Results 1 to 10 of about 2,137,135 (205)

Tidal forces in dirty black hole spacetimes

European Physical Journal C: Particles and Fields, 2022
Black holes can be inserted in very rich astrophysical environments, such as accretion disks. Although isolated black holes are simple objects in general relativity, their accretion disks may significantly enrich the field configurations of their ...
Haroldo C. D. Lima Junior, Mateus M. Corrêa, Caio F. B. Macedo, Luís C. B. Crispino   +3 more
doaj   +1 more source

How a Klein–Nishina Modified Eddington-limited Accretion Explains Rapid Black Hole Growth in the Early Universe

The Astrophysical Journal
The discovery of quasars and their supermassive black holes (SMBHs) over 10 ^9 ${M}_{{\rm{\odot }}}$ merely hundreds of millions of years after the Big Bang generates tension with the idea of Eddington-limited accretion and pressures the community into ...
Jackson Frangos, Erick Rosen, Michael Williams, Chandra B. Singh, David Garofalo   +4 more
doaj   +1 more source

Electric Currents along Astrophysical Jets

Galaxies, 2017
Astrophysical black holes and their surrounding accretion disks are believed to be threaded by grand design helical magnetic fields. There is strong theoretical evidence that the main driver of their winds and jets is the Lorentz force generated by these
Ioannis Contopoulos
doaj   +1 more source

Principal Component‐Based Classification of Blazar Candidates of Uncertain Type in the 4FGL/LAT

Astronomische Nachrichten, EarlyView.
ABSTRACT We adopted principal component analysis (PCA), linear discriminant analysis (LDA), and support vector machines (SVM), to study classification for a sample of 2708 Fermi blazars: 1142 BL Lac objects (BLLs), 759 flat spectrum radio quasars (FSRQs), and 807 blazar candidates of uncertain type (BCUs).
Wen‐Xin Yang, Guo‐Hai Chen, Jing‐Tian Zhu, Hong‐Guang Wang, Denis Bastieri, Xu‐Hong Ye, Jing‐Chao Liang, De‐Xiang Wu, Jiang‐He Yang, Anton A. Strigachev, Rumen S. Bachev, Jun‐Jie Feng, Yi Liu, Jun‐Hui Fan   +13 more
wiley   +1 more source

Direct SMBH Formation Driven by Runaway Stellar Collisions in Globally Unstable Stellar Systems

Astronomische Nachrichten, EarlyView.
ABSTRACT The fueling problem addresses the ultimate fate of the reservoirs of gas and stars driven into the deepest gravitational potential wells of galaxies, thus it may contain the Universe's densest concentrations of gas and stars. This raises a key question: does the infalling material collapse directly into a supermassive black hole, or can it ...
Marcelo C. Vergara, Andrés Escala
wiley   +1 more source

Hypervelocity Stars Trace a Supermassive Black Hole in the Large Magellanic Cloud

The Astrophysical Journal
Hypervelocity stars (HVSs) are produced by the Hills mechanism when a stellar binary is disrupted by a supermassive black hole (SMBH). The HVS Survey detected 21 unbound B-type main-sequence stars in the Milky Way’s outer halo that are consistent with ...
Jiwon Jesse Han, Kareem El-Badry, Scott Lucchini, Lars Hernquist, Warren Brown, Nico Garavito-Camargo, Charlie Conroy, Re’em Sari   +7 more
doaj   +1 more source

Rotating black holes in Horndeski gravity: thermodynamic and gravitational lensing

European Physical Journal C: Particles and Fields, 2022
The lack of rotating black holes, typically found in nature, hinders testing modified gravity from astrophysical observations. We present the axially symmetric counterpart of an existing spherical hairy black hole in Horndeski gravity having additional ...
Rahul Kumar Walia, Sunil D. Maharaj, Sushant G. Ghosh   +2 more
doaj   +1 more source

Flexible Direct‐Conversion X‐Ray Detectors: From Emerging Materials to Conformal Imaging

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
This comprehensive review analyzed the performance, challenges, and future directions of four emerging material systems for next‐generation flexible direct‐conversion X‐ray detectors: organic semiconductors, perovskites, metal–organic frameworks, and inorganic metal compounds.
Haipeng Di, Guoliang Ma, Jiaxin Mu, Kailian Dong, Haibin Li, Manjing Wang, Xin Song, Haojin Li, Jianwei Xu, Yiying Zhao, Jingjing Zhao, Guojia Fang   +11 more
wiley   +1 more source

Construction optimization and functional applications of fluorescent nanodiamonds

Responsive Materials, EarlyView.
This review summarizes synthesis, surface modification and optical properties of fluorescent nanodiamonds. Their advances in quantum sensing, single‐photon emission and biomedicine are discussed, and existing challenges and future directions are presented.
Yunpeng Yang, Sen Zhang, Chao Chen, Wensi Yang, Zuanquan Chen, Rui Fan, Linlin Liu, Benjian Liu, Kang Liu, Zhibo Zhang, Bing Dai, Jiaqi Zhu   +11 more
wiley   +1 more source

Nonthermal Synchrotron Emission and Polarization Signatures during Black Hole Flux Eruptions

The Astrophysical Journal
In this work, we investigate synchrotron emission and the observational signatures of anisotropic nonthermal electrons during magnetic flux eruptions in a magnetically arrested disk, using 3D GRMHD simulations.
Fan Zhou, Jiewei Huang, Yuehang Li, Zhenyu Zhang, Yehui Hou, Minyong Guo, Bin Chen   +6 more
doaj   +1 more source