Information on Service 'LoTSS-DR3 mosaics'

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In this data release from the LOw-Frequency ARray (LOFAR) Two-metre Sky Survey (LoTSS) we present 120-168 MHz images covering 88% of the northern sky. The individual pointing images (at 6'' and 20'' resolution) were derived from 12,950 hrs (18.6 PB) of LOFAR High Band Antenna data which were processed through fully automated direction-independent and direction-dependent calibration pipelines that correct for instrumental effects as well as spatially and temporally varying ionospheric distortions. The Stokes I images were then combined, accounting for the rms noise level and telescope beam, to form the final Stokes I mosaic images at 6'' and 20'' resolution, with a central frequency of 144MHz. From the 6'' resolution Stokes mosaics we derived a catalogue of 13,664,379 radio sources (consisting of 16,943,656 Gaussian components), the majority of which have never been detected at radio wavelengths before. These mosaics have a median rms sensitivity of 92 μJy/beam; a random and systematic flux density scale accuracy of approximately 6% and 2%, respectively; an astrometric accuracy of 0.24''; and we estimate that we detect more than 95% of sources with integrated flux densities exceeding nine times the local root mean square noise. To enable thorough scientific exploitation of this unique dataset, we have published two sub-collections. The first contains all the Stokes I mosaic products described above. The second contains the individual pointing products, including calibrated uv data (measurement sets and direction-dependent calibration solutions) to allow for re-imaging or post-processing; Stokes I images at 6' ' and 20'' resolution (with associated scaling factors required to reproduce the mosaic images); Stokes V images at 6'' resolution for each observing epoch; and Stokes Q and U image cubes at 20'' and 4' resolution. This service queries the Stokes I continuum mosaic images.

For a list of all services and tables belonging to this service's resource, see Information on resource 'lotss_dr3/q'

Overview

You can access this service using:

This service is published as follows:

local means it is listed on our front page, ivo_managed means it has a record in the VO registry.

Other services provided on the underlying data include:

Spatial Coverage

Input Fields

The following fields are available to provide input to the service (with some renderers, some of these fields may be unavailable):

NameTable Head DescriptionUnitUCD
FORMAT Output format Requested format of the image data N/A N/A
hFORMAT Output format Requested format of the image data N/A N/A
hINTERSECT Intersection type Relation of image and specified Region of Interest. N/A N/A
hPOS Position ICRS Position, RA,DEC, or Simbad object (e.g., 234.234,-32.45) deg pos.eq
hSIZE Field size Size in decimal degrees (e.g., 0.2 or 1,0.1) deg N/A
INTERSECT Intersection type Relation of image and specified Region of Interest. N/A N/A
MAXREC Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
POS Position ICRS Position, RA,DEC decimal degrees (e.g., 234.234,-32.46) deg pos.eq
RESPONSEFORMAT Output Format File format requested for output. N/A meta.code.mime
SIZE Field size Size in decimal degrees (e.g., 0.2 or 1,0.1) deg N/A
VERB Verbosity Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. N/A N/A

Default Output Fields

The following fields are contained in the output by default. More fields may be available for selection; these would be given below in the VOTable output fields.

NameTable Head DescriptionUnitUCD
accref Product key Access key for the data N/A N/A
accsize File size Size of the data in bytes byte VOX:Image_FileSize
bandpassHi Band upper Upper limit of the bandpass (in BandPass_Unit units) m VOX:BandPass_HiLimit
bandpassId Bandpass Freeform name of the bandpass used N/A VOX:BandPass_ID
bandpassLo Band lower Lower limit of the bandpass (in BandPass_Unit units) m VOX:BandPass_LoLimit
bandpassRefval Band Ref. Characteristic quantity for the bandpass of the image m VOX:BandPass_RefValue
bandpassUnit Bandpass unit Unit of bandpass specifications (always m). N/A VOX:BandPass_Unit
centerAlpha Ctr. RA Approximate center of image, RA deg POS_EQ_RA_MAIN
centerDelta Ctr. Dec Approximate center of image, Dec deg POS_EQ_DEC_MAIN
coverage Coverage Field covered by the image deg N/A
dateAllObs Date all obs. Epoch of all observations N/A time.epoch
dateFirstObs Date first obs. Epoch of first observation d time.epoch;time.start
dateLastObs Date last obs. Epoch of last observation d time.epoch;time.end
dateObs Obs. date Epoch at midpoint of observation d VOX:Image_MJDateObs
imageTitle Title Synthetic name of the image N/A VOX:Image_Title
instId Instrument Identifier of the originating instrument N/A INST_ID
mime Type MIME type of the file served N/A meta.code.mime
mosaic_id Mosaic ID The name of the mosaic. N/A meta.id;meta.main
nAxes #axes Number of axes in data N/A VOX:Image_Naxes
pixelScale Scales The pixel scale on each image axis deg/pix VOX:Image_Scale
pixelSize Axes Lengths Number of pixels along each of the axes pix VOX:Image_Naxis
pixflags P. Flags Flags specifying the processing done (C-original; F-resampled; Z-fluxes valid; X-not resampled; V-for display only N/A VOX:Image_PixFlags
refFrame Ref. Frame Coordinate system reference frame N/A VOX:STC_CoordRefFrame
related_products Related products Link related products for the observation N/A meta.ref.url
wcs_cdmatrix CD matrix FITS WCS CDij matrix deg/pix VOX:WCS_CDMatrix
wcs_equinox Equinox Equinox of the given coordinates yr VOX:STC_CoordEquinox
wcs_projection Proj. FITS WCS projection type N/A VOX:WCS_CoordProjection
wcs_refPixel Ref. pixel WCS reference pixel pix VOX:WCS_CoordRefPixel
wcs_refValues Ref. values World coordinates at WCS reference pixel deg VOX:WCS_CoordRefValue

