Results 31 to 40 of about 210,241 (186)

Tidal origin of dark matter-free dwarf galaxies in the NGC 1052 group

open access: yesAstronomy & Astrophysics
The discovery of dark matter-free (DM-free) dwarf galaxies in the NGC 1052 neighborhood has had a considerable impact on modern cosmology. The galaxies have been explained through a dwarf–dwarf head-on collision, a rare event.
Hammer F., Yang Y. B.
doaj   +1 more source

A Solar Analog Model for Decrease in Far Ultraviolet Irradiance Under a Grand Minimum

open access: yesEarth and Space Science, Volume 13, Issue 9, September 2026.
Abstract Solar analog field stars having a range of magnetic activity can provide an estimate of solar spectral irradiance (SSI) variability relevant to understanding the Sun's influence on terrestrial climate. This approach is particularly useful for far ultraviolet (FUV) irradiance that cannot be observed from the Earth surface.
D. Lubin, C. Melis, D. Tytler
wiley   +1 more source

Search for dark matter annihilation in the Wolf-Lundmark-Melotte dwarf irregular galaxy with H.E.S.S. [PDF]

open access: yes, 2021
International audienceWe search for an indirect signal of dark matter through very high-energy γ rays from the Wolf-Lundmark-Melotte (WLM) dwarf irregular galaxy.
C van Rensburg (7722008)   +999 more
core   +1 more source

Energy Evolution in the Progenitor of Galaxy Shells: A Semi-analytical Model

open access: yesThe Astrophysical Journal
The stellar shells surrounding an elliptical galaxy, as remnants of a dwarf galaxy disrupted during merging, reveal the distribution of energy and angular momentum of the progenitor dwarf galaxy. We develop a semi-analytical model to describe the changes
Beibei Guo   +3 more
doaj   +1 more source

The ORCA‐TWIN qCMOS Experiment I. Science Case and Commissioning at Calar Alto Observatory

open access: yesAstronomische Nachrichten, Volume 347, Issue 7, August 2026.
ABSTRACT We describe a pilot study to explore a new generation of fast and low noise CMOS image sensors for time domain astronomy, using two remote telescopes with a baseline of 1635 km. The experiment involves direct imaging with novel qCMOS image sensor technology that combines fast readout with sub‐electron readout noise.
Martin M. Roth   +20 more
wiley   +1 more source

Low-mass Galaxy Interactions Trigger Black Hole Activity

open access: yesThe Astrophysical Journal Letters
The existence of high- z overmassive supermassive black holes represents a major conundrum in our understanding of black hole evolution. In this Letter, we probe from the observational point of view how early Universe environmental conditions could have ...
Marko Mićić   +5 more
doaj   +1 more source

Molecular hydrogen in galaxies [PDF]

open access: yes, 1987
This study aims to understand the key role played by molecular hydrogen in the evolution of galaxies, with a view to constraining its radial distribution in the Galaxy and the CO→H(_2) conversion factor α(_20).The star formation rate is shown to be ...
Wilkinson, David Adam, Wilkinson, D.A
core  

The central density cusp of the Sagittarius dwarf spheroidal galaxy

open access: yes, 2005
We present an analysis of the density profile in the central region of the Sagittarius dwarf spheroidal galaxy. A strong density enhancement of Sgr stars is observed.
FERRARO, FRANCESCO ROSARIO   +3 more
core   +1 more source

Harassment origin for kinematic substructures in dwarf elliptical galaxies? [PDF]

open access: yes, 2005
[EN]We have run high resolution N-body models simulating the encounter of a dwarf galaxy with a bright elliptical galaxy. The dwarf absorbs orbital angular momentum and shows counter-rotating features in the external regions of the galaxy. To explain the
M. Balcells   +5 more
core   +1 more source

X-Ray Bright Active Galactic Nuclei in Local Dwarf Galaxies: Insights from eROSITA

open access: yesThe Astrophysical Journal
Although supermassive black holes (SMBHs) reside in the heart of virtually every massive galaxy, it remains debated whether dwarf galaxies commonly host SMBHs. Because low-mass galaxies may retain memory of the assembly history of their black holes (BHs),
Andrea Sacchi   +3 more
doaj   +1 more source

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