scholarly journals N-body Self-consistent Stellar-halo Modeling of the Fornax Dwarf Galaxy

2021 ◽  
Vol 909 (2) ◽  
pp. 147
Author(s):  
Galina Shchelkanova ◽  
Kohei Hayashi ◽  
Sergei Blinnikov
Keyword(s):  
Dwarf Galaxy ◽  
Self Consistent ◽  
Stellar Halo ◽  
Body Self

scholarly journals Distance to the nearby dwarf galaxy [TT2009] 25 in the NGC 891 group using the tip of the red giant branch

2019 ◽  
Vol 629 ◽  
pp. L2 ◽  
Author(s):  
Oliver Müller ◽  
Rodrigo Ibata ◽  
Marina Rejkuba ◽  
Lorenzo Posti
Keyword(s):  
Milky Way ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Small Scale ◽  
Accurate Information ◽  
Standard Candle ◽  
Stellar Halo ◽  
Red Giant ◽  
Small Field Of View

Dwarf galaxies are key objects for small-scale cosmological tests like the abundance problems or the planes-of-satellites problem. A crucial task is therefore to get accurate information for as many nearby dwarf galaxies as possible. Using extremely deep, ground-based V and i-band Subaru Suprime Cam photometry with a completeness of i = 27 mag, we measure the distance of the dwarf galaxy [TT2009] 25 using the tip of the red giant branch as a standard candle. This dwarf resides in the field around the Milky Way-analog NGC 891. Using a Bayesian approach, we measure a distance of 10.28−1.73+1.17 Mpc, which is consistent with the distance of NGC 891, and thus confirm it as a member of NGC 891. The dwarf galaxy follows the scaling relations defined by the Local Group dwarfs. We do not find an extended stellar halo around [TT2009] 25. In the small field of view of 100 kpc covered by the survey, only one bright dwarf galaxy and the giant stream are apparent. This is comparable to the Milky Way, where one bright dwarf resides in the same volume, as well as the Sagittarius stream – excluding satellites which are farther away but would be projected in the line-of-sight. It is thus imperative to survey for additional dwarf galaxies in a larger area around NGC 891 to test the abundance of dwarf galaxies and compare this to the number of satellites around the Milky Way.

scholarly journals The Enrichment of the Intracluster Medium

1996 ◽  
Vol 171 ◽  
pp. 381-381
Author(s):  
B.K. Gibson ◽  
F. Matteucci
Keyword(s):  
Chemical Evolution ◽  
Dwarf Galaxy ◽  
Observational Evidence ◽  
Intracluster Medium ◽  
X Ray ◽  
Galactic Wind ◽  
Galactic Winds ◽  
Luminosity Functions ◽  
Self Consistent

Recent observational evidence for steep dwarf galaxy luminosity functions in several rich clusters has led to speculation that their precursors, via supernovae (SNe)-driven galactic winds, may be the source of the majority of gas and metals inferred from intracluster medium (ICM) x-ray observations (Trentham 1994). Utilising a fully self-consistent photo-chemical evolution package (Gibson 1995), and insisting that the post-galactic wind dwarfs obey the observed colour-luminosity-metallicity relations, we demonstrate that the bulk of the ICM gas does not originate within their precursors (Gibson & Matteucci 1995).

scholarly journals SMC in space and time: a project to study the evolution of the prototype interacting late-type dwarf galaxy

2008 ◽  
Vol 4 (S255) ◽  
pp. 381-386 ◽  
Author(s):  
M. Tosi ◽  
J. Gallagher ◽  
E. Sabbi ◽  
K. Glatt ◽  
E. K. Grebel ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxy ◽  
Variable Stars ◽  
Star Formation History ◽  
Space And Time ◽  
Deep Well ◽  
Formation History ◽  
Central Regions ◽  
Stellar Halo ◽  
Hubble Time

AbstractWe introduce the SMC in space and time, a large coordinated space and ground-based program to study star formation processes and history, as well as variable stars, structure, kinematics and chemical evolution of the whole SMC. Here, we present the Colour-Magnitude Diagrams (CMDs) resulting from HST/ACS photometry, aimed at deriving the star formation history (SFH) in six fields of the SMC. The fields are located in the central regions, in the stellar halo, and in the wing toward the LMC. The CMDs are very deep, well beyond the oldest Main Sequence Turn-Off, and will allow us to derive the SFH over the entire Hubble time.

