Results 81 to 90 of about 195 (150)

On the physical nature of the source of ultraluminous X-ray pulsations [PDF]

Astrophysics and Space Science, 2015
Extended and revised version, which will appear in Astrophysics and Space Science (ASTR-D-15-00411R2-accepted).
openaire   +2 more sources

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

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

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

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

An Alternative Model for the Orbital Decay of M82 X-2: The Anomalous Magnetic Braking of a Bp Star

The Astrophysical Journal
Recently, the first pulsating ultraluminous X-ray source M82 X-2 was reported to be experiencing a rapid orbital decay at a rate of $\dot{P}=-(5.69\pm 0.24)\times {10}^{-8}\,{\rm{s}}\,{{\rm{s}}}^{-1}$ based on 7 yr NuSTAR data.
Wen-Cong Chen
doaj   +1 more source

Electromagnetic counterparts to massive black-hole mergers. [PDF]

Living Rev Relativ, 2022
Bogdanović T, Miller MC, Blecha L.
europepmc   +1 more source

A Deeper Look into eFEDS AGN Candidates in Dwarf Galaxies with Chandra

The Astrophysical Journal
The ability to accurately discern active massive black holes (BHs) in nearby dwarf galaxies is paramount to understanding the origins and processes of “seed” BHs in the early Universe.
Adonis A. Sanchez, Amy E. Reines, Ákos Bogdán, Ralph P. Kraft   +3 more
doaj   +1 more source

Search for Fast Radio Bursts and Radio Pulsars from Pulsing Ultraluminous X-Ray Sources

The Astrophysical Journal
We conducted targeted fast radio burst (FRB) and pulsar searches on eight pulsing ultraluminous X-ray sources (PULXs) using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) and the Parkes 64 m Radio Telescope (Murriyang) to investigate ...
Juntao Bai, Na Wang, Rui Luo, Wei-Yang Wang, Shi Dai, Songbo Zhang, Shiqian Zhao, Shuangqiang Wang   +7 more
doaj   +1 more source

Modeling Reflection Spectra of Super-Eddington X-Ray Sources

The Astrophysical Journal
Relativistic reflection is a common feature in the X-ray observations of accreting compact objects. We present reflux , a new X-ray reflection model for spectral analysis of super-Eddington sources.
Swarnim Shashank, Askar B. Abdikamalov, Honghui Liu, Temurbek Mirzaev, Jiachen Jiang, Cosimo Bambi, Fergus Baker, Andrew Young   +7 more
doaj   +1 more source