Results 41 to 50 of about 36,081 (203)

Deep Space Network Radio Science and Ground‐Based Planetary Radar in the Next Decade

Radio Science, Volume 60, Issue 7, July 2025.
Abstract The Deep Space Network (DSN) has been a core operational element of NASA's crewed and robotic exploration of the Solar System since the early 1960s. The primary role of the DSN has been to acquire telemetry and navigation data, but over the years, its radiometric and radar capabilities have expanded to form a system for obtaining unique ...
R. S. Park, J. E. Riedel, N. Rodriguez‐Alvarez, M. Brozovic, L. A. M. Benner, P. Vergados, D. Buccino, C. S. Jacobs, L. S. Locke, S. W. Asmar, R. Castano, T. J. W. Lazio, J. Jao, C. Lee   +13 more
wiley   +1 more source

Fundamental physics opportunities with the next-generation Event Horizon Telescope

Living Reviews in Relativity
The Event Horizon Telescope (EHT) Collaboration recently published the first images of the supermassive black holes in the cores of the Messier 87 and Milky Way galaxies.
Dimitry Ayzenberg, Lindy Blackburn, Richard Brito, Silke Britzen, Avery E. Broderick, Raúl Carballo-Rubio, Vitor Cardoso, Andrew Chael, Koushik Chatterjee, Yifan Chen, Pedro V. P. Cunha, Hooman Davoudiasl, Peter B. Denton, Sheperd S. Doeleman, Astrid Eichhorn, Marshall Eubanks, Yun Fang, Arianna Foschi, Christian M. Fromm, Peter Galison, Sushant G. Ghosh, Roman Gold, Leonid I. Gurvits, Shahar Hadar, Aaron Held, Janice Houston, Yichao Hu, Michael D. Johnson, Prashant Kocherlakota, Priyamvada Natarajan, Héctor Olivares, Daniel Palumbo, Dominic W. Pesce, Surjeet Rajendran, Rittick Roy, Saurabh, Lijing Shao, Shammi Tahura, Aditya Tamar, Paul Tiede, Frédéric H. Vincent, Luca Visinelli, Zhiren Wang, Maciek Wielgus, Xiao Xue, Kadri Yakut, Huan Yang, Ziri Younsi   +47 more
doaj   +1 more source

Black-Hole Bombs and Photon-Mass Bounds

, 2012
Generic extensions of the standard model predict the existence of ultralight bosonic degrees of freedom. Several ongoing experiments are aimed at detecting these particles or constraining their mass range.
A. A. Starobinsky, Akihiro Ishibashi, B. J. Carr, Emanuele Berti, Leonardo Gualtieri, Paolo Pani, S. Hawking, Vitor Cardoso, Y. B. Zel’Dovich   +8 more
core   +1 more source

Redshift‐Agnostic Machine Learning Classification: Unveiling Peak Performance in Galaxy, Star, and Quasar Classification (Using SDSS DR17)

Astronomische Nachrichten, Volume 346, Issue 5, June 2025.
ABSTRACT Classification of galaxies, stars, and quasars using spectral data is fundamental to astronomy, but often relies heavily on redshift. This study evaluates the performance of 10 machine learning algorithms on SDSS data to classify these objects, with a particular focus on scenarios where redshift information is unavailable.
Debashis Chatterjee, Prithwish Ghosh
wiley   +1 more source

Observational Evidence for a Correlation between the Magnetic Field of Jets and Star Formation Rate in Host Galaxies

The Astrophysical Journal
Accretion supermassive black holes in the center of active galaxies usually produce “jet”-collimated bipolar outflows of relativistic particles. Magnetic fields near the black hole event horizon may play a crucial role in the formation of jets/outflows ...
Yongyun Chen, Qiusheng Gu, Junhui Fan, Xiaotong Guo, Xiaoling Yu, Nan Ding, Dingrong Xiong   +6 more
doaj   +1 more source

Close supermassive binary black holes

, 2009
It has been proposed that when the peaks of the broad emission lines in active galactic nuclei (AGNs) are significantly blueshifted or redshifted from the systemic velocity of the host galaxy, this could be a consequence of orbital motion of a ...
Gaskell, C. Martin
core   +1 more source

Stochastic Quantum Mechanics in Curved Spaces: Application to Schwarzschild Black Holes

Astronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.
ABSTRACT In this work, we start from the hypothesis that the universe lives in a Gravitational Wave Background (GWB). From this hypothesis, it follows that space–time is not locally flat because we have to take into account the fluctuations of the GWB in space–time. This implies that sufficiently small particles will feel these oscillations, preventing
Juan S. Jerez‐Rodriguez, Tonatiuh Matos   +1 more
wiley   +1 more source

