GECO café-club “Dust properties of low surface brightness galaxies and their implications for future large sky surveys” by JUNAIS

“Dust properties of low surface brightness galaxies and their implications for future large sky surveys” by JUNAIS (National Centre for the Nuclear Research – Astrophysics Division, Warsaw),

The cafe-club will take place at 13:00 **in the Mistral room** (2nd floor) >>> UNUSUAL TIME <<< and on the usual AMU virtual room:

You can find the schedule of upcoming café-clubs and the video of old ones at http://wiki.lam.fr/geco/CafeClub .
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ABSTRACT

Low surface brightness galaxies (LSBs) contribute a large fraction of the total number density of galaxies. Despite this, their properties are still poorly known. LSBs are often considered to be “dust-poor”. However, this assumption is based only on a few studies. To verify this, we use a large sample of LSBs and high surface brightness galaxies with deep observational data. We study their dust properties as a function of surface brightness. Our sample, which is the largest in the literature to study dust in LSBs, consists of 1631 galaxies (1003 LSBs) at z < 0.1 from the North Ecliptic Pole (NEP) wide field. The NEP field consists of a large multi-wavelength set of ancillary data ranging from UV to FIR. We analyzed the spectral energy distributions of the sample using the CIGALE code. Our results show that most LSBs have a negligible dust attenuation (Av < 0.1 mag), except for about 4% of them that show significant attenuation with a mean Av of 0.8 mag. We found that the LSBs with a significant attenuation also have a higher r-band mass-to-light ratio than the others. These outlier LSBs show similarity to the giant LSBs from the literature, like Malin 1, indicating a possibly high dust attenuation in them as well. Consistently, our recent deep spectroscopic measurements of Malin 1 suggest a dust attenuation of Av ~ 0.4 mag for its faint disk. This work emphasizes that the dust content of LSBs is more varied than previously thought. We found that some of the LSBs have significant attenuation making them fainter than their intrinsic value. This will have serious implications for the observation and analysis of LSBs with upcoming large sky surveys like VRO/LSST.