Image of Alice in Wonderland at the Mad Hatter's tea party You are cordially invited to afternoon tea and biscuits wine and chocolate

Astronomy Tea Talks at Caltech

Mondays, Hameetman auditorium (Cahill)
Tea:  4.00pm
Talk: 4.15pm

Organized by:

2009 - 2010 season:
25 January 2010 Nicolas Bouche

'The impact of gas accretion on the scaling relations'

Galaxies lie on specific scaling relations, such as the Tully-Fischer
relation and the SFR-Mass relation. Using the underlying growth of
structure and normal star formation efficiencies, we will present
a simple model for star-forming galaxies (SFGs) that has only 3
parameters. We find that a mass floor (below which gas accretion is
suppressed) is important in reproducing the two scaling relations
(TF, and SFR-Mass relation) for SFGs. We will show that these two
scaling relations are not independent. Surprisingly, the model
naturally leads to `downsizing', where more massive halos form
first on a shorter time scale, and the model also accounts for the
baryonic fraction as a function of halo mass, the evolution of gas
fraction over cosmic times. The model helps to understand the rise
and decline in the cosmic star-formation history. We will discuss
the role of feedback and SF on the global galaxy properties.

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Last modified on 20th Jul 2011 by Dominik A. Riechers.  

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