Seminars : Documents

DustKING: revealing the dust attenuation in nearby galaxies
Marjorie Decleir (U Gent)

Dust attenuation is a crucial but highly uncertain parameter that hampers the determination of intrinsic galaxy properties, such as stellar masses, star formation rates and star formation histories. The shape of the dust attenuation law is proven to vary between galaxies, and within a galaxy. Our DustKING project sets to study these variations in nearby galaxies of the KINGFISH sample. To this aim, we use the CIGALE SED fitting code to fit models with varying dust extinction properties to a multi-wavelength dataset from the UV to the IR. Particularly important for our goal are UV data from the SWIFT space telescope, whose filters uniquely cover the curious bump feature in the attenuation curve at 2175 Å. This enables us to characterize the strength of this bump and the UV slope of the attenuation curve.

In this talk, I will first present the method and results of our spatially resolved study of the spiral galaxy NGC628 (Decleir et al. 2019), which clearly illustrates the potential of the SWIFT data in obtaining the characteristics of the dust attenuation curve. We observe variations in the shape of the attenuation law within the galaxy, but the average curve is fairly steep and has a Milky Way-like bump. Secondly, I will discuss the current status and future goals of our ongoing global dust attenuation curve study of the KINGFISH galaxy sample.