Astronomy and Astrophysics – Astronomy
Scientific paper
Feb 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010apj...710..648l&link_type=abstract
The Astrophysical Journal, Volume 710, Issue 1, pp. 648-662 (2010).
Astronomy and Astrophysics
Astronomy
4
Dust, Extinction, Gamma Rays: General
Scientific paper
The quantities and wavelength dependencies of the dust extinction along the lines of sight toward 33 nearby gamma-ray bursts (GRBs) with redshifts z < 2 are derived from fitting their afterglow spectral energy distributions. Unlike previous studies which often assume a specific extinction law like that of the Milky Way (MW) and the Large and Small Magellanic Clouds (LMC/SMC), our approach—we call it the "Drude" approach—is more flexible in determining the true wavelength dependence of the extinction (while the shape of the extinction curve inferred from that relying on a priori assumption of a template extinction law is, of course, fixed). The extinction curves deduced from the Drude approach display a wide diversity of shapes, ranging from relatively flat curves to curves which are featureless and steeply rise toward the far-ultraviolet, and from curves just like that of the MW, LMC, and SMC to curves resembling that of the MW and LMC but lacking the 2175 Å bump. The visual extinction AV derived from the Drude approach is generally larger by a factor of ~2-5 than that inferred by assuming a SMC-type template extinction law. Consistent with previous studies, the extinction-to-gas ratio is mostly smaller than that of the MW, and does not seem to correlate with the shape of the extinction curve. It is shown that the standard silicate-graphite interstellar grain model closely reproduces the extinction curves of all 33 GRBs host galaxies. For these 33 bursts at z < 2, we find no evidence for the evolution of the dust extinction, dust sizes, and relative abundances of silicate to graphite on redshifts.
Li Aigen
Liang Shun-Lin
No associations
LandOfFree
Probing Extragalactic Dust through Nearby Gamma-ray Burst Afterglows does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Probing Extragalactic Dust through Nearby Gamma-ray Burst Afterglows, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Probing Extragalactic Dust through Nearby Gamma-ray Burst Afterglows will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1309552