Results 51 to 60 of about 887 (163)

The Outer Halos of Very Massive Galaxies: BCGs and their DSC in the Magneticum Simulations

Galaxies, 2017
Recent hydrodynamic cosmological simulations cover volumes up to Gpc 3 and resolve halos across a wide range of masses and environments, from massive galaxy clusters down to normal galaxies, while following a large variety of physical processes ...
Rhea-Silvia Remus, Klaus Dolag, Tadziu L. Hoffmann   +2 more
doaj   +1 more source

Minor Mergers Are Not Enough: The Importance of Major Mergers during Brightest Cluster Galaxy Assembly

The Astrophysical Journal Supplement Series, 2023
We investigate the roles of major and minor mergers during brightest cluster galaxy (BCG) assembly using surface brightness profiles, line indices, and fundamental plane relations.
Matthias Kluge, Ralf Bender
doaj   +1 more source

Redshift‐Agnostic Machine Learning Classification: Unveiling Peak Performance in Galaxy, Star, and Quasar Classification (Using SDSS DR17)

Astronomische Nachrichten, EarlyView.
ABSTRACT Classification of galaxies, stars, and quasars using spectral data is fundamental to astronomy, but often relies heavily on redshift. This study evaluates the performance of 10 machine learning algorithms on SDSS data to classify these objects, with a particular focus on scenarios where redshift information is unavailable.
Debashis Chatterjee, Prithwish Ghosh
wiley   +1 more source

Structure of Brightest Cluster Galaxies and Intracluster Light [PDF]

The Astrophysical Journal Supplement Series, 2020
Abstract Observations of 170 local (z ≲ 0.08) galaxy clusters in the northern hemisphere have been obtained with the Wendelstein Telescope Wide Field Imager (WWFI). We correct for systematic effects such as point-spread function broadening, foreground star contamination, relative bias offsets, and charge persistence.
M. Kluge, B. Neureiter, A. Riffeser, R. Bender, C. Goessl, U. Hopp, M. Schmidt, C. Ries, N. Brosch   +8 more
openaire   +4 more sources

A Slowly Pulsating Run‐Away B Star at High Galactic Latitude Ejected From a Spiral Arm

Astronomische Nachrichten, EarlyView.
ABSTRACT We report the discovery of the young B6 V run‐away star LAMOST J083323.18 + 430825.4, 2.5 kpc above the Galactic plane. Its atmospheric parameters and chemical composition are determined from LAMOST spectra, indicating normal composition. Effective temperature (Teff$$ {T}_{\mathrm{eff}} $$ = 14,500$$ \mathrm{14,500} $$ K) and gravity (logg ...
Ulrich Heber, Maximilian Halenke, Aakash Bhat, Veronika Schaffenroth   +3 more
wiley   +1 more source

Parsec Scale Properties of Brightest Cluster Galaxies. [PDF]

Proceedings of The 9th European VLBI Network Symposium on The role of VLBI in the Golden Age for Radio Astronomy and EVN Users Meeting — PoS(IX EVN Symposium), 2009
6 pages, 2 figures. Contributed talk. To be published in the proceedings of "The 9th European VLBI Network Symposium on The role of VLBI in the Golden Age for Radio Astronomy and EVN Users Meeting", September 23-26, 2008, Bologna ...
Gabriele Giovannini, Marcello Giroletti, Elisabetta Liuzzo   +2 more
openaire   +3 more sources

COSMIC: A Galaxy Cluster–Finding Algorithm Using Machine Learning

The Astrophysical Journal Supplement Series
Building a comprehensive catalog of galaxy clusters is a fundamental task for studies on structure formation and galaxy evolution. In this paper, we present Cluster Optical Search using Machine Intelligence in Catalogs (COSMIC), an algorithm utilizing ...
Da-Chuan Tian, Yang Yang, Zhong-Lue Wen, Jun-Qing Xia   +3 more
doaj   +1 more source

Powerful Yet Lonely: Is 3C 297 a High-redshift Fossil Group?

The Astrophysical Journal Supplement Series, 2022
The environment of the high-redshift ( z = 1.408), powerful radio-loud galaxy 3C 297 has several distinctive features of a galaxy cluster. Among them, a characteristic halo of hot gas revealed by Chandra X-ray observations.
Valentina Missaglia, Juan P. Madrid, Mischa Schirmer, Francesco Massaro, Alberto Rodríguez-Ardila, Carlos J. Donzelli, Martell Valencia, Alessandro Paggi, Ralph P. Kraft, Chiara Stuardi, Belinda J. Wilkes   +10 more
doaj   +1 more source

Volume measurement of microparticles using SEM photogrammetry and 3‐D reconstruction

Meteoritics &Planetary Science, EarlyView.
Abstract In this paper, we introduce a method for volume measurement of microparticles that includes scanning electron microscope photogrammetry with 3‐D model construction. Our results show that our method limits the volume uncertainty to ±10%, which is a significant improvement compared to previous methods (which likely overestimated volume by 100 ...
Y. Zheng, X. Yang, M. Valdes, A. M. Davis, P. R. Heck   +4 more
wiley   +1 more source

Models for the magnitude-distribution of brightest cluster galaxies [PDF]

Monthly Notices of the Royal Astronomical Society, 2001
Abstract submitted to AAS.
J. P. Bernstein, S. P. Bhavsar, S. P. Bhavsar   +2 more
openaire   +4 more sources