Physics Galaxy:

This is a proceedings book of the symposium "Mapping the Galaxy and Nearby Galaxies" held on Ishigaki Island, Okinawa, Japan, on June 25 – 30, 2006. The symposium focused on mapping the interstellar media and other components in galaxies.

Dwarf galaxy research constitutes an extremely vibrant field of astrophysical research, with many long-standing questions still unsettled and new ones constantly arising. The intriguing diversity of the dwarf galaxy population, observed with advanced ground-based and space-borne observatories over a wide spectral window providing an unprecedented level of detail, poses new challenges for both observers and theoreticians.

The formation of galaxies is one of the greatest puzzles in astronomy, the solution is shrouded in the depths of space and time, but has profound implications for the universe we observe today.

This book uses new data from the very low radio frequency telescope LOFAR to analyse the magnetic structure in the giant radio galaxy NGC6251. This analysis reveals that the magnetic field strength in the locality of this giant radio galaxy is an order of magnitude lower than in other comparable systems. Due to the observational limitations associated with capturing such huge astrophysical structures, giant radio galaxies are historically a poorly sampled population of objects; however, their preferential placement in the more rarefied regions of the cosmic web makes them a uniquely important probe of large-scale structures.

Galaxies, along with their underlying dark matter halos, constitute the building blocks of structure in the Universe. Of all fundamental forces, gravity is the dominant one that drives the evolution of structures from small density seeds at early times to the galaxies we see today. The interactions among myriads of stars, or dark matter particles, in a gravitating structure produce a system with fascinating connotations to thermodynamics, with some analogies and some fundamental differences.