Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

In particular, the protocols offered are the Tabular Access Protocol (TAP), Simple Application Messaging Protocol (SAMP) and the Simple Image Access protocol (SIA). TAP and SAMP enables queries to explore the data in a tabular form using tools such as TOPCAT. TOPCAT is an interactive graphical viewer and editor for tabular data, it enables the interactive exploration of large tables performing several types of plotting, statistics, editing and visualization of tables. SIA enables the rapid display of images and cubes through all sky atlas tools such as ALADIN. ALADIN is an interactive sky atlas allowing the user to visualize digitized astronomical images/cubes and superimpose entries from astronomical catalogues or databases.

Edited till here (note to self)


The data published in the VO can also be accessed using a web browser at https://vo.astron.nl. This web interface provides a page on which all the collections present in the registry are listed, including the published LoTSS DR2 data sets (Fig. 39).:

Captioned Item
anchorvoservices
nameTable
captionList of LoTSS DR2 services in the ASTRON VO.


Service nameService Description

LoTSS-DR2 Gaussian catalog cone search

This service queries the Stokes I continuum mosaic gaussian component catalogue.
LoTSS-DR2 Source catalog cone searchThis service queries the Stokes I continuum mosaic source catalogue.
LoTSS-DR2 mosaicsThis service queries the Stokes I continuum mosaic images
Info
iconfalse
Relative flux errorImage RemovedFig. 39 ASTRON VO interface
.




Selecting a data collection allows the user to perform a cone search through a webform (Fig. 40) for all data products of that given class overlapping a given pointing. The size of the continuum images as well as the cubes extend beyond the 10% primary beam level for cleaning the secondary lobes of bright offset sources. To ensure that the search is done in the area of maximum sensitivity the search is performed on a maxim radius of 0.75 degrees from the center (this represents the average value of where the sensitivity drops). This value can be modified using the Max distance from center. A different output with respect to the default can be customized using More output fields selection button.

...

Table names to be used in the ADQL query.

Table name

obscore type

obscore subtype

apertif_dr1.continuum_images

image

continuum

apertif_dr1.pol_cubes

cube

polarization cube

apertif_dr1.spectral_cubes

cube

spectral cube

apertif_dr1.beam_cubes

cube

dirty beam

Access via TOPCAT

The Apertif DR1 data collection tables can be accessed using TOPCAT, an interactive graphical viewer and editor for tabular data. The data can be sent from vo.astron.nl to TOPCAT using one of the two protocols: SAMP or TAP. The two subsections below provide a description on how to access the tabular data using either SAMP(link to Send via SAMP subsection) or TAP(link to VO Table Access Protocol (TAP) subsection).

...