ISO-SWS observations of Herbig Ae/Be stars: HI recombination lines in MWC1080 and CoD -42d 11721
Benedettini, M.; Lorenzetti, D.; Nisini, B.; Smith, H. A.; Giannini, T.; Saraceno, P.; Tommasi, E.
Italy, Spain, United States
Abstract
ISO-SWS grating spectra are obtained towards the two Herbig Ae/Be stars MWC1080 and CoD -42(deg) 11721, showing hydrogen recombination lines of the Brackett, Pfund and Humphreys series. The observed line decrements in each spectral series are consistent with emission from ionized winds, as expected from these early-type stars. We compare the observed line emission with a wind model assuming a constant rate of mass flow from the star, which allows to consistently derive mass loss rate and distance of both stars. We also show that the observed decrements can only be explained by assuming a ionization bounded compact regions whose sizes are a few tens of the stellar radii. Based on observations with ISO, an ESA project with instruments funded by ESA Member States and with the partecipation of ISAS and NASA