Pal 1: Another Young Galactic Halo Globular Cluster?

Details Pal 1: Another Young Galactic Halo Globular Cluster? Pal 1: Another Young Galactic Halo Globular Cluster?

1997-10-22

arxiv.org/abs/astro-ph/9710242v1

Astronomy and Astrophysics

Astrophysics

25 pages, 12 figures, 4 tables. To be published in the Astronomical Journal

Scientific paper

10.1086/300200

Deep V and I CCD images of the loosely populated Galactic globular cluster Pal 1 and the surrounding field have been obtained with the INT. A color magnitude diagram down to V(lim) ~ 24, and a luminosity function complete down to V(lim) ~ 23.25 have been constructed. Adopting a reddening E(V-I)=0.20+/-0.04 and comparing the CMD of Pal 1 with 47 Tucanae, we obtain a distance modulus (m-M)o=15.25+/-0.25, indicating that Pal 1 is located 3.7+/-0.4 kpc above the Galactic disc and 17.3+/-1.6 kpc from the Galactic center. Comparison with 47 Tuc and M71 shows that Pal 1 must be significantly younger. The best fitting isochrones (Bertelli et al, 1994) give an age between 6.3 and 8 Gyrs, which would make Pal 1 the youngest Galactic globular cluster so far identified, casting some doubt on the real nature of this object. The luminosity function shows some evidence for mass segregation, consistent with the very short relaxation time. The global mass function can be fitted with a power law of slope x=-1.4+/-0.7. This mass function is anomalously flat, suggesting either a strong dynamical evolution or an initial mass function significantly different from most of the other halo globular clusters. A discussion on the possible nature of Pal 1 is presented.

Affiliated with

Also associated with

No associations

Rating

Pal 1: Another Young Galactic Halo Globular Cluster? 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 Pal 1: Another Young Galactic Halo Globular Cluster?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pal 1: Another Young Galactic Halo Globular Cluster? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-614738