4 papers · 1 filter
Optical studies of ultra-luminous X-ray sources in nearby galaxies
Ji-Feng Liu, Joel N. Bregman, Patrick Seitzer +1
Optical studies of ultra-luminous X-ray sources is an essential step in understanding the nature of these enigmatic sources, and in this paper we report our studies of five ULXs in…
Dwarf Spheroidal Galaxies in the M81 Group Imaged with WFPC2
I. D. Karachentsev, V. E. Karachentseva, A. E. Dolphin +7
We obtained HST/WFPC2 images of the dwarf spheroidal (dSph) galaxies K61, K63, K64, DDO78, BK6N, and kk77 in the M81 group. Our color-magnitude diagrams show red giant branches wit…
A Dwarf Galaxy Survey in the Local Volume
E. K. Grebel, P. Seitzer, A. E. Dolphin +6
We are carrying out a comprehensive multi-wavelength study of dwarf galaxies in the Local Volume (< 5 Mpc). After our all-sky survey more than doubled the dwarf census we are now m…
The dwarf spheroidal galaxy DDO 44: stellar populations and distance
I. D. Karachentsev, M. E. Sharina, E. K. Grebel +7
We present ground-based and HST WFPC2 imaging of the nearby low surface brightness dwarf spheroidal galaxy DDO 44. For the first time DDO 44 was resolved into stars. The resulting…