Results 51 to 60 of about 10,594 (212)

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

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

Kinematics and Metallicity of the Dwarf Spheroidal Galaxy Andromeda XVIII

The Astrophysical Journal
Andromeda XVIII is an isolated dwarf galaxy 579 kpc away from the nearest large galaxy, M31. It is a candidate “backsplash galaxy” that might have been affected by a close passage to M31.
Kateryna A. Kvasova, Evan N. Kirby, Rachael L. Beaton   +2 more
doaj   +1 more source

Scientific photography and astronomy: Technology applied to understanding the universe

Mètode Science Studies Journal: Annual Review
In 1925, Edwin Hubble took the first step towards increasing the size of the known universe by several orders of magnitude using the precarious photographic methods available at the time: glass plates and photosensitive emulsions.
Fernando Abalos Vazquez, Javier Ábalos
doaj   +1 more source

The satellite distribution of M31

, 2005
(Abridged) The spatial distribution of the Galactic satellite system plays an important role in Galactic dynamics and cosmology, where its successful reproduction is a key test of simulations of galaxy halo formation.
Irwin, Mike, McConnachie, Alan
core   +2 more sources

Resolved SPLASH Chemodynamics in Andromeda’s PHAT Stellar Halo and Disk: On the Nature of the Inner Halo along the Major Axis

The Astronomical Journal, 2023
Stellar kinematics and metallicity are key to exploring formation scenarios for galactic disks and halos. In this work, we characterized the relationship between kinematics and photometric metallicity along the line of sight to M31's disk.
Ivanna Escala, Amanda C. N. Quirk, Puragra Guhathakurta, Karoline M. Gilbert, J. Leigh Wojno, Lara Cullinane, Benjamin F. Williams, Julianne Dalcanton   +7 more
doaj   +1 more source

Mass modelling the Andromeda Dwarf Galaxies: Andromeda VI and Andromeda XXIII

Monthly Notices of the Royal Astronomical Society
ABSTRACT Accurately mapping the mass profiles of low mass dwarf spheroidal (dSph) galaxies allows us to test predictions made by dark matter (DM) models. To date, such analyses have primarily been performed on Milky Way (MW) satellites.
Connor S Pickett, Michelle L M Collins, R Michael Rich, Justin I Read, Emily J E Charles, Nicolas Martin, Scott Chapman, Alan McConnachie, Alessandro Savino, Daniel R Weisz   +9 more
openaire   +2 more sources

Organized Chaos: Scatter in the relation between stellar mass and halo mass in small galaxies [PDF]

, 2016
We use Local Group galaxy counts together with the ELVIS N-body simulations to explore the relationship between the scatter and slope in the stellar mass vs. halo mass relation at low masses, $M_\star \simeq 10^5 - 10^8 M_\odot$. Assuming models with log-
Bardwell, Emma, Boylan-Kolchin, Michael, Bullock, James S., Garrison-Kimmel, Shea   +3 more
core   +2 more sources

The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. VIII. A Census of Long-period Variable Stars across the Andromeda Dwarf Satellite System

The Astrophysical Journal
We present a comprehensive catalog, in the Sloan i and Harris V filters, of long-period variable (LPV) stars in the spheroidal dwarf satellites of the Andromeda galaxy based on a dedicated survey for variable stars in Local Group dwarf systems.
Hedieh Abdollahi, Atefeh Javadi, Jacco Th. van Loon, Iain McDonald, Mahdi Abdollahi, Elham Saremi, Habib G. Khosroshahi, László Molnár, Hamidreza Mahani   +8 more
doaj   +1 more source

On the α/Fe Bimodality of the M31 Disks

The Astrophysical Journal Letters, 2023
An outstanding question is whether the α /Fe bimodality exists in disk galaxies other than in the Milky Way. Here we present a bimodality using our state-of-the-art galactic chemical evolution models that can explain various observations in the Andromeda
Chiaki Kobayashi, Souradeep Bhattacharya, Magda Arnaboldi, Ortwin Gerhard   +3 more
doaj   +1 more source

A comprehensive study of Cepheid variables in the Andromeda galaxy. Period distribution, blending and distance determination [PDF]

, 2007
Extragalactic Cepheids are the basic rungs of the cosmic distance scale. They are excellent standard candles, although their luminosities and corresponding distance estimates can be affected by the particular properties of the host galaxy. Therefore, the
Alcock, Antonello, Antonello, Antonello, Baade, Baade, Barnes, Beaulieu, Becker, Benedict, Bresolin, C. Jordi, Cotton, F. Vilardell, Feast, Fernie, Fitzpatrick, Fitzpatrick, Fliri, Freedman, Gibson, Hubble, I. Ribas, Kennicutt, Kennicutt, Landolt, Leavitt, Macri, Mochejska, Mochejska, Ngeow, Petersen, Pietrzynski, Ribas, Saha, Sandage, Schwarzenberg-Czerny, Simien, Udalski, Udalski, van Leeuwen, Vilardell, Wozniak, Zakrzewski   +43 more
core   +1 more source