The EUV spectrum of AU Microscopii: temperature and density diagnostic from EUVE Spectrometers observations.

Abstract

EXOSAT and IUE observations of the active star AU Mic are used to develop a model of the differential emission measure distribution (DEM) versus temperature. The signals detectable by the Extreme UltraViolet Explorer Spectrometers are predicted. The computation indicates the presence of several highly ionized iron lines in the EUV spectral region. These lines are identified in the observations of AU Mic performed by the Short (70 -190 A) and Medium (140-380 A) Wavelength Spectrometers on EUVE. Using the recorded EUVE spectra a more accurate DEM model for the transition region and corona of the star has been evaluated and using density sensitive lines an upper limit on the electron density has been put.