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

We investigate the correlation between far‐infrared (FIR) and radio luminosities in distant galaxies, a lynchpin of modern astronomy. We use data from the Balloon‐borne Large Aperture Submillimetre Telescope (BLAST),  Spitzer , the Large Apex BOlometer CamerA (LABOCA), the Very Large Array and the Giant Metre‐wave Radio Telescope (GMRT) in the Extended  Chandra  Deep Field South (ECDFS). For a catalogue of BLAST 250‐μm‐selected galaxies, we remeasure the 70–870‐μm flux densities at the positions of their most likely 24‐μm counterparts, which have a median [interquartile] redshift of 0.74 [0.25, 1.57]. From these, we determine the monochromatic flux density ratio,   q  250 (= log 10  [  S  250 μm / S  1400 MHz  ]), and the bolometric equivalent,  q  IR . At   z ≈ 0.6 , where our 250‐μm filter probes rest‐frame 160‐μm emission, we find no evolution relative to   q  160   for local galaxies. We also stack the FIR and submm images at the positions of 24‐μm‐ and radio‐selected galaxies. The difference between  q  IR  seen for 250‐μm‐ and radio‐selected galaxies suggests that star formation provides most of the IR luminosity in ≲100‐μJy radio galaxies, but rather less for those in the mJy regime. For the 24‐μm sample, the radio spectral index is constant across  0 &lt;  z  &lt; 3 , but  q  IR  exhibits tentative evidence of a steady decline such that   q  IR ∝ (1 + z ) −0.15±0.03  – significant evolution, spanning the epoch of galaxy formation, with major implications for techniques that rely on the FIR/radio correlation. We compare with model predictions and speculate that we may be seeing the increase in radio activity that gives rise to the radio background.

BLAST: the far‐infrared/radio correlation in distant galaxies