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Evidence For The Supernova-Synthesized Dust From The Rising Afterglow Of Grb071025 At Z ∼ 5, Daniel A. Perley, J. S. Bloom, C. R. Klein, S. Covino, T. Minezaki, P. Wozniak, W. T. Vestrand, G. G. Williams, P. Milne, N R. Butler, A C. Updike, T Kruhler, P Afonso, A Antonelli, L Cowie, P Ferrero, J Greiner, Dieter H. Hartmann, Y Kakazu, A Küpcü Yoldaş, A N. Morgan, P A. Price, J X. Prochaska, Y Yoshii
Evidence For The Supernova-Synthesized Dust From The Rising Afterglow Of Grb071025 At Z ∼ 5, Daniel A. Perley, J. S. Bloom, C. R. Klein, S. Covino, T. Minezaki, P. Wozniak, W. T. Vestrand, G. G. Williams, P. Milne, N R. Butler, A C. Updike, T Kruhler, P Afonso, A Antonelli, L Cowie, P Ferrero, J Greiner, Dieter H. Hartmann, Y Kakazu, A Küpcü Yoldaş, A N. Morgan, P A. Price, J X. Prochaska, Y Yoshii
Publications
We present observations and analysis of the broad-band afterglow of Swift GRB 071025. Using optical and infrared (RIYJHK) photometry, we derive a photometric redshift of 4.4 < 5.2; at this redshift our simultaneous multicolour observations begin at ∼30 s after the gamma-ray burst trigger in the host frame, during the initial rising phase of the afterglow. We associate the light-curve peak at ∼580 s in the observer frame with the formation of the forward shock, giving an estimate of the initial Lorentz factor 0 ∼ 200. The red spectral energy distribution (even in regions not affected by the Lyman α break) provides secure evidence of a large dust column. However, the inferred extinction curve shows a prominent flat component between 2000 and 3000 Å in the rest frame, inconsistent with any locally observed template but well fitted by models of dust formed by supernovae. Time-dependent fits to the extinction profile reveal no evidence of dust destruction and limit the decrease in the extinction column to A3000 < 0.54 mag after t = 50 s in the rest frame. Together with studies of high-z quasars, our observations suggest a transition in dust properties in the early Universe, possibly associated with a transition between supernova-dominated and asymptotic giant branch-dominated modes of dust production.
Early-Time Chromatic Variations In The Wind-Swept Medium Of Grb 021211 And The Faintness Of Its Afterglow, M. C. Nysewander, D. E. Reichart, H.-S. Park, G. G. Williams, K. Kinugasa, D. Q. Lamb, A. A. Henden, S. Klose, T. Kato, A Harper, H Yamaoka, C Laws, K Torii, D G. York, J C. Barentine, J Dembicky, R J. Mcmillan, J A. Moran, Dieter H. Hartmann, B Ketzeback, M B. Bayliss, J A. Crain, A C. Foster, M Schwartz, P Holvorcem, P A. Price, R Canterna, G B. Crew, G R. Ricker, S D. Barthelmy
Early-Time Chromatic Variations In The Wind-Swept Medium Of Grb 021211 And The Faintness Of Its Afterglow, M. C. Nysewander, D. E. Reichart, H.-S. Park, G. G. Williams, K. Kinugasa, D. Q. Lamb, A. A. Henden, S. Klose, T. Kato, A Harper, H Yamaoka, C Laws, K Torii, D G. York, J C. Barentine, J Dembicky, R J. Mcmillan, J A. Moran, Dieter H. Hartmann, B Ketzeback, M B. Bayliss, J A. Crain, A C. Foster, M Schwartz, P Holvorcem, P A. Price, R Canterna, G B. Crew, G R. Ricker, S D. Barthelmy
Publications
We present Follow-Up Network for Gamma-Ray Bursts (FUN GRB) Collaboration observations of the optical afterglow of GRB 021211 made between 143 s and 102 days after the burst. Our unique data set includes the earliest filtered detections and color information for an afterglow in the pre-Swift era. We find that the afterglow is best described by (1) a propagation through a wind-swept medium, (2) a cooling break that is blueward of the observed optical frequencies, and (3) a hard electron energy distribution. However, superimposed on this ‘‘standard model’’ behavior we find, one and possibly two, significant chromatic variations during the …
Supernova Reverse Shocks: Sic Growth And Isotopic Composition, Ethan A-N. Deneault, Donald D. Clayton, Alexander Heger
Supernova Reverse Shocks: Sic Growth And Isotopic Composition, Ethan A-N. Deneault, Donald D. Clayton, Alexander Heger
Publications
We present new mechanisms by which the isotopic compositions of X-type grains of presolar SiC are altered by reverse shocks in Type II supernovae. We address three epochs of reverse shocks: pressure wave from the H envelope near t ¼ 106 s, reverse shock from the presupernova wind near 108–109 s, and reverse shock from the interstellar medium near 1010 s. Using one-dimensional hydrodynamics we show that the first creates a dense shell of Si and C atoms near 106 s in which the SiC surely condenses. The second reverse shock causes precondensed grains to move rapidly forward through decelerated …
A Search For Optical Afterglow From Grb 970828, P. J. Groot, T. J. Galama, J. Van Paradijs, C. Kouveliotou, R. A. M. J. Wijers, J. Bloom, N. Tanvir, R. Vanderspek, J. Greiner, A. J. Castro-Tirado, J. Gorosabel, T. Von Hippel, M. Lehnert, K. Kuijken, H. Hoekstra, N. Metcalfe, C. Howk, C. Conselice, J. Telting, R. G. M. Rutten, J. Rhoads, A. Cole, D. J. Pisano, R. Naber, R. Schwarz
A Search For Optical Afterglow From Grb 970828, P. J. Groot, T. J. Galama, J. Van Paradijs, C. Kouveliotou, R. A. M. J. Wijers, J. Bloom, N. Tanvir, R. Vanderspek, J. Greiner, A. J. Castro-Tirado, J. Gorosabel, T. Von Hippel, M. Lehnert, K. Kuijken, H. Hoekstra, N. Metcalfe, C. Howk, C. Conselice, J. Telting, R. G. M. Rutten, J. Rhoads, A. Cole, D. J. Pisano, R. Naber, R. Schwarz
Publications
We report on the results of R-band observations of the error box of the g-ray burst of 1997 August 28 made between 4 hr and 8 days after this burst occurred. No counterpart was found varying by more than 0.2 mag down to R 5 23.8. We discuss the consequences of this nondetection for relativistic blast wave models of g-ray bursts and the possible effect of redshift on the relation between optical absorption and the low-energy cutoff in the X-ray afterglow spectrum.
Sic Particles From Asymptotic Giant Branch Stars: Mg Burning And The S-Process, Lawrence E. Brown, Donald D. Clayton
Sic Particles From Asymptotic Giant Branch Stars: Mg Burning And The S-Process, Lawrence E. Brown, Donald D. Clayton
Publications
The question of whether isotopically anomalous SiC particles found in meteorites originate in AGB stars is addressed. It is shown that if the peak helium shell flash temperatures of massive (6-9 solar masses) stars are about 10 percent larger than they are normally assumed to be, alpha particle reactions with the magnesium will become significant. Then the (Mg-29)(alpha, n)Si-29 reaction produces a large excess of Si-29. With a light element nuclear reaction network, the evolution of the silicon isotopic composition during AGB evolution is calculated. It is found that the experimentally determined correlation between excess Si-29 and excess Si-30 in …