Modeling Extragalactic Extinction through Gamma-Ray Burst Afterglows
Journal
Date Issued
2016
Author(s)
Abstract
We analyze extragalactic extinction profiles derived through gamma-ray burst afterglows, using a dust model specifically constructed on the assumption that dust grains are not immutable but respond, time-dependently, to the local physics. Such a model includes core-mantle spherical particles of mixed chemical composition (silicate core, sp2, and sp3 carbonaceous layers), and an additional molecular component in the form of free-flying polycyclic aromatic hydrocarbons. We fit most of the observed extinction profiles. Failures occur for lines of sight, presenting remarkable rises blueward of the bump. We find a tendency for the carbon chemical structure to become more aliphatic with the galactic activity, and to some extent with increasing redshifts. Moreover, the contribution of the molecular component to the total extinction is more important in younger objects. The results of the fitting procedure (either successes and failures) may be naturally interpreted through an evolutionary prescription based on the carbon cycle in the interstellar medium of galaxies.
Volume
829
Issue
1
Start page
22
Issn Identifier
0004-637X
Ads BibCode
2016ApJ...829...22Z
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
Zonca_2016_ApJ_829_22.pdf
Size
378.4 KB
Format
Adobe PDF
Checksum (MD5)
71d2e1cfae338162f46d8cfc00979df7