Information on Service 'LoTSS-DR2 Gaussian catalog cone search'

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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. This service queries the Stokes I continuum mosaic gaussian component catalogue.

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:

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
DEC Delta (ICRS) Declination (ICRS decimal) deg pos.eq.dec
hscs_pos Position/Name Coordinates (as h m s, d m s or decimal degrees), or SIMBAD-resolvable object N/A N/A
hscs_sr Search radius Search radius in arcminutes N/A N/A
MAXREC Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
RA Alpha (ICRS) Right Ascension (ICRS decimal) deg pos.eq.ra
RESPONSEFORMAT Output Format File format requested for output. N/A meta.code.mime
SR Search Radius Search radius 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
DC_Maj DC_Maj The FWHM of the major axis of the source, after de-convolution with the 6-arcsec LOFAR beam arcsec phys.angsize
DC_Min DC_Min The FWHM of the minor axis of the source, after de-convolution with the 6-arcsec LOFAR beam arcsec phys.angsize
DC_PA DC_PA The position angle of the major axis of the source measured east of north, after de-convolution with the 6-arcsec LOFAR beam deg pos.posang
DEC Dec Position from PyBDSF or combination of PyBDSF components deg pos.eq.dec;meta.main
E_DC_Maj E_DC_Maj The 1-sigma error on the FWHM of the deconvolved major axis of the source arcsec stat.error;phys.angsize
E_DC_Min E_DC_Min The 1-sigma error on the FWHM of the deconvolved minor axis of the source arcsec stat.error;phys.angsize
E_DC_PA E_DC_PA The 1-sigma error on the position angle of the deconvolved major axis of the source deg stat.error;pos.posang
E_DEC error Dec Estimated by PyBDSF. Only fitting uncertainties are included arcsec stat.error;pos.eq.dec
E_Maj E_Maj The 1-sigma error on the FWHM of the major axis of the source arcsec stat.error;phys.angsize
E_Min E_Min The 1-sigma error on the FWHM of the minor axis of the source arcsec stat.error;phys.angsize
E_PA E_PA The 1-sigma error on the position angle of the major axis of the source deg stat.error;pos.posang
E_Peak_flux error Peak flux The 1-sigma error on the peak flux density per beam of the source mJy/beam stat.error;phot.flux.density;em.radio
E_RA error RA Estimated by PyBDSF. Only fitting uncertainties are included arcsec stat.error;pos.eq.ra
E_Total_flux error Total flux The 1-sigma on the total flux density of the source mJy stat.error;phot.flux.density;em.radio
Gaus_id Gaussian ID ID of the fitted Gaussian. N/A meta.id
Isl_rms RMS noise The average background rms value of the island mJy/beam instr.det.noise
Majax Major Axis The FWHM of the major axis of the source, INCLUDING convolution with the 6-arcsec LOFAR beam arcsec phys.angsize
Minax Minor Axis The FWHM of the minor axis of the source, INCLUDING convolution with the 6-arcsec LOFAR beam arcsec phys.angsize
Mosaic_ID Mosaic The name of the mosaic in which the FITS image can be found N/A meta.id;obs.image
mosaic_url Mosaic_url DataLink to the corresponding mosaic N/A meta.id;obs.image
PA PA The position angle of the major axis of the source measured east of north, INCLUDING convolution with the 6-arcsec LOFAR beam deg pos.posang
Peak_flux Peak flux The peak Stokes I flux density per beam of the source mJy/beam phot.flux.density;em.radio
RA RA Position from PyBDSF or combination of PyBDSF components deg pos.eq.ra;meta.main
S_Code Morphological Code A code that defines the source structure 'S' for single Gaussian, 'M' for multiple Gaussian, 'C' = a single-Gaussian source in an island with other sources N/A meta.code;src.morph
Source_Name ID The radio name of the source, automatically generated from RA and DEC in most cases N/A meta.id;meta.main
Total_flux Total flux The total, integrated Stokes I flux density of the source at the reference frequency mJy phot.flux.density;em.radio

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
Source_Name ID The radio name of the source, automatically generated from RA and DEC in most cases N/A meta.id;meta.main 1
RA RA Position from PyBDSF or combination of PyBDSF components deg pos.eq.ra;meta.main 1
E_RA error RA Estimated by PyBDSF. Only fitting uncertainties are included arcsec stat.error;pos.eq.ra 1
DEC Dec Position from PyBDSF or combination of PyBDSF components deg pos.eq.dec;meta.main 1
E_DEC error Dec Estimated by PyBDSF. Only fitting uncertainties are included arcsec stat.error;pos.eq.dec 1
Peak_flux Peak flux The peak Stokes I flux density per beam of the source mJy/beam phot.flux.density;em.radio 1
E_Peak_flux error Peak flux The 1-sigma error on the peak flux density per beam of the source mJy/beam stat.error;phot.flux.density;em.radio 1
Total_flux Total flux The total, integrated Stokes I flux density of the source at the reference frequency mJy phot.flux.density;em.radio 1
E_Total_flux error Total flux The 1-sigma on the total flux density of the source mJy stat.error;phot.flux.density;em.radio 1
Majax Major Axis The FWHM of the major axis of the source, INCLUDING convolution with the 6-arcsec LOFAR beam arcsec phys.angsize 1
E_Maj E_Maj The 1-sigma error on the FWHM of the major axis of the source arcsec stat.error;phys.angsize 1
Minax Minor Axis The FWHM of the minor axis of the source, INCLUDING convolution with the 6-arcsec LOFAR beam arcsec phys.angsize 1
E_Min E_Min The 1-sigma error on the FWHM of the minor axis of the source arcsec stat.error;phys.angsize 1
DC_Maj DC_Maj The FWHM of the major axis of the source, after de-convolution with the 6-arcsec LOFAR beam arcsec phys.angsize 1
E_DC_Maj E_DC_Maj The 1-sigma error on the FWHM of the deconvolved major axis of the source arcsec stat.error;phys.angsize 1
DC_Min DC_Min The FWHM of the minor axis of the source, after de-convolution with the 6-arcsec LOFAR beam arcsec phys.angsize 1
E_DC_Min E_DC_Min The 1-sigma error on the FWHM of the deconvolved minor axis of the source arcsec stat.error;phys.angsize 1
PA PA The position angle of the major axis of the source measured east of north, INCLUDING convolution with the 6-arcsec LOFAR beam deg pos.posang 1
E_PA E_PA The 1-sigma error on the position angle of the major axis of the source deg stat.error;pos.posang 1
DC_PA DC_PA The position angle of the major axis of the source measured east of north, after de-convolution with the 6-arcsec LOFAR beam deg pos.posang 1
E_DC_PA E_DC_PA The 1-sigma error on the position angle of the deconvolved major axis of the source deg stat.error;pos.posang 1
Isl_rms RMS noise The average background rms value of the island mJy/beam instr.det.noise 1
S_Code Morphological Code A code that defines the source structure 'S' for single Gaussian, 'M' for multiple Gaussian, 'C' = a single-Gaussian source in an island with other sources N/A meta.code;src.morph 1
Mosaic_ID Mosaic The name of the mosaic in which the FITS image can be found N/A meta.id;obs.image 1
mosaic_url Mosaic_url DataLink to the corresponding mosaic N/A meta.id;obs.image 1
Gaus_id Gaussian ID ID of the fitted Gaussian. N/A meta.id 1

Copyright, License, Acknowledgements

LoTSS Data Release 2 is licensed under the Creative Commons Attribution Share-Alike 3.0 License

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