Tag Archives: clusters

Interview with Martin Sahlén

We continue our interview series of Oskar Klein Centre fellows. Today we meet Martin Sahlén, starting his third year around. Martin works in the CoPS, Cosmoparticle Physics Group.

When did you start working for the OKC, and how it is going so far?
I arrived at the Oskar Klein Centre in September 2009, and it has been both enjoyable and stimulating. Much of my time has been spent preparing a computer code to model the cosmological distribution of galaxy clusters in great detail, to be used for a number of projects. At present I am mainly working on utilizing the code in the different projects and preparing resulting articles, so although it’s been slow going periodically things are now coming together. Some good joint projects also appear to be coming together in the near future, which I think will be excellent.

Why did you choose the OKC for doing a postdoc?
I chose the OKC knowing the excellent facilities here, the quality/profile of the group and also the rather generous funding in the Oskar Klein Fellowship. The broad approach of the centre appealed to me and was a strong reason for applying.

What is your field of research? Can you describe the project/projects in which you are involved?

My general field is cosmology, both towards the observational and towards the theoretical. The projects I am involved in centre largely around multi-consistent analysis and testing of beyond-concordance cosmology.

One area is clusters of galaxies, where I work on cosmological constraints from the XMM Cluster Survey (XCS) and the XXL Survey. Both are X-ray surveys of galaxy clusters based on XMM-Newton images. Continue reading Interview with Martin Sahlén

Workshop: clusters of galaxies as cosmic laboratories

Galaxy clusters occupy a central role in the ongoing efforts to understand some of the greatest questions in particle astrophysics and cosmology: the nature of Dark Matter and Dark Energy. Moreover, these huge mass concentrations serve as Nature’s own telescopes, capable of amplifying faint high-redshift sources that would otherwise be beyond our reach. At the same time, the use of galaxy clusters as probes for fundamental physics requires a good understanding of the state of the intra-cluster medium.

No wonder that the Oskar Klein Centre got involved in the organization of a workshop in Stockholm, 12-14 September. Ariel Goobar, professor at the Oskar Klein Centre, explains that there is a large effort by the community to collect multi-wavelength galaxy cluster data, which present a great opportunity to make significant progress over a broad range of topics: Continue reading Workshop: clusters of galaxies as cosmic laboratories