Abstract
Supernovae have been confirmed to redshift z ≈ 1.7 (refs 1, 2) for type Ia (thermonuclear detonation of a white dwarf) and to z ≈ 0.7 (refs 1, 3–5) for type II (collapse of the core of the star). The subclass type IIn (ref. 6) supernovae are luminous7,8,9 core-collapse explosions of massive stars8,9,10,11 and, unlike other types, are very bright in the ultraviolet12,13,14,15, which should enable them to be found optically at redshifts z ≈ 2 and higher14,16. In addition, the interaction of the ejecta with circumstellar material creates strong, long-lived emission lines that allow spectroscopic confirmation of many events of this type at z ≈ 2 for 3–5 years after explosion (ref. 14). Here we report three spectroscopically confirmed type IIn supernovae, at redshifts z = 0.808, 2.013 and 2.357, detected in archival data using a method14 designed to exploit these properties at z ≈ 2. Type IIn supernovae directly probe the formation of massive stars at high redshift. The number found to date is consistent with the expectations of a locally measured17 stellar initial mass function, but not with an evolving initial mass function proposed18,19,20 to explain independent observations at low and high redshift.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Get just this article for as long as you need it
$39.95
Prices may be subject to local taxes which are calculated during checkout


References
Poznanski, D. et al. Supernovae in the Subaru deep field: an initial sample and type Ia rate out to redshift 1.6. Mon. Not. R. Astron. Soc. 382, 1169–1186 (2007)
Riess, A. G. et al. The farthest known supernova: support for an accelerating Universe and a glimpse of the epoch of deceleration. Astrophys. J. 560, 49–71 (2001)
Botticella, M. T. et al. Supernova rates from the Southern inTermediate Redshift ESO Supernova Search (STRESS). Astron. Astrophys. 479, 49–68 (2008)
Della Valle, M. et al. Hypernova signatures in the late rebrightening of GRB 050525A. Astrophys. J. 642, 103–106 (2006)
Soderberg, A. M. et al. An HST study of the supernovae accompanying GRB 040924 and GRB 041006. Astrophys. J. 636, 391–399 (2006)
Schlegel, E. M. A new subclass of type II supernovae? Mon. Not. R. Astron. Soc. 244, 269–271 (1990)
Richardson, D. et al. A comparative study of the absolute magnitude distributions of supernovae. Astron. J. 123, 745–752 (2002)
Smith, N. et al. SN 2006gy: discovery of the most luminous supernova ever recorded, powered by the death of an extremely massive star like η Carinae. Astrophys. J. 666, 1116–1128 (2007)
Smith, N. et al. SN 2006tf: precursor eruptions and the optically thick regime of extremely luminous type IIn supernovae. Astrophys. J. 686, 467–484 (2008)
Kotak, R. & Vink, J. S. Luminous blue variables as the progenitors of supernovae with quasiperiodic radio modulations. Astron. Astrophys. 460, 5–8 (2006)
Gal-Yam, A. et al. On the progenitor of SN 2005gl and the nature of type IIn supernovae. Astrophys. J. 656, 372–381 (2007)
Fransson, C. et al. Optical and ultraviolet spectroscopy of SN 1995N: evidence for strong circumstellar interaction. Astrophys. J. 572, 350–370 (2002)
Fransson, C. et al. Hubble Space Telescope and ground-based observations of SN 1993J and SN 1998S: CNO processing in the progenitors. Astrophys. J. 622, 991–1007 (2005)
Cooke, J. Detecting z > 2 type IIn supernovae. Astrophys. J. 677, 137–145 (2008)
Brown, P. et al. Ultraviolet light curves of supernovae with Swift UVOT. Preprint at 〈http://arXiv.org/abs/0803.1265〉 (2008)
Dahlén, T. & Fransson, C. Rates and redshift distributions of high-z supernovae. Astron. Astrophys. 350, 345–367 (1999)
Salpeter, E. E. The luminosity function and stellar evolution. Astrophys. J. 121, 161–167 (1955)
van Dokkum, P. G. Evidence of cosmic evolution of the stellar initial mass function. Astrophys. J. 674, 29–50 (2008)
Chary, R.-R. The stellar initial mass function at the epoch of reionization. Astrophys. J. 680, 32–40 (2008)
