Carbon star survey in the Local Group. VIII. Probing the stellar halo of NGC 147

Details Carbon star survey in the Local Group. VIII. Probing the stellar halo of NGC 147 Carbon star survey in the Local Group. VIII. Probing the stellar halo of NGC 147

Apr 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004a%26a...418...33b&link_type=abstract

Astronomy and Astrophysics, v.418, p.33-40 (2004)

Astronomy and Astrophysics

Astrophysics

24

Galaxies: Individual: Ngc 147, Galaxies: Stellar Content, Galaxies: Structure

Scientific paper

We have imaged a 42' × 28' field centered on the spheroidal galaxy NGC 147 to study its AGB population and determine the main structural properties of this M 31 companion. This field was observed through two broadband (R and I) and two narrowband (CN and TiO) filters, following the standard approach of our systematic survey of C stars in nearby galaxies. We identified 288 C stars in NGC 147. The average I-magnitude of such sample of C stars is < I > = 20.31 with σ = 0.40. If we adopt a distance modulus μ0 = 24.39, derived from the luminosity of both the tip of the red giant branch (TRGB) and the horizontal branch (HB) by Han et al., we conclude that the average absolute I-magnitude of C stars is < MI> = -4.39, thus slightly under luminous with respect to what was found for other galaxies in our survey. From the radial surface profile we derive a scale length of 4.1 ± 0.1' and a tidal radius rt = 33.9 ± 2.4', a value quite larger than previous estimates. The C star population shows a scale length remarkably similar, thus suggesting that intermediate-age stars in NGC 147 are well mixed with the older population. Finally, the overall C/M ratio is 0.24 ± 0.02 and its local values increase monotonically from the center up to 3.5 scale lengths (beyond which counts become too low to yield reliable C/M ratios). Such radial behaviour implies a corresponding decrease of about 0.4 dex in [Fe/H], confirming a well defined metallicity gradient in NGC 147.
Based on observations carried on at the Canada-France-Hawaii Telescope, operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique de France, and the University of Hawaii and on observations obtained at the Italian Telescopio Nazionale Galileo.

Affiliated with

Also associated with

No associations

Rating

Carbon star survey in the Local Group. VIII. Probing the stellar halo of NGC 147 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 Carbon star survey in the Local Group. VIII. Probing the stellar halo of NGC 147, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carbon star survey in the Local Group. VIII. Probing the stellar halo of NGC 147 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1385659