Showing posts from June, 2014

The Nature and Origin of Substructure in the Outskirts of M31 -- II. Detailed Star Formation Histories

I am still playing catch up on papers, and I've just woken up early here in San Francisco and have a small amount of time before I have to prepare for my talk today. So, this will be quick. The topic again is our nearest largest companion, the Andromeda Galaxy, especially working out the history of how stars have formed in the (relatively) inner regions of the galaxy. It might seem a little strange that we can work that out, because all we can see is stars, but with the magic of science, it is possible. That's the topic of this new paper by postdoctoral researcher,  Edouard Bernard . This beautiful science is done with the Hubble Space Telescope. The first thing you need to do is decide where to look. So, here's the fields we looked at One of the sad things is that the area Hubble can image (its field of view) is tiny compared to the extent of Andromeda, and so we are doing key-hole surgery in select areas on interesting bits of Andromeda, especially prominent bits

The outer halo globular cluster system of M31 - II. Kinematics

Well, I don't know where that month vanished, but I now find myself sitting in the very nice  Swan's Hotel  in Victoria, Canada, after doing some nice new work with  Alan McConnachie  at the  Herzberg Institute of Astrophysics . The week has gone fast, and I've given two talks, and have four more to give in California next week. But I realised that I have neglected the blog, and there has been quite a few papers of mine put on the arxiv I should talk about. I have quite a bit of catching up to do, so here's a first post, and I will try and post some more over the next couple of weeks. A few weeks ago, I posted an article about the fact that we now have  the final catalog  of the globular clusters found in the PAndAS survey. This has been a major undertaking, seeing out these balls of a few million stars in the outer reaches of Andromeda. But it's been very successful, and we can now start to ask the question "what have we learnt?" This is the topic of