Results 131 to 140 of about 59,782 (271)
The Emergence of a Brightest Cluster Galaxy in a Protocluster Core at z = 2.24
The Astrophysical JournalWe report the detection of a pair of massive quiescent galaxies likely in the process of merging at the center of the spectroscopically confirmed, extremely massive protocluster BOSS1244 at z = 2.24 ± 0.02.
Dong Dong Shi +6 more
doaj +1 more source
Astronomische Nachrichten, Volume 346, Issue 5, June 2025.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
A Slowly Pulsating Run‐Away B Star at High Galactic Latitude Ejected From a Spiral Arm
Astronomische Nachrichten, Volume 346, Issue 5, June 2025.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 +3 more
wiley +1 more source
Spectral Energy Distribution Fitting of Globular Clusters in NGC 4874: Masses and Metallicities
The Astrophysical JournalIn most nearby galaxies, photometry of the integrated light of their globular clusters (GCs) has been obtained in only two filters, yielding just a single color index.
Kate Hartman +2 more
doaj +1 more source
Spectroscopic and X-ray Modeling of the Strong Lensing Galaxy Cluster MACS J0138.0-2155
The Open Journal of AstrophysicsWe model the total mass and galactic substructure in the strong lensing galaxy cluster MACS J0138.0-2155 using a combination of Chandra X-ray data, Multi-Unit Spectroscopic Explorer (MUSE) spectroscopy, and Hubble Space Telescope imaging.
Abigail Flowers +4 more
doaj +1 more source
PEARLS: Globular Clusters and Ultracompact Dwarfs in the El Gordo Galaxies at z = 0.87
The Astrophysical JournalJWST/NIRCam 0.9 to 2.0 μ m images reveal a population of point sources around the major galaxies in the El Gordo cluster at redshift z = 0.87. Their distribution in the color–magnitude diagrams shows a narrow sequence well separated from field-galaxy ...
William E. Harris +13 more
doaj +1 more source
Brightest cluster galaxies and the intracluster light
In this chapter, we delve into the formation and primary characteristics of two significant components within galaxy clusters: the brightest cluster galaxies (BCGs) and the intracluster light (ICL). Drawing upon recent and pertinent studies in the field, we explore the mechanisms driving their growth from high redshift to the present day, i.e., mergers
Contini, Emanuele +2 more
openaire +2 more sources
XRISM Reveals Low Nonthermal Pressure in the Core of the Hot, Relaxed Galaxy Cluster A2029
The Astrophysical Journal LettersWe present XRISM Resolve observations of the core of the hot, relaxed galaxy cluster Abell 2029 (A2029). We find that the line-of-sight bulk velocity of the intracluster medium (ICM) within the central 180 kpc is at rest with respect to the brightest ...
XRISM Collaboration +138 more
doaj +1 more source
Weak-lensing Characterization of the Dark Matter in 29 Merging Clusters that Exhibit Radio Relics
The Astrophysical Journal Supplement SeriesWe present a multiwavelength analysis of 29 merging galaxy clusters that exhibit radio relics. For each merging system, we perform a weak-lensing analysis on Subaru optical imaging.
Kyle Finner +7 more
doaj +1 more source
Alignment Effects of Brightest Cluster Galaxies [PDF]
, 1988 D. G. Lambas +2 more
openalex +1 more source