SEMINAR ANNOUNCEMENT: OATs-DAUT Seminar on Wednesday April 2nd, at 12:00 noon, Villa Bazzoni

[Gabriella Schiulaz]

I announce you this week seminar:

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                    OATS-DAUT SEMINAR 
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Speaker: Pavel Kroupa (Argelander-Institut fuer Astronomie (AIfA), Bonn University) 

Title: Are the dSph satellite galaxies tidal-dwarfs? 

Date: Wednesday, April 2nd, 2008 
Time: 12:00 
Venue: Villa Bazzoni (via Bazzoni, 2)

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Abstract: 
The Milky Way has about 15 low-mass dwarf-spheroidal (dSph) satellites. These have luminosities and internal velocity dispersions similar to globular clusters but are about 100 times larger. The usual interpretation is that these objects are dark-matter dominated: the stars are located in the innermost regions of 10-100 times more massive dark-matter sub-halos. However, many of the dSph satellites are sub-structured and appear to be distorted. Such distortions are most readily explained if the satellites are significantly affected by the Milky Way tide such that dark matter does not significantly shield them. Furthermore, the satellites are distributed in a relatively thin plane extending to 250 kpc which is highly inclined to the disk of the Milky Way. This plane appears to be rotationally supported. This is most readily explained if the dSph satellites are causally related, i.e. if they share a common orbital angular momentum vector. All of this can be understood within a conservative framework, in which early galaxy-galaxy encounters produce tidal-dwarf galaxies. Applied to the Milky Way this suggests an early (about 10 Gyr ago) encounter which left a population of related TDGs in orbit. 
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contact: Simone Recchi (OATS) 


Next Seminar:
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                  OATS-DAUT SEMINAR 
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Speaker: Dan Maoz (School of Physics and Astronomy, Tel-Aviv University) 

Title: Supernova Rates: Near and Far, Cluster and Field 

Date: Wednesday, April 9th, 2008 
Time: 12:00 
Venue: Villa Bazzoni 
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contact: Elena Pian (OATS) 



For additional information on OAT seminars see:
http://adlibitum.oats.inaf.it/seminari/



Gabriella Schiulaz
segreteria OAT
Phone: 040-3199241
schiulaz at oats.inaf.it
segreteria at oats.inaf.it