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

The LOFAR Two-metre Sky Survey (LoTSS) will cover the full northern sky and,additionally, aims to observe the LoTSS deep fields to a noise level of ~10microJy/bm over several tens of square degrees in areas that have the mostextensive ancillary data. This paper presents the ELAIS-N1 deep field, thedeepest of the LoTSS deep fields to date. With an effective observing time of163.7 hours, it reaches a root mean square (RMS) noise level below 20microJy/bm in the central region (and below 30 microJy/bm over 10 squaredegrees). The resolution is 6 arcsecs and 84862 radio sources were detected inthe full area (68 sq. deg.) with 74127 sources in the highest quality area atless than 3 degrees from the pointing centre. The observation reaches a skydensity of more than 5000 sources per sq. deg. in the central ~5 sq. deg.region. We present the calibration procedure, which addresses the specialconfiguration of some observations and the extended bandwidth covered (115 to177 MHz; central frequency 146.2 MHz) compared to standard LoTSS. We alsodescribe the methods used to calibrate the flux density scale usingcross-matching with sources detected by other radio surveys in the literature.We find the flux density uncertainty related to the flux density scale to be~6.5%. By studying the variations of the flux density measurements betweendifferent epochs, we show that relative flux density calibration is reliableout to about a 3 degree radius, but that additional flux density uncertainty ispresent for all sources at about the 3 per cent level; this is likely to beassociated with residual calibration errors, and is shown to be moresignificant in datasets with poorer ionosphere conditions. We also provideintra-band spectral indices, which can be useful to detect sources with unusualspectral properties. The final uncertainty in the flux densities is estimatedto be ~10% for ELAIS-N1.

The LOFAR Two Metre Sky Survey: Deep Fields. II. The ELAIS-N1 LOFAR deep field