Results 41 to 50 of about 525 (178)

Upper Limits on the Radio Pulses from Magnetars and a Central Compact Object with FAST

The Astrophysical Journal
Magnetars and central compact objects (CCOs) are subgroups of neutron stars that show a number of properties distinguished from canonical radio pulsars. We performed radio observations of three magnetars, SGR 0418+5729, 1E 2259+586, and 4U 0142+61, and a
Wan-Jin Lu, Ping Zhou, Pei Wang, Yi-Xuan Shao, Xiang-dong Li, Jacco Vink, Di Li, Yang Chen   +7 more
doaj   +1 more source

The Role of XMM–Newton in the Investigation of Persistent BeXRBs

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT The persistent BeXRBs are a class of high‐mass X‐ray binaries (HMXRBs), which are characterized by persistent low X‐ray luminosities (LX~1034$$ {L}_{\mathrm{X}}\sim {10}^{34} $$ erg s −1$$ {}^{-1} $$) and wide (Porb>$$ {P}_{\mathrm{orb}}> $$ 30 days), almost circular orbits. In these sources the NS is slowly rotating (with Pspin$$ {P}_{\mathrm{
Nicola La Palombara, Lara Sidoli, Sandro Mereghetti, Gian Luca Israel, Paolo Esposito   +4 more
wiley   +1 more source

Estimation of the detected background by the future gamma ray transient mission CAMELOT

Astronomische Nachrichten, Volume 340, Issue 7, Page 666-673, August 2019., 2019
Abstract This study presents a background estimation for the CubeSats Applied for MEasuring and LOcalising Transients (CAMELOT), which is a proposed fleet of nanosatellites for the all‐sky monitoring and timing‐based localization of gamma ray transients with precise localization capability at low Earth orbits.
Jakub Řípa, Gábor Galgóczi, Norbert Werner, András Pál, Masanori Ohno, László Mészáros, Tsunefumi Mizuno, Norbert Tarcai, Kento Torigoe, Nagomi Uchida, Yasushi Fukazawa, Hiromitsu Takahashi, Kazuhiro Nakazawa, Naoyoshi Hirade, Kengo Hirose, Syohei Hisadomi, Teruaki Enoto, Hirokazu Odaka, Yuto Ichinohe, Zsolt Frei, László Kiss   +20 more
wiley   +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

Alfvén QPOs in Magnetars [PDF]

Journal of Physics: Conference Series, 2009
We investigate torsional Alfvén oscillations of relativistic stars with a global dipole magnetic field, via two-dimensional numerical simulations. We find that a) there exist two families of quasi-periodic oscillations (QPOs) with harmonics at integer multiples of the fundamental frequency, b) the lower-frequency QPO is related to the region of closed ...
Sotani, Hajime, Kokkotas, Kostas, Stergioulas, Nikolaos   +2 more
openaire   +2 more sources

A Brief, Biased View of Neutron Star Cooling

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT This is a concise and non‐technical review of topics related to neutron star (NS) cooling, for both young NSs and NSs in low‐mass x‐ray binaries. Neutrino emission from the NS core drives cooling rates, via different processes including Urca processes and pair breaking and formation at the neutron superfluid critical temperature.
Craig Heinke
wiley   +1 more source

Magnetars

, 2005
P-stars are compact stars made of up and down quarks in beta-equilibrium with electrons in a chromomagnetic condensate. P-stars are able to account for compact stars like RXJ 1856.5-3754 and RXJ 0720.4-3125, stars with radius comparable with canonical neutron stars, as well as super massive compact objects like SgrA*.
openaire   +4 more sources

The role of magnetar transient activity in time-domain and multimessenger astronomy

Frontiers in Astronomy and Space Sciences
Time-domain and multimessenger astronomy (TDAMM) involves the study of transient and time-variable phenomena across various wavelengths and messengers.
Michela Negro, George Younes, Zorawar Wadiasingh, Zorawar Wadiasingh, Zorawar Wadiasingh, Eric Burns, Aaron Trigg, Matthew Baring   +7 more
doaj   +1 more source

Characterizing the dynamical magnetosphere of the extremely slowly rotating magnetic O9.7 V star HD 54879 using rotational modulation of the Hα profile

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract The magnetic field in the O9.7 V star HD 54879 has been monitored for almost a decade. Spectropolarimetric observations reveal a rather strong mean longitudinal magnetic field that varies with a period of about 7.41 years. Observations in the Hα$$ \alpha $$ line show a variation with the same period, while the Hβ$$ \beta $$ line shows only ...
Manfred Küker, S. P. Järvinen, S. Hubrig, Ilya Ilyin, M. Schöller   +4 more
wiley   +1 more source

Search for Galactic Sources of Trans-GZK Cosmic Rays in the Local Void Sky Region

Galaxies
Identifying the sources of Ultra-High Energy Cosmic Rays (UHECRs, E>1018 eV) remains a fundamental challenge in astrophysics due to the significant deflections of charged particles by Galactic and extragalactic magnetic fields.
Lidiia Zadorozhna, Olexandr Gugnin, Bohdan Hnatyk, Olena Prykhodko, Valentyna Babur, Vadym Voitsekhovskyi, Pavlo Panasiuk   +6 more
doaj   +1 more source