Panchromatic Spectra Of M-Stars ("MSTARPANSPEC")

The team presents a panchromatic spectrum, from 1 Angstrom to 10 microns, of the planet-hosting M dwarfs LHS 3844 and K2-3. These data products are motivated by high-energy measurements of LHS 3844 and K2-3 in the ultraviolet with the Cosmic Origins Spectrograph on board the Hubble Space Telescope (HST/COS), and an upper limit on the X-ray flux from Swift's X-ray Telescope (Swift-XRT) and XMM-Newton. The HST/COS data cover the far and near ultraviolet (FUV and NUV) with the G130M, G160M, and G230L gratings. Due to the large aperture of COS the prominent Lyman-α line is obscured by geocoronal emission. The team employs the UV-UV line correlations developed by the MUSCLES program to estimate the Lyman-α flux using measured UV emission lines in the rest of the COS data. For the rest of the high-energy spectrum, which is not measured directly, the team employs a differential emission measure (DEM) to fill in the gaps. Redward of the NUV we use either a PHOENIX model plus a blackbody curve or a BT-Settl model to fill out the spectrum.