Dust and inclination corrected star-formation and interstellar medium scaling relations in nearby galaxies

Author:

Bogdan A. Pastrav

Keyword:

Astrophysics, Astrophysics of Galaxies, Astrophysics of Galaxies (astro-ph.GA), Cosmology and Nongalactic Astrophysics (astro-ph.CO)

journal:

date:

2023-05-29 16:00:00

Abstract

Following from our recent work, we present here a detailed analysis of dust and star-formation scaling relations, done on a representative sample of nearby galaxies. H$\alpha$ images are analysed in order to derive the integrated flux / luminosity for each galaxy, used as a more instantenous and accurate star-formation rate (SFR) tracer, and the relevant photometric and structural parameters. Dust and inclination corrected H$\alpha$ luminosities and SFRs are subsequently determined using a method that circumvents the assumption of a dust attenuation curve and the use of the Balmer decrements or other hydrogen recombination lines in order to estimate the dust attenuation, which have been shown to be affected by various biases or being inconsistent between different types of galaxies. We investigate the extent to which dust and inclination effects bias the specific parameters of these relations, the scatter and degree of correlation between the parameters, and which relations are fundamental or are just a consequence of others. Our results are consistent within errors with other similar studies. By comparing the scalelengths of the B band optical and H$\alpha$ (star-forming) discs, we found on average, the distribution of star-formation to be more extended than the stellar continuum emission one (the ratio being 1.10), this difference increasing with stellar mass. Similarly, more massive galaxies have a more compact stellar emission surface density than the star-formation one (average ratio of 0.77) for our sample. The method proposed can be applied in larger scale studies of star-formation and ISM evolution, at low to intermediate redshifts.

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