Atmospheric stellar parameters from cross-correlation functions

Estimation of stellar atmospheric parameters from SDSS/SEGUE spectra

We present techniques for the estimation of stellar atmospheric parameters (Teff , log g, [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 ...

Extracting Stellar Parameters from Observed Spectra: the Role of Cross-correlation and Minimum Distance Methods

One may consider cross-correlation routines applied to stellar spectra as a way to determine not only the radial velocities but also to assess the properties of stellar atmospheres. We show that this is not the case. High value of the cross-correlation coefficient between the observed and a template spectrum does not mean that the template corresponds to correct values of stellar temperature, g...

Predicting Atmospheric Parameters using Canonical Correlation Analysis

Niho Type Cross-Correlation Functions and Related Equations Niho Type Cross-Correlation Functions and Related Equations

Stellar Halo Parameters from 4588 Subdwarfs

Using a reduced proper motion discriminator, I obtain a sample of 4588 subdwarfs from the Revised NLTT Catalog of Salim & Gould. The ample statistics and low contamination permit much more precise determinations of halo parameters than has previously been possible. The stellar halo is not moving with respect to the Local Standard of Rest (LSR) in either the vertical or radial direction, up to u...