Results 61 to 70 of about 53,848 (207)

TeV gamma-UHECR anisotropy by decaying nuclei in flight: first neutrino traces?

, 2012
Ultra High Cosmic Rays) made by He-like lightest nuclei might solve the AUGER extragalactic clustering along Cen A. Moreover He like UHECR nuclei cannot arrive from Virgo because the light nuclei fragility and opacity above a few Mpc, explaining the ...
Abbasi, Auger Collaboration, AugerCollaboration, B. Pattison, Bertou, Bertou, Daniele Fargion, Fargion, Fargion, Fargion, Fargion, Fargion, Fargion, Feng, Gorbunov, Gorbunov, Greisen, K.-H. Kampert, Learned, M. Fukushima, Pierre Auger, Collaboration, R. Engel   +21 more
core   +2 more sources

Modeling the Emission and Polarization Properties of Pulsating Ultraluminous X‐Ray Sources

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT Pulsating Ultraluminous X‐ray Sources (PULXs) are a class of extragalactic sources with high X‐ray luminosity, in excess of 1039$$ {10}^{39} $$ erg s−1$$ {\mathrm{s}}^{-1} $$, and showing pulsations that associate them with neutron stars accreting at a super‐Eddington rate.
S. Conforti, L. Zampieri, R. Taverna, R. Turolla, N. Brice, F. Pintore, G. L. Israel   +6 more
wiley   +1 more source

Preimpact Detection of Chelyabinsk‐Type Objects in the Thermal Infrared: Possibilities and Limitations

Advances in Astronomy, Volume 2025, Issue 1, 2025.
The Chelyabinsk meteor entered Earth’s atmosphere on 15 February 2013, producing a shock wave that injured about 1500 people and damaged thousands of buildings. Despite its relatively large size (∼20 m), the progenitor asteroid approached Earth undetected. Its apparent radiant was too close to the Sun for standard ground‐based near‐Earth asteroid (NEA)
Thomas Müller, Luca Conversi, Javier Licandro, Marco Delbo, Alan Fitzsimmons, Karri Muinonen, Marcel Popescu, Paolo Tanga, Richard Moissl, Michael Kueppers   +9 more
wiley   +1 more source

Opacity in compact extragalactic radio sources and its effect on astrophysical and astrometric studies

, 2008
The apparent position of the "core" in a parsec-scale radio jet (a compact, bright emitting region at the narrow end of the jet) depends on the observing frequency, owing to synchrotron self-absorption and external absorption.
A. B. Pushkarev, A. P. Lobanov, Afanasiev, Beasley, Bietenholz, Blandford, Blandford, Bloom, Böttcher, Charlot, Cohen, Croke, Fey, Fey, Fey, Fomalont, Frey, Hirotani, Hirotani, Homan, Hutter, J. A. Zensus, Jennison, Johnston, Junor, Kadler, Kellermann, Kovalev, Kovalev, Kovalevsky, Königl, Lara, Lestrade, Lindegren, Lobanov, Lobanov, Lobanov, Lobanov, Lobanov, Ma, Marcaide, Marscher, Peterson, Petrov, Petrov, Readhead, Shao, Souchay, Sowards-Emmerd, Vermeulen, Véron-Cetty, Walker, Y. Y. Kovalev   +52 more
core   +1 more source

An Extragalactic Widefield Search for Technosignatures with the Murchison Widefield Array

The Astrophysical Journal
It is common for surveys that are designed to find artificial signals generated by distant civilizations to focus on galactic sources. Recently, researchers have started focusing on searching for all other sources within the field observed, including the
C. D. Tremblay, S. J. Tingay
doaj   +1 more source

The Art of Measuring Physical Parameters in Galaxies: A Critical Assessment of Spectral Energy Distribution Fitting Techniques

The Astrophysical Journal, 2023
The study of galaxy evolution hinges on our ability to interpret multiwavelength galaxy observations in terms of their physical properties. To do this, we rely on spectral energy distribution (SED) models, which allow us to infer physical parameters from
Camilla Pacifici, Kartheik G. Iyer, Bahram Mobasher, Elisabete da Cunha, Viviana Acquaviva, Denis Burgarella, Gabriela Calistro Rivera, Adam C. Carnall, Yu-Yen Chang, Nima Chartab, Kevin C. Cooke, Ciaran Fairhurst, Jeyhan Kartaltepe, Joel Leja, Katarzyna Małek, Brett Salmon, Marianna Torelli, Alba Vidal-García, Médéric Boquien, Gabriel G. Brammer, Michael J. I. Brown, Peter L. Capak, Jacopo Chevallard, Chiara Circosta, Darren Croton, Iary Davidzon, Mark Dickinson, Kenneth J. Duncan, Sandra M. Faber, Harry C. Ferguson, Adriano Fontana, Yicheng Guo, Boris Haeussler, Shoubaneh Hemmati, Marziye Jafariyazani, Susan A. Kassin, Rebecca L. Larson, Bomee Lee, Kameswara Bharadwaj Mantha, Francesca Marchi, Hooshang Nayyeri, Jeffrey A. Newman, Viraj Pandya, Janine Pforr, Naveen Reddy, Ryan Sanders, Ekta Shah, Abtin Shahidi, Matthew L. Stevans, Dian Puspita Triani, Krystal D. Tyler, Brittany N. Vanderhoof, Alexander de la Vega, Weichen Wang, Madalyn E. Weston   +54 more
doaj   +1 more source

Daris, a low-frequency distributed aperture array for radio astronomy in space [PDF]

, 2010
DARIS (Distributed Aperture Array for Radio Astronomy in Space) is a radio astronomy space mission concept aimed at observing the low-frequency radio sky in the range 1-10 MHz.
Bentum, M.J., Boonstra, A.J., Falcke, H., Klooster, K. van 't, Saks, N.   +4 more
core   +1 more source

Antimatter Gravity and the Results of the ALPHA‐g Experiment

Annalen der Physik, Volume 536, Issue 7, July 2024.
The recent results of the ALPHA‐g experiment, which show gravitational attraction between antihydrogen atoms and the Earth, seem to undermine the success of repulsive‐gravity models in the cosmological field. Analyzing the theory of CPT gravity, two solutions are found that are consistent with the experimental results, while preserving the large‐scale ...
Massimo Villata
wiley   +1 more source

Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto, J. F. Steiner, A. Bodaghee, P. Chakraborty, M. Sobolewska, D. R. Pasham, A. Ogorzalek, J. Zuhone, A. Bogdan, M. Vogelsberger   +9 more
wiley   +1 more source

Environments of Luminous Low-frequency Radio Galaxies Since Cosmic Noon: Jet-mode Feedback Dominates in Groups

The Astrophysical Journal
Coupling between relativistic jets launched by accreting supermassive black holes and the surrounding gaseous media is a vital ingredient in galaxy evolution models.
Grayson C. Petter, Ryan C. Hickox, Leah K. Morabito, David M. Alexander   +3 more
doaj   +1 more source