The grand design galaxy M81

This research project took place at Harvard-Smithsonian Center for Astrophysics in Boston, USA. It is a combination of optical and X-ray observations of the spiral galaxy M81, having the title: “X-ray sources and stellar populations in the spiral galaxy M81”. The purpose of this -still undergoing- project is the analysis and interpretation of HST data of the prototypical spiral galaxy M81 (PI A. Zezas). These data map the whole galaxy in three optical bands B, V and I, as well as one UV band. My main goal was to study the stellar populations and the star formation history in different regions of the galaxy (spiral arms, inter-arm regions and bulge). This is the most detailed investigation of stellar population in M81 and will provide important information on galaxy formation and different star formation modes. The purpose of the future analysis is to compare our results with the star formation of the spiral galaxies in our own Local Group (i.e. Milky Way, M31, M33).

These results will be used to investigate the link between X-ray sources and stellar populations in M81, based on the existing Chandra X-ray observations. The comparison of these results with predictions from theoretical population synthesis models, will constrain X-ray binary formation channels. In total, with this work I will derive spatially resolved star-formation history in the prototypical spiral galaxy M81, and connect it with its X-ray source populations in order to understand the formation and evolution of X-ray binaries.

This project results so far in a paper on refereed journal and a few conference announcements:

Nantais, Julie B.; Huchra, John P.; Zezas, Andreas; Gazeas, Kosmas; Strader, Jay, "Hubble Space Telescope Photometry of Globular Clusters in M81", 2011, AJ, 142., 183

Gazeas K., Zezas A., Huchra J., Nantais J.,“X-ray binary population and star formation history in M81” in “A population explosion: The Nature and Evolution of X-ray Binaries in Diverse Environments”, electronic conference proceedings, R.M. Bandyopadhyay, S. Wachter, D. Gelino, C.R. Gelino eds., St.Petersburg, Florida, USA, 2008, AIPC, 1010, 401

Zezas, A.; Gazeas, K.; Gallagher, J.; Huchra, J.; Fabbiano, G.; Nantais, J., "X-ray Source Populations And Star-formation History In M81", 2007, AAS, 21112201

Zezas, A.; Gazeas, K.; Gallagher, J.; Huchra, J.; Nantais, J.; Fabbiano, G., ”X-ray source populations in the M81 and Antennae galaxies”, 2008, xng, conf, 61

Zezas, A., Gazeas, K., Gallagher, J., Mutchler, M., Levay, Z., Huchra, J., “Initial results from the deep HST-ACS survey of the spiral galaxy M81”, 2007, AAS, 21011402

A new refereed paper is also under process, which describes the data reduction and presents the stellar catalogue, extracted from this study.

Stellar Populations on M81 collaborators include:

Andreas Zezas - University of Crete, Greece

Kosmas Gazeas - University of Athens, Greece

John Huchra - Harvard-Smithsonian Center for Astrophysics, MA, USA

More information about M81 mosaic image and biographies of collaborators can be found here:

Hubble Heritage - M81

Biographies