MIT Astrophysics Colloquia - Fall 2020

(To be revised for virtual format.)
Tuesdays at 4:00 PM in the Marlar Lounge, Room 37-252
MIT Kavli Institute for Astrophysics and Space Research
70 Vassar Street, Cambridge, MA
(unless location otherwise noted)
Refreshments are served at 3:45 PM.

Sponsored by
the Astrophysics Division of the MIT Department of Physics and
the MIT Kavli Institute for Astrophysics and Space Research.
MKI logo

Tuesday 08 September :
A New Perspective on the Assembly of Mass
Danail Obreschkow
University of Western Australia
Host: Paul Schechter

NOTE SPECIAL TIME: 10AM EDT

Abstract: Linking observable properties of galaxies to the assembly history of their host haloes is one of the great challenges in cosmology. In this colloquium, I will address this challenge from the view-point of the ``tree entropy'', an interesting mathematical way to characterize the structure merger trees. The tree entropy puts every halo merger tree on a scale between a ``minimal tree'', grown entirely by smooth accretion, and a ``maximal tree'', grown exclusively by equal-mass major mergers. I will try my best to provide an intuitive geometric way to think about this entropy. I will then discuss the tree entropies found in a LCDM cosmology and elaborate on how the properties of simulated galaxies relate to their tree entropies. The talk will end with an inspiring illustration of how the tree entropy of the Milky Way, inferred from GAIA data, can help us understand the Galaxy's morphology.

Tuesday 15 September :
How do galaxies form? New insights from the FIRE simulations
Claude-Andre Faucher-Giguere
Northwestern University
Host: Rob Simcoe



Abstract: Galaxies are remarkably diverse in their properties, ranging from irregular to disky to elliptical in morphology, and from blue to red in color. At the same time, when analyzed systematically, galaxy populations exhibit striking regularities, with clear trends with mass and redshift. How does this `regular complexity' emerge from the hot Big Bang? I will present results from the FIRE simulations which shed some light onto the processes that shape galaxies. The FIRE zoom-in simulations resolve the multiphase interstellar medium of galaxies and model several different feedback processes (including Type II/Ia supernovae, stellar winds, and radiation) while including the cosmological environment. I will highlight recent results on the formation of galactic disks, the `burstiness' of star formation, galactic winds, and the growth of supermassive black holes. Our new results indicate that transitions in the properties of each of these important phenomena can be simultaneously explained by a phase transition (virialization) in the inner circumgalactic medium, and arise from the interplay between feedback energy produced on small scales and the physics of halo gas on larger scales.

Tuesday 22 September :
TBA
Sarah Horst
Johns Hopkins University
Host: TBA



Abstract: TBA

Tuesday 29 September :
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Justin Read
University of Surrey
Host: Tracy Slatyer



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Tuesday 06 October :
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Tejaswi Venumadhav
UC Santa Barbara
Host: Scott Hughes



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Tuesday 13 October :
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Smadar Naoz
UCLA
Host: TBA



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Tuesday 20 October :
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Tuesday 27 October :
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Lou Strolger
STScI
Host: TBA



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Tuesday 03 November :
TBA
Kirpal Nandra
Max Planck Institute for Extraterrestrial Physics
Host: Erin Kara

NOTE SPECIAL TIME: 10AM EDT

Abstract: TBA

Tuesday 10 November :
TBA
Ingrid Stairs
University of British Columbia
Host: Kiyoshi Masui



Abstract: TBA

Tuesday 17 November :
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John Belcher
MIT
Host: TBA



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Tuesday 01 December :
TBA
Benedetta Ciardi
MPE Garching
Host: Christina Eilers

NOTE SPECIAL TIME: 10AM EDT

Abstract: TBA

Tuesday 08 December :
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