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- ID:
- ivo://astron.nl/lolss/q/cutout
- Title:
- LoLSS - Image Cutout Service
- Short Name:
- LoLSS Cutout
- Date:
- 02 Feb 2023 15:08:05
- Publisher:
- ASTRON
- Description:
- This service provides cutouts from the images of the LOFAR LBA Sky Survey (LoLSS).
- ID:
- ivo://astron.nl/hetdex/lotss-dr1-img/imgs
- Title:
- LoTSS-DR1 Image Archive
- Short Name:
- LoTSS-DR1 images
- Date:
- 12 Nov 2021 16:37:07
- Publisher:
- ASTRON
- Description:
- 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.
- ID:
- ivo://astron.nl/hetdex/lotss-dr1-img/cutout
- Title:
- LoTSS-DR1 Image Cutout Service
- Short Name:
- LoTSS-DR1 Cutout
- Date:
- 12 Nov 2021 16:37:07
- Publisher:
- ASTRON
- Description:
- This service provides cutouts from the images of 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.
- ID:
- ivo://astron.nl/lotss_dr2/q/query_mosaics
- Title:
- LoTSS-DR2 mosaics
- Short Name:
- "Mosaics"
- Date:
- 28 Sep 2023 14:12:45
- Publisher:
- ASTRON
- Description:
- 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 images.
- ID:
- ivo://astron.nl/lofartier1/q_img/imgs
- Title:
- LoTSS-PDR Image Archive
- Short Name:
- LoTSS-PDR images
- Date:
- 28 Apr 2021 10:35:08
- Publisher:
- ASTRON
- Description:
- This service queries the catalog of images from the LOFAR HBA Tier-1 preliminary data release (LoTSS-PDR). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field. In excess of 40,000 sources are detected in the images that cover an area of over 350 square degrees, have a resolution of 25 arcsec, and typical noise levels of less than 0.5 mJy/beam.
- ID:
- ivo://astron.nl/lofartier1/q_img/cutout
- Title:
- LoTSS-PDR Image Cutout Service
- Short Name:
- LoTSS-PDR Cutout
- Date:
- 28 Apr 2021 10:35:08
- Publisher:
- ASTRON
- Description:
- This service provides cutouts from the images of the LOFAR HBA Tier-1 preliminary data release (LoTSS-PDR). This data release contains images and catalogs that characterise the low-frequency radio emission in the region of the HETDEX Spring Field. In excess of 40,000 sources are detected in the images that cover an area of over 350 square degrees, have a resolution of 25 arcsec, and typical noise levels of less than 0.5 mJy/beam.
- ID:
- ivo://astron.nl/__system__/siap2/sitewide
- Title:
- The VO @ ASTRON SIAP Version 2 Service
- Short Name:
- ASTRON VO SIA2
- Date:
- 09 Jan 2020 07:54:53
- Publisher:
- ASTRON
- Description:
- The The VO @ ASTRON's sitewide SIAP version 2 service publishes all the images published through the site. For more advanced queries including uploads, all this data is also available through ObsTAP.
