Astronomy and Astrophysics – Astrophysics
Scientific paper
Jul 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006a%26a...453..895w&link_type=abstract
Astronomy and Astrophysics, Volume 453, Issue 3, July III 2006, pp.895-902
Astronomy and Astrophysics
Astrophysics
1
Galaxy: Halo, Stars: Variables: Rr Lyr, Galaxy: Abundances
Scientific paper
Context: .The iron abundance of halo RR Lyrae stars can provide important information about the formation history of the Galactic halo. Aims: .We determine the [Fe/H] of the sample of halo RRab stars by using the P-ϕ31-[Fe/H] relation developed by Jurcsik & Kovács based on their light curves. We need to extend the relation from the V band to our unfiltered CCD band. Methods: .To do this, we use the low-dispersion spectroscopic [Fe/H] of literatures and the photometric data released by the first-generation Robotic Optical Transient Search Experiment (ROTSE-I) project. We do regression analyses for the calibrating sample using a linear function and test its validity by comparing of the predicted [Fe/H] with the spectroscopic [Fe/H]. In general, the fit accuracy for the two different [Fe/H] is better than 0.19 dex. Results: . We derive an empirical P-ϕ31-[Fe/H] linear relation for the unfiltered CCD band (ROTSE-I), i.e. [ Fe/H]=-3.766-5.350P+1.044ϕ31. In our test, the P-ϕ31-[Fe/H] relation is also fit for our unfiltered CCD band. In addition, another linear relation, ϕ31_V=0.882+0.792ϕ31_W, is also derived for the transformation between the V and W bands. We present the predicted [Fe/H] of the sample (the 31 halo RRab stars) in a catalog. Conclusions: . The mean [Fe/H] of the sample is -1.63 with dispersion of 0.45 dex in distribution, which is consistent with the results derived from the blue horizontal branch star candidates by Kinnman et al. (2000, A&A, 364, 102). The mean [Fe/H] values of the RRab stars in the range of 1 kpc, 2 kpc, and 3 kpc from the star 91 (a double-mode RR Lyrae star), are all lower than that of the background halo stars. These values are consistent with that of star 91 suggested by Wu et al. (2005, AJ, 130, 1640), which indicates they might have a common origin.
Deng Jin-Song
Hu Jiang-Yao
Qiu Y.-L.
Wu Congjun
Zhao Yong-Heng
No associations
LandOfFree
[Fe/H] derived from the light curves of RR Lyrae stars in 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 [Fe/H] derived from the light curves of RR Lyrae stars in the Galactic halo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and [Fe/H] derived from the light curves of RR Lyrae stars in the Galactic halo will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1135911