IRTF spectral stellar library - Astro-SMG/IRTF_spectral_stellar_library GitHub Wiki
The following information is detailed presented in Paper I of the series of paper concerning the SSP models in the NIR.
The IRTF spectral library is a compilation of spectra of stars observed with the medium-resolution spectrograph, SpeX, at the NASA Infrared Telescope Facility on Mauna Kea (Rayner et al. 2009; Cushing et al. 2005). This library covers the NIR range from 0.8 to 2.5 μm or 5.2 μm. We focus on the spectral region for the J, H and K bands (0.94 to 2.41 μm). These spectra were observed at a resolving power of R = 2000 (R = λ/∆λ) and their spectra continua were not normalized, keeping the strong molecular absorption features from cool stars. Keeping the spectral shape also allowed relative flux calibration between the stars, by scaling the spectra to published Two Micron All Sky Survey (2MASS) photometry, implying that the integrated colours obtained from the spectra are consistent with those obtained by 2MASS. The spectral types of the 210 library stars range from F, G, K, M, L, S to C type, with luminosity classes from supergiants (I) to dwarfs (V). The majority of the stars are cool stars, which dominate the light in the NIR. A considerable number of these stars have multiple spectra in the library, which we take into account in this analysis as individual stars leaving us with a sample of 292 spectra. We did not combine the multiple spectra because they belong to variable stars which have different temperatures and surface gravities depending on their phase.
We characterised the spectra of the IRTF spectral library and determined the stellar parameters, Teff , log g and metallicity ([Z/Z⊙]) of the stars. We test the flux calibration of the library and the behaviour of the integrated colours of its stars and their stellar parameters. And finally, we measure the Full Width at Half Maximum (FWHM) and resolution of the library spectra.
The stars composing the IRTF spectral library and their atmospheric parameters are presented here.
The spectra in fits format used in the analysis and SSP modeling is available in this link. The difference between these spectra and the originals are the steps in wavelength. Our spectra is at a constant Δλ of ~ 1 Å.