VOTable Output Fields

The following fields are available in VOTable output. The verbosity level is a number intended to represent the relative importance of the field on a scale of 1 to 30. The services take a VERB argument. A field is included in the output if their verbosity level is less or equal VERB*10.

NameTable Head DescriptionUnitUCD Verb. Level
centerAlpha Ctr. RA Approximate center of image, RA deg POS_EQ_RA_MAIN 0
centerDelta Ctr. Dec Approximate center of image, Dec deg POS_EQ_DEC_MAIN 0
imageTitle Title Synthetic name of the image N/A VOX:Image_Title 0
dateObs Obs. date Epoch at midpoint of observation d VOX:Image_MJDateObs 0
accref Product key Access key for the data N/A N/A 1
related_products Related products Link related products for the observation N/A meta.ref.url 1
bandpassId Bandpass Freeform name of the bandpass used N/A VOX:BandPass_ID 10
accsize File size Size of the data in bytes byte VOX:Image_FileSize 11
pixelScale Scales The pixel scale on each image axis deg/pix VOX:Image_Scale 12
instId Instrument Identifier of the originating instrument N/A INST_ID 15
pixelSize Axes Lengths Number of pixels along each of the axes pix VOX:Image_Naxis 15
mime Type MIME type of the file served N/A meta.code.mime 20
nAxes #axes Number of axes in data N/A VOX:Image_Naxes 20
refFrame Ref. Frame Coordinate system reference frame N/A VOX:STC_CoordRefFrame 20
wcs_equinox Equinox Equinox of the given coordinates yr VOX:STC_CoordEquinox 20
wcs_projection Proj. FITS WCS projection type N/A VOX:WCS_CoordProjection 20
wcs_refPixel Ref. pixel WCS reference pixel pix VOX:WCS_CoordRefPixel 20
wcs_refValues Ref. values World coordinates at WCS reference pixel deg VOX:WCS_CoordRefValue 20
wcs_cdmatrix CD matrix FITS WCS CDij matrix deg/pix VOX:WCS_CDMatrix 20
bandpassUnit Bandpass unit Unit of bandpass specifications (always m). N/A VOX:BandPass_Unit 20
bandpassRefval Band Ref. Characteristic quantity for the bandpass of the image m VOX:BandPass_RefValue 20
bandpassHi Band upper Upper limit of the bandpass (in BandPass_Unit units) m VOX:BandPass_HiLimit 20
bandpassLo Band lower Lower limit of the bandpass (in BandPass_Unit units) m VOX:BandPass_LoLimit 20
pixflags P. Flags Flags specifying the processing done (C-original; F-resampled; Z-fluxes valid; X-not resampled; V-for display only N/A VOX:Image_PixFlags 20
coverage Coverage Field covered by the image deg N/A 20
mosaic_id Mosaic ID The name of the mosaic. N/A meta.id;meta.main 20
dateFirstObs Date first obs. Epoch of first observation d time.epoch;time.start 20
dateLastObs Date last obs. Epoch of last observation d time.epoch;time.end 20
dateAllObs Date all obs. Epoch of all observations N/A time.epoch 20
owner Owner Owner of the data N/A N/A 25
embargo Embargo ends Date the data will become/became public a N/A 25
record_id Record ID Surf Data Repository record ID. N/A meta.bib 25

Copyright, License, Acknowledgements

LoTSS Data Release 3 is licensed under the Creative Commons Attribution Share-Alike 3.0 License

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