Population III detected at last?

[Garth]

Is the identification of a GRB with a 'hyper-nova' at z = 6.295 when the universe was 900 Myrs old (standard model) the first detection of the long awaited Population III stars that caused the 'first light'?Ancient blast comes to light

That article speaks of a mass of 20M_Solar, but I don't know whether that is a determined or 'guessitmated' value.

Garth

 

[wolram]

Is the identification of a GRB with a 'hyper-nova' at z = 6.295 when the universe was 900 Myrs old (standard model) the first detection of the long awaited Population III stars that caused the 'first light'?Ancient blast comes to light

That article speaks of a mass of 20M_Solar, but I don't know whether that is a determined or 'guessitmated' value.

Garth

An observation that should be viewed with utmost caustion, until some
confirmation is forthcomming.

 

[matt.o]

as should any observation at z=6.295!

 

[Garth]

Cusumano, G. et al. Nature 440, 164 (2006).
Kawai, N. et al. Nature 440, 184–186 (2006).

Letter
Nature 440, 184-186 (9 March 2006) | doi:10.1038/nature04498

An optical spectrum of the afterglow of a -ray burst at a redshift of z = 6.295
N. Kawai1, G. Kosugi2, K. Aoki3, T. Yamada2, T. Totani4, K. Ohta4, M. Iye2, T. Hattori3, W. Aoki2, H. Furusawa3, K. Hurley5, K. S. Kawabata6, N. Kobayashi7, Y. Komiyama3, Y. Mizumoto2, K. Nomoto8, J. Noumaru3, R. Ogasawara2, R. Sato1, K. Sekiguchi3, Y. Shirasaki2, M. Suzuki9, T. Takata2, T. Tamagawa9, H. Terada3, J. Watanabe2, Y. Yatsu1 and A. Yoshida10

The prompt -ray emission from \gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe1, 2, 3, 4. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 Å due to Lyman absorption at z 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.

Haislip, J. B. et al. Nature 440, 181–183 (2006).

Letter
Nature 440, 181-183 (9 March 2006) | doi:10.1038/nature04552

A photometric redshift of z = 6.39 0.12 for GRB 050904
J. B. Haislip1, M. C. Nysewander1, D. E. Reichart1, A. Levan2, N. Tanvir2, S. B. Cenko3, D. B. Fox4, P. A. Price5, A. J. Castro-Tirado6, J. Gorosabel6, C. R. Evans1, E. Figueredo7,8, C. L. MacLeod1, J. R. Kirschbrown1, M. Jelinek6, S. Guziy6, A. de Ugarte Postigo6, E. S. Cypriano8,9, A. LaCluyze1, J. Graham10, R. Priddey2, R. Chapman2, J. Rhoads11, A. S. Fruchter11, D. Q. Lamb12, C. Kouveliotou13, R. A. M. J. Wijers14, M. B. Bayliss1,12, B. P. Schmidt15, A. M. Soderberg3, S. R. Kulkarni3, F. A. Harrison16, D. S. Moon3, A. Gal-Yam3, M. M. Kasliwal3, R. Hudec17, S. Vitek18, P. Kubanek19, J. A. Crain1, A. C. Foster1, J. C. Clemens1, J. W. Bartelme1, R. Canterna20, D. H. Hartmann21, A. A. Henden22, S. Klose23, H.-S. Park24, G. G. Williams25, E. Rol26, P. O'Brien26, D. Bersier27, F. Prada6, S. Pizarro8, D. Maturana8, P. Ugarte8, A. Alvarez8, A. J. M. Fernandez6, M. J. Jarvis28, M. Moles6, E. Alfaro6, K. M. Ivarsen1, N. D. Kumar1, C. E. Mack1, C. M. Zdarowicz1, N. Gehrels29, S. Barthelmy29 and D. N. Burrows4

Gamma-ray bursts (GRBs) and their afterglows are the most brilliant transient events in the Universe. Both the bursts themselves and their afterglows have been predicted to be visible out to redshifts of z ~ 20, and therefore to be powerful probes of the early Universe1, 2. The burst GRB 000131, at z = 4.50, was hitherto the most distant such event identified3. Here we report the discovery of the bright near-infrared afterglow of GRB 050904 (ref. 4). From our measurements of the near-infrared afterglow, and our failure to detect the optical afterglow, we determine the photometric redshift of the burst to be (refs 5–7). Subsequently, it was measured8 spectroscopically to be z = 6.29 +/- 0.01, in agreement with our photometric estimate. These results demonstrate that GRBs can be used to trace the star formation, metallicity, and reionization histories of the early Universe.

Hmm. Quite a lot of collaboration and three independent observations.

Garth

 

[Chronos]

The metal enriched environment thing makes me doubt the examples given are pop III stars. A cart before the horse thing.

 

[Garth]

The metal enriched environment thing makes me doubt the examples given are pop III stars. A cart before the horse thing.

Well, z = 6.295 would be a late PopIII star, formed in an already metal rich environment, even then metals would have been produced by the star itself during its own lifetime.

The suggestion, put as a question, that this early super/hyper-nova should be identified with a PopIII star is actually mine, made in the title of this thread.

Garth