Paolo D’Avanzo (INAF-Osservatorio Astronomico di Brera); The afterglow and host galaxy of GRB 090205: evidence for a Ly-α emitter at z = 4.65 Paolo D’Avanzo (INAF-Osservatorio Astronomico di Brera); in collaboration with:

GRB 090205 No UVOT detection @ t-t0 = 92 s T90 = 8.8 ± 1.8 s 15-350 keV T90 = 8.8 ± 1.8 s Perri et al. 2009, GCN 8884 Cummings et al. 2009, GCN 8886 0.5-10 keV Perri et al. 2009, GCN 8884 Evans et al. 2009, GCN 8885 Perri & Stratta, 2009, GCN 8891 No UVOT detection @ t-t0 = 92 s Perri et al. 2009, GCN 8884 Landsman & Perri, 2009, GCN 8893

GRB 090205 t-t0 ~ 7 h RAB ~ 22.3; IAB ~ 20.8 F(t) t -α ; α ~ 1.4 (D’Avanzo et al. 2009;, GCN 8887) F(t) t -α ; α ~ 1.4

GRB 090205 t-t0 ~ 7 h RAB ~ 22.3; IAB ~ 20.8 F(t) t -α ; α ~ 1.4 (D’Avanzo et al. 2009;, GCN 8887) F(t) t -α ; α ~ 1.4 z =4.65 (Thoene et al. 2009, GCN 8889; Fugazza et al. 2009, GCN 8892)

GRB 090205 afterglow tb,1 tb,2 complex X-ray AG: brightening at ~T0+1000s and flaring activity α2 ГX,2 F(t) t -α α1 ~ 1.4; α2 ~ -1.7; α3 ~ 1.2; Time resolved X-ray spectroscopy: absorbed power-law with ГX,1~ ГX,2~ ГX,3~ 2.0 Galactic NH ~ 8 x 1020 cm-2 (no evidence for intrinsic absorbtion; NH < 3.5 x 1022 cm-2) α1 ГX,1 α3 ГX,3 X-ray and optical AG explained within the standard FS model with νc,νm < νopt and νX X-ray “brightnening” possibly due to energy injection into the FS by the engine

GRB 090205: classification T90,rf = 1.6s Lag(Ch2-Ch1): -15 +/- 867 ms Ch1 = 15-25 keV Ch2 = 25-50 keV Ch3 = 50-100 keV Ch4 = 100-350 keV Eγ,iso = (7.86 ± 1.21)x 1051 erg Ep,i = 192 ± 85 keV

GRB 090205: classification T90,rf = 1.6s Lag(Ch2-Ch1): -15 +/- 867 ms Ch1 = 15-25 keV Ch2 = 25-50 keV Ch3 = 50-100 keV Ch4 = 100-350 keV Eγ,iso = (7.86 ± 1.21)x 1051 erg Ep,i = 192 ± 85 keV (Antonelli et al. 2009) GRB 090205 Consistent with the Ep,i - Eγ,iso correlation (Amati et al. 2008)

GRB 090205: evidence for a LAE (I)

GRB 090205: evidence for a LAE (I) Lyman-α emission line

GRB 090205: evidence for a LAE (II) Lyman-α emission line 0.4” offset with respect to the continuum (3 kpc @ z=4.65) The same offset is found in imaging frames Ly-α emission from the host galaxy Farthest GRB host galaxy spectroscopically confirmed

GRB 090205 host galaxy τ < 150 Myr LLy-α ~ 0.6-0.7 L* SFR ~ 4.2 MSun/yr Z ≥ 0.27 ZSun τ < 150 Myr M* < 150 MSun

GRB 090205: conclusions D’Avanzo et al., A&A submitted optical afterglow and host galaxy discovery; redshift determination complex X-ray AG: brightening at ~T0+1000s and flaring activity rest frame short duration (1.6s), but likely long, of massive stellar collapse origin the host galaxy is a LAE @ z = 4.65 SFR ~ 4.2 MSun/yr young stellar population (< 150 Myr) high metallicity (Z ≥ 0.27 ZSun) farthest GRB HG spectroscopically confirmed GRBs as one of the most effective way, complementary to surveys, to study the high-z Universe D’Avanzo et al., A&A submitted