The Formation and Evolution of the First Massive Black Holes

, 2004
The first massive astrophysical black holes likely formed at high redshifts (z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations.
A Cattaneo, A Cavaliere, A Gould, A Heger, A Jenkins, A Kashlinsky, A Kogut, A Lidz, A Soltan, A Songaila, A Venkatesan, A Wandel, AA Thoul, AC Fabian, AJ Barger, AR King, AR King, AW Graham, B Ciardi, B Ciardi, BJ Carr, CF Gammie, CF Gammie, CJ Willott, CL Bennett, CS Kochanek, D Eisenstein, D Galli, D Lynden-Bell, D Lynden-Bell, D Merritt, D Proga, DC Heggie, DE Berk Van den, DM Alexander, DM Alexander, DN Spergel, DQ Lamb, DR Garnett, E Quataert, EE Salpeter, EJM Colbert, ET Vishniac, F Haardt, F Hoyle, F Palla, F Walter, FA Rasio, G Efstathiou, G Efstathiou, G Kauffmann, G Quinlan, GA Shields, GJ Wasserburg, GL Granato, GM Fuller, GP Holder, GT Richards, H Baumgardt, H Kang, H Kang, H Netzer, H Susa, H Zhao, HM Lee, I Igumenshchev, I Shlosman, J Arons, J Binney, J Comerford, J Goodman, J Magorrian, J Miralda-Escudé, J Silk, J Silk, J Stone, J Tumlinson, J-H Woo, JA Sellwood, JA Tyson, JE Gunn, JF Navarro, JM Shull, JM Stone, JP Ostriker, K Gebhardt, K Gebhardt, K Menou, K Menou, L Ciotti, L Ciotti, L Ferrarese, L Ferrarese, L Ferrarese, L Hui, LL Spitzer Jr, M Dijkstra, M Elvis, M Fukugita, M Kaplinghat, M Milosavljevic, M Saijo, M Shibata, M Tegmark, M Vestergaard, M Vestergaard, M Volonteri, M Zaldarriaga, MC Begelman, MC Begelman, MC Begelman, MC Begelman, MC Begelman, MC Begelman, MG Haehnelt, MG Haehnelt, MG Haehnelt, MG Haehnelt, MJ Kukula, MJ Rees, MJ Rees, NI Shakura, NY Gnedin, NY Gnedin, NY Gnedin, O Blaes, P Hut, P Kaaret, P Madau, P Madau, P Madau, P Madau, P Martini, P Martini, P McDonald, P Monaco, P Salucci, P Valageas, P Väisänen, PA Shaver, PJ Armitage, PR Shapiro, PR Shapiro, Q Yu, Q Yu, R Barkana, R Barkana, R Cen, R Cen, RD Blandford, RD Blandford, RF Mushotzky, RH Becker, RK Islam, RK Sheth, RL White, RP Marel Van der, RP Marel Van der, RP Marel Van der, RV Wagoner, S Croom, S Kaspi, S Lepp, S Wyithe, S Wyithe, S Wyithe, S Wyithe, SA Hughes, SDM White, SE Woosley, SF Portegies Zwart, SL Shapiro, SL Shapiro, SP Oh, SP Oh, SP Oh, SP Oh, SR Heap, T Abel, T Abel, T Abel, T Abel, T Hirasawa, T Kitayama, T Matsuda, T Matteo Di, T Miyaji, T Theuns, TA Small, V Bromm, V Bromm, V Bromm, WC Saslaw, WH Press, X Fan, X Fan, X Fan, X Fan, X Wu, YB Zel’dovich, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman, Z Haiman   +214 more
core   +1 more source

Interplay of Magnetic Reconnection and Current Sheet Kink Instability in the Earth's Magnetotail

Geophysical Research Letters, Volume 52, Issue 2, 28 January 2025.
Abstract Magnetic reconnection and current sheet kink instability often develop concurrently in current sheets, yet their dynamic interplay remains unclear. We investigate their interaction in the magnetotail of a 3D global magnetospheric hybrid‐Vlasov simulation. We identify the instability growth and saturation phase and estimate the evolution of the
G. Cozzani, M. Alho, I. Zaitsev, H. Zhou, S. Hoilijoki, L. Turc, M. Grandin, K. Horaites, M. Battarbee, Y. Pfau‐Kempf, U. Ganse, K. Papadakis, M. Palmroth   +12 more
wiley   +1 more source

Threshold drop in accretion density if dark energy is accreting onto a supermassive black hole

European Physical Journal C: Particles and Fields, 2019
Recent studies of galactic cores tell us that supermassive black holes are hosted at each of these cores. We got some evidences even. Besides, dark energy is expected to be distributed all over in our universe.
Ritabrata Biswas, Sandip Dutta
doaj   +1 more source