Speaker
Description
We compare vertical profiles of the extraplanar H𝛼 emission to those of the UV emission for 38 nearby edge-on late-type galaxies. It is found that detection of the “diffuse” extraplanar dust (eDust), traced by the vertically extended, scattered UV starlight, always coincides with the presence of the extraplanar H𝛼 emission. A strong correlation between the scale heights of the extraplanar H𝛼 and UV emissions is also found; the scale height at H𝛼 is found to be ~0.74 of the scale height at FUV. Our results may indicate the multiphase nature of the diffuse ionized gas and dust in the galactic halos. The existence of eDust in galaxies where the extraplanar H𝛼 emission is detected suggests that a larger portion of the extraplanar H𝛼 emission than that predicted in previous studies may be caused by H𝛼 photons that originate from H II regions in the galactic plane and are subsequently scattered by the eDust. This possibility raise a in studing the eDIG. We also find that the scale heights of the extraplanar emissions normalized to the galaxy size correlate well with the star formation rate surface density of the galaxies. The properties of eDust in our galaxies is on a continuation line of that found through previous observations of the extraplanar polycyclic aromatic hydrocarbons emission in more active galaxies known to have galactic winds.
| Consider for a poster? | Yes |
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