CCAPP Seminar: Alexie Leauthaud (UC Santa Cruz)

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alexie leauthaud portrait
December 3, 2019
11:30AM - 12:30PM
Location
PRB 4138

Date Range
Add to Calendar 2019-12-03 11:30:00 2019-12-03 12:30:00 CCAPP Seminar: Alexie Leauthaud (UC Santa Cruz) Alexie Leauthaud (UC Santa Cruz)  Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums   I will present a variety of new results on the connection between super massive galaxies and their dark matter halos. First, I will discuss the “lensing is low” puzzle. This is the observation that the lensing signal around luminous red galaxies from the BOSS survey is lower by 20- 30% than predicted by galaxy clustering. Second, I will show how not only galaxy mass, but also the shapes of their light profiles are connected with halo mass (the M10-M100 plane). I will connect this observation with the assembly history of massive galaxies and the growth of their in-situ and ex-situ components. I will present comparisons between the light profiles of massive galaxies in the Hyper-Surime Cam surveys and predictions from the Illustris and TNG simulations. I will briefly present new results on the accuracy and precision of detections of the splash-back radius of dark matter halos. Finally, I will discuss future applications with the DESI survey which is currently commissioning and will soon collect science verification data.   PRB 4138 Center for Cosmology and AstroParticle Physics (CCAPP) ccapp@osu.edu America/New_York public
Description

Alexie Leauthaud (UC Santa Cruz) 

Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums

Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums
Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums
Galaxies and Dark Matter: Cosmology, Correlations, and Conundrums
 
I will present a variety of new results on the connection between super massive galaxies and
their dark matter halos. First, I will discuss the “lensing is low” puzzle. This is the observation
that the lensing signal around luminous red galaxies from the BOSS survey is lower by 20-
30% than predicted by galaxy clustering. Second, I will show how not only galaxy mass, but
also the shapes of their light profiles are connected with halo mass (the M10-M100 plane). I
will connect this observation with the assembly history of massive galaxies and the growth of
their in-situ and ex-situ components. I will present comparisons between the light profiles of
massive galaxies in the Hyper-Surime Cam surveys and predictions from the Illustris and
TNG simulations. I will briefly present new results on the accuracy and precision of detections
of the splash-back radius of dark matter halos. Finally, I will discuss future applications with
the DESI survey which is currently commissioning and will soon collect science verification
data.

 

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