Star formation in Deep Radio Surveys

Nicholas Seymour

ARC Future Fellow

CSIRO Astronomy and Space Science

Bologna 13th September 2011

Precision Galactic Evolution

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Redshift

Precision Galactic Evolution

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Redshift

★

Precision Galactic Evolution

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CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

What SFG science can we do with deep radio surveys?

• Not a discussion on how to identify AGN or SFGs• Example of what we can do once we have a sample of SFGs• Based on Seymour et al. (2008) and unpublished follow-up

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Radio Luminosity/Redshift Distribution

• Not a

Seymour et al. (2008)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Optical Magnitudes

Red triangles = SFGsBlue Squares = AGN

Seymour et al. (2008)

Far-Infrared/Radio Correlation for SFGs

Condon et al. (1992)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Source Counts by type

• Not a

Seymour et al. (2008)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Source Counts by type

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Stellar Mass

Highest SFRs found at high-z and in the most massive galaxies.

6df SF galaxies

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Stellar Mass

Highest SFRs found at high-z and in the most massive galaxies.

6df SF galaxies

Seymour et al. (2008)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Star Formation History

• Not a

Seymour et al. (2008)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Contribution by SFR to the >10L* top of the luminosity function

• Not a

Seymour et al. (2008)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Characteristic Time (inverse of Specific SFR)

• Not a

Seymour et al. (2008)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

IR/SFR luminosity density

Separated into LIRGs, ULIRGsHyLIRGs

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Radio AGN Luminosity Density

Uncorrected

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Radio AGN Luminosity Density

Corrected

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Future Meetings

EMU International Meetings:• 5th Meeting: Auckland – February 2012• 6th Meeting: Sydney - 28-29th May 2012 (provisional)

SPARCS• 2nd Workshop: Sydney - 30th May to 1st June 2012 (provisional)

Southern Cross Astrophysics Conference V – 4th-8th June 2012 (provisional)

This conference on "Large Surveys" is the fifth in the "Southern Cross Astrophysics Conference Series" which are held annually at a suitable venue in Australia. It will be held from June 4 to 8 2012. We hope to hold the conference amongst the vineyards of the Hunter Valley, one of Australia’s premier wine growing regions.

Other face-to-face meetings??• SPARCS Source-finding sub-group??

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

BETA (Boolardy Engineering Test Array)

First six ASKAP antennae – already in place awaiting first PAFs

Potentially time available for science, after BETA commissioning and before full ASKAP commissioning.

Specs: • Resolution 60-80”• Sensitivity: 450uJy (1hr)

320uJy (2hr) 260uJy (3hr)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

BETA (Boolardy Engineering Test Array)

203040

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

BETA (Boolardy Engineering Test Array)

First six ASKAP antennae – already in place awaiting first PAFs

Potentially time available for science, after BETA commissioning and before full ASKAP commissioning.

Specs: • Resolution 60-80”• Sensitivity: 450uJy (1hr)

320uJy (2hr) 260uJy (3hr)

• Maybe confusion limited after a few hours• Long exposures may be needed to obtain uv coverage

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

EMU Value-Added Catalogue (EVACat)

• EMU committed to releasing XID catalogue to the community• VO-compatible• 6monthly releases

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Other issues

• Use ATLAS as a test for science we can do with EMU• Obtain a better calibration of radio luminosity to SFR conversion• Obtain a better understanding of the detailed physics behind the radio/IR

correlation (on which the radio luminosity/SFR conversion is based)• Develop a plan to get the crucial redshifts (combine deep well studied

fields with wide area ‘photometric’ redshifts)• Calculate how well we can obtain derived scientific results, like the star

formation history, for different surveys (e.g. 8deg2 ATLAS, 30deg2 of EMU with deep ancillary data, 400deg2 of EMU using shallow data, future SKA continuum surveys)

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Mean SED (normalised around 1.6um)

Probably should normalise by SFR

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

Radio v 24um flux

Note 24um excess sources

CSIRO. EMU Bologna Meeting, Nick Seymour, September 13th 2011

SFR v environment

Note redshift effects!

CSIRO. ATLAS Meeting, Nick Seymour, August 9th 2011

Radio v 24um flux

Note 24um excess sources

CSIRO. ATLAS Meeting, Nick Seymour, August 9th 2011

Flux ratios:

Radio/K-band and radio/24um

Seymour et al. (2008)