Date/Time: Wed Mar 04 2026 at 13:00<br/><br/>Location: Theory Room<br/><br/>Speaker: Maximilian Ruhdorfer (Stanford University)<br/><br/>Title: Robust bounds on MACHOs and intra-galactic substructure from Ultra-Faint Dwarf Galaxies<br/><br/>Abstract: Ultra-faint dwarf (UFD) galaxies provide a powerful laboratory to test dark matter in the purely gravitational scenario. In the first part of this talk, I will present robust constraints on Massive Compact Halo Objects (MACHOs) from the absence of dynamical heating in UFD stellar populations. Accounting for observational uncertainties in structural and halo properties, I show that multiple systems, including Segue I, yield consistently strong limits over the mass range 10 Msun < M < 10^9 Msun. I will also discuss the potential impact of recently discovered ultracompact UFD candidates, such as Ursa Major III/UNIONS 1, which could significantly strengthen bounds in the intermediate mass window if confirmed as a bona fide UFD. In the second part, I extend the analysis to dark matter substructure more broadly. The absence of stellar heating in UFDs places stringent constraints on intra-galactic substructure, which translate into strong bounds on the primordial matter power spectrum down to kiloparsec scales, with important implications for dark matter microphysics.
---
Remote Connection:
https://ubc.zoom.us/j/62535266430?pwd=THVrUzhMdjAyVkNnM05OUWRZYUppZz09
Meeting ID: 625 3526 6430
Passcode: 307647
<br/><br/>MOB220<br/><br/>______________________________<br/><br/>Detailed information available can be found at <a href='https://www.triumf.ca/research-program/lectures-conferences/upcoming-seminars-lectures'>https://www.triumf.ca/research-program/lectures-conferences/upcoming-seminars-lectures</a> <br/><br/>Date/Time: Thu Mar 05 2026 at 14:00<br/><br/>Location: Auditorium/Remote<br/><br/>Speaker: Esther Schirrmacher (TRIUMF)<br/><br/>Title: IAMI meets Life Sciences<br/><br/>Abstract: IAMI was designed to provide the infrastructure required for modern accelerator-based science and radiochemistry. The building brings together specialized hot labs with shielded workspaces and flexible experimental areas that support a range of research programs, including isotope production, targetry development, and applied radiopharmaceutical research.
This colloquium will outline the key design features of the facility and how they align with the scientific needs identified by the research community. Topics include the flexible layouts that allow experiments to adapt over time and the ways in which regulatory requirements are incorporated into the design.
The goal is to provide a clear picture of the types of research that will take place in IAMI, how the building supports this work, and how it positions TRIUMF for future growth.
**********
https://uvic.zoom.us/j/84125146059?pwd=rruPUPfkERmdeuctvNOlpyUppD0nBk.1
**********
Meeting ID: 841 2514 6059
**********
Password: TRColloq<br/><br/>Light refreshments available 15 min prior; bring your own mug!<br/><br/>______________________________<br/><br/>Detailed information available can be found at <a href='https://www.triumf.ca/research-program/lectures-conferences/upcoming-seminars-lectures'>https://www.triumf.ca/research-program/lectures-conferences/upcoming-seminars-lectures</a> <br/><br/>