Davé, R. The galaxy stellar mass-star formation rate relation: evidence for an evolving initial mass function. Mon. Not. R. Astron. Soc. 385, 147–160 (2008)
Steidel, C. C. et al. Lyman break galaxies at redshift z ∼ 3: survey description and full data set. Astrophys. J. 592, 728–754 (2003)
Steidel, C. C. et al. A survey of star-forming galaxies in the 1.4 < z 2.5 redshift desert: overview. Astrophys. J. 604, 534–550 (2004)
Cooke, J. et al. Survey for galaxies associated with z ∼ 3 damped Ly-α systems. I. Spectroscopic calibration of u′BVRI photometric selection. Astrophys. J. 621, 596–614 (2005)
Le Fèvre, O. et al. Virmos-VLT deep survey (VVDS). Proc. SPIE 4834, 173–182 (2003)
Neill, J. D. et al. The type Ia supernova rate at z ≈ 0.5 from the supernova legacy survey. Astron. J. 132, 1126–1145 (2006)
Faber, S. M. et al. The DEIMOS spectrograph for the Keck II telescope: integration and testing. Proc. SPIE 4841, 1657–1669 (2003)
Oke, J. B. et al. The Keck low-resolution imaging spectrometer. Publ. Astron. Soc. Pacif. 107, 375–385 (1995)
McCarthy, J. K. et al. Blue channel of the Keck low-resolution imaging spectrometer. Proc. SPIE 3355, 81–91 (1998)
Riess, A. G. et al. Identification of type Ia supernovae at redshift 1.3 and beyond with the Advanced Camera for Surveys on the Hubble Space Telescope. Astrophys. J. 600, L163–L166 (2004)
Shapley, A. E. et al. Rest-frame ultraviolet spectra of z ∼ 3 Lyman break galaxies. Astrophys. J. 558, 65–89 (2003)
Acknowledgements
J.C. thanks D. Leonard for discussions. This work was made possible by support from the Gary McCue postdoctoral fellowship and the Center for Cosmology at the University of California, Irvine. We acknowledge support from NSERC and the Royal Society. The analysis pipeline used to reduce the DEIMOS data was developed at UC Berkeley with support from the NSF (grant AST-0071048). The CFHT-LS relies on observations with MegaCam, a joint project of CFHT and CEA/DAPNIA, at the CFHT. We used data products from the Canadian Astronomy Data Centre as part of the CFHT-LS. Both CFHT and the W. M. Keck Observatory are located near the summit of Mauna Kea, Hawai'i. We acknowledge the cultural role that the summit of Mauna Kea has within the indigenous Hawaiian community.
Author Contributions J.C. led the survey design, and performed observations, data reduction and analysis, candidate selection, and data interpretation. M.S. was responsible for the data reduction and analysis of the CFHT-LS yearly stacked images, the supernova light curves, interpretation and key discussions. E.J.B. performed observations and provided observing time, discussions, and input regarding survey design, data analysis and interpretation. J.S.B. provided observing time, performed observations, contributed discussions, and helped in manuscript preparation. R.G.C. was one of the proponents of the CFHT-LS and became the Canadian PI, assembling the team responsible for much of the real-time operation and analysis of the Supernova Legacy Survey. A.G.-Y. provided advice about the analysis and helped prepare the manuscript. E.T. performed spectroscopic observations for two of the z ≈ 2 supernovae.
Author information
Authors and Affiliations
Corresponding author
Supplementary information
Supplementary Information
This file contains Supplementary Data, Supplementary References, Supplementary Tables S1-S2 and Supplementary Figures S1- S3 with Legends. (PDF 1202 kb)
PowerPoint slides
Rights and permissions
About this article
Cite this article
Cooke, J., Sullivan, M., Barton, E. et al. Type IIn supernovae at redshift z ≈ 2 from archival data. Nature 460, 237–239 (2009). https://doi.org/10.1038/nature08082
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/nature08082
This article is cited by
-
Circumstellar Interaction in Supernovae in Dense Environments—An Observational Perspective
Space Science Reviews (2018)
-
Cosmic explosions in the young Universe
Nature (2012)
-
Superluminous supernovae at redshifts of 2.05 and 3.90
Nature (2012)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.