April 11, 2023
Speaker: Alexander Ji (University of Chicago)
Contact Information: alexji@uchicago.edu
Title: Dwarf Galaxy Archaeology in the Gaia Era
Abstract: The Milky Way's satellite dwarf galaxies are powerful probes of many important astrophysical processes. Their kinematics provide insights into galactic dynamics and the nature of dark matter, while their chemical compositions preserve a history of early galaxy formation and nucleosynthesis. Recently, all-sky astrometry from the Gaia satellite has enabled the discovery and characterization of dwarf galaxies at different stages of tidal disruption. These new galaxies lie at the extremes of dwarf galaxy parameter space, whether in their structural properties or their star formation histories. In this talk, I will show how spectroscopic observations of the kinematics and chemistry of these newly discovered dwarf galaxies can provide crucial insights into galactic dynamics and nucleosynthesis. I will present a recent kinematic study of the extremely diffuse dwarf galaxy Antlia II that shows it is in the early stages of tidal disruption. The kinematics of Antlia II also clearly show that the Milky Way reference frame has been perturbed by the Large Magellanic Cloud. I will also highlight how two completely disrupted dwarf galaxies contribute to increasingly clear evidence that the rapid neutron-capture process requires both prompt and delayed sources to explain the diverse chemical evolution histories of dwarf galaxies.
Visitor's room: Room 111A
Visit Schedule:
Tuesday (11 Apr. 2023):
9:30 a.m.: Robert Lupton (25X -- basement, near the loading dock)
10:00 a.m: Adam Burrows
10:30 a.m.: Coffee and refreshments (Grand Central)
11:00 a.m.: Colloquium
11:30 a.m.: Colloquium
12:00 p.m.: Bahcall lunch
12:30 p.m.: Bahcall lunch
1:00 p.m.: Bahcall lunch
1:30 p.m.: Peter Melchior (131)
2:00 p.m.: Tea Time with Grad Students in Grand Central
2:30 p.m.: Tea Time with Grad Students in Grand Central
3:00 p.m.: Brandon Hensley (110A)
3:30 p.m.: Josh Winn (125)
4:00 p.m.: Jenny Greene (001)
4:30 p.m.: Jiaxuan Li (111A)
5:00 p.m.: Eliot (127)
Dinner Sign-up - add your name here:
Tuesday (11 Apr. 2023) -- Joint dinner with the IAS (only 6 Peyton Hall members + the speaker)
Alex Ji
Faculty Host: Robert Lupton
Postdoc Host: Shany Danieli
Jeff Shen
Jiaxuan LI
He Jia
Shaunak Modak
Waitlist
Jake Nibauer
STUDENTS HAVE PRIORITY.
PLEASE NO MORE THAN 8 PEOPLE (it is more difficult to properly interact with the speaker in larger groups).