Description:
<jats:title>Summary</jats:title><jats:p>Measurements of H<jats:sub>α</jats:sub>-emission in fields known to emit 21cm radiation at intermediate and high velocities are presented. The observations are partial results of a survey being carried out at the Calar Alto Observatory with a dedicated Fabry-Perot spectrometer of 15cm aperture, providing velocity and angular resolutions of 11km s<jats:sup>-1</jats:sup> and 0.5 deg<jats:sup>2</jats:sup>. The limited material available indicates that the H<jats:sub>α</jats:sub>-emission, when detected at a radial velocity nearly the same as that measured in 21cm, appears more extended in the sky than the HI-radiation.</jats:p>