Results 61 to 70 of about 533 (185)

Probing the High-frequency Variability of NGC 5044: The Key to Active Galactic Nucleus Feedback

open access: yesThe Astrophysical Journal
The active galactic nucleus (AGN) feeding and feedback process in the centers of galaxy clusters and groups is still not well understood. NGC 5044 is the ideal system in which to study AGN feedback. It hosts the largest known reservoir of cold gas in any
Gerrit Schellenberger   +12 more
doaj   +1 more source

Biomimetic Polymerization of Tellurocysteine: Breaking the Natural Amino Acid Radioprotection Limitation

open access: yesAdvanced Science, Volume 13, Issue 37, 3 July 2026.
Inspired by natural amino acid polymer‐melanin systems, this study strategically incorporated tellurocysteine to develop advanced radiation‐shielding materials. This approach transformed the primary interaction mechanism between melanin‐based materials and incident photons from Compton scattering to the photoelectric effect. Tellurocysteine‐polymerized
Wei Chen   +6 more
wiley   +1 more source

EVN observations of low-luminosity flat-spectrum active galactic nuclei [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2001
We present and discuss the results of very-long baseline interferometry (VLBI, EVN) observations of three low-luminosity (P-5GHz <10(25) W Hz(-1)) broad emission line active galactic nuclei (AGNs) carefully selected from a sample of flat-spectrum radio sources (CLASS). Based on the total and the extended radio power at 5 and at 1.4 GHz respectively,
Caccianiga, A.   +3 more
openaire   +2 more sources

You Shall Not Pass! The Propagation of Low-/Moderate-powered Jets Through a Turbulent Interstellar Medium

open access: yesThe Astrophysical Journal
Feedback from black-hole-powered jets has been invoked in many cosmological simulations to regulate star formation and quench galaxies. Despite this, observational evidence of how jets might be able to affect their hosts remains scarce, especially for ...
Olga Borodina   +8 more
doaj   +1 more source

Feasibility Study for Application of Digitized Henize Mt. Wilson Michigan Southern Sky Hα$$ \boldsymbol{\alpha} $$ Survey Low‐Dispersive Spectral Plates for Searches for Anomalous and Highly Redshifted Objects

open access: yesAstronomische Nachrichten, Volume 347, Issue 6, July 2026.
ABSTRACT The goal of this study is to confirm the feasibility of the use of digitized low dispersive MtWilson Michigan Southern Sky Hα$$ \alpha $$ survey astronomical photographic plates for modern astrophysical research. The detection of highly redshifted objects, such as early galaxies and quasars, is fundamental to understanding the universe's ...
Tauseef Ahmad Zafar   +3 more
wiley   +1 more source

Hot, Cold, and Multicomponent Accretion Flows around Supermassive Black Hole Binaries

open access: yesThe Astrophysical Journal
We develop a model for supermassive black hole binaries (SMBHBs) accreting below their Eddington limit, focusing on systems where hot, advection-dominated flows become viable.
Christopher Tiede, Daniel J. D’Orazio
doaj   +1 more source

First M87 Event Horizon Telescope Results. VII. Polarization of the Ring

open access: yesThe Astrophysical Journal Letters, 2021
In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source morphology.
The Event Horizon Telescope Collaboration   +240 more
doaj   +1 more source

The Formation of Cirrus‐Like Water and Carbon Dioxide Ice Clouds in the Venusian Upper Haze Region

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 7, July 2026.
Abstract The upper haze region of the Venusian atmosphere (∼70–100 km) experiences localized cooling, probably due to gravity waves, creating transient cold pockets. Water ice clouds may form in these cold pockets when sulfuric acid droplets undergo hygroscopic growth and subsequent freezing.
Kathleen A. Alden   +5 more
wiley   +1 more source

Using Faded Changing-look Quasars to Unveil the Spectral Energy Distribution Evolution of Low-luminosity Active Galactic Nuclei

open access: yesThe Astrophysical Journal
The structure of accretion flows in low-luminosity active galactic nuclei (AGNs) at low Eddington ratios (∼10 ^−2 –10 ^−3 ) are poorly understood, and can be probed using the spectral energy distributions (SEDs) of faded changing-look (CL) quasars ...
Olivier Gilbert   +9 more
doaj   +1 more source

Ghost in the Shell: Evidence for Past Active Galactic Nucleus Activities in NGC 5195 from a Newly Discovered Large-scale Ionized Structure

open access: yesThe Astrophysical Journal, 2023
The early-type galaxy NGC 5195 (alternatively known as M51b) possesses extended gas features detected in the multiwavelength, postulated to be associated with previous activities of the central supermassive black hole.
Xiaoyu Xu, Junfeng Wang
doaj   +1 more source

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