Related papers: Silicon nanoparticles and interstellar extinction
By combining the photometric, spectroscopic, and astrometric information of the stars in the sightline of SNRs, the distances to and the extinctions of 32 Galactic supernova remnants (SNRs) are investigated. The stellar atmospheric…
In the framework of the silicate core-carbonaceous organic mantle interstellar dust model, the bulk of the visual/near-IR extinction and the entire polarization are from nonspherical and aligned core-mantle grains. The 3.4 micron C-H and…
We construct a quasar extinction curve based on the blue and red composite quasar spectra of Richards et al. (2003) prepared from the SDSS survey. This extinction curve does not show any traces of the 2200 A feature characteristic of the…
The nature of Galactic interstellar extinction is tested using reddening line parameters for several fields in conjunction with equivalent widths $W(\lambda4430)$ for the diffuse interstellar band at $4430$ \AA. The Cardelli et…
Bulk silicon carbide (SiC) is a very promising material system for bio-applications and quantum sensing. However, its optical activity lies beyond the near infrared spectral window for in-vivo imaging and fiber communications due to a large…
In this work, we report a new nanoscale phenomenon observed as photoemission intermittency (On-Off electron emission), manifested as stochastic bursts in electron yield at quasi-one-dimensional organic wires and silver nanoparticles…
We derive the extinction curve towards the Galactic Center from 1 to 19 micron. We use hydrogen emission lines of the minispiral observed by ISO-SWS and SINFONI. The extinction free flux reference is the 2 cm continuum emission observed by…
We present a new version of our analytical model of the spatial interstellar extinction variations within the nearest kiloparsec. This model treats the 3D dust distribution as a superposition of three overlapping layers: (1) the layer along…
We have studied the interstellar extinction in a field of ~3' x 3' at the core of the 30 Doradus nebula, including the central R136 cluster, in the Large Magellanic Cloud. Observations at optical and near-infrared wavelengths, obtained with…
It is generally agreed that interstellar dust grains consist of two main components, namely, silicates and graphites. Some models, like MRN model, assume these grains to be homogeneous spheres following a power law size distribution. This…
Infrared carbon stars without visible counterparts are generally known as extreme carbon stars. We have selected a subset of these stars with absorption features in the 10-13 $\mu$m range, which has been tentatively attributed to silicon…
The study of scattering and extinction properties of possible nanodiamond grains in the ISM are reported. Calculations using Discrete Dipole Approximation (DDA) for varying ellipsoidal shapes and sizes from 2.5 to $10 nm$ are considered.…
We present an extinction map of the inner $\sim$\SI{15}{\arcminute} by {16}{\arcminute} of the Galactic Center (GC) with map `pixels' measuring \SI{5}{\arcsecond} $\times$ \SI{5}{\arcsecond} using integrated light color measurements in the…
The Galactic bulge is one of the most information-dense regions to study resolved stellar populations, variables, and transients, such as microlensing events. Studies toward the Galactic bulge are complicated by the large and variable…
The composite grain is made up of a host silicate spheroid and graphite inclusions. The extinction efficiencies of the composite spheroidal grains for three axial ratios are computed using the discrete dipole approximation (DDA). The…
Magnitude-limited samples of spiral galaxies drawn from the Ursa Major and Pisces clusters are used to determine their extinction properties as a function of inclination. Imaging photometry is available for 87 spirals in B,R,I and K' bands.…
Extended Red Emission (ERE) was recently attributed to the photo-luminescence of either doubly ionized Polycyclic Aromatic Hydrocarbons (PAH$^{++}$), or charged PAH dimers. We analysed the visible and mid-infrared (mid-IR) dust emission in…
We have analyzed the 9.7 and ``18'' micron interstellar silicate absorption features along the line of sight toward four heavily extincted galactic WC-type Wolf-Rayet (WR) stars. We construct two interstellar extinction curves from 1.25 to…
Current data indicate that the reionization of the Universe was complete by redshift z~6-7, and while the sources responsible for this process have yet to be identified, star-forming galaxies are often considered the most likely candidates.…
The abundance of both amorphous and crystalline silicates in very small grains is limited by the fact that the 10 micron silicate emission feature is not detected in the diffuse ISM. On the basis of the observed IR emission spectrum for the…