A wide-field survey of satellite galaxies around the spiral galaxy M106


E-mail: ekim@csa.yonsei.ac.kr (EK); hbann@pusan.ac.kr (HBA)


We present a wide-field survey of satellite galaxies in M106 (NGC 4258) covering a inline image× 2° field around M106 using Canada–France–Hawaii Telescope/MegaCam. We find 16 satellite galaxy candidates of M106. Eight of these galaxies are found to be dwarf galaxies that are much smaller and fainter than the remaining galaxies. Three of these galaxies are new findings. Surface brightness profiles of 15 out of 16 satellite galaxies can be represented well by an exponential disc profile with varying scalelength. We derive the surface number density distribution of these satellite galaxies. The central number density profile (d < 100 kpc) is well fitted by a power law with a power index of −2.1 ± 0.5, similar to the expected power index of isothermal distribution. The luminosity function of these satellites is represented well by the Schechter function with a faint-end slope of −1.19+0.03−0.06. Integrated photometric properties (total luminosity, total colour and disc scalelength) and the spatial distribution of these satellite galaxies are found to be roughly similar to those of the Milky Way and M31.