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9C 15-GHz Ryle Telescope Survey of VSA Fields Source Catalog

Metadata Updated: August 30, 2025

The fields chosen for the first observations of the cosmic microwave background (CMB) with the Very Small Array (VSA) have been surveyed with the Ryle Telescope at 15 GHz. The authors have covered three regions around RA = 00<sup>h</sup>20<sup>m</sup> and Dec = +30<sup>o</sup>, RA = 09<sup>h</sup>40m and Dec = +32<sup>o</sup> and RA = 15<sup>h</sup>40<sup>m</sup> and Dec = +43<sup>o</sup> (J2000.0), comprising an area of 520 deg<sup>2</sup>. There are 465 sources in this entire area which are above the estimated completeness limit of ~ 25 mJy, although a total of ~ 760 sources were detected, some as faint as 10 mJy. The prime motivation of this study was to define a catalog of the foreground sources that must be monitored by the VSA during its observations at 34 GHz. In particular, it provides a means of identifying GigaHertz peaked spectrum (GPS) sources, which are important for the study of radio source evolution, as well as being a significant foreground for CMB observations over a range of wavelengths. Since this will be a new and quite extensive survey, it was desgignated as '9C' or the Ninth Cambridge survey. For the purpose of this particular component of the 9C survey, the authors designated as a subset, 3 circular areas, VSA1, VSA2 and VSA3, defined by the properties listed in Table 2 of the reference paper and reproduced below: <pre> Field Centre J2000.0 Center B1950.0 Radius Area RA Dec RA Dec (degrees) (sq. degrees) VSA1 00 17 36.5 +30 16 39 00 15 00.0 +30 00 00 5.5 95.0 VSA2 09 40 57.7 +31 46 21 09 38 00.0 +32 00 00 6.0 113.0 VSA3 15 36 42.7 +43 20 11 15 35 00.0 +43 30 00 5.0 78.5 </pre> There are 242 sources which were both above the 25 mJy completeness limit and were in the 286.5 deg<sup>2</sup> contained within these 3 circular fields. These source were listed in 3 tables in the reference paper, Table 4 (VSA1), Table 5 (VSA2) and Table 6 (VSA3). These have been combined into this one HEASARC table, in which the HEASARC added a new parameter vsa_field, which is set to 1 for the VSA1 sources, 2 for the VSA2 sources, and 3 for the VSA3 sources. This table was created in November 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/342/915">CDS catalog J/MNRAS/342/915</a> files table4.dat, table5.dat and table6.dat. This is a service provided by NASA HEASARC .

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date April 11, 2025
Metadata Updated Date August 30, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date August 30, 2025
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/rtv9c15ghz
Data Last Modified 2025-08-27
Category Astrophysics
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id c4d3b886-9246-4e70-8bac-579e0a1f238a
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/rtv9c15ghz.html
Program Code 026:000
Source Datajson Identifier True
Source Hash d26f09801816c2fda7a66b9d6a48027e5ad832a61458597c27cacf93d09f9e20
Source Schema Version 1.1

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