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

Infrared‐faint radio sources (IFRSs) are a class of source which are bright at radio frequencies, but do not appear in deep infrared images. We report the detection of 14 IFRSs within the  Spitzer  extragalactic First Look Survey field, eight of which are detected near to the limiting magnitude of a deep  R ‐band image of the region, at   R ∼ 24.5 . Sensitive  Spitzer Space Telescope  images are stacked in order to place upper limits on their mid‐infrared flux densities, and using recent 610‐MHz and 1.4‐GHz observations we find that they have spectral indices which vary between  α= 0.05  and 1.38, where we define α such that   S  ν = S  0 ν −α  , and should not be thought of as a single source population. We place constraints on the luminosity and linear size of these sources, and through comparison with well‐studied local objects in the Revised Revised Third Cambridge catalogue demonstrate that they can be modelled as being compact (&lt;20 kpc) Fanaroff–Riley type II (FR II) radio galaxies located at high redshift  ( z ∼ 4) .

monthly notices of the royal astronomical society

Deep 610‐MHz Giant Metrewave Radio Telescope observations of the  Spitzer  extragalactic First Look Survey field – III. The radio properties of infrared‐faint radio sources