Zafar, T., Watson, D. J., Malesani, D., Vreeswijk, P. M., Fynbo, J. P. U., Hjorth, J. (Jens), Levan, A. J. and Michałowski, M. J.. (2010) No evidence for dust extinction in GRB 050904 at z ~ 6.3. Astronomy & Astrophysics, Vol.515 (No.A94). ISSN 0004-6361

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Abstract

Context. Gamma-ray burst (GRB) afterglows are excellent and sensitive probes of gas and dust in star-forming galaxies at all epochs. It has been posited that dust in the early Universe must be different from dust at lower redshifts. To date two reports in the literature directly support this contention, one of which is based on the spectral shape of the afterglow spectrum of GRB050904 at z = 6.295. Aims. Here we reinvestigate the afterglow of GRB050904 to understand cosmic dust at high redshift.We address the claimed evidence for unusual (supernova-origin) dust in its host galaxy by simultaneously examining the X-ray and optical/near-infrared spectrophotometric data of the afterglow. Methods. We derived the intrinsic spectral energy distribution (SED) of the afterglow at three different epochs, 0.47, 1.25, and 3.4 days after the burst. We reduced again the Swift X-ray data, the 1.25 days FORS2 z-Gunn photometric data, the spectroscopic and z-band photometric data at ∼3 days from the Subaru telescope, as well as the critical UKIRT Z-band photometry at 0.47 days, upon which the claim of dust detection largely relies. Results. We find no evidence of dust extinction in the SED at any time.We computed flux densities at λrest = 1250Å directly from the observed counts at all epochs. In the earliest epoch, 0.47 days, where the claim of dust is strongest, the Z-band suppression is found to be weaker (0.3 ± 0.2 mag) than previously reported and statistically insignificant (<1.5σ). Furthermore, we find that the photometry of this band is unstable and difficult to calibrate. Conclusions. From the afterglow SED we demonstrate that there is no evidence of dust extinction in GRB 050904 – the SED at all times can be reproduced without dust, and at 1.25 days in particular, significant extinction can be excluded, with A(3000Å) < 0.27 mag at 95% confidence using the supernova-type extinction curve. We conclude that there is no evidence of any extinction in the afterglow of GRB050904 and that the presence of supernova-origin dust in the host of GRB050904 must be viewed skeptically.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science > Physics
Library of Congress Subject Headings (LCSH):	Cosmic dust, Gamma ray bursts, Afterglow (Physics), Red shift, Spectral energy distribution
Journal or Publication Title:	Astronomy & Astrophysics
Publisher:	EDP Sciences
ISSN:	0004-6361
Date:	June 2010
Volume:	Vol.515
Number:	No.A94
Identification Number:	10.1051/0004-6361/200913795
Status:	Peer Reviewed
Access rights to Published version:	Open Access
Funder:	Danmarks Grundforskningsfond [Danish National Research Foundation]
References:	Baba, H., Yasuda, N., Ichikawa, S.-I., et al. 2002, in Astronomical Data Analysis Software and Systems XI, ed. D. A. Bohlender, D. Durand,&T. H. Handley, ASP. Conf. Ser., 281, 298 Beuermann, K., Hessman, F. V., Reinsch, K., et al. 1999, A&A, 352, L26 Bianchi, S., & Schneider, R. 2007, MNRAS, 378, 973 Blair, W. P., Ghavamian, P., Long, K. S., et al. 2007, ApJ, 662, 998 Burrows, D. N., Falcone, A., Chincarini, G., et al. 2007, Royal Soc. London Philos. Trans. Ser. A, 365, 1213 Butler, N. R., Li, W., Perley, D., et al. 2006, ApJ, 652, 1390 Campana, S., Lazzati, D., Ripamonti, E., et al. 2007, ApJ, 654, L17 Cardelli, J. A., Clayton, G. C., & Mathis, J. S. 1989, ApJ, 345, 245 Cummings, J., Angelini, L., Barthelmy, S., et al. 2005, GCN Cric., 3910 Cusumano, G., Mangano, V., Chincarini, G., et al. 2006, Nature, 440, 164 de Ugarte Postigo, A., Fatkhullin, T. A., Jóhannesson, G., et al. 2007, A&A, 462, L57 Diplas, A., & Savage, B. D. 1994, ApJ, 427, 274 Dutra, C. M., Ahumada, A. V., Clariá, J. J., Bica, E., & Barbuy, B. 