SIMBAD references

In a series of two papers we present results of a new Hα imaging survey, aiming at the detection of extraplanar diffuse ionized gas in halos of late-type spiral galaxies. We have investigated a sample of 74 nearby edge-on spirals, covering the northern and southern hemisphere. In 30 galaxies we detected extraplanar diffuse emission at mean distances of |z|∼1-2kpc. Individual filaments can be traced out to |z|≤6kpc in a few cases. We find a good correlation between the FIR flux ratio (S₆₀/S₁₀₀) and the SFR per unit area (L_FIR/D²₂₅), based on the detections/non-detections. This is actually valid for starburst, normal and for quiescent galaxies. A minimal SFR per unit area for the lowest S₆₀/S₁₀₀ values, at which extended emission has been detected, was derived, which amounts to {dot}(E)_A25^thres=(3.2±0.5)x10⁴⁰erg/s/kpc². There are galaxies where extraplanar emission was detected at smaller values of L_FIR/D²₂₅, however, only in combination with a significantly enhanced dust temperature. The results corroborate the general view that the gaseous halos are a direct consequence of SF activity in the underlying galactic disk.