Results 101 to 110 of about 9,171,233 (161)

Pulsed Iron Line Emission from the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124

The Astrophysical Journal
We report the phase-resolved spectral results of the first Galactic pulsating ultraluminous X-ray source (PULX) Swift J0243.6+6124, modeling its 2017–2018 outburst peak using data collected by the Hard X-ray Modulation Telescope (Insight-HXMT). The broad
Y. X. Xiao, Y. J. Xu, M. Y. Ge, F. J. Lu, S. N. Zhang, S. Zhang, L. Tao, J. L. Qu, P. J. Wang, L. D. Kong, Y. L. Tuo, Y. You, S. J. Zhao, J. Q. Peng, Y. F. Du, Y. H. Zhang, W. T. Ye   +16 more
doaj   +1 more source

X-ray stellar feedback in low-metallicity starbursts

Astronomy & Astrophysics
Context. The X-ray output of low-metallicity starburst galaxies is a key component of stellar feedback, tracing the processes responsible for gas ionization and chemical enrichment.
Chatzis M., Oskinova L. M., Reyero Serantes S., Lehmer B. D., Östlin G., Bik A., Hayes M., Mas-Hesse J. M., Gallagher J. S., Fürst F.   +9 more
doaj   +1 more source

Galactic Superaccreting X-Ray Binaries as Super-PeVatron Accelerators

The Astrophysical Journal Letters
The extension of the cosmic-ray (CR) spectrum well beyond 1 PeV necessitates the existence of a population of accelerators in the Milky Way, which we refer to as super-PeVatrons. Identifying the nature of these sources remains a challenge to the paradigm
Jieshuang Wang, Brian Reville, Felix A. Aharonian   +2 more
doaj   +1 more source

Long-term Study of the First Galactic Ultraluminous X-Ray Source Swift J0243.6+6124 Using NICER

The Astrophysical Journal
We present the results obtained from detailed X-ray timing and spectral studies of X-ray pulsar Swift J0243.6+6124 during its giant and normal X-ray outbursts between 2017 and 2023 observed by the Neutron star Interior Composition Explorer (NICER).
Birendra Chhotaray, Gaurava K. Jaisawal, Prantik Nandi, Sachindra Naik, Neeraj Kumari, Mason Ng, Keith C. Gendreau   +6 more
doaj   +1 more source

Investigating ultraluminous X-ray sources through their multiwavelength variability and broadband spectra

, 2016
The population of ultraluminous X-ray sources encompasses accreting compact objects with significantly different masses, from black holes of intermediate mass, to black holes of stellar origin, to neutron stars.
Elena Ambrosi, Amid Nayerhoda, Luca Zampieri   +2 more
core   +1 more source

On the Eddington Capture Surface around Spherically Symmetric Compact Objects with Separable Luminosity Distributions

The Astrophysical Journal
Radiation exerts pressure, and therefore it is possible for an intensely bright object to balance the gravitational force near a massive compact object. General relativity demonstrates that this balance occurs for super-Eddington luminosities at a finite
Noah Monk, Adam Rogers
doaj   +1 more source

A Multiwavelength Assessment Disfavoring the X-Ray Binary Origin of He iii Regions in Metal-poor Star-forming Dwarf Galaxies

The Astrophysical Journal
Recent observations of metal-poor, star-forming dwarf galaxies reveal He III regions, traced by nebular He ii λ 4686 emission, that require a strong source of extreme-ultraviolet (EUV) radiation.
Ivan Altunin, Christopher Ellis, Richard M. Plotkin, Roberto Soria, Ryan Tanner, Erica Thygesen, Elena Gallo, Manfred W. Pakull, Andrea H. Prestwich, Amy Reines, Ryan Urquhart, Aarran W. Shaw   +11 more
doaj   +1 more source

The Geometric Crisis in Cygnus X-3: Limitations of Wind-fed Accretion and the Case for Roche Lobe Overflow

The Astrophysical Journal
Cygnus X-3 is a Galactic X-ray binary with a 4.8 hr orbital period operating in the ultraluminous regime. Although the system is viewed at a relatively low inclination ( i  ≈ 28°), it exhibits a deep orbital modulation.
Nicholas E. White
doaj   +1 more source

X-Ray Bright Active Galactic Nuclei in Local Dwarf Galaxies: Insights from eROSITA

The Astrophysical Journal
Although supermassive black holes (SMBHs) reside in the heart of virtually every massive galaxy, it remains debated whether dwarf galaxies commonly host SMBHs. Because low-mass galaxies may retain memory of the assembly history of their black holes (BHs),
Andrea Sacchi, Ákos Bogdán, Urmila Chadayammuri, Angelo Ricarte   +3 more
doaj   +1 more source

The First Insights into an Ultraluminous X-Ray Pulsar with XRISM: Phase-resolved High-resolution Spectroscopy of the Fe K-shell Band of M82 X-2

The Astrophysical Journal
During its performance-verification phase, XRISM observed the M82 galaxy for a net exposure of 207.7 ks, with the ultraluminous X-ray pulsar (ULXP) X-2 included in the field of view. A pulsation search identified a candidate signal with a period close to
Shogo B. Kobayashi, Peter Kosec, Erin Boettcher, Renata Cumbee, Adam Foster, Yutaka Fujita, Kotaro Fukushima, Skylar Grayson, Gabriel Grell, Edmund Hodges-Kluck, Ann Hornschemeier, Richard Kelley, Caroline Kilbourne, Mike Loewenstein, Ikuyuki Mitsuishi, Dustin Nguyen, Evan Scannapieco, Takeshi Tsuru, Noriko Yamasaki, Mihoko Yukita   +19 more
doaj   +1 more source