The role of internal feedback in the evolution of the dwarf spheroidal galaxy Leo II

2019 ◽  
Vol 15 (S359) ◽  
pp. 278-279
Author(s):  
Roberto Hazenfratz ◽  
Gustavo A. Lanfranchi ◽  
Anderson Caproni
Keyword(s):  
Large Distance ◽  
Milky Way ◽  
Local Group ◽  
Galactic Evolution ◽  
External Effects ◽  
Dwarf Spheroidal Galaxies ◽  
First Results ◽  
Formation And Evolution ◽  
Spheroidal Galaxies

AbstractThis work aims to explore the different processes of formation and evolution of dwarf spheroidal galaxies in the Local Group analyzing internal and external feedbacks, taking Leo II as a model of parametrization due to its adequate large distance to the Milky Way, in order to minimize potential external effects. We present a discussion of the first results regarding the processes of formation and galactic evolution from the gas hydrodynamics. Combined with previous studies for other similar systems, such results have the potential to establish strong links for the elaboration of a consistent and coherent scenario of formation and evolution of the dwarf spheroidal galaxies in the Local Group.

scholarly journals Evidence for Light-weight Local Group Dwarf Spheroidal Galaxies

2004 ◽  
Vol 220 ◽  
pp. 365-366
Author(s):  
J. R. Kuhn ◽  
D. Kocevski
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Local Group ◽  
Light Weight ◽  
Natural Explanation ◽  
Dwarf Spheroidal Galaxies ◽  
Ursa Minor ◽  
Matter Component ◽  
Morphological State ◽  
Spheroidal Galaxies

A simple and natural explanation for the dynamics and morphology of the Local Group Dwarf Spheroidal galaxies, Draco (Dra) and Ursa Minor (UMi), is that they are weakly unbound stellar systems with no significant dark matter component. A gentle, but persistent, Milky Way (MW) tide has left them in their current kinematic and morphological state (the “parametric tidal excitation”). A new test of a dark matter dominated dS potential follows from a careful observation of the “clumpiness” of the dS stellar surface density.

Stellar chemo-kinematics of isolated dwarf spheroidal galaxies

2018 ◽  
Vol 14 (S344) ◽  
pp. 222-223
Author(s):  
S. Taibi ◽  
G. Battaglia ◽  
M. Rejkuba ◽  
N. Kacharov ◽  
M. Zoccali
Keyword(s):  
Galaxy Evolution ◽  
Milky Way ◽  
Local Group ◽  
Intrinsic Properties ◽  
Dwarf Spheroidal Galaxies ◽  
Preliminary Results ◽  
Low Mass ◽  
Insight Into ◽  
Spheroidal Galaxies

AbstractThe study of dwarf spheroidal galaxies (dSph) is of great importance to understand galaxy evolution at the low-mass end. In the Local Group the majority of them are found to be satellites of the Milky Way or M31. The closest ones have been studied in great detail, however it is hard to constrain if their present-day observed properties are mainly caused by internal or environmental mechanisms. In order to minimize these effects and gain an insight into their intrinsic properties, we are studying two of the three isolated dSph galaxies in the Local Group, i.e. Cetus and Tucana, located far beyond the virial radius of the Milky Way and M31. We present here results from our recently published analysis of Cetus (Taibi2018) and preliminary results for Tucana (Taibi et al. in prep.).

scholarly journals Observed Properties of Dark Matter on Small Spatial Scales

2007 ◽  
Vol 3 (S244) ◽  
pp. 44-52 ◽  
Author(s):  
Rosemary F.G. Wyse ◽  
Gerard Gilmore
Keyword(s):  
Dark Matter ◽  
Galaxy Evolution ◽  
Local Group ◽  
Spatial Scales ◽  
Critical Role ◽  
Large Datasets ◽  
Dwarf Spheroidal Galaxies ◽  
Internal Motions ◽  
Spheroidal Galaxies

AbstractThe nature of dark matter is one of the outstanding questions of astrophysics. The internal motions of member stars reveal that the lowest luminosity galaxies in the Local Group are the most dark-matter dominated. New large datasets allow one to go further, and determine systematic properties of their dark matter haloes. We summarise recent results, emphasising the critical role of the dwarf spheroidal galaxies in understanding both dark matter and baryonic processes that shape galaxy evolution.

scholarly journals Dwarf spheroidal evolution: global view

2008 ◽  
Vol 4 (S255) ◽  
pp. 341-345
Author(s):  
Stefania Salvadori ◽  
Andrea Ferrara ◽  
Raffaella Schneider
Keyword(s):  
Milky Way ◽  
Dwarf Spheroidal Galaxies ◽  
Global View ◽  
Formation And Evolution ◽  
Spheroidal Galaxies

