Speaker
Description
We present a spatially resolved analysis of the CO-to-H2 conversion
factor (αCO) and dust-to-gas ratio (DGR) for NGC4214, NGC2976,
NGC3077, NGC2403 and NGC0925. We have simultaneously solved for αCO
and the DGR by assuming that the DGR is approximately constant on
kiloparsec scales. With this assumption, we can combine maps of dust
mass surface density, CO-integrated intensity, and HI density to solve
for both αCO and the DGR. This study uses the spatially resolved
optical observations of the Metal-THINGS survey, the 12CO J = (2–1)
maps from the IRAM 30 m large program HERACLES, and HI 21 cm line maps
from THINGS. For NGC 4214, NGC2976 and NGC3077, we observe a generally
flat profile of αCO as a function of galactocentric radius while for
NGC2403 and NGC0925 we observe a positive relation. The DGR as a
function of galactocentric radius shows a negative slope except for
NGC4214 and NGC3077. For the αCO with metallicity we observe a
similar flat behaviour for NGC 4214, NGC2976 and NGC3077 while for
NGC2403 and NGC0925 there is a potential negative relation. Finally we
find that the DGR is well-correlated with metallicity, with an
approximately linear slope. Our results show interesting cases of
study and the potential future for the new era of IFU surveys that
will easily reach galaxies with stellar masses log(M*/Msun) < 8
