A PHOTOMETRIC REDSHIFT OF z {approx} 9.4 FOR GRB 090429B

Journal Article · Wed Jul 20 00:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/736/1/7· OSTI ID:21578361

Cucchiara, A; Fox, D B; Wu, X F; Toma, K ^[1]; Levan, A J ^[2]; Tanvir, N R; Rowlinson, A ^[3]; Ukwatta, T N ^[4]; Berger, E ^[5]; Kruehler, T; Greiner, J; Olivares, F E ^[6]; Yoldas, A Kuepcue ^[7]; Amati, L ^[8]; Sakamoto, T ^[9]; Roth, K; Stephens, A; Fritz, Alexander ^[10]; Fynbo, J P. U.; Hjorth, J ^[11]

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1. Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States)
2. Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom)
3. Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom)
4. Department of Physics, The George Washington University, Washington, DC 20052 (United States)
5. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
6. Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstr. 1, 85740 Garching (Germany)
7. European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching (Germany)
8. INAF-IASF Bologna, via P. Gobetti 101, 40129 Bologna (Italy)
9. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
10. Gemini Observatory, 670 North A'ohoku Place, Hilo, HI 96720 (United States)
11. Dark Cosmology Centre, Niels Bohr Institute, Copenhagen University, Juliane Maries Vej 30, 2100 Copenhagen Oe (Denmark)

Gamma-ray bursts (GRBs) serve as powerful probes of the early universe, with their luminous afterglows revealing the locations and physical properties of star-forming galaxies at the highest redshifts, and potentially locating first-generation (Population III) stars. Since GRB afterglows have intrinsically very simple spectra, they allow robust redshifts from low signal-to-noise spectroscopy, or photometry. Here we present a photometric redshift of z {approx} 9.4 for the Swift detected GRB 090429B based on deep observations with Gemini-North, the Very Large Telescope, and the GRB Optical and Near-infrared Detector. Assuming a Small Magellanic Cloud dust law (which has been found in a majority of GRB sight lines), the 90% likelihood range for the redshift is 9.06 < z < 9.52, although there is a low-probability tail toward somewhat lower redshifts. Adopting Milky Way or Large Magellanic Cloud dust laws leads to very similar conclusions, while a Maiolino law does allow somewhat lower redshift solutions, though in all cases the most likely redshift is found to be z > 7. The non-detection of the host galaxy to deep limits (Y(AB) {approx} 28, which would correspond roughly to 0.001L* at z = 1) in our late-time optical and infrared observations with the Hubble Space Telescope strongly supports the extreme-redshift origin of GRB 090429B, since we would expect to have detected any low-z galaxy, even if it were highly dusty. Finally, the energetics of GRB 090429B are comparable to those of other GRBs and suggest that its progenitor is not greatly different from those of lower redshift bursts.

• OSTI ID: 21578361
• Journal Information: Astrophysical Journal, Vol. 736, Issue 1; Other Information: DOI: 10.1088/0004-637X/736/1/7; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AFTERGLOW
COSMIC GAMMA BURSTS
DUSTS
MAGELLANIC CLOUDS
MILKY WAY
PHOTOMETRY
RED SHIFT
COSMIC RADIATION
GALAXIES
IONIZING RADIATIONS
PRIMARY COSMIC RADIATION
RADIATIONS