XSL: The X-Shooter Spectral Library

PIs: S.C. Trager & R.F. Peletier (Kapteyn Astronomical Institute, University of Groningen)

CoIs: Y.P. Chen (U. Groningen), P. Hauschildt (U. Hamburg), A. Lançon (Obs. Strasbourg), P. Prugniel (Obs. Lyon), D. Silva (NOAO), A. Vazdekis (IAC)

Associates: J. Cenarro (CEFCA), J. Falcón Barroso (IAC), M. Koleva (IAC), E. Marmól Queraltó (IAC), P. Sánchez Blázquez (UAM), J. Walcher (AIP)

XSL is an on-going project to produce the largest homogeneous library of stellar spectra covering simultaneously the entire wavelength range from 3200Å to 2.5 µm to date using the X-Shooter spectrograph mounted on UT2 at ESO's VLT.

To date, 251 observations of 236 unique stars have been made; including calibration stars (flux and telluric correction stars), the total number of stars observed is over 500.  A complete table of stars observed for XSL can be found here

Here is a Hertzsprung-Russell diagram of the 114 XSL stars with known effective temperature (increasing from right to left) and gravity (increasing from top to bottom).

Here is the distribution of metallicities of the 100 XSL stars with known metallicites.

Here are the spectral types of the XSL sample (excluding calibration stars), retrieved from the SIMBAD database or based on educated guesses from the literature source or atmospheric parameters.  "C" are carbon stars (C-rich AGB stars).  "LPV" are long-period variables of unknown type (O- or C- rich).
Spectral types

Here are a handful of example XSL spectra.  In the left-hand (UV+visible) panels, the spectra have been placed onto a consistent flux scale; this is not true for the NIR spectra, so the instrumental response is obvious from the strong "bump" feature at 2.1 µm.  Telluric corrections have not been applied to these spectra.
XSL example spectra