Results 61 to 70 of about 53,924 (236)

All-sky Galactic radiation at 45 MHz and spectral index between 45 and 408 MHz

, 2010
Aims: We study the Galactic large-scale synchrotron emission by generating a reliable all-sky spectral index map and temperature map at 45 MHz. Methods: We use our observations, the published all-sky map at 408 MHz, and a bibliographical compilation to ...
A. E. Guzmán, Allen, Alvarez, Alvarez, Alvarez, Andrew, Andrews, Ariskin, Baldwin, Berkhuijsen, Blythe, Bolton, Bridle, Cane, Caswell, Clark, de Oliveira-Costa, Dröge, Dwarakanath, Ellis, Ellis, Ellis, Fukao, Fukao, Gervasi, H. Alvarez, Hamilton, Hamilton, Han, Hanbury Brown, Hartz, Haslam, Haslam, Haslam, Heiles, Hill, Hill, Hornby, Howell, J. May, Jones, K. Maeda, Ko, Lallement, Landecker, Large, Lawson, Maeda, Mathewson, May, Milogradov-Turin, Moran, Pauliny-Toth, Piddington, Piddington, Price, Purton, Reich, Reich, Reich, Reich, Reich, Roger, Rohan, Seeger, Shain, Shain, Simon, Sironi, Sun, Testori, Turtle, Véron, Wall, Webster, Wielebinski, Wolleben, Yates, Yates, Yates   +79 more
core   +1 more source

Beyond Accretion Limits: The Rise of Pulsating Gems

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT The discovery of several ultraluminous X‐ray sources exhibiting fast and rapidly evolving X‐ray pulsations unequivocally associates these sources with accreting neutron stars orbiting relatively massive companion stars (> 8M ⊙$$ {}_{\odot } $$).
Gian Luca Israel, Roberta Amato, Matteo Imbrogno, Nicoló Oreste Pinciroli Vago, on behalf of a Larger Team, Guillermo Andres Rodríguez Castillo, Andrea Belfiore, Luigi Stella, Matteo Bachetti, Felix Fürst, Dom Walton, Matthew Middleton, Murray Brightman, Fabio Pintore, Ciro Pinto, Silvia Conforti, Luca Zampieri, Chiara Salvaggio, Anna Wolter, Andrea Tiengo, Andrea De Luca, Paolo Esposito, Ruben Salvaterra, Hannah Earnshaw, Tim Roberts, Andres Gúrpide, Sara Motta   +26 more
wiley   +1 more source

Discovery of very high energy gamma-rays from the flat spectrum radio quasar 3C 279 with the MAGIC telescope

, 2008
3C 279 is one of the best studied flat spectrum radio quasars located at a comparatively large redshift of z = 0.536. Observations in the very high energy band of such distant sources were impossible until recently due to the expected steep energy ...
D. Kranich, D. Mazin, E. Lorenz, E. Prandini, F. Tavecchio, Felix A. Aharonian, Frank Rieger, M. Errando, M. Mariotti, M. Teshima, null null, P. Majumdar, R. Bock, R. Wagner, Werner Hofmann   +14 more
core   +1 more source

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

Classifying Optical (Out)bursts in Cataclysmic Variables: The Distinct Observational Characteristics of Dwarf Novae, Micronovae, Stellar Flares, and Magnetic Gating

The Astrophysical Journal Letters
Cataclysmic variables can experience short optical brightenings, which are commonly attributed to phenomena such as dwarf novae outbursts, micronovae, donor flares, or magnetic gating bursts.
Krystian Iłkiewicz, Simone Scaringi, Martina Veresvarska, Domitilla De Martino, Colin Littlefield, Christian Knigge, John A. Paice, Anwesha Sahu   +7 more
doaj   +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

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

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

Status of neutrino astronomy

, 2008
Astrophysical neutrinos can be produced in proton interactions of charged cosmic rays with ambient photon or baryonic fields. Cosmic rays are observed in balloon, satellite and air shower experiments every day, from below 1e9 eV up to macroscopic ...
Achterberg A, Becker J K, DeYoung T, Gaisser T K, Ginzburg V L, Halzen F, Halzen F, Hess V F, Julia K Becker, Kachelriess M, Kang H, Koers H B J, Münich K, Stecker F W, Volkova L V   +14 more
core   +1 more source

SXDF-ALMA 2 Arcmin^2 Deep Survey: Resolving and Characterizing the Infrared Extragalactic Background Light Down to 0.5 mJy

, 2016
We present a multi-wavelength analysis of five submillimeter sources (S_1.1mm = 0.54-2.02 mJy) that were detected during our 1.1-mm-deep continuum survey in the SXDF-UDS-CANDELS field (2 arcmin^2, 1sigma = 0.055 mJy beam^-1) using the Atacama Large ...
Aretxaga, Itziar, Dunlop, James S., Hatsukade, Bunyo, Hughes, David, Ikarashi, Soh, Ishii, Shun, Ivison, Rob J., Izumi, Takuma, Kawabe, Ryohei, Kodama, Tadayuki, Kohno, Kotaro, Lee, Minju, Makiya, Ryu, Matsuda, Yuichi, Nakanishi, Kouichiro, Ohta, Kouji, Rujopakarn, Wiphu, Tadaki, Ken-ichi, Tamura, Yoichi, Umehata, Hideki, Wang, Wei-Hao, Wilson, Grant W., Yabe, Kiyoto, Yamaguchi, Yuki, Yun, Min S.   +24 more
core   +1 more source