Results 91 to 100 of about 253,449 (279)
The Astrophysical Journal LettersRecent James Webb Space Telescope observations have revealed a population of compact extragalactic objects at z ≳ 4 with red near-infrared colors, which have been dubbed as “Little Red Dots” (LRDs).
Minghao Yue +5 more
doaj +1 more source
Update on the German and Australasian Optical Ground Station Networks
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT Networks of ground stations designed to transmit and receive at visible and infra‐red wavelengths through the atmosphere offer an opportunity to provide on‐demand, high‐bandwidth, secure communications with spacecraft in Earth orbit and beyond. This work describes the operation and activities of current free space optical communications (FSOC)
Nicholas J. Rattenbury +24 more
wiley +1 more source
The cosmic ray luminosity of the nearby active galactic nuclei [PDF]
arXiv, 2008 The pointing directions of extensive air showers observed at the Pierre Auger Observatory were fitted within 3.1 degree with positions of the nearby active galactic nuclei from the Veron-Cetty and P. Veron catalog. The cosmic ray luminosity of the active galactic nuclei which happened to be a source of the particular cosmic ray event constitutes a ...
arxiv
A Catalog of Broad Hα and Hβ Active Galactic Nuclei in MaNGA
The Astrophysical JournalBroad H α and H β emission lines (FWHM > 1000 km s ^−1 ) are incredibly efficient tracers of the high-velocity clouds encircling active galactic nuclei (AGNs).
James Negus +2 more
doaj +1 more source
Discovery of Active Galactic Nuclei in Mid- and Far-Infrared Deep Surveys with ISO [PDF]
arXiv, 2001 We present a summary on the discovery of active galactic nuclei in mid- and far-infrared deep surveys with use of the Infrared Space Observatory.
arxiv
The role of the central stellar cluster in active galactic nuclei. I. Semi-analytical model [PDF]
, 2002 The subject of the paper is the role of the massive stellar cluster in the activity phenomenon and in the structure of active galactic nuclei. We introduce a simple model of stellar dynamics in the internal part of the cluster, which allows us to include both the star-disk and the star-star interactions.
arxiv +1 more source
Radiation-Driven Outflows in Active Galactic Nuclei
, 2009 We review the results from multi-dimensional, time-dependent simulations of gas dynamics in AGN. We will focus on two types of outflows powered by radiation emitted from the AGN central engine: (i) outflows driven from the innermost part of an accretion ...
Daniel Proga +5 more
core +1 more source
Naked active galactic nuclei [PDF]
Astronomy & Astrophysics, 2004 17 pages including 11 figures.
openaire +4 more sources
Structural Concrete, EarlyView.Abstract This review paper provides a comprehensive analysis of radiation shielding concrete, covering its properties, design, evaluation, and applications. It begins with an introduction, stating the objective and scope. The paper explores radiation shielding basics, including ionizing radiation, shielding principles, and materials used for shielding.
Salim Barbhuiya +3 more
wiley +1 more source
Gas flows in galactic nuclei: observational constraints on BH-galaxy coevolution [PDF]
, 2016 Galaxy nuclei are a unique laboratory to study gas flows. High-resolution imaging of the gas flows in galactic nuclei are instrumental in the study of the fueling and the feedback of star formation and nuclear activity in nearby galaxies. Several fueling mechanisms can be now confronted in detail with observations done with state-of-the-art ...
arxiv +1 more source