Open AccessThe stellar content and distance of UGC 4483
Author(s) -
Dolphin A. E.,
Makarova L.,
Karachentsev I. D.,
Karachentseva V. E.,
Geisler D.,
Grebel E. K.,
Guhathakurta P.,
Hodge P. W.,
Sarajedini A.,
Seitzer P.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04312.x
Subject(s) - physics , astrophysics , photometry (optics) , distance modulus , metallicity , stellar mass , galaxy , star formation , star cluster , content (measure theory) , red giant branch , stars , measure (data warehouse) , mathematical analysis , mathematics , database , computer science
We present HST /WFPC2 observations of UGC 4483, an irregular galaxy in the M81/NGC 2403 complex. Stellar photometry was carried out with HSTphot, and is complete to V≃26.0 and I≃24.7. We measure the red giant branch tip at I=23.56±0.10, and calculate a distance modulus of μ 0 =27.53±0.12 (corresponding to a distance of 3.2±0.2 Mpc), placing UGC 4483 within the NGC 2403 subgroup. We were able to measure properties of a previously known young star cluster in UGC 4483, finding integrated magnitudes of V=18.66±0.21 and I=18.54±0.10 for the stellar contribution (integrated light minus H α and [O iii ] contribution), corresponding to an age of ∼10–15 Myr and an initial mass of ∼10 4 M ⊙ . This is consistent with the properties of the cluster's brightest stars, which were resolved in the data for the first time. Finally, a numerical analysis of the galaxy's stellar content yields a roughly constant star formation rate of 1.3×10 −3 M ⊙ yr −1 and mean metallicity of [Fe/H]=−1.3 dex from 15 Gyr ago to the present.