Related papers: The Dust cloud around the White Dwarf G 29-38. 2. …
We present a compositional analysis of the 10 micron silicate spectra for brown dwarf disks in the Taurus and Upper Scorpius (UppSco) star-forming regions, using archival Spitzer/IRS observations. A variety in the silicate features is…
We present low-resolution mid-infrared spectra of nine classical T Tauri stars associated with the Chamaeleon I dark cloud. The data were obtained with the PHOT-S instrument on-board the Infrared Space Observatory (ISO) in the two…
We study the far-infrared emission from the nearby spiral galaxy M33 in order to investigate the dust physical properties such as the temperature and the luminosity density across the galaxy. Taking advantage of the unique wavelength…
The depletion of iron and sulphur into dust in the interstellar medium and the exact nature of interstellar amorphous silicate grains is still an open question. We study the incorporation of iron and sulphur into amorphous silicates of…
Infrared excess is an important probe of sub-stellar companions and/or debris disks around white dwarfs (WDs). Such systems are still rare for in-depth understanding of their formation and long-term evolution. One of the largest…
We are modeling the spectra of dwarf galaxies from infrared to submillimeter wavelengths to understand the nature of the various dust components in low-metallicity environments, which may be comparable to the ISM of galaxies in their early…
(ABRIDGED) Studies of debris disks have shown that most systems are analogous to the Edgeworth-Kuiper Belt. However a rare subset of sun-like stars possess dust which lies in the terrestrial planet region. In this study we aim to determine…
We report the discovery of four rare debris disks with warm excesses around F-stars, significantly increasing the number of such systems known in the solar neighborhood. Three of the disks are consistent with the predictions of steady state…
We present mid-infrared spectro-imaging (5 - 16 microns) observations of the infrared luminous interacting system Arp 299 (=Mrk171 =IC694+NGC3690) obtained with the ISOCAM instrument aboard ISO. Our observations show that nearly 40% of the…
The inwards scattering of planetesimals towards white dwarfs is expected to be a stochastic process with variability on human time-scales. The planetesimals tidally disrupt at the Roche radius, producing dusty debris detectable as excess…
We have compiled the $\sim$4-400 GHz broad spectra of 32 Class II protoplanetary disks in the Taurus-Auriga region, which represents the brightest one-third of sources detected in the submillimeter band in this region. The spectra at >20…
We present near-infrared spectroscopic observations of 20 previously known DAZ white dwarfs obtained at the NASA Infrared Telescope Facility. Two of these white dwarfs (G29-38 and GD362) are known to display significant K-band excesses due…
The infrared dust emission from the white dwarf GD 56 is found to rise and fall by 20% peak-to-peak over 11.2 yr, and is consistent with ongoing dust production and depletion. It is hypothesized that the dust is produced via collisions…
Warped discs have been found on (sub-)parsec scale in some nearby Seyfert nuclei, identified by their maser emission. Using dust radiative transfer simulations we explore their observational signatures in the infrared in order to find out…
Infrared (IR) excess emission around white dwarfs (WDs) is commonly attributed to circumstellar debris disks and/or low-mass companions, providing a unique window into the evolution of planetary systems and binary evolution after the…
Recent interferometric surveys of nearby main-sequence stars show a faint but significant near-infrared excess in roughly two dozen systems, i.$\,$e. around $10\,\%$ to $30\,\%$ of stars surveyed. This excess is attributed to dust located…
An accurate knowledge of the mineralogy (chemical composition and crystal structure) of the silicate dust in the interstellar medium (ISM) is crucial for understanding its origin in evolved stars, the physical and chemical processing in the…
Transitional disks around the Herbig Ae/Be stars are fascinating targets in the contexts of disk evolution and also planet formation. Oph IRS 48 is one of such Herbig Ae stars, which shows an inner dust cavity and azimuthally lopsided large…
Interplanetary dust (IPD) is thought to be recently supplied from asteroids and comets. Grain properties of the IPD can give us the information about the environment in the proto-solar system, and can be traced from the shapes of silicate…
We present the first Spitzer Infrared Spectrograph (IRS; The IRS was a collaborative venture between Cornell University and Ball Aerospace Corporation funded by NASA through the Jet Propulsion Laboratory and the Ames Research Center.)…