Related papers: A polycrystalline graphite model for the 2175 Angs…
Graphene, a single infinite, planar, sheet of graphite, has the same dielectric resonances as bulk graphite, but solid state theory indicates that its features are about half as wide. Based on this theory, the dielectric functions of mono-…
Constraints on the possible shape and clustering, as well as optical properties, of grains responsible for the 2175 angstrom interstellar extinction feature (interstellar UV bump) are discussed. These constraints are based on the…
The most striking characteristics of the mysterious 2175 Angstrom extinction bump, the strongest spectroscopic absorption feature seen on the interstellar extinction curve, are the invariant central wavelength and variable bandwidth: its…
The exact nature of the 2175 Angstrom extinction bump, the strongest spectroscopic absorption feature superimposed on the interstellar extinction curve, remains unknown ever since its discovery in 1965. Popular candidate carriers for the…
The broad absorption bump at 2175 angstrom due to dust, which is ubiquitous in the Galaxy and is seen in the Magellanic clouds, is also seen in a composite spectrum of Mg II absorbers. The composite absorber spectrum is obtained by taking…
How dust scatters and absorbs starlight in the interstellar medium (ISM) contains important clues about the size and composition of interstellar dust. While the ultraviolet (UV) and visible interstellar extinction is well studied and can be…
The diffuse interstellar bands (DIBs) are ubiquitous absorption spectral features arising from the tenuous material in the space between stars -- the interstellar medium (ISM). Since their first detection nearly nine decades ago, over 400…
Space Telescope Imaging Spectrograph (STIS) and archival International Ultraviolet Explorer (IUE) data were used to search for structure in the ultraviolet interstellar extinction curve. Between 1250 and 3200 A, in addition to the…
Although interstellar grains are known to be aspherical, their actual shapes remain poorly constrained. We assess whether three continuous distributions of ellipsoidal shapes from the literature are suitable for describing the shapes of…
Observations of interstellar extinction and polarization indicate that the interstellar medium consists of aligned non-spherical dust grains which show variation in the interstellar extinction curve for wavelengths ranging from NIR to UV.…
The aim of the paper is to give a physical explanation of the absence of the feature in the Calzetti extinction curve. We analyze the dust attenuation of a homogeneous source seen through a distant inhomogeneous distant screen. The…
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…
A large number of interstellar absorption features at ~ 4000\AA\ -- 1.8 {\mu}m, known as the "diffuse interstellar bands" (DIBs), remains unidentified. Most recent works relate them to large polycyclic aromatic hydrocarbon (PAH) molecules…
Spinning small silicate grains were recently invoked to account for the Galactic foreground anomalous microwave emission. These grains, if present, will absorb starlight in the far ultraviolet (UV). There is also renewed interest in…
The UV bump is a broad absorption feature centered at 2175{\AA} that is seen in the attenuation/extinction curve of some galaxies, but its origin is not well known. Here, we use a sample of 86 star-forming galaxies at z=1.7-2.7 with deep…
The recent spectacular progress in the experimental and theoretical understanding of graphene, the basic constituent of graphite, is applied here to compute, from first principles, the UV extinction of nano-particles made of stacks of…
The carrier of the 2175 Angstrom interstellar extinction feature remains unidentified since its first detection over 40 years ago. In recent years carbon buckyonions have been proposed as a carrier of this feature, based on the close…
Context. As revealed by high-resolution spectral investigations in the wavelength range between 300 and 400 nm, the interstellar extinction curve does not display any of the sharp electronic absorption bands that are characteristic for…
A solid-state feature was detected at around 2175 cm-1 towards 30 embedded young stellar objects in spectra obtained using the ESO VLT-ISAAC. We present results from laboratory studies of CO adsorbed at the surface of Zeolite wafers, where…
Any distortion of a chemical structure causes new features to appear in the absorption spectrum of the structure, especially in the visible and near UV (see Paper I). Chemical modeling, using molecular orbital theory, showed that the…