2003, A&A, 408, 287 Dwek, E., Galliano, F., & Jones, A. P. 2007, ApJ, 662, 927 Elíasdóttir, Á., Fynbo, J. P. U., Hjorth, J., et al. 2009, ApJ, 697, 1725 Elmhamdi, A., Danziger, I. J., Chugai, N., et al. 2003, MNRAS, 338, 939 Foley, R. J., Perley, D. A., Pooley, D., et al. 2006, ApJ, 645, 450 Fontana, A., & Ballester, P. 1995, The Messenger, 80, 37 Fruchter, A., Krolik, J. H., & Rhoads, J. E. 2001, ApJ, 563, 597 Fukugita, M., Ichikawa, T., Gunn, J. E., et al. 1996, AJ, 111, 1748 Fynbo, J. P. U., Jakobsson, P., Prochaska, J. X., et al. 2009, ApJS, 185, 526 Galama, T. J., & Wijers, R. A. M. J. 2001, ApJ, 549, L209 Galama, T. J., Vreeswijk, P. M., van Paradijs, J., et al. 1998, Nature, 395, 670 Gehrz, R. 1989, in Interstellar Dust, ed. L. J. Allamandola, & A. G. G. M. Tielens, IAU Symp., 135, 445 Gendre, B., Corsi, A., & Piro, L. 2006, A&A, 455, 803 Gordon, K. D., Clayton, G. C., Misselt, K. A., Landolt, A. U., & Wolff, M. J. 2003, ApJ, 594, 279 Gou, L., Fox, D. B., & Mészáros, P. 2007, ApJ, 668, 1083 Greiner, J., Krühler, T., Fynbo, J. P. U., et al. 2009, ApJ, 693, 1610 Haislip, J. B., Nysewander, M. C., Reichart, D. E., et al. 2006, Nature, 440, 181 Hirashita, H., Nozawa, T., Kozasa, T., Ishii, T. T., & Takeuchi, T. T. 2005, MNRAS, 357, 1077 Hjorth, J., Møller, P., Gorosabel, J., et al. 2003a, ApJ, 597, 699 Hjorth, J., Sollerman, J., Møller, P., et al. 2003b, Nature, 423, 847 Iye, M., Karoji, H., Ando, H., et al. 2004, PASJ, 56, 381 Jensen, B. L., Fynbo, J. U., Gorosabel, J., et al. 2001, A&A, 370, 909 Kann, D. A., Klose, S., & Zeh, A. 2006, ApJ, 641, 993 Kann, D. A., Masetti, N., & Klose, S. 2007, AJ, 133, 1187 Kashikawa, N., Aoki, K., Asai, R., et al. 2002, PASJ, 54, 819 Kawai, N., Kosugi, G., Aoki, K., et al. 2006, Nature, 440, 184 Lamb, D. Q., & Reichart, D. E. 2000, ApJ, 536, 1 Maiolino, R., Schneider, R., Oliva, E., et al. 2004, Nature, 431, 533 Malesani, D., Tagliaferri, G., Chincarini, G., et al. 2004, ApJ, 609, L5 Marchenko, S. V. 2006, in Stellar Evolution at Low Metallicity: Mass Loss, Explosions, Cosmology, ed. H. J. G. L. M. Lamers, N. Langer, T. Nugis, & K. Annuk, ASP Conf. Ser., 353, 299 Meikle, W. P. S., Mattila, S., Gerardy, C. L., et al. 2006, ApJ, 649, 332 Michałowski, M. J., Watson, D., & Hjorth, J. 2010, ApJ, 712, 942 Morgan, H. L., & Edmunds, M. G. 2003, MNRAS, 343, 427 Nozawa, T., Kozasa, T., Umeda, H., Maeda, K., & Nomoto, K. 2003, ApJ, 598, 785 Pei, Y. C. 1992, ApJ, 395, 130 Perley, D. A., Bloom, J. S., Klein, C. R., et al. 2009, MNRAS, submitted, [arXiv:0912.2999] Perna, R., Lazzati, D., & Fiore, F. 2003, ApJ, 585, 775 Price, P. A., Cowie, L. L., Minezaki, T., et al. 2006, ApJ, 645, 851 Prochaska, J. X., Sheffer, Y., Perley, D. A., et al. 2009, ApJ, 691, L27 Sakon, I., Onaka, T.,Wada, T., et al. 2009, ApJ, 692, 546 Salvaterra, R., Della Valle, M., Campana, S., et al. 2009, Nature, 461, 1258 Schlegel, D. J., Finkbeiner, D. P., & Davis, M. 1998, ApJ, 500, 525 Skrutskie, M. F., Cutri, R. M., Stiening, R., et al. 2006, AJ, 131, 1163 Stanek, K. Z., Matheson, T., Garnavich, P. M., et al. 2003, ApJ, 591, L17 Stratta, G., Fiore, F., Antonelli, L. A., Piro, L., & De Pasquale, M. 2004, ApJ, 608, 846 Stratta, G., Maiolino, R., Fiore, F., & D’Elia, V. 2007, ApJ, 661, L9 Tagliaferri, G., Antonelli, L. A., Chincarini, G., et al. 2005, A&A, 443, L1 Tanvir, N. R., Fox, D. B., Levan, A. J., et al. 2009, Nature, 461, 1254 Todini, P., & Ferrara, A. 2001, MNRAS, 325, 726 Totani, T., Kawai, N., Kosugi, G., et al. 2006, PASJ, 58, 485 Valiante, R., Schneider, R., Bianchi, S., & Andersen, A. C. 2009, MNRAS, 397, 1661 Vreeswijk, P. M., Smette, A., Fruchter, A. S., et al. 2006, A&A, 447, 145 Watson, D., Fynbo, J. P. U., Ledoux, C., et al. 2006a, ApJ, 652, 1011 Watson, D., Reeves, J. N., Hjorth, J., et al. 2006b, ApJ, 637, L69 Wooden, D. H., Rank, D. M., Bregman, J. D., et al. 1993, ApJS, 88, 477
URI:	http://wrap.warwick.ac.uk/id/eprint/3417

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