Results 1 to 10 of about 9,171,233 (161)

A NuSTAR Study of Quasiperiodic Oscillations from the Ultraluminous X-Ray Sources in M82

The Astrophysical Journal
The study of quasiperiodic oscillations (QPOs) in X-ray binaries provides valuable insights into the physics of accretion around compact objects. The M82 galaxy hosts multiple ultraluminous X-ray sources, including two prominent ones—X-1 and X-2—where X ...
Hamza El Byad, Matteo Bachetti, Silvia Columbu, Giuseppe Rodriguez, Maura Pilia, Matthew J. Middleton, Dominic J. Walton, Murray Brightman, Hannah Earnshaw, Karl Forster, Brian Grefenstette, Felix Fürst, Marianne Heida, Matteo Imbrogno, Eleonora Veronica Lai, Thomas Maccarone   +15 more
doaj   +1 more source

Modelling quantum aspects of disruption of a white dwarf star by a black hole. [PDF]

Sci Rep, 2021
Karpiuk T, Nikołajuk M, Gajda M, Brewczyk M.   +3 more
europepmc   +1 more source

A Phase-resolved View of Millihertz Quasiperiodic Oscillations in the Ultraluminous X-Ray Source M51 ULX-7: Evidence for a Magnetically Truncated Disk and Geometrical Beaming

The Astrophysical Journal
X-ray quasiperiodic oscillations (QPOs) are commonly observed in Galactic X-ray binaries and extragalactic ultraluminous X-ray sources (ULXs). In this study, we perform a phase-resolved analysis of recently discovered X-ray mHz QPOs in M51 ULX-7.
Qing-Cang Shui, Shu Zhang, Hua Feng, Yu-Peng Chen, Shuang-Nan Zhang, Jing-Qiang Peng   +5 more
doaj   +1 more source

A candidate proton cyclotron feature in the ultraluminous X-ray source NGC 4656 ULX-1

Astronomy & Astrophysics
Ultraluminous X-ray sources represent extreme super-Eddington accretion regimes, and a subset is now known to host highly magnetized neutron stars. However, direct observational probes of their surface magnetic fields remain scarce.
Cruz-Sanchez Nelson, Saavedra Enzo A., Fogantini Federico A., García Federico, Combi Jorge A., Bachetti Matteo, Imbrogno Matteo, Sidoli Lara, Marino Alessio   +8 more
doaj   +1 more source

Extragalactic Science with the Orbiting Astronomical Satellite Investigating Stellar Systems (OASIS) Observatory. [PDF]

Space Sci Rev, 2023
Aalto S, Battersby C, Chin G, Hunt LK, Rigopoulou D, Stark AA, Viti S, Walker CK.   +7 more
europepmc   +1 more source

ULX Collimation by Outflows in Moderately Magnetized Neutron Stars

The Astrophysical Journal
We perform radiative magnetohydrodynamics simulations in general relativity of super-Eddington disk accretion onto neutron stars endowed with a magnetic dipole corresponding to surface strengths not exceeding 100 Giga-Gauss.
Fatemeh Kayanikhoo, Włodek Kluźniak, Miljenko Čemeljić   +2 more
doaj   +1 more source

Possible Supercritical Accretion on the Ultraluminous X-Ray Source in the Metal-poor Galaxy I Zw 18

The Astrophysical Journal
We present an analysis of X-ray observations of the ultraluminous X-ray source (ULX) in I Zw 18 based on archival data taken with Chandra, XMM-Newton, and Suzaku. This ULX is considered to be an intermediate-mass black hole candidate simply because it is
Marina Yoshimoto, Tomokage Yoneyama, Hirofumi Noda, Hirokazu Odaka, Hironori Matsumoto   +4 more
doaj   +1 more source

Isomer-specific kinetics of the C⁺ + H₂O reaction at the temperature of interstellar clouds. [PDF]

Sci Adv, 2021
Yang T, Li A, Chen GK, Yao Q, Suits AG, Guo H, Hudson ER, Campbell WC.   +7 more
europepmc   +1 more source

Explainable Machine Learning Classification of Chandra X-Ray Sources: SHAP Analysis of Multiwavelength Features

The Astrophysical Journal
Extensive astronomical surveys, like those conducted with the Chandra X-ray Observatory, detect hundreds of thousands of unidentified cosmic sources. Machine learning (ML) methods offer an efficient, probabilistic approach to classifying them, which can ...
Shivam Kumaran, Samir Mandal, Sudip Bhattacharyya   +2 more
doaj   +1 more source

Synchrotron Radiation from NGC 470 HLX1—a Hidden Hyperluminous Accreting Neutron Star?

The Astrophysical Journal
We present the first broadband spectral analysis of NGC 470 HLX1, a hyperluminous X-ray source (HLX) that exhibits significant flux variability over different epochs.
Tanuman Ghosh, Shiv Sethi, Gulab Chand Dewangan, Matteo Bachetti, Vikram Rana, Ranjeev Misra   +5 more
doaj   +1 more source