WFPC2 observations of two dwarf spheroidal galaxies in the M 81 group

Karachentsev, ID; Sharina, ME; Dolphin, AE; Geisler, D; Grebel, EK; Guhathakurta P.; HODGE, PW; Karachentseva, VE; Sarajedini, A; Seitzer, P

Abstract

We have obtained HST WFPC2 and ground-based images of two low surface brightness dwarf spheroidal galaxies in the M 81 group, FM1 and KKH57. Their colour-magnitude diagrams show red giant branches with tips at I = 23.77 ± 0.14 and I = 23.97 ± 0.17, respectively. The derived true distance moduli, 27.66 ± 0.16 and 27.96 ± 0.19, agree well with the mean distance modulus of the M 81 group, 27.84 ± 0.05. Absolute V magnitudes of the galaxies (-11.46 and -10.85), their colours ((B - V) = 0.88 and 0.80), and central surface brightnesses (?0,V = 24.8 and 24.4 mag/??) are in the range of other dSph companions of M 81, M 31, and Milky Way. With two new objects the maximum projected radius of the dwarf spheroidal subsystem around M 81 is 380 kpc.

Más información

Título según WOS: WFPC2 observations of two dwarf spheroidal galaxies in the M 81 group
Título según SCOPUS: WFPC2 observations of two dwarf spheroidal galaxies in the M 81 group
Título de la Revista: ASTRONOMY & ASTROPHYSICS
Volumen: 375
Número: 2
Editorial: EDP SCIENCES S A
Fecha de publicación: 2001
Página de inicio: 359
Página final: 365
Idioma: English
URL: http://www.edpsciences.org/10.1051/0004-6361:20010716
DOI:

10.1051/0004-6361:20010716

Notas: ISI, SCOPUS