English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

[Abridged] We describe the near-infrared reddening signature of giantmolecular clouds (GMCs) in external galaxies. In particular, we examine theE(J-H) and E(H-K) color-excesses, and the effective extinction law observed indiscrete GMC regions. We also study the effect of the relative scale height ofthe GMC distribution to the color-excesses, and to the observed mass functionof GMCs. We perform Monte Carlo radiative transfer simulations with 3D modelsof stellar radiation and clumpy dust distributions, resembling a face-ongeometry. The scattered light is included in the models, and near-infraredcolor maps are calculated from the simulated data. The effective near-infraredreddening law, i.e. the ratio E(J-H)/E(H-K), has a value close to unity in GMCregions. The ratio depends on the relative scale height of GMCs, xi, and for xivalues 0.1...0.75 we find the typical ratios of 0.6...1.1. The effectiveextinction law turns out to be very flat in GMC regions. We find the ratios ofapparent extinctions of A(H)/A(K)=1.35...1.55 and A(J)/A(H)=1.15. The effect ofthe scattered flux on the effective reddening law, as well as on the effectiveextinction law, is significant. Regarding the GMC mass function, we find nocorrelation between the input and observed slopes of the mass functions.Rather, the observed slope reflects the parameter $\xi$ and the dynamical rangeof the mass function. We estimate that only a fraction of 10...20 % of thetotal mass of GMCs is recovered, if the observed color-excess values aretransformed to masses using the Galactic reddening law. In the case ofindividual clouds the fraction can vary between ~0...50 %.

Near-infrared reddening of extra-galactic GMCs in a face-on geometry