Related papers: Effect of Dust Extinction on Gamma-ray Burst After…
A composite dust grain model which simultaneously explains the observed interstellar extinction, polarization, IR emission and the abundance constraints, is required. We present a composite grain model, which is made up of a host silicate…
Understanding variations in the dust extinction curve is imperative for using dust as a tracer of local structure in the interstellar medium, understanding dust chemistry, and observational color corrections where dust is a nuisance…
Dust properties within a galaxy are known to change from the diffuse medium to dense clouds due to increased local gas density. However, the question of whether dust properties change with redshift remains elusive. In this paper, using the…
The distance to the stars is a fundamental parameter, which is determined via two primary methods - parallax and luminosity. While the parallax is a direct trigonometric method, the luminosity distance is usually influenced by interstellar…
(Abridged) Until recently the information inferred from gamma-ray burst follow-up observations was mostly limited to optically bright afterglows, biasing all demographic studies against sight-lines that contain large amounts of dust. Here,…
We present the results of a systematic analysis of gamma-ray burst afterglow spectral energy distributions (SEDs) in the optical/near-infrared bands. Our input list includes the entire world sample of afterglows observed in the pre-Swift…
Fundamental properties of the extinction curve, like the slope in the rest-frame ultraviolet (UV) and the presence/absence of a broad absorption excess centred at 2175 A (the UV bump), are investigated for a sample of 108 massive,…
We report BVR surface photometry of a lenticular galaxy, NGC4753 with prominent dust lanes. We have used the multicolor broadband photometry to study dust-extinction as a function of wavelength and derived the extinction curve. We find the…
We show that the clumpy structure of star-forming regions can naturally explain the fact that 50-70% of GRB afterglows are optical``dark.'' We also show that dust echos from the GRB and its afterglow, produced by the clumpy structure of the…
A dust scattering model was recently proposed to explain the shallow X-ray decay (plateau) observed prevalently in Gamma-Ray Burst (GRB) early afterglows. In this model the plateau is the scattered prompt X-ray emission by the dust located…
Despite its small mass fraction typically observed in the interstellar medium, dust plays a significant role as a key component of galaxies, affecting a wide range of properties. This review focuses specifically on how dust grains influence…
The sizes of interstellar grains are widely distributed, ranging from a few angstroms to a few micrometers. The ultraviolet (UV) and optical extinction constrains the dust in the size range of a couple hundredth micrometers to several…
We present broadband observations and analysis of Swift gamma-ray burst (GRB) 120119A. Our early-time afterglow detections began under 15 s after the burst in the host frame (redshift z = 1.73), and they yield constraints on the burst…
Observations of gamma ray bursts (GRB) afterglows in different spectral bands provide a most valuable information about their nature, as well as about properties of surrounding medium. Powerful infrared afterglow was observed from the…
We present JHK surface photometry of 15 highly inclined, late-type (Sab-Sc) spirals and investigate the quantitative effects of dust extinction. Using the (J - H, H - K) two-color diagram, we compare the color changes along the minor axis…
Context: Thirteen years after the discovery of the first afterglows, the nature of dark gamma-ray bursts (GRB) still eludes explanation: while each ng-duration GRB typically has an X-ray afterglow, optical/NIR emission is only seen for…
The joint use of accurate near- and mid-infrared photometry from the 2MASS and WISE catalogues has allowed the variations of the extinction law and the dust grain size distribution in high Galactic latitudes (|b|>50) at distances up to 3…
We study the extinction properties of the composite dust grains, consisting of host silicate spheroids and graphite as inclusions, using discrete dipole approximation (DDA). We calculate the extinction cross sections of the composite grains…
Similar to the magnification of the galaxies' fluxes by gravitational lensing, the extinction of the fluxes by comic dust, whose existence is recently detected by Menard et al (2009), also modify the distribution of a flux-selected galaxy…
The afterglows of gamma-ray bursts (GRBs) have more soft X-ray absorption than expected from the foreground gas column in the Galaxy. While the redshift of the absorption can in general not be constrained from current X-ray observations, it…