[4] Univ La Laguna, Dept Astrofis, Tenerife 38200, Spain
来源:
ASTRONOMY & ASTROPHYSICS
|
2012年
/
548卷
关键词:
galaxies: dwarf;
Local Group;
galaxies: individual: NGC 6822;
RED GIANT BRANCH;
STELLAR EVOLUTION DATABASE;
POPULATION SYNTHESIS;
STARS;
TIP;
ISOCHRONES;
MODELS;
CALIBRATION;
ABUNDANCES;
PHOTOMETRY;
D O I:
10.1051/0004-6361/201220554
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
On the basis of a new photometric analysis of the Local Group dwarf irregular galaxy NCG 6822 based on observations obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope, we have obtained a new estimate of the extinction of two fields located in the southeast region of the galaxy. Because of significant differences in the distance estimates to NGC 6822 available in literature, we decided to provide an independent determination of the distance to this galaxy based on an updated and self-consistent theoretical calibration of the tip of the red giant branch brightness. As a result we newly determined the distance to NGC 6822 to be equal to (m - M)(0) = 23.54 +/- 0.05, and compared our measurement with the most recent determinations of this distance.