Stellar Populations in Local Star-Forming Galaxies

Abstract

One of the main issues in today's Astrophysics is how present day galaxies formed and how they have evolved over time. A considerable observational effort is being made to study galaxies from the earliest possible times to the present. One approach to understand how present-day galaxies came into being is to study in detail the properties of local active star-forming galaxies, and in particular their star-formation histories. In this respect, it is important to quantify the relative importance of the current episode of star formation in comparison to the underlying older stellar populations.

J-PLUS: The star formation main sequence and rate density at d ≲ 75 Mpc

“…We find the strongest disagreement with the works by Westra et al (2010) and Pérez-González et al (2003). Despite the determination by Westra et al (2010) is drawn from a sample that covers a similar redshift range to the one of Gunawardhana et al (2013), in their case the HαLF lies significantly below our distribution at log L Hα 41.…”

“…Thus, we believe that our dust correction is appropriate. Gallego et al (1995) 41.87 ± 0.08 −1.30 ± 0.20 −2.76 ± 0.03 Pérez-González et al (2003) 42.43 ± 0.17 −1.20 ± 0.20 −3.00 ± 0.20 Nakamura et al (2004) 41.99 ± 0.10 −1.43 ± 0.10 −3.02 ± 0.17 Westra et al (2010) 41.74 ± 0.13 −1.22 ± 0.06 −2.90 ± 0.10…”

“…In their work, Pérez-González et al use a sample of 79 galaxies drawn from a parent sample of 191 UCM Survey galaxies. Gallego et al (1995) 0 ≤ z ≤ 0.045 0.026 −1.88 ± 0.04 Pérez-González et al (2003) 0 ≤ z ≤ 0.045 0.026 −1.61 ± 0.10 Nakamura et al (2004) 0.01 ≤ z ≤ 0.12 0.054 −1.95 ± 0.04 Hanish et al (2006) 0.001 ≤ z ≤ 0.017 0.010 −1.80± 0.13 0.08 James et al (2008) The Hα fluxes of these galaxies are measured using narrowband imaging, so no aperture correction is needed. However, we note that some of their galaxies present Hα luminosities that we do not find in our volume (log L Hα ≥ 42, and even ≥ 42.5).…”

“…In their study, they emphasize that the UCM Survey galaxies present enhanced star formation when compared with normal, quiescent spiral galaxies. Hence, part of the discrepancies with Pérez-González et al (2003) and Gallego et al (1995) could be attributed to the target pre-selection with objective prism spectroscopy (Zamorano et al 1994).…”

The Radio-FIR Correlation in the Milky Way

“…The effects of different dust geometries and opacities in the immediate vicinity of different star forming regions potentially adds a significant complication (Calzetti et al 1995;Calzetti 1997). There is also a strong trend for higher levels of dust obscuration to occur preferentially in galaxies of higher SFR (e.g., Hopkins et al 2001;Afonso et al 2003;Pérez-González et al 2003), so it is not unreasonable to expect a similar variation in individual star forming regions.…”