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

Context: Observations at the radio continuum band below the gigahertz bandare key when the nature and properties of nonthermal sources are investigatedbecause their radio radiation is strongest at these frequencies. The low radiofrequency range is therefore the best to spot possible counterparts to veryhigh-energy (VHE) sources: relativistic particles of the same population arelikely to be involved in radio and high-energy radiation processes. Some ofthese counterparts to VHE sources can be stellar sources. Aims: The Cygnusregion in the northern sky is one of the richest in this type of sources thatare potential counterparts to VHE sources. We surveyed the central ~15sq deg ofthe Cygnus constellation at the 325 and 610~MHz bands with angular resolutionsand sensitivities of 10" and 6", and 0.5 and 0.2 mJy/beam, respectively.Methods: The data were collected during 172 hours in 2013 - 2017, using theGiant Metrewave Radio Telescope (GMRT) with 32MHz bandwidth, and werecalibrated using the SPAM routines. The source extraction was carried out withthe PyBDSF tool, followed by verification through visual inspection of everyputative catalog candidate source in order to determine its reliability.Results: In this first paper we present the catalog of sources, consisting of1048 sources at 325 MHz and 2796 sources at 610MHz. By cross-matching thesources from both frequencies with the objects of the SIMBAD database, we foundpossible counterparts for 143 of them. Most of the sources from the 325-MHzcatalog (993) were detected at the 610MHz band, and their spectral index alphawas computed adopting S(nu) ~ nu^alpha. The maximum of the spectral indexdistribution is at alpha=-1, which is characteristic of nonthermal emitters andmight indicate an extragalactic population.

Cygnus survey with the Giant Metrewave Radio Telescope at 325 and 610 MHz: the catalog