Starcounts Redivivus II: Deep Starcounts with Keck and HST and the Luminosity Function of the Galactic Halo

Details Starcounts Redivivus II: Deep Starcounts with Keck and HST and the Luminosity Function of the Galactic Halo Starcounts Redivivus II: Deep Starcounts with Keck and HST and the Luminosity Function of the Galactic Halo

1996-07-05

arxiv.org/abs/astro-ph/9607033v1

Astronomy and Astrophysics

Astrophysics

Accepted for publication in the Astronomical Journal. 20 pages, TeX type, 17 postscript figures

Scientific paper

10.1086/118115

We have combined deep starcount data with Galaxy model predictions to investigate how effectively such measurements probe the faint end of the halo luminosity function. We have tested a number of star/galaxy classification techniques using images taken in 0.5 arcsecond seeing with LRIS on the Keck telescope, and we find that different combinations of these techniques can produce variations of 10 \% in the inferred starcounts at R=22.5 and 30 \% at R=24.5 magnitudes. The decreasing average angular size of galaxies with fainter magnitude effectively limits ground-based work to R $<$ 25.5 magnitudes. The higher angular resolution provided by HST allows one to probe at least 2 magnitudes fainter, but the small field-size is a significant limitation. In either case, our models show that the contribution from halo subdwarfs is effectively limited to colours of (R-I) $<$ 1.0, with the redder stars being members of the Galactic disk. The apparent increase in number density for M$_V > 10$ in the derived luminosity function is a result of contributions from disk stars at fainter absolute magnitudes and does not provide evidence for an upturn in the halo subdwarf mass function. Indeed, starcount data alone are {\it not} an effective method of probing the shape of the halo luminosity function close to the hydrogen-burning limit. Finally, we examine how the Hubble Deep Field observations can be used to constrain the contribution of various stellar components to the dark-matter halo.

Affiliated with

Also associated with

No associations

Rating

Starcounts Redivivus II: Deep Starcounts with Keck and HST and the Luminosity Function of the Galactic Halo 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 Starcounts Redivivus II: Deep Starcounts with Keck and HST and the Luminosity Function of the Galactic Halo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Starcounts Redivivus II: Deep Starcounts with Keck and HST and the Luminosity Function of the Galactic Halo will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-80820