[31/03/2022] The TAR file containing the XSL P/C Salpeter models was replaced, as the XSL SSP model of log age 8.3 and metallicity 0.1 was faulty.
A PDF of figures of all the SSPs was added to the XSL P/C Kroupa and Salpeter models TAR files.
Models
The XSL simple stellar population models were released on March 1st 2022. The models span the metallicity range −2.2 < [Fe/H] < +0.2 and ages above 50 Myr. The spectra are provided as FITS files, where the wavelength scale is specifyied in the a header.
The XSL population models are calculated for two sets of isochrones (
PARSEC/COLIBRI and Padova00) and two sets of initial mass functions (Salpeter, Kroupa). In the future, models calculated with other IMFs will be provided (Verro et al. in prep.).
See
Verro et al. (2022b) for the details of stellar population modelling.
The models are provided as FITS files, each containing the flux column. The wavelength information (log10 sampled, in nm) is provided in the header keywords: CRVAL1, CDELT1, CRPIX1.
XSL SSP models are in cgs flux units F\(_\lambda\) [erg cm\(^{-2}\) s\(^{-1}\) \(\unicode{xC5}\)\(^{-1}\)].
To convert them to L\(_\lambda\)/ L\(_\odot\) M\(_\odot^{-1}\) \(\unicode{xC5}\)\(^{-1}\), multiply the flux array by:
\begin{equation}
\mathrm{C}_{Salp} = (4 \cdot\pi \cdot(3.08567758128\cdot 10^{19})^2 ) / 3.826 \cdot 10^{33} / 0.319 = 9799552.50
\end{equation}
\begin{equation}
\mathrm{C}_{Kroupa} = (4 \cdot\pi \cdot(3.08567758128\cdot10^{19})^2 ) / 3.826 \cdot 10^{33} / 0.562 = 5567946.09
\end{equation}
where \(3.08567758128\cdot10^{19}\) is 10pc in cm, \(L_\odot = 3.826 \cdot 10^{33} \mathrm{erg}~\mathrm{s}^{-1}\),
and 0.319 or 0.562 is the total initial mass of the SSP, for a mass range of 0.09-120 M\(_\odot\) (depending on IMF normalisation).
