Results 91 to 100 of about 195 (150)
Multiwavelength Study of a Hyperluminous X-Ray Source near NGC 6099: A Strong IMBH Candidate
The Astrophysical JournalWe report on the intriguing properties of a variable X-ray source projected at the outskirts of the elliptical galaxy NGC 6099 ( d ≈ 139 Mpc). If truly located near NGC 6099, this is a hyperluminous X-ray source that reached an X-ray luminosity L _X ...
Yi-Chi Chang +5 more
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Galactic Superaccreting X-Ray Binaries as Super-PeVatron Accelerators
The Astrophysical Journal LettersThe 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 +2 more
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X-ray stellar feedback in low-metallicity starbursts
Astronomy & AstrophysicsContext. 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. +9 more
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Pulsed Iron Line Emission from the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124
The Astrophysical JournalWe 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 +16 more
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Long-term Study of the First Galactic Ultraluminous X-Ray Source Swift J0243.6+6124 Using NICER
The Astrophysical JournalWe 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 +6 more
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The Astrophysical JournalRadiation 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
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The Astrophysical JournalRecent 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 +11 more
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The Astrophysical JournalCygnus 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
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X-Ray Bright Active Galactic Nuclei in Local Dwarf Galaxies: Insights from eROSITA
The Astrophysical JournalAlthough 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 +3 more
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Polarimetry of Ultraluminous X-ray sources
Ultraluminous X-ray sources (ULXs) are non-nuclear X-ray emitters exceeding the Eddington luminosity, offering key insights into extreme accretion physics. Their origin is attributed to either sub-Eddington accretion onto intermediate-mass black holes (IMBHs) or supercritical accretion onto stellar-mass compact objects in binary systems.
openaire +2 more sources