A Universe of Dwarf Galaxies in Lyon, France

Beth Willman, assistant professor, here.  I just wrapped up at a meeting held in Lyon, France from June 14 – 18 titled “A Universe of Dwarf Galaxies”.  Overall, the conference was very well organized, with plenty of time set aside for poster viewing and discussion.  The lunches were also ridiculously good (3 course, sit down lunches plus wine). There were over 150 participants at this meeting, so there were loads of excellent talks and posters.

This meeting included a broad range of presentations about many aspects of dwarf galaxy formation and evolution (as well as some star clusters thrown in for good measure).   There was even some discussion about “What is a galaxy?”, but it was contained to the session about Ultra Compact Dwarf galaxies (UCDs).  Even though these objects are called “dwarfs”, there isn’t uniform agreement about whether they are the high-mass end of globular star clusters or whether they are instead galaxies.  I think they are star clusters, but agree that it may not be 110% clear.

The observational result presented at this conference that stood out as the most new and exciting was a new result found by Sergey Koposov and collaborators, as presented by Matt Walker (one of Sergey’s collaborators).  Their team has been awarded a large amount of time on the VLT to obtain many repeat measurements of individual stars belonging to the very least luminous galaxies known in the universe.  This is important to investigate the effects of binary stars which could potentially have a huge effect on the observed dynamics of these tiny galaxies. Matt Walker showed the results of 21(!) epochs of imaging of stars in the Bootes I galaxies, and the velocity dispersion of 3 km/sec they computed from their dataset.  The dataset was to die for.  I look forward to seeing their upcoming paper, to read about the technique in more detail and to seeing the results they obtain from their other targets.

My own talk was about observational biases in our current census of the least luminous galaxies known in the universe and on imminent/future prospects for overcoming those biases. (I’m the world expert in the detectability of the teeniest galaxies in the universe, if I may say so myself.)

The ample time for discussion was my favorite part of the workshop, because it gave me a chance to speak with many of my current colleagues that I don’t typically get to see in person, including (in no particular order): Ricardo Munoz, Dave Sand, Evan Kirby, Erik Tollerud, Helmut Jerjen, and Gary Da Costa.  I have lots of ongoing projects to talk with all of those folks about; unfortunately time ran short for science chats because I arrived a bit late and I didn’t have much of a chance to talk with some other folks that I wanted to – like Nicolas Martin from MPIA.

I also got to spend quality time with some friends and older colleagues of mine, including (in no particular order): Julianne Dalcanton, Lucio Mayer, and Gurtina Besla.  Gurtina is a computational astrophysics graduate student at Harvard I got to know when I was there as a postdoc. It was great to have the chance to catch up with her.  We had dinner one night with Julianne Dalcanton, my dissertation advisor and then also on the last night of the conference. She is an expert in modelling the Magellanic Clouds.   Au revoir for now!

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