Optical and infrared imaging of stars in the metal-rich globular clusters NGC 6304 and NGC 6316

Details Optical and infrared imaging of stars in the metal-rich globular clusters NGC 6304 and NGC 6316 Optical and infrared imaging of stars in the metal-rich globular clusters NGC 6304 and NGC 6316

Jul 1992

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992apjs...81..251d&link_type=abstract

Astrophysical Journal Supplement Series (ISSN 0067-0049), vol. 81, no. 1, July 1992, p. 251-266. Research supported by NSERC.

Astronomy and Astrophysics

Astronomy

27

Giant Stars, Globular Clusters, Infrared Astronomy, Metallic Stars, Stellar Spectrophotometry, Color-Magnitude Diagram, Metallicity, Stellar Evolution, Globular Clusters: Individual (Ngc 6304, Ngc 6316), Stars: Evolution, Stars: Horizontal-Branch

Scientific paper

V and K images of NGC 6304 and NGC 6316 are used to investigate the properties of giants and horizontal branch stars in these metal-rich clusters. We confirm previous reddening estimates for NGC 6304, which indicate that E(B - V) ˜0.5; however, for NGC 6316, our data indicate that E(B - V) ˜0.6, higher than most previous values. In order to assess the relative metallicities of NGC 6304 and NGC 6316 we define the quantity Δ(V- K), which measures the slope of the upper giant branch. The results suggest that NGC 6304 and NGC 6316 have similar metallicities, and are slightly more metal-rich than 47 Tuc, a conclusion consistent with previous metallicity estimates. The ratio of horizontal branch stars to bright first-ascent giants, R, in NGC 6304 and NGC 6316 are also similar, suggesting that the helium abundances of these clusters are not different. However, the computed values of R are lower than in 47 Tuc, and various morphological properties of the horizontal branches in NGC 6304, NGC 6316, and 47 Tuc are examined to investigate further the relative helium abundances of these clusters. The brightness widths of the horizontal branches in NGC 6304 and NGC 6316 are comparable to what is seen in 47 Tuc, while the color widths are narrower. The latter is consistent with a difference in helium abundance, while the former is not. Finally, although the integrated spectroscopic properties of NGC 6304 and NGC 6316 show systematic differences, there is as yet no photometric evidence to support a difference in mean age between these two clusters.

Affiliated with

Also associated with

No associations

Rating

Optical and infrared imaging of stars in the metal-rich globular clusters NGC 6304 and NGC 6316 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 Optical and infrared imaging of stars in the metal-rich globular clusters NGC 6304 and NGC 6316, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical and infrared imaging of stars in the metal-rich globular clusters NGC 6304 and NGC 6316 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1204991