Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-12-14
Astronomy and Astrophysics
Astrophysics
19 pages, 3 tables, 14 figures To be published in AJ
Scientific paper
10.1086/300838
We present a detailed study of the color magnitude diagram (CMD) of the dwarf spheroidal galaxy Leo I, based on archival Hubble Space Telescope data. Our photometric analysis, confirming previous results on the brighter portion of the CMD, allow us to obtain an accurate sampling of the stellar populations also at the faint magnitudes corresponding to the Main Sequence. By adopting a homogeneous and consistent theoretical scenario for both hydrogen and central helium-burning evolutionary phases, the various features observed in the CMD are interpreted and reliable estimations for both the distance modulus and the age(s) for the main stellar components of Leo I are derived. More in details, from the upper luminosity of the Red Giant Branch and the lower luminosity of the Subgiant Branch we simultaneously constrain the galaxy distance and the age of the oldest stellar population in Leo I. In this way we obtain a distance modulus (m-M)_V=22.00$\pm$0.15 mag and an age of 10--15 Gyr or 9--13 Gyr, adopting a metallicity Z=0.0001 and 0.0004, respectively. The reliability of this distance modulus has been tested by comparing the observed distribution of the Leo I anomalous Cepheids in the period-magnitude diagram with the predicted boundaries of the instability strip, as given by convective pulsating models.
Caputo Filippina
Cassisi Santi
Castellani Marco
Marconi Gianni
Santolamazza Patrizia
No associations
LandOfFree
Stellar populations in the dwarf spheroidal galaxy Leo I does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Stellar populations in the dwarf spheroidal galaxy Leo I, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stellar populations in the dwarf spheroidal galaxy Leo I will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-388345