The PAndAS view of the Andromeda satellite system - II. Detailed properties of 23 M31 dwarf spheroidal galaxies

Understand

We present a comprehensive analysis of the structural properties and luminosities of the 23 dwarf spheroidal galaxies that fall within the footprint of the Pan-Andromeda Archaeological Survey (PAndAS).

• These dwarf galaxies represent the large majority of Andromeda's known satellite dwarf galaxies and cover a wide range in luminosity ($-11.6<M_V<-5.8$ or $10^{4.2}< L <10^{6.5} L_\odot$) and surface brightness ($25.1<\mu_0<29.3$ mag/arcsec$^2$).
• We confirm most previous measurements, but find And XIX to be significantly larger than before ($r_h=3065^{+1065}_{-935}$ pc, $M_V=-10.1^{+0.8}_{-0.4}$) and cannot derive parameters for And XXVII as it is likely not a bound stellar system.
• We also significantly revise downward the luminosities of And~XV and And~XVI, which are now $M_V\sim-7.5$ or $L\sim10^5 L_\odot$.