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Astronomy surveys

Exploring the universe
Many astronomical surveys are used by astrophysicists in the Sydney Institute for Astronomy (SIfA). Some are products of SIfA itself, while others have their origins elsewhere but significantly involve SIfA staff.

SIfA Surveys

The SAMI Galaxy Survey began in March 2013, with the intention of creating a large survey of 3000 galaxies across a large range of environment. The key science goals of the SAMI Survey are to answer the following questions:

  • What is the physical role of environment in galaxy evolution?
  • What is the relationship between stellar mass growth and angular momentum development in galaxies?
  • How does gas get into and out of galaxies, and how does this drive star formation?
  • Learn more about the survey at the SAMI Galaxy Survey site

SUMSS is dedicated to our friend and colleague Dr. Michael Large, whose expertise and vision made the project possible.

The Sydney University Molonglo Sky Survey (SUMSS) is a wide-field radio imaging survey of the southern sky at 843 MHz. The survey was completed in 2007, and covers the whole sky south of declination -30 degrees with |b| > 10 degrees. The Galactic Plane region |b| < 10 degrees is covered by MGPS-2. 

A full description of the survey and data catalogue is given in the following two papers:
Primary reference: D. Bock, M.I. Large & E.M. Sadler (1999) AJ, 117, 1578-1593
SUMSS: A Wide-Field Radio Imaging Survey of the Southern Sky. I. Science goals, survey design and instrumentation 
Catalogue reference: T. Mauch, T. Murphy, H.J. Buttery, J. Curran, R.W. Hunstead, B. Piestrzynska, J.G. Robertson and E.M. Sadler (2003), MNRAS, 342, 1117-1130
SUMSS: A wide field radio imaging Survey of the Southern Sky. II. The source catalogue'

Related Surveys:

The data can be found here (PDF, 210kb).

The first epoch Molonglo Galactic Plane Survey (MGPS-1) is a radio continuum survey made using the Molonglo Observatory Synthesis Telescope (MOST) at 843 MHz with a resolution of 43 x 43 cosec |dec|. The region surveyed is 245 < L < 355, |b| < 1.5 degrees. The root-mean-square sensitivity over much of the mosaiced survey is 1-2 mJy/beam (1 sigma), and the positional accuracy is 1-2''. The dynamic range is no better than 250:1, and this also constrains the sensitivity in some parts of the images. The survey area of 330 sq deg contains well over 12,000 unresolved or barely resolved objects, almost all of which are extra-galactic sources lying in the Zone of Avoidance. In addition a significant fraction of this area is covered by extended, diffuse emission associated with thermal complexes, discrete H II regions, supernova remnants, and other structures in the Galactic interstellar medium. 

Primary reference: A.J. Green. L.E. Cram, M. Large & T. Ye (1999), ApJS, 122, 207-219
The Molonglo Galactic Plane Survey : I. Overview and Images

The data can be found here (PDF, 210kb).

The second epoch Molonglo Galactic Plane Survey (MGPS-2) was carried out at 843 MHz with the Molonglo Observatory Synthesis Telescope (MOST) in its upgraded wide-field capability. The survey consists of 4.3 x 4.3 degree mosaic images with a 45 x 45 '' cosec(dec) restoring beam. It covers the range |b| < 10 degrees and 245 < l < 365 degrees and is the Galactic counterpart to the Sydney University Molonglo Sky Survey (SUMSS) which covers the whole southern sky with declination < -30 degrees.

People involved in the MGPS-2 survey are:
Tara Murphy
Anne Green
Tom Mauch
Dick Hunstead
Tony Turtle

It is closely related to the SUMSS survey, and much of the work has been done in common with SUMSS. 

The data can be found here (PDF, 210kb).

"A Broadband Polarization Catalog of Extragalactic Radio Sources" by Farnes, J. S., Gaensler, B. M., & Carretti, E., 2014, ApJS, 212, 15.

The catalog provides multiwavelength (from 400 MHz to 100 GHz) linear polarization and total intensity radio data for polarized sources from the NRAO VLA Sky Survey. These sources have been cross-matched with a number of complementary measurements, combining data from major radio polarization and total intensity surveys such as AT20G, B3-VLA, GB6, NORTH6CM, Texas, and WENSS, together with other polarization data published over the last 50 years. The catalog provided the largest published compilation of both polarized spectral energy distributions (SEDs) and radio spectral indices and their curvature, alongside models of these SEDs and information on each source's optical counterpart.

The Data

Note that the data are in binary FITS table format and have been gzipped. After gunzipping, the files can be read with your favourite FITS reader such as Topcat or fv, or packages such as PyFITS or the IDL Astronomy Library.

The full set of data: PolCat_ApJ.tar.gz (7.8 MB) 

Note that the .tar archive contains two .fits files:
Full-catalog.fits - The accumulated data for all 37,543 objects from the Taylor, Stil & Sunstrum (2009) catalog
SED-catalog.fits - A subset of the data, containing only the 951 objects that have three or more datapoints in the polarized spectral energy distribution. 

"A Precision Multi-band Two-epoch Photometric Catalog of 44 Million Sources in the Northern Sky from a Combination of the USNO-B and Sloan Digital Sky Survey Catalogs" by Madsen & Gaensler, ApJS, 209, 33 (2013).

This page provides links to a new precision, multi-epoch photometric catalog that spans 60 years by combining the USNO-B and SDSS Data Release 9 catalogs. We recalibrate the photometry of the original USNO-B catalog and create a catalog with two epochs of photometry in up to five different bands for 43,647,887 optical point sources that lie in the DR9 footprint of the northern sky. The recalibrated objects span a magnitude range 14 < m < 20 and are accurate to 0.1 mag. We minimize the presence of spurious objects and those with inaccurate magnitudes by identifying and removing several sources of systematic errors in the two originating catalogs, with a focus on spurious objects that exhibit large apparent magnitude variations. After accounting for these effects, we find 250,000 stars and quasars that show significant (> 4σ) changes in brightness between the USNO-B and SDSS DR9 epochs.

The Data

Note that the data are in binary FITS table format and have been gzipped. The headers of the files give a full description of the contents. After gunzipping, the files can be read with your favourite FITS reader such as Topcat or fv, or packages such as PyFITS or the IDL Astronomy Library.

  • The full set of data in Table 1 (recalibration coefficients): table_1.fits.gz (43 MB)
  • The full set of data in Table 3 (all recalibrated objects): table_3.fits.gz (3.8 GB)
  • A partial set of data from Table 3 (only the ~250k objects classified as candidate variables): table_3_vars.fits.gz (23 MB)
  • All data files combined: Full tarball (3.8 GB)

Copy of poster presented at Jan 2014 AAS meeting in Washington DC can be downloaded here. (PDF, 1.4 MB)

If you have any comments or questions, please contact Greg Madsen.

Other surveys