Astrophysics Group

Cavendish Laboratory


The AMI SA Galactic Plane Survey


The 15.7-GHz, AMI Galactic Plane Survey is currently being carried out using the Arcminute Microkelvin Imager (AMI) Small Array (SA), which is operated by the Cavendish Astrophysics Group at Lord’s Bridge, Cambridgeshire. The SA is one of the two AMI arrays (see AMI Consortium: Zwart et al. 2008 for detailed technical information about AMI); it is a radio synthesis telescope comprising ten 3.7-metre-diameter dishes and is used to observe between frequencies of 13.5 and 18.0 GHz with a resolution of approximately 3 arcmin. The SA is optimised for detecting extended Sunyaev-Zel’dovich effects on arcminute scales, but is also used extensively for Galactic astronomy.

The first AMIGPS results from an area of ≈ 868 sq. degrees between 76° < l < 170°, |b|<5° have now been released. This includes a catalogue of ≈ 3500 sources, and 38 raster maps accompanied by noise maps and resolution parameter cubes.

First Data Release

Technical information about the observing, mapping and source extraction techniques used to collect and analyse the AMIGPS data can be found in AMI Consortium: Perrott et al. (2012).

The first results from the survey, which is the most sensitive Galactic plane survey of large extent at centimetre-wave frequencies greater than 1.4 GHz, will be released in a following paper.

The AMIGPS catalogue is available in ASCII and FITS formats. The accompanying README file provides information about the various parameters contained in the catalogue.

The AMIGPS 6 × 6 degree2 raster maps are available below. The maps are in FITS format in Galactic coordinates. Each link below is a tarball containing:

  • The map;
  • A noise map showing the estimated thermal noise level at every pixel;
  • An adjusted noise map showing (flux density detection threshold)/5 at each pixel, accounting for exclusion zones around bright sources – see paper for more detail;
  • Resolution parameter cubes showing the synthesised beam major axis FWHM, minor axis FWHM and position angle at each pixel.

The AMI Small Array

Last modified 11 Oct 2012

Yvette Perrott (