Discovery of a Redshifted Iron K Line in the X-Ray Afterglow of GRB 000214
Author(s)
Antonelli, L. A.
Piro, L.
Vietri, M.
ASI Sponsor
Date Issued
2000-12-01
Abstract
We report the detection (3 sigma significance level) of a strong iron emission line in the X-ray
spectrum of the afterglow of GRB 000214 (Valentines Day Burst) observed by BeppoSAX . An
emission-line feature was observed with a centroid energy of 4.7 ± 0.2 keV, which, if interpreted as
Kalpha emission from hydrogen-like iron, corresponds to a redshift of z = 0.47. The intensity (EW 2
keV) and duration (tens of hours) of the line give information on the distance, from the burst
region, of the emitting material ( R ≥ 3 × 10 15 cm) and its mass ( M ≥ 1.4 M ☉ ). These results are
not easily reconciled with the binary merger and hypernova models for gamma-ray bursts because they
require large amounts of mass (about 1 M ☉ ) at large distances (≈10 16 cm) and at Newtonian speeds.
spectrum of the afterglow of GRB 000214 (Valentines Day Burst) observed by BeppoSAX . An
emission-line feature was observed with a centroid energy of 4.7 ± 0.2 keV, which, if interpreted as
Kalpha emission from hydrogen-like iron, corresponds to a redshift of z = 0.47. The intensity (EW 2
keV) and duration (tens of hours) of the line give information on the distance, from the burst
region, of the emitting material ( R ≥ 3 × 10 15 cm) and its mass ( M ≥ 1.4 M ☉ ). These results are
not easily reconciled with the binary merger and hypernova models for gamma-ray bursts because they
require large amounts of mass (about 1 M ☉ ) at large distances (≈10 16 cm) and at Newtonian speeds.
ISSN
0004637X
Journal
The Astrophysical Journal