Ultraviolet Halos Around Spiral Galaxies. I. Morphology

Abstract

We examine ultraviolet halos around a sample of highly inclined galaxies within 25 Mpc to measure their morphology and luminosity. Despite contamination from galactic light scattered into the wings of the point-spread function, we find that UV halos occur around each galaxy in our sample. Around most galaxies the halos form a thick, diffuse disk-like structure, but starburst galaxies with galactic superwinds have qualitatively different halos that are more extensive and have filamentary structure. The spatial coincidence of the UV halos above star-forming regions, the lack of consistent association with outflows or extraplanar ionized gas, and the strong correlation between the halo and galaxy UV luminosity suggest that the UV light is an extragalactic reflection nebula. UV halos may thus represent 1-10 million solar masses of dust within 2-10 kpc of the disk, whose properties may change with height in starburst galaxies.

29 pages, 10 tables, 12 figures, accepted to ApJ

References in corpus (8)

• HyperLEDA. III. The catalogue of extragalactic distances
• An H-alpha Imaging Survey of Galaxies in the Local 11 Mpc Volume
• The cold gaseous halo of NGC 891
• Extended Mid-Infrared Aromatic Feature Emission in M 82
• The Interstellar Medium and Star Formation in Edge-On Galaxies. II. NGC 4157, 4565, and 5907
• The influence of diffuse scattered light II. Observations of galaxy haloes and thick discs and hosts of BCGs
• Diffuse Extraplanar Dust in NGC 891
• Exploring the Dust Content of Galactic Winds with Herschel. I. NGC 4631

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• CHANG-ES XXXII: Spatially Resolved Thermal/Nonthermal Separation from Radio Data Alone -- New Probes into NGC 3044 and NGC 5775
• Extraplanar emission in isolated edge-on late-type galaxies. I. The H$\alpha$ distribution versus to the old and young stellar discs