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Description
Planets orbiting within the close-in habitable zones of M dwarf stars will be exposed to elevated high-energy radiation driven by strong magnetohydrodynamic dynamos during stellar youth. Near-ultraviolet (NUV) irradiation can erode and alter the chemistry of planetary atmospheres, and a quantitative description of the evolution of NUV emission from M dwarfs is needed when modeling these effects. The authors investigated the NUV luminosity evolution of early M-type dwarfs by cross-correlating the Lepine & Gaidos (LG11: 2011, AJ, 142, 138) catalog of bright M dwarfs (available at the HEASARC as the MDWARFASC table) with the Galaxy Evolution Explorer (GALEX) catalog of NUV (1771-2831 Angstrom) sources. Of the 4,805 sources with GALEX counterparts, 797 have NUV emission significantly (> 2.5 sigma) in excess of an empirical basal level. The authors inspected these candidate active stars using visible-wavelength spectra, high-resolution adaptive optics imaging, time-series photometry, and literature searches to identify cases where the elevated NUV emission is due to unresolved background sources or stellar companions; they estimated the overall occurrence of these "false positives" (FPs) as ~ 16%. The authors constructed an NUV luminosity function that accounted for FPs, detection biases of the source catalogs, and GALEX upper limits. They found the NUV luminosity function to be inconsistent with predictions from a constant star-formation rate and simplified age-activity relation defined by a two-parameter power law. This table was created by the HEASARC in March 2015 based on an electronic versions of Table 4 from the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
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