Results 81 to 90 of about 20,094 (246)

QZO: A Catalog of 5 Million Quasars from the Zwicky Transient Facility

The Astrophysical Journal
Machine learning methods are well established in the classification of quasars (QSOs). However, the advent of light-curve observations adds a great amount of complexity to the problem.
S. J. Nakoneczny, M. J. Graham, D. Stern, G. Helou, S. G. Djorgovski, E. C. Bellm, T. X. Chen, R. Dekany, A. Drake, A. A. Mahabal, T. A. Prince, R. Riddle, B. Rusholme, N. Sravan   +13 more
doaj   +1 more source

The Nature of LoBAL QSOs. II. HST/WFC3 Observations Reveal Host Galaxies Dominated by Mergers

The Astrophysical Journal, 2023
Low-ionization broad absorption line QSOs (LoBALs) are suspected to be merging systems in which extreme, active galactic nucleus-driven outflows have been triggered.
Mariana S. Lazarova, Gabriela Canalizo, Mark Lacy, Wyatt Behn, Kaitlyn Raub, Vardha N. Bennert, Duncan Farrah   +6 more
doaj   +1 more source

The Distribution of Redshifts in New Samples of Quasi-stellar Objects [PDF]

, 2000
Two new samples of QSOs have been constructed from recent surveys to test the hypothesis that the redshift distribution of bright QSOs is periodic in $\log(1+z)$. The first of these comprises 57 different redshifts among all known close pairs or multiple
Arp H., Arp H., Arp H. C., Box T. C., Burbidge E. M., Burbidge G., Burbidge G., Busarello G., de Jager O. C., Depaquit S., Fang L.-Z., G. Burbidge, Karlsson K. G., Karlsson K. G., Karlsson K. G., Radecke H.-D., Roukema B. F., Rowan-Robinson M., Scott D., Thompson D. J., van de Weygaert R., W. M. Napier, Wills D., Zhu X.-F.   +23 more
core   +2 more sources

Topological transport of a classical droplet in a lattice of time

Natural Sciences, Volume 4, Issue 4, October 2024.
A gravitationally bouncing droplet may lock into a 2T periodic motion, where T is the period of the drive, and be described as a classical time crystal. By modulating the drive the droplet may be pumped from one site to the neighbouring site along the time lattice. The pumping process of such topological time crystal pump is characterised by an integer
Tapio Simula, Niels Kjærgaard, Tilman Pfau   +2 more
wiley   +1 more source

Confrontation of the Magnetically Arrested Disc Scenario with Observations of FR II Sources

Frontiers in Astronomy and Space Sciences, 2017
The main aim of our work was to check whether powers of jets in FR II radio galaxies (RGs) and quasars (QSOs) can be reproduced by the Magnetically Arrested Disc (MAD) scenario.
Katarzyna Rusinek, Marek Sikora
doaj   +1 more source

The Star Formation Across Cosmic Time (SFACT) Survey. II. The First Catalog from a New Narrowband Survey for Emission-line Objects

The Astronomical Journal, 2023
Star Formation Across Cosmic Time (SFACT) is a new narrowband (NB) survey designed to detect faint emission-line galaxies (ELGs) and QSOs over a broad range of redshifts.
Jennifer Sieben, David J. Carr, John J. Salzer, Alec S. Hirschauer   +3 more
doaj   +1 more source

Extended Lyman alpha emission around bright quasars

, 2006
Quasars trace the most massive structures at high redshifts and their presence may influence the evolution of the massive host galaxies. We study the extended Lyman alpha emission line regions (EELRs) around seven bright, mostly radio-quiet quasars (QSOs)
Antonucci, Barthel, Benn, Bergeron, Bremer, Bunker, Christensen, Christensen, Crawford, Croton, Di Matteo, Dunlop, Durret, Fried, Fynbo, Haiman, Hall, Heckman, Heckman, Hook, Hopkins, Hu, Hu, Isobe, Jahnke, K. Jahnke, Koratkar, L. Christensen, L. Wisotzki, Lehnert, McCarthy, Møller, Petitjean, Roth, S. F. Sánchez, Schlegel, Scott, Songaila, Springel, Steidel, Sánchez, Sánchez, Sánchez, Sánchez, Sánchez, Tytler, van Ojik, Vanden Berk, Villar-Martin, Villar-Martín, Weidinger, Weidinger, White, Wisotzki   +53 more
core   +3 more sources

Near Infrared Adaptive Optics Imaging of QSO Host Galaxies [PDF]

, 2006
We report near-infrared (primarily H-band) adaptive optics (AO) imaging with the Gemini-N and Subaru Telescopes, of a representative sample of 32 nearby ...
Alan Stockton, D. B. Sanders, Dunlop J. S., Haas M., Hyland A. R., Mobasher B., O. Guyon, Polletta M., Takami H., Taylor G. L., Zheng Z.   +10 more
core   +2 more sources

A survey of the state‐of‐the‐art approaches for evaluating trust in software ecosystems

Journal of Software: Evolution and Process, Volume 36, Issue 10, October 2024.
In this article, we explore current approaches used to evaluate trust in software ecosystems, focusing on analyzing the specific techniques utilized, the primary factors in trust evaluation, the diverse formats for result presentation, as well as the software ecosystem entities considered in the approaches. Abstract Third‐party software has streamlined
Fang Hou, Slinger Jansen
wiley   +1 more source

Cosmic Chronometers, Pantheon+ Supernovae, and Quasars Favor Coasting Cosmologies over the Flat ΛCDM Model

The Astrophysical Journal
We test and compare coasting cosmological models with curvature parameters $k=\left\{-1,0,+1\right\}$ in ${H}_{0}^{2}{c}^{-2}$ units and the flat ΛCDM model by fitting them to cosmic chronometers (CCs), the Pantheon+ sample of Type Ia supernovae (SNe ...
Peter Raffai, Adrienn Pataki, Rebeka L. Böttger, Alexandra Karsai, Gergely Dálya   +4 more
doaj   +1 more source