scholarly journals Galaxies lacking dark matter in the Illustris simulation

2019 ◽  
Vol 626 ◽  
pp. A47 ◽  
Author(s):  
M. Haslbauer ◽  
J. Dabringhausen ◽  
P. Kroupa ◽  
B. Javanmardi ◽  
I. Banik
Keyword(s):  
Dark Matter ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Large Magellanic Cloud ◽  
Early Type ◽  
Number Density ◽  
The Standard Model ◽  
Ram Pressure ◽  
Self Consistent ◽  
First Time

Context. Any viable cosmological model in which galaxies interact predicts the existence of primordial and tidal dwarf galaxies (TDGs). In particular, in the standard model of cosmology (ΛCDM), according to the dual dwarf galaxy theorem, there must exist both primordial dark matter-dominated and dark matter-free TDGs with different radii. Aims. We study the frequency, evolution, and properties of TDGs in a ΛCDM cosmology. Methods. We use the hydrodynamical cosmological Illustris-1 simulation to identify TDG candidates (TDGCs) and study their present-day physical properties. The positions of galaxies in the radius–mass plane, depending on their nonbaryonic content, are compared with observational data and other simulations. We also present movies on the formation of a few galaxies lacking dark matter, confirming their tidal dwarf nature. Tidal dwarf galaxy candidates can however also be formed via other mechanisms, such as from ram-pressure-stripped material or, speculatively, from cold-accreted gas. Results. We find 97 TDGCs with Mstellar > 5 × 107M⊙ at redshift z = 0, corresponding to a co-moving number density of 2.3 × 10−4 h3 cMpc−3. The most massive TDGC has Mtotal = 3.1 × 109 M⊙, comparable to that of the Large Magellanic Cloud. Tidal dwarf galaxy candidates are phase-space-correlated, reach high metallicities, and are typically younger than dark matter-rich dwarf galaxies. Conclusions. We report for the first time the verification of the dual dwarf theorem in a self-consistent ΛCDM cosmological simulation. Simulated TDGCs and dark matter-dominated galaxies populate different regions in the radius–mass diagram in disagreement with observations of early-type galaxies. The dark matter-poor galaxies formed in Illustris-1 have comparable radii to observed dwarf galaxies and to TDGs formed in other galaxy-encounter simulations. In Illustris-1, only 0.17 percent of all selected galaxies with Mstellar = 5 × 107−109 M⊙ are TDGCs or dark matter-poor dwarf galaxies. The occurrence of NGC 1052-DF2-type objects is discussed.

scholarly journals Evidence for two early accretion events that built the Milky Way stellar halo

2019 ◽  
Vol 488 (1) ◽  
pp. 1235-1247 ◽  
Author(s):  
G C Myeong ◽  
E Vasiliev ◽  
G Iorio ◽  
N W Evans ◽  
V Belokurov
Keyword(s):  
Globular Cluster ◽  
Total Mass ◽  
Globular Clusters ◽  
Milky Way ◽  
Dwarf Galaxy ◽  
High Energy ◽  
Stellar Mass ◽  
Milky Way Galaxy ◽  
Stellar Halo ◽  
Chemical Evidence

AbstractThe Gaia Sausage is the major accretion event that built the stellar halo of the Milky Way galaxy. Here, we provide dynamical and chemical evidence for a second substantial accretion episode, distinct from the Gaia Sausage. The Sequoia Event provided the bulk of the high-energy retrograde stars in the stellar halo, as well as the recently discovered globular cluster FSR 1758. There are up to six further globular clusters, including ω Centauri, as well as many of the retrograde substructures in Myeong et al., associated with the progenitor dwarf galaxy, named the Sequoia. The stellar mass in the Sequoia galaxy is ∼5 × 10  M⊙ , whilst the total mass is ∼1010 M⊙ , as judged from abundance matching or from the total sum of the globular cluster mass. Although clearly less massive than the Sausage, the Sequoia has a distinct chemodynamical signature. The strongly retrograde Sequoia stars have a typical eccentricity of ∼0.6, whereas the Sausage stars have no clear net rotation and move on predominantly radial orbits. On average, the Sequoia stars have lower metallicity by ∼0.3 dex and higher abundance ratios as compared to the Sausage. We conjecture that the Sausage and the Sequoia galaxies may have been associated and accreted at a comparable epoch.

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