Results 51 to 60 of about 5,289 (173)

Outflows from Quasars and Ultraluminous X-ray Sources

, 2003
Mass outflows from Eddington-limited accreting compact objects appear to be a very widespread phenomenon. They may provide the soft excess observed in quasars and ULXs, and imply that such objects have a major effect on their surroundings.
A.R. King, Blandford, Fabbiano, Fabian, Ferrarese, Gebhardt, Haehnelt, King, King, King, Lamers, Mukai, Pakull, Pounds, Pounds, Reeves, Roberts, Silk, Soltan, Spergel, Tremaine, Yu   +21 more
core   +2 more sources

Magnetic Inclination Evolution of Accreting Neutron Stars in Intermediate/Low-mass X-Ray Binaries

The Astrophysical Journal, 2023
The magnetic inclination angle χ , namely the angle between the spin and magnetic axes of a neutron star, plays a vital role in its observational characteristics. However, there are few systematic investigations of its long-term evolution, especially for
Hao-ran Yang, Xiang-dong Li
doaj   +1 more source

Modeling the Emission and Polarization Properties of Pulsating Ultraluminous X‐Ray Sources

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT Pulsating Ultraluminous X‐ray Sources (PULXs) are a class of extragalactic sources with high X‐ray luminosity, in excess of 1039$$ {10}^{39} $$ erg s−1$$ {\mathrm{s}}^{-1} $$, and showing pulsations that associate them with neutron stars accreting at a super‐Eddington rate.
S. Conforti, L. Zampieri, R. Taverna, R. Turolla, N. Brice, F. Pintore, G. L. Israel   +6 more
wiley   +1 more source

Searching for X-ray sources in nearby late-type galaxies with low star formation rates

, 2015
Late type non-starburst galaxies have been shown to contain X-ray emitting objects, some being ultraluminous X-ray sources. We report on XMM-Newton observations of 11 nearby, late-type galaxies previously observed with the Hubble Space Telescope (HST) in
Brorby, M., Chatterjee, K., Farrell, S., Grise, F., Kaaret, P., Kajava, J. J. E., Poutanen, J.   +6 more
core   +2 more sources

Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto, J. F. Steiner, A. Bodaghee, P. Chakraborty, M. Sobolewska, D. R. Pasham, A. Ogorzalek, J. Zuhone, A. Bogdan, M. Vogelsberger   +9 more
wiley   +1 more source

Chilled disks in ultraluminous X-ray sources [PDF]

Proceedings of the International Astronomical Union, 2006
AbstractIf the standard disk-blackbody approximation is used to estimate black hole (BH) masses in ultraluminous X-ray sources (ULXs), the inferred masses are ∼ 1000 M⊙. However, we argue that such an approximation cannot be applied to ULXs, because their disks are only radiating a small fraction of the accretion power, and are therefore cooler than ...
Roberto Soria, Zdenka Kuncic, Anabela C. Gonçalves   +2 more
openaire   +1 more source

Ultraluminous X-ray Sources: Bubbles and Optical Counterparts

, 2006
Optical studies of ultraluminous X-ray sources (ULX) in nearby galaxies have turned out to be instrumental in discriminating between various models including the much advertised intermediate mass black hole hypothesis and various beaming scenarios.
Grise, Fabien, Motch, Christian, Pakull, Manfred W.   +2 more
core   +1 more source

Chemical Evolution of the Universe and its Consequences for Gravitational‐Wave Astrophysics

Annalen der Physik, Volume 536, Issue 2, February 2024.
Population properties of double compact object mergers (especially binary black holes) are sensitive to the metallicity dependent cosmic star formation history. The uncertainty of this quantity cannot be ignored and makes the interpretation of current gravitational wave observations difficult.
Martyna Chruślińska
wiley   +1 more source

Discovery of a 9.67 s Pulsar in an Ultraluminous X-Ray Source in NGC 4631 with XMM-Newton

The Astrophysical Journal Letters
Thanks to a recent observation with XMM-Newton, we discovered periodic pulsations at P  = 9.6652 ± 0.0002 s in a new ultraluminous X-ray source (ULX) in the galaxy NGC 4631. This source, dubbed as X−8, shows one of the largest spin-up rates ever observed,
Lorenzo Ducci, Sandro Mereghetti, Fabio Pintore, Sinan Allak, Andrea Santangelo, Manami Sasaki, Patrick Kavanagh   +6 more
doaj   +1 more source

Ultraluminous X-ray sources. Optical data. [PDF]

Proceedings of Accretion Processes in Cosmic Sources — PoS(APCS2016), 2018
The origin of Ultraluminous X-ray Sources (ULXs) in external galaxies whose X-ray luminosities exceed those of the brightest black holes in our Galaxy by hundreds and thousands of times is mysterious. The most popular models for the ULXs involve either intermediate mass black holes (IMBHs) or stellar-mass black holes accreting at super-Eddington rates.
openaire   +1 more source