Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

Giant Metrewave Radio Telescope All-Sky 150-MHz Radio Source Catalog

Metadata Updated: September 19, 2025

This table contains results from the first full release of a survey of the 150-MHz radio sky, observed with the Giant Metrewave Radio Telescope (GMRT) between April 2010 and March 2012 as part of the TIFR GMRT Sky Survey (TGSS) project. Aimed at producing a reliable compact source survey, the authors' automated data-reduction pipeline efficiently processed more than 2000 hours of observations with minimal human interaction. Through application of innovative techniques such as image-based flagging, direction-dependent calibration of ionospheric phase errors, correcting for systematic offsets in antenna pointing, and improving the primary beam model, the authors created good quality images for over 95% of the 5,336 pointings. This data release covers 36,900 deg<sup>2</sup> (or 3.6 pi steradians) of the sky between -53 and +90 degrees Declination, which is 90% of the total sky. The majority of pointing images has a noise level below 5 mJy/beam (the median RMS background noise is 3.5 mJy per beam), with an approximate resolution of 25" x 25" (or 25" x 25"/cos(Dec-19<sup>o</sup>) for pointings south of 19 degrees Declination). The authors have produced a catalog of 0.62 Million radio sources with flux densities ranging from 11.1 mJy to 9.22 kJy that are derived from an initial, high-reliability source extraction at the 7-sigma level. For the bulk of the survey, the measured overall astrometric accuracy is better than 2 arcseconds in Right Ascension and Declination, while the flux density accuracy is estimated at approximately 10%. Within the scope of the TGSS Alternative Data Release (TGSS ADR) project, the source catalog, as well as 5,336 mosaic images (5 x 5 degree<sup>2</sup>) and an image cutout service, are made publicly available as a service to the astronomical community. (The TGSS images and cutout server are available through the project website at <a href="http://tgssadr.strw.leidenuniv.nl/">http://tgssadr.strw.leidenuniv.nl/</a>;). In addition to enabling a wide range of different scientific investigations, the authors anticipate that these survey products will provide a solid reference for various new low-frequency radio aperture array telescopes (LOFAR, LWA, MWA, SKA-low), and can play an important role in characterizing the epoch-of-reionization (EoR) foreground. The TGSS ADR project aims at continuously improving the quality of the survey data products. Near-future improvements include replacement of bright source snapshot images with archival targeted observations, using new observations to fill the holes in sky coverage and to replace very poor quality observational data, and an improved flux calibration strategy for less severely affected observational data. This table was created by the HEASARC in February 2017 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/598/A78">CDS Catalog J/A+A/598/A78</a> file table3.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.

Downloads & Resources

Dates

Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/gmrtas150m
Data Last Modified 2025-09-10
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 94859407-dbbb-453d-826b-22e2c42bd7f5
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/gmrtas150m.html
Program Code 026:000
Source Datajson Identifier True
Source Hash 12c0b8d1fd17f5e26ed2d31c3037c2328bf8e551dc495f688750598d0fd1d55f
Source Schema Version 1.1

Didn't find what you're looking for? Suggest a dataset here.