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Related papers: Tests of a Structure for Quasars

200 papers

It is observationally as well as theoretically well established that the winds of hot, massive OB-stars are highly structured on a broad range of spatial scales. This paper first discusses consequences of the small-scale structures…

Solar and Stellar Astrophysics · Physics 2012-05-16 J. O. Sundqvist , S. P. Owocki

An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar absorption line spectra with laboratory spectra provides a sensitive probe for…

Galactic winds are a crucial player in galaxy formation and evolution, but observations of them have proven extraordinarily difficult to interpret, leaving large uncertainties even in basic quantities such as mass outflow rates. Part of…

Astrophysics of Galaxies · Physics 2022-11-30 Yuxuan Yuan , Mark R. Krumholz , Crystal L. Martin

We demonstrate that Gaia's detection of stars on wide orbits around black holes opens a new observational window on dark matter structures -- such as scalar clouds and dark matter spikes -- predicted in a range of theoretical scenarios.…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-17 Nuno P. Branco , Ricardo Z. Ferreira , João G. Rosa , Rodrigo Vicente

I review recent results for quasars and discuss how they are related to activity in galaxies. Topics included are studies of quasar host galaxies with HST; searches for quasars in the Hubble Deep Field; evolution of the quasar luminosity…

Astrophysics · Physics 2007-05-23 Patrick S. Osmer

Photoionization modeling of certain low-ionization broad absorption lines in quasars implies very compact (Delta R~0.01 pc), galaxy-scale (R kpc) absorbers blueshifted by several 1000 km s^-1. While these are likely signatures of quasar…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-09 C. -A. Faucher-Giguere

The martian atmosphere hosts dynamical phenomena ranging from planet-encircling dust storms to mesoscale orographic clouds and nocturnal low-level jets. General circulation model show capability to simulate these phenomena, but is…

Space weather at Earth, driven by the solar activity, poses growing risks to satellites around our planet as well as to critical ground-based technological infrastructure. Major space weather contributors are the solar wind and coronal mass…

Computer Vision and Pattern Recognition · Computer Science 2025-11-14 Daniela Martin , Jinsu Hong , Connor O'Brien , Valmir P Moraes Filho , Jasmine R. Kobayashi , Evangelia Samara , Joseph Gallego

The properties of the proton has been investigated considering a proton as diquark-quark system. A model for diquark has been suggested in an analogy with the quasi-particle in a crystal lattice. The mass of the diquark obtained in the…

High Energy Physics - Phenomenology · Physics 2010-09-09 A. Bhattacharya , S. N. Banerjee , B. Chakraborti , S. Banerjee

Winds arising from galaxies, star clusters, and active galactic nuclei are crucial players in star and galaxy formation, but it has proven remarkably difficult to use observations of them to determine physical properties of interest,…

Astrophysics of Galaxies · Physics 2017-08-30 Mark R. Krumholz , Todd A. Thompson , Eve C. Ostriker , Crystal L. Martin

The main purpose of this work is to improve the existing knowledge about the most powerful engines in the Universe - quasars. Although a lot is already known, we still have only a vague idea how these engines work exactly, why they behave…

Astrophysics · Physics 2009-11-13 R. Bachev , A. Strigachev , E. Semkov , B. Mihov

The debate concerning the viability of f(R)-gravity as a natural extension of General Relativity could be realistically addressed by using results coming from binary pulsars like PSR 1913+16. To this end, we develop a quadrupolar approach…

General Relativity and Quantum Cosmology · Physics 2014-11-13 Mariafelicia De Laurentis , Salvatore Capozziello

A pedagogical review of the past 50 years of study of resonances, leading to our understanding of the quark content of baryons and mesons. The level of this review is intended for undergraduates or first-year graduate students. Topics…

High Energy Physics - Phenomenology · Physics 2015-05-13 J. T. Londergan

We review the main results from axisymmetric, time-dependent hydrodynamical simulations of radiation driven disk winds in AGN. We illustrate the capability of such simulations to provide useful insights into the three domains of…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-18 Daniel Proga , Paola Rodríguez Hidalgo , Fred Hamann

The CGM around unobscured AGN has received much attention in recent years. Comparatively, nebulae associated with obscured AGN are less studied. Here, we simulate the Ly$\alpha$, H$\alpha$, and HeII nebulae around the two types of AGN at…

We construct a radiation-hydrodynamics model for the obscuring toroidal structure in active galactic nuclei. In this model the obscuration is produced at parsec scale by a dense, dusty wind which is supported by infrared radiation pressure…

High Energy Astrophysical Phenomena · Physics 2015-05-30 A. Dorodnitsyn , G. S. Bisnovatyi-Kogan , T. Kallman

Recent observational results obtained with SCUBA, COBE and ISO have greatly improved our knowledge of the infrared and sub-mm background radiation. These limits become constraining given the realization that most AGNs are heavily obscured…

Astrophysics · Physics 2009-11-07 G. Risaliti , M. Elvis , R. Gilli

The fundamental properties of detached eclipsing binary stars can be measured very accurately, which could make them important objects for constraining the treatment of convection in theoretical stellar models. However, only four or five…

Astrophysics · Physics 2009-11-11 John Southworth , Hans Bruntt

We deploy the new Arkenstone galactic wind model in cosmological simulations for the first time, allowing us to robustly resolve the evolution and impact of high specific energy winds. In a (25 $h^{-1}$ Mpc)$^3$ box we perform a set of…

We discuss how existing astrophysical measurements of various combinations of the fine-structure constant $\alpha$, the proton-to-electron mass ratio $\mu$ and the proton gyromagnetic ratio g$_{p}$ towards the radio source PKS1413+135 can…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 A. M. R. V. L. Monteiro , M. C. Ferreira , M. D. Julião , C. J. A. P. Martins
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