Information on Service 'Mosaic download service'
In this data release from the ongoing LOw-Frequency ARray (LOFAR)
Two-metre Sky Survey (LoTSS) we present 120-168 MHz images covering
27% of the northern sky. Our coverage is split into two regions
centred at approximately 12h45m +44°30′ and 1h00m +28°00′ and spanning
4178 and 1457 square degrees respectively. The images were derived
from 3,451 hrs (7.6 PB) of LOFAR High Band Antenna data which were
corrected for the direction-independent instrumental properties as
well as direction-dependent ionospheric distortions during extensive,
but fully automated, data processing. A catalogue of 4,395,448 radio
sources is derived from our total intensity (Stokes I) maps, where the
majority of these have never been detected at radio wavelengths
before. At 6′′ resolution, our full bandwidth Stokes I continuum maps
with a central frequency of 144 MHz have: a median rms sensitivity of
83 μ Jy/beam; a flux density scale accuracy of approximately 10%; an
astrometric accuracy of 0.2′′; and we estimate the point-source
completeness to be 90% at a peak brightness of 0.8 mJy/beam. By
creating three 16 MHz bandwidth images across the band we are able to
measure the in-band spectral index of many sources, albeit the error
on the derived spectral index is > ±0.2 which is a consequence of our
flux-density scale accuracy and small fractional bandwidth. Our
circular polarisation (Stokes V) 20′′ resolution 120-168 MHz continuum
images have a median rms sensitivity of 95 μ Jy/beam, and we estimate
a Stokes I to Stokes V leakage of 0.056%. Our linear polarisation
(Stokes Q and Stokes U) image cubes consist of 480 97.6 kHz wide
planes and have a median rms sensitivity per plane of 10.8mJy/beam at
4′ and 2.2mJy/beam at 20′′; we estimate the Stokes I to Stokes Q/U
leakage to be approximately 0.2%. Here we characterise and publicly
release our Stokes I, Q, U and V images in addition to the calibrated
uv-data to facilitate the thorough scientific exploitation of this
unique dataset.
For a list of all services and tables belonging to this service's
resource, see Information on resource 'lotss_dr2/q'
Overview
You can access this service using:
-
dlmeta --
a datalink interface for discovering access options (processed data, related datasets...) for a dataset. You usually need a publisherDID to use this kind of service. For special applications, the base URL of this service might still come handy: https://vo.astron.nl/lotss_dr2/q/dlmosaic/dlmeta
This service is not published.
This can mean that it was deemed too unimportant, for internal
use only, or is just a helper for a published service.
Equally likely, however,
it is under development, abandoned in development or otherwise
unfinished. Exercise caution.
Other services provided on the underlying data
include:
Spatial Coverage
Copyright, License, Acknowledgements
LoTSS Data Release 2 is licensed under the Creative Commons Attribution Share-Alike 3.0 License
VOResource XML (that's something exclusively for VO nerds)