Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-03-13
Astron.Astrophys.467:1373-1387,2007
Astronomy and Astrophysics
Astrophysics
17 pages, 13 figures, accepted for publication in A&A
Scientific paper
10.1051/0004-6361:20077334
We present techniques for the estimation of stellar atmospheric parameters (Teff,logg,[Fe/H]) for stars from the SDSS/SEGUE survey. The atmospheric parameters are derived from the observed medium-resolution (R=2000) stellar spectra using non-linear regression models trained either on (1) pre-classified observed data or (2) synthetic stellar spectra. In the first case we use our models to automate and generalize parametrization produced by a preliminary version of the SDSS/SEGUE Spectroscopic Parameter Pipeline (SSPP). In the second case we directly model the mapping between synthetic spectra (derived from Kurucz model atmospheres) and the atmospheric parameters, independently of any intermediate estimates. After training, we apply our models to various samples of SDSS spectra to derive atmospheric parameters, and compare our results with those obtained previously by the SSPP for the same samples. We obtain consistency between the two approaches, with RMS deviations of 150K in Teff, 0.35dex in logg, and 0.22dex in [Fe/H]. The models are applied to pre-processed spectra, either via Principal Components Analysis or a Wavelength Range Selection method, which employs a subset of the full 3850-9000A spectral range. This is both for computational reasons, and because it delivers higher accuracy. From an analysis of cluster candidates with available SDSS spectroscopy (M15, M13, M2, and NGC2420), we find evidence for small systematic offsets in Teff and/or logg for the atmospheric parameter estimates from the model trained on real data with the SSPP. Thus, this model turns out to derive more precise, but less accurate, atmospheric parameters than the model trained on synthetic data.
Allende Prieto Carlos
Bailer-Jones Coryn A. L.
Beers Timothy C.
Lee Young Sam
Norris John. E.
No associations
LandOfFree
Estimation of stellar atmospheric parameters from SDSS/SEGUE spectra 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 Estimation of stellar atmospheric parameters from SDSS/SEGUE spectra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Estimation of stellar atmospheric parameters from SDSS/SEGUE spectra will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-438332