AbstractWe propose a cosmological approach to investigate the formation and evolution of dwarf spheroidal galaxies, satellites of the Milky Way, which allows us to follow self-consistently the dSphs and MW formation, matching simultaneously most of their observed properties.

scholarly journals Variable Stars in Dwarf Spheroidal Galaxies

1973 ◽  
Vol 21 ◽  
pp. 35-48
Author(s):  
Steven Van Agt
Keyword(s):  
Globular Clusters ◽  
Local Group ◽  
Elliptical Galaxies ◽  
Variable Stars ◽  
Dwarf Spheroidal Galaxies ◽  
Theoretical Predictions ◽  
History Of ◽  
Set Up ◽  
Theoretical Considerations ◽  
Spheroidal Galaxies

Interest in dwarf spheroidal galaxies is motivated by a number of reasons; an important one on the occasion of this colloquium is the abundance of variable stars. The theory of stellar evolution and stellar pulsations is now able to predict from theoretical considerations characteristic properties of variable stars in the colour-magnitude diagram (Iben, 1971). By observing the variable stars in the field, and in as wide a selection of objects as possible, more insight can be obtained into the history of the oldest members of our Galaxy (the globular clusters) and of the dwarf spheroidal galaxies in the Local Group. It is worthwhile to explore the spheroidal galaxies as observational tests for the theoretical predictions of conditions in space away from our Galaxy. The numbers of variable stars in the dwarf spheroidal galaxies are such that we may expect well-defined relations to emerge once reliable magnitude sequences have been set up, the variable stars found, and their periods determined. Six dwarf spheroidal galaxies are presently known in the Local Group within a distance of 250 kpc. In Table I, which lists members of the Local Group, they are at the low-luminosity end of the sequence of elliptical galaxies (van den Bergh, 1968).

How many suns are in the sky? Multiplicity surveys of exoplanet host stars

2018 ◽  
Vol 14 (S345) ◽  
pp. 316-317 ◽  
Author(s):  
M. Mugrauer ◽  
C. Ginski ◽  
N. Vogt ◽  
R. Neuhäuser ◽  
C. Adam
Keyword(s):  
Milky Way ◽  
Planet Formation ◽  
High Contrast ◽  
Contrast Imaging ◽  
Direct Imaging ◽  
High Contrast Imaging ◽  
Multiple Stars ◽  
First Results ◽  
Formation And Evolution ◽  
Host Stars

AbstractIn order to determine the true impact of stellar multiplicity on the formation and evolution of planets, we initiated direct imaging surveys to search for (sub)stellar companions of exoplanet host stars on close orbits, as their gravitational impact on the planet bearing disk at first and on formed planets afterwards is expected to be maximal. According to theory these are the most challenging environments for planet formation and evolution but might occur quite frequently in the milky way, due to the large number of multiple stars within our galaxy. On this poster we showed results, obtained so far in the course of our AO and Lucky-imaging campaigns of exoplanet host stars, conducted with NACO/ESO-VLT for southern and with AstraLux/CAHA2.2m for northern targets, respectively. In addition, we introduced our new high contrast imaging survey with SPHERE/ESO-VLT to search for close companions of southern exoplanet host stars, and presented some first results.

scholarly journals THE MASSES OF LOCAL GROUP DWARF SPHEROIDAL GALAXIES: THE DEATH OF THE UNIVERSAL MASS PROFILE

2014 ◽  
Vol 783 (1) ◽  
pp. 7 ◽  
Author(s):  
Michelle L. M. Collins ◽  
Scott C. Chapman ◽  
R. M. Rich ◽  
Rodrigo A. Ibata ◽  
Nicolas F. Martin ◽  
...  
Keyword(s):  
Local Group ◽  
Dwarf Spheroidal Galaxies ◽  
Mass Profile ◽  
The Masses ◽  
Spheroidal Galaxies

scholarly journals Too big to fail in light of Gaia

2019 ◽  
Vol 490 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Manoj Kaplinghat ◽  
Mauro Valli ◽  
Hai-Bo Yu
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Large Scatter ◽  
Too Big To Fail ◽  
Dwarf Spheroidal Galaxies ◽  
Ursa Minor ◽  
Spheroidal Galaxies

ABSTRACT We point out an anticorrelation between the central dark matter (DM) densities of the bright Milky Way dwarf spheroidal galaxies (dSphs) and their orbital pericenter distances inferred from Gaia data. The dSphs that have not come close to the Milky Way centre (like Fornax, Carina and Sextans) are less dense in DM than those that have come closer (like Draco and Ursa Minor). The same anticorrelation cannot be inferred for the ultrafaint dSphs due to large scatter, while a trend that dSphs with more extended stellar distributions tend to have lower DM densities emerges with ultrafaints. We discuss how these inferences constrain proposed solutions to the Milky Way’s too-big-to-fail problem and provide new clues to decipher the nature of DM.

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