Jeff Cooke

ARC Future Fellow - Centre for Astrophysics & Supercomputing,
Swinburne University of Technology, PO Box 218, Mail number H30, Hawthorn, VIC 3122 Australia
office: +61 3 9214 5392 -- fax: +61 3 9214 8797 -- email:

AR 315

Detection of high-redshift super-luminous supernovae: Pair-instability supernovae and the first stars

Using my technique to detect supernovae in very high redshift (z > 2) Lyman break galaxies (Cooke 2008), I recently discovered two events (Cooke et al. 2012) belonging to a rare class of supernovae that are 10 - 100 times more luminous than 'normal' supernovae and are termed 'super-luminous supernovae'. Moreover, our two super-luminous supernovae exhibit light curves that exhibit the behavior of a long-theorized third type of supernova explosion termed pair-instability supernovae. One event potentially from this class was found at low redshift (z = 0.129). The two super-luminous supernovae that we have found are at z = 2.05 and z = 3.90, where the latter is by far the highest redshift supernova known, probing nearly 12 billion years into the past and only 1.5 billion years after the Big Bang.

The stars that end their lives as pair-instability supernovae have 150 - 250 times the mass of the Sun. Such massive stars are believed to have been more common in the early Universe when the environment had a lower metallicity and when the only cooling agents for clouds of gas and was hydrogen and hydrogenic molecules. The first generation of stars to form out of the pristine gas clouds created by the Big Bang are termed Population III stars. Thoery predicts that regions of pristine gas existed as late as 2 - 3 billion years after the Big Bang, or at redshifts as low as z ~ 2. Two such clouds of pristine gas have been found at z ~ 3. Thus, using our supernova detection technique, we are able to detect supernovae out to z ~ 4 and, for the first time, overlap with the distances in which we would expect to see the deaths of some of the very first stars to have formed.

After analyzing the host galaxies and environments of our two high redshift super-luminous supernovae, it's not likely that they are the deaths of Population III stars. However, we will continue to search for Population III supernovae in new surveys based on my supernova detection technique that are now underway. We should be able to detect supernovae to z ~ 6, even farther back in time when the deaths of Population III stars were more prevalent.

Click here to access the ADS link displaying a list of articles describing this work and other research of mine.



Simulation of a super-luminous supernova exploding in a galaxy in the early Universe. The galaxies in this image were generated by a high-resolution cosmological simulation (credit: Marie Martig, Swinburne University). This snapshot was taken at z ~ 3, at an equivalent cosmological time representative of the galaxies in which we are detecting the supernovae. Galaxies are undergoing radical formation and their environments can be chaotic as seen in the image. The super-luminous supernova event can outshine an entire galaxy as seen in this impression (credit: Adrian Malec, Swinburne University).

Light curve for super-luminous supernova SN2213-1745 at z = 2.05. These events emit an enormous amount of energy (>10^53 ergs in ultraviolet light alone!). The light in this plot extends over a year and a half in the obsever's frame of reference. The gap in data near the middle of the plot is the time of the year (approximately 6 months) when the field in which this supernova resides is not visible in the sky.

The Hubble Space Telescope

The Milky Way can be seen, as well as two of our closest companion galaxies, the Large and Small Magellenic Clouds, in this long-exposure image of the 4 meter telescope at the CTIO located in the Southern Hemisphere (Chile).
  Astronomy 110
Physics 20A  
  Physics 7D
Curriculum Vitae
  Astro Grad Seminar
Centre for Astrophysics & Supercomputing
  Caltech Astronomy Department
Center for Cosmology
UC Irvine
  Center for Astrophysics and Space Sciences
UC San Diego
W. M. Keck Observatory  
  Palomar Observatory