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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present results on the interstellar medium (ISM) properties of 29 galaxiesbased on a comparison of {\it Spitzer} far-infrared and Westerbork SynthesisRadio Telescope radio continuum imagery. Of these 29 galaxies, 18 are closeenough to resolve at $\la$1 kpc scales at 70 $\micron$ and 22 cm. We extend the\citet{ejm06a,ejm06b} approach of smoothing infrared images to approximatecosmic-ray (CR) electron spreading and thus largely reproduce the appearance ofradio images. Using a wavelet analysis we decompose each 70 $\micron$ imageinto one component containing the star-forming {\it structures} and a secondone for the diffuse {\it disk}. The components are smoothed separately, andtheir combination compared to a free-free corrected 22 cm radio image; thescale-lengths are then varied to best match the radio and smoothed infraredimages. We find that late-type spirals having high amounts of ongoing starformation benefit most from the two-component method. We also find that thedisk component dominates for galaxies having low star formation activity,whereas the structure component dominates at high star formation activity. Wepropose that this result arises from an age effect rather than from differencesin CR electron diffusion due to varying ISM parameters. The bulk of the CRelectron population in actively star-forming galaxies is significantly youngerthan that in less active galaxies due to recent episodes of enhanced starformation; these galaxies are observed within $\sim10^{8}$ yr since the onsetof the most recent star formation episode. The sample irregulars haveanomalously low best-fit scale-lengths for their surface brightnesses comparedto the rest of the sample spirals which we attribute to enhanced CR electronescape.

Learning about the Recent Star Formation History of Galaxy Disks by  Comparing their Far-Infrared and Radio Morphologies: Cosmic-Ray Electron  Diffusion after Star Formation Episodes