris, K. Matthews, S. Nishiyama, R. Campbell, S. Chappell, Zhuo Chen, A. Ciurlo, A. Dehghanfar, E. Gallego-Cano, W. E. Kerzendorf, J. Lyke, S. Naoz, H. Saida, R. Schödel, M. Takahashi, Yohsuke Takamori, G. Witzel, P. Wizinowich   +28 more
semanticscholar   +1 more source

A tool to understand emission mechanisms of blazars through their high‐energy gamma‐ray emission

Astronomische Nachrichten, Volume 344, Issue 6, August 2023., 2023
The blazar SED is characterized by two energy components. Evidence suggests that the low‐energy component is generated by the synchrotron mechanism, but for the high‐energy component, the mechanism is still uncertain. Two main models have been proposed to explain this emission. According to the leptonic model, a correlation between the emission of both
Mabel Osorio, Erick Rangel, José Rodrigo Sacahui, María Magdalena González   +3 more
wiley   +1 more source

THE SINFONI BLACK HOLE SURVEY: THE BLACK HOLE FUNDAMENTAL PLANE REVISITED AND THE PATHS OF (CO)EVOLUTION OF SUPERMASSIVE BLACK HOLES AND BULGES [PDF]

, 2016
We investigate the correlations between the black hole (BH) mass MBH, the velocity dispersion σ, the bulge mass MBu, the bulge average spherical density &rgr; h ?> , and its spherical half-mass radius rh, constructing a database of 97 galaxies (31 core ...
R. Saglia, M. Opitsch, P. Erwin, Jens Thomas, A. Beifiori, M. Fabricius, X. Mazzalay, N. Nowak, S. Rusli, R. Bender   +9 more
semanticscholar   +1 more source

Unraveling the enigmatic soft x‐ray excess: Current understanding and future perspectives

Astronomische Nachrichten, Volume 344, Issue 6, August 2023., 2023
Abstract This article explores various theoretical models proposed to explain the soft x‐ray excess phenomenon, including warm Comptonization, ionized reflection models, and ionized outflowing disc winds. The soft x‐ray excess is better understood thanks to crucial observations made by ROSAT, XMM‐Newton, and eROSITA.
Thomas Boller
wiley   +1 more source

Supermassive Black Holes in Bulges [PDF]

The Astrophysical Journal, 2001
26 pages, 11 Postscript figures, accepted for publication on ...
Gregory Rudnick, Gregory Rudnick, Hans-Walter Rix, Wallace L. W. Sargent, Alexei V. Filippenko, Marc Sarzi, Marc Sarzi, Joseph C. Shields, Daniel H. McIntosh, Luis C. Ho   +9 more
openaire   +4 more sources

Energy Flux and Particle Flux in Steady-state Solutions of Nuclear Star Clusters

The Astrophysical Journal, 2023
We examine the effects of two-body interactions in a nuclear star cluster surrounding a supermassive black hole. We evaluate the energy flux, analogously to the particle flux calculation of Bahcall and Wolf.
Barak Rom, Itai Linial, Re’em Sari
doaj   +1 more source