Naslov
Behind the dust curtain : the spectacular case of GRB 160623A

Autori
Pintore, F. ; Tiengo, A. ; Mereghetti, S. ; Vianello, G. ; Giuliani, A. ; Salvaterra, R. ; Esposito, P. ; Costantini, E. ; Bošnjak, Željka

Izvornik
Monthly notices of the Royal Astronomical Society (0035-8711) 472 (2017), 2; 1465-1472

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
scattering–gamma-ray burst ; individual ; GRB 160623A–dust ; extinction– galaxies ; haloes – X-rays ; bursts – X-rays: ISM

Sažetak
We report on the X-ray dust-scattering features observed around the afterglow of the gamma-ray burst GRB 160623A. With an XMM–Newton observation carried out ∼2 d after the burst, we found evidence of at least six rings, with angular size expanding between ∼2 and 9 arcmin, as expected for X-ray scattering of the prompt gamma-ray burst (GRB) emission by dust clouds in our Galaxy. From the expansion rate of the rings, we measured the distances of the dust layers with extraordinary precision: 528.1 ± 1.2, 679.2 ± 1.9, 789.0 ± 2.8, 952 ± 5, 1539 ± 20 and 5079 ± 64 pc. A spectral analysis of the ring spectra, based on an appropriate dust-scattering model (BARE-GR-B) and the estimated burst fluence, allowed us to derive the column density of the individual dust layers, which are in the range 7 × 10^20– 1.5 × 10^22 cm^−2. The farthest dust layer (i.e. the one responsible for the smallest ring) is also the one with the lowest column density and it is possibly very extended, indicating a diffuse dust region. The properties derived for the six dust layers (distance, thickness and optical depth) are generally in good agreement with independent information on the reddening along this line of sight and on the distribution of molecular and atomic gas.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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