| | |
| | |
Stat |
Members: 3645 Articles: 2'506'133 Articles rated: 2609
27 April 2024 |
|
| | | |
|
Article overview
| |
|
Probing GRB environments with time variability: ULTRASPEC fast imaging of GRB 080210 | A. De Cia
; P. Jakobsson
; G. Björnsson
; P. M. Vreeswijk
; V. S. Dhillon
; T. R. Marsh
; R. Chapman
; J. P. U. Fynbo
; C. Ledoux
; S. P. Littlefair
; D. Malesani
; S. Schulze
; A. Smette
; T. Zafar
; E. H. Gudmundsson
; | Date: |
18 Nov 2010 | Abstract: | We present high time resolution (1.09 s) photometry of GRB 080210 obtained
with ULTRASPEC mounted on the ESO/3.6-m telescope, starting 68.22 min after the
burst and lasting for 26.45 min. The light curve is smooth on both short (down
to 2.18 s) and long time scales, confirmed by a featureless power spectrum. On
top of the fireball power-law decay, bumps and wiggles at different time scales
can, in principle, be produced by density fluctuations in the circumburst
medium, substructures in the jet or by refreshed shocks. Comparing our
constraints with variability limits derived from kinematic arguments, we
exclude under-density fluctuations producing flux dips larger than 1 per cent
with time scales Deltat > 9.2 min (2 per cent on Deltat > 2.3 min for many
fluctuating regions). In addition, we study the afterglow VLT/FORS2 spectrum,
the optical-to-X-ray spectral energy distribution (SED) and the time decay. The
SED is best fit with a broken power law with slopes {eta}opt = 0.71 pm 0.01
and {eta}X = 1.59 pm 0.07, in disagreement with the fireball model,
suggesting a non-standard afterglow for GRB 080210. We find AV = 0.18 pm 0.03
mag optical extinction due to SMC-like dust and an excess X-ray absorption of
log (NH/cm-2) = 21.58 +0.18 -0.26 assuming Solar abundances. The spectral
analysis reveals a damped Ly{alpha} absorber (log (NH I /cm-2) = 21.90 pm
0.10) with a low metallicity ([X/H] = -1.21 pm 0.16), likely associated with
the interstellar medium of the GRB host galaxy (z = 2.641). | Source: | arXiv, 1011.4239 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |