Open group seminar: Adam Samuels (Boston University)

3:00–4:00 pm ERC 517

Host: Alex Drlica-Wagner

Adam Samuels (Boston University) "Lopsided Satellite Distributions around Isolated Host Galaxies"

The spatial distributions of the satellites of isolated host galaxies have the potential to provide insight into the shapes and assembly histories of their hosts’ dark matter halos. In this talk, I will present an analysis of the spatial distributions of the satellites of isolated host galaxies in the observed universe and in a mock redshift survey based on the Millennium LCDM simulation. In both cases, host and satellite galaxies were obtained using identical redshift space selection criteria. Two independent metrics of clustering and directionality reveal a strong tendency for groups of satellites to be located on the same side of their host, resulting in lopsided spatial distributions. In both the observational sample and the simulated sample, the lopsidedness is greatest for the satellites of blue hosts. Overall, the lopsidedness of the simulated sample exceeds that of the observational sample, particularly in the case of the satellites of red hosts. If the hosts’ dark matter halos are relaxed, these lopsided distributions suggest that satellites do not faithfully trace the shapes of their hosts’ halos, particularly in the case of blue hosts.

Event Type


Nov 10