Results 1 to 10 of about 234,067 (182)

The Distribution of Open Clusters in the Galaxy

open access: yesFrontiers in Astronomy and Space Sciences, 2021
In this work we explore the new catalog of galactic open clusters that became available recently, containing 1,750 clusters that have been re-analyzed using the Gaia DR2 catalog to determine the stellar memberships.
Hektor Monteiro   +3 more
doaj   +1 more source

The Quest for the Nature of the Dark Matter: The Need of a New Paradigm

open access: yesAstronomy, 2023
The phenomenon of the Dark matter baffles the researchers: the underlying dark particle has escaped so far the detection and its astrophysical role appears complex and entangled with that of the standard luminous particles.
Fabrizio Nesti   +2 more
doaj   +1 more source

The Principle of Maximum Entropy and the Distribution of Mass in Galaxies

open access: yesUniverse, 2022
We do not have a final answer to the question of why galaxies choose a particular internal mass distribution. Here we examine whether the distribution is set by thermodynamic equilibrium (TE).
Jorge Sánchez Almeida
doaj   +1 more source

Quantitative Morphology of High-Redshift Galaxies Using GALEX Ultraviolet Images of Nearby Galaxies [PDF]

open access: yesJournal of Astronomy and Space Sciences, 2017
We present simulations of the optical-band images of high-redshift galaxies utilizing 845 near-ultraviolet (NUV) images of nearby galaxies obtained through the Galaxy Evolution Explorer (GALEX). We compute the concentration (C), asymmetry (A), Gini (G),
Bum-Suk Yeom   +6 more
doaj   +1 more source

Warm Dark Matter Galaxies with Central Supermassive Black Holes

open access: yesUniverse, 2022
We generalize the Thomas–Fermi approach to galaxy structure to include central supermassive black holes and find, self-consistently and non-linearly, the gravitational potential of the galaxy plus the central black hole (BH) system.
Hector J. de Vega, Norma G. Sanchez
doaj   +1 more source

JWST Reveals a Population of Ultrared, Flattened Galaxies at 2 ≲ z ≲ 6 Previously Missed by HST

open access: yesThe Astrophysical Journal Letters, 2023
With just a month of data, JWST is already transforming our view of the universe, revealing and resolving starlight in unprecedented populations of galaxies.
Erica J. Nelson   +25 more
doaj   +1 more source

Galaxy Phase-Space Density Data Preclude That Bose–Einstein Condensate Be the Total Dark Matter

open access: yesUniverse, 2022
Ultralight scalars with a typical mass of the order m∼10−22 eV and light scalars forming a Bose–Einstein condensate (BEC) exhibit a Jeans length in the kpc scale and were therefore proposed as dark matter (DM) candidates.
Héctor J. de Vega, Norma G. Sanchez
doaj   +1 more source

Spirality: A Novel Way to Measure Spiral Arm Pitch Angle

open access: yesGalaxies, 2022
We present the MATLAB code Spirality, a novel method for measuring spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. Computation time is typically on the order of 2 min per galaxy, assuming 8 GB of working memory.
Deanna Shields   +9 more
doaj   +1 more source

A Rest-frame Near-IR Study of Clumps in Galaxies at 1 < z < 2 Using JWST/NIRCam: Connection to Galaxy Bulges

open access: yesThe Astrophysical Journal, 2023
A key question in galaxy evolution has been the importance of the apparent “clumpiness” of high-redshift galaxies. Until now, this property has been primarily investigated in rest-frame UV, limiting our understanding of their relevance.
Boris S. Kalita   +6 more
doaj   +1 more source

RR Lyrae Variables as Tracers of the Galactic Bulge Kinematic Structure

open access: yesUniverse, 2022
RR Lyrae stars are recognized as some of the oldest stars in the Universe. In addition, they are some of the few old celestial objects for which distances can be reliably inferred.
Andrea M. Kunder
doaj   +1 more source

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