相关论文: Do cement nanoparticles exist in space ?

Astronomical infrared spectral features at ~6.6, 9.8 and 20 micronm have recently been suggested as being due to the planar graphene form of C24 carbon cluster. Here we report density functional theory and coupled cluster calculations on…

We interpret the interstellar extinction observed towards the Galactic Center (GC) in the wavelength range $\lambda = 1 - 20\,\mkm$. Its main feature is the flat extinction at $3 - 8\,\mkm$ whose explanation is still a problem for the…

Large dust grains in thermal equilibrium dominate the far-infrared and contribute to the millimetre continuum of star-forming galaxies, but constraining their properties is difficult due to free-free and synchrotron contamination. We study…

We combine HST/NICMOS imaging photometry of the HR 4796A disk at previously unobserved wavelengths between 1.71-2.22\micron with reprocessed archival observations to produce a measure of the dust's scattering efficiency as a function of…

An accurate estimate of the interstellar gas density distribution is crucial to understanding the interstellar medium (ISM) and Galactic cosmic rays (CRs). To comprehend the ISM and CRs in a local environment, a study of the diffuse…

We discuss the different dust components of a protoplanetary disk with a special emphasis on grain composition, size and structure. The paper will highlight the role dust grains play in protoplanetary disks, as well as observational results…

We present results from a mini-survey of dust spectral features arising in galaxies at redshifts $0.5 < z < 1.2$ in our James Webb Space Telescope (JWST) mid-infrared spectra of physically-unrelated background quasars. We analyze the JWST…

We use photometric and spectroscopic infrared observations obtained with the Spitzer Space Telescope of 12 radio-loud active galactic nuclei (AGN) to investigate the dust geometry. Our approach is to look at the change of the infrared…

While it is well recognized that interstellar grains are made of amorphous silicates and some form of carbonaceous materials, it remains debated regarding what exact chemical and physical form the carbonaceous component takes. Contemporary…

The incorporation of nanosilica in cementitious systems helps in accelerating the cement hydration process and early-stage formation of the main hydration product, that is, calcium silicate hydrate. Nanosilica reacts with the other key…

The Planck-HFI all-sky survey from 353 to 857GHz combined with the 100 microns IRAS show that the dust properties vary in the diffuse ISM at high Galactic latitude (1e19<NH<2.5e20 H/cm2). Our aim is to explain these variations with changes…

We present a new technique for determining the *quantity and composition* of dust in astrophysical environments using <6keV X-rays. We argue that high resolution X-ray spectra as enabled by the Chandra and XMM-Newton gratings should be…

Observational evidence seems to indicate that the depletion of interstellar carbon into dust shows rather wide variations and that carbon undergoes rather rapid recycling in the interstellar medium (ISM). Small hydrocarbon grains are…

We examine the possibility of using near-infrared scattering to constrain the local radiation field and the dust properties, for example, the size distribution of the grains, and maximum grain size. We use radiative transfer modelling to…

We discuss the composition and size distribution of the dust in the coma of comet Hale-Bopp. We do this by fitting simultaneously the infrared emission spectrum measured by the infrared space observatory (ISO) and the measured degree of…

The dynamical structure and infrared emission of winds around late-type stars are studied in a self-consistent model that couples the equations of motion and radiative transfer. Both the dynamics and IR spectrum of the solution are fully…

The approach to model composite interstellar dust grains, using the exact solution to the light scattering problem for multi-layered spheres as suggested by Voshchinnikov & Mathis (1999), is further developed. Heterogeneous scatteres are…

A wealth of data from the Herschel and Planck satellites and now from ALMA, revealing cold dust thermal emission, is available for astronomical environments ranging from interstellar clouds, cold clumps, circumstellar envelops, and…

Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant. Using low resolution Spitzer IRS spectra (5-35 $\mu$m), and broad-band…

New multi-epoch, mid-infrared (8-13 microns) spectrophotometric observations are presented for 30~late-type stars. The observations were collected over a four year period (1994-1997), permitting an investigation of the mid-infrared spectral…