Artículos de revistas
The near-ultraviolet luminosity function of young, early M-type dwarf stars
Fecha
2015-01Registro en:
Ansdell, Megan; Gaidos, Eric; Mann, Andrew W.; Lépine, Sebastien; James, David; et al.; The near-ultraviolet luminosity function of young, early M-type dwarf stars; Iop Publishing; Astrophysical Journal; 798; 1; 1-2015; 1-17; 41
0004-637X
Autor
Ansdell, Megan
Gaidos, Eric
Mann, Andrew W.
Lépine, Sebastien
James, David
Buccino, Andrea Paola
Baranec, Christoph
Law, Nicholas M.
Riddle, Reed
Mauas, Pablo Jacobo David
Petrucci, Romina Paola
Resumen
Planets orbiting within the close-in habitable zones of M dwarf stars will be exposed to elevated high-energy radiation driven by strong magneto-hydrodynamic 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. We investigated the NUV luminosity evolution of early M-type dwarfs by cross-correlating the Lepine & Gaidos (2011) catalog of bright M dwarfs with the GALEX catalog of NUV (1771-2831 A) sources. Of the 4805 sources with GALEX counterparts, 797 have NUV emission signicantly (larger than 2.5 sigma) in excess of an empirical basal level. We inspected these candidate active stars using visible-wavelengthspectra, 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; we estimated the overall occurrence of these "false positives" as around 16%. We constructed a NUV luminosity function that accounted for false positives, detection biases of the source catalogs, and GALEX upper limits. We found the NUV luminosity function to be inconsistent with predictions from a constant star-formation rate and simplied age-activity relation defined by a two-parameter power law.