Results 21 to 30 of about 3,265,657 (290)

Early assembly of the most massive galaxies [PDF]

open access: yes, 2009
The current consensus is that galaxies begin as small density fluctuations in the early Universe and grow by in situ star formation and hierarchical merging(1).
Chris A. Collins   +53 more
core   +1 more source

The distribution and lifetime of powerful radio galaxies as a function of environment and redshift

open access: yesScientific Reports, 2018
Correlations between jet power and active time for z 
David Garofalo   +2 more
doaj   +1 more source

Active galaxies and radiative heating

open access: yesPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2005
There is abundant evidence that heating processes in the central regions of elliptical galaxies have both prevented large–scale cooling flows and assisted in the expulsion of metal rich gas. We now know that each such spheroidal system harbours in its core a massive black hole weighing ca.
J. P. Ostriker, CIOTTI, LUCA
openaire   +3 more sources

Active galaxies and cluster gas [PDF]

open access: yesPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2005
Two lines of evidence indicate that active galaxies, principally radio galaxies, have heated the diffuse hot gas in clusters. The first is the general need for additional heating to explain the steepness of the X–ray luminosity–temperature relation in clusters, the second is to solve the cooling–flow problem in cluster cores.
openaire   +3 more sources

Line-strength indices and velocity dispersions for 148 early-type galaxies in different environments [PDF]

open access: yes, 2002
We have derived high quality line-strength indices and velocity dispersions for a sample of 148 early-type galaxies in different environments. The wavelength region covered by the observations ($\lambda \simeq 4600$ to 6600 Å) includes the Lick/IDS ...
R. Bender   +9 more
core   +1 more source

Accretion-modified Stars in Accretion Disks of Active Galactic Nuclei: The Low-luminosity Cases and an Application to Sgr A*

open access: yesThe Astrophysical Journal Letters, 2023
In this paper, we investigate the astrophysical processes of stellar-mass black holes (sMBHs) embedded in advection-dominated accretion flows (ADAFs) of supermassive black holes (SMBHs) in low-luminosity active galactic nuclei.
Jian-Min Wang   +5 more
doaj   +1 more source

Chemical abundances in active galaxies [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2020
ABSTRACT The Sloan Digital Sky Survey (SDSS) has proved to be a powerful resource for understanding the physical properties and chemical composition of star-forming galaxies in the local Universe. The SDSS population of active galactic nuclei (AGNs) remains as of yet less explored in this capacity.
Flury, Sophia R., Moran, Edward C.
openaire   +2 more sources

Euclid Quick Data Release (Q1)

open access: yesAstronomy & Astrophysics
Active galactic nuclei (AGN) are an important phase in galaxy evolution. However, they can be difficult to identify due to their varied observational signatures.
Margalef-Bentabol B.   +332 more
doaj   +3 more sources

The Origin and Evolution of Giant Radio Galaxies

open access: yesFrontiers in Astronomy and Space Sciences, 2022
Giant radio galaxies are arguably the least understood of jetted active galactic nuclei (AGN). We propose that radio galaxies are the product of large mergers that do not involve radio galaxies or radio quasars, such as in merging spiral galaxies, while ...
David Garofalo
doaj   +1 more source

Shock Excitation in Narrow-line Regions Powered by AGN Outflows

open access: yesThe Astrophysical Journal, 2023
Outflows in an active galactic nucleus (AGN) are considered to play a key role in the evolution of the host galaxy through transfer of a large amount of energy.
Misaki Mizumoto   +12 more
doaj   +1 more source

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