Information on Service 'LoTSS-DR1 Image Archive'

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This service queries the catalog of images from the LOFAR Two-metre Sky Survey First Data Release (LoTSS-DR1). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field (right ascension 10h45m00s to15h30m00s and declination 45◦00′00′′ to 57◦00′00′′). A total of 325,694 radio sources are detected in a region covering 424 square degrees. The maps have a median sensitivity of 71 uJy/beam and a resolution of 6 arcsec. Optical counterparts for 71% of the radio sources have been identified and where possible photometric redshifts for these sources have been derived.

For a list of all services and tables belonging to this service's resource, see Information on resource 'LoTSS-DR1 Image Catalogue'

Service Documentation

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
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
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
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
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
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

VOResource XML (that's something exclusively for VO nerds)