Related papers: The Dust cloud around the White Dwarf G 29-38. 2. …
The tori around active galactic nuclei (AGN) are potential formation sites for large amounts of dust, and they may help resolve the so-called dust budget crisis at high redshift. We investigate the dust composition in 53 of the 87 Palomar…
HD32297 is a young A-star (~30 Myr) 112 pc away with a bright edge-on debris disk that has been resolved in scattered light. We observed the HD32297 debris disk in the far-infrared and sub-millimeter with the Herschel Space Observatory PACS…
A number of metal-rich white dwarfs (WDs) are known to host compact, dense particle disks, which are thought to be responsible for metal pollution of these stars. In many such systems the inner radii of disks inferred from their spectra are…
We report a Spitzer/IRAC search for infrared excesses around white dwarfs, including 14 newly-observed targets and 16 unpublished archived stars. We find a substantial infrared excess around two warm white dwarfs --- J220934.84+122336.5 and…
Disks around very low-mass stars (VLMS) provide environments for the formation of Earth-like planets. Mid-infrared observations have revealed that these disks exhibit weak silicate features and strong hydrocarbon emissions. This study…
We present opacity sampling model atmospheres, synthetic spectra and colors for brown dwarfs and very low mass stars in two limiting case of dust grain formation: 1) inefficient gravitational settling i.e. the dust is distributed according…
The composition and properties of interstellar silicate dust are not well understood. In X-rays, interstellar dust can be studied in detail by making use of the fine structure features in the Si K-edge. The features in the Si K-edge offer a…
We present a search for debris discs amongst M-dwarf members of nearby, young (5-150 Myr) moving groups (MGs) using infrared (IR) photometry, primarily from the Wide Infrared Survey Explorer (WISE). A catalogue of 100 MG M-dwarfs that have…
Understanding the chemistry of the interstellar medium (ISM) is fundamental for the comprehension of the Galactic and stellar evolution. X-rays provide an excellent way to study the dust chemical composition and crystallinity along…
Debris disk detections around M dwarfs are rare, and so far no gas emission has been detected from an M dwarf debris disk. This makes the 45 Myr old M dwarf WISEJ080822.18-644357.3 a bit of a curiosity; it has a strong infrared excess at an…
We present a quantitative model for the infrared emission from dust in the diffuse interstellar medium. The model consists of a mixture of amorphous silicate grains and carbonaceous grains, each with a wide size distribution ranging from…
We present the Infrared Database of Extragalactic Observables from Spitzer (IDEOS), a homogeneous, publicly available, database of 77 fitted mid-infrared observables in the 5.4-36um range, comprising measurements for 3335 galaxies observed…
We describe Spitzer images of a sample of dwarf and low surface brightness galaxies, using the high sensitivity and spatial resolution to explore the morphologies of dust in these galaxies. For the starbursting dwarf UGC 10445, we present a…
Brown dwarf disks are excellent laboratories to test our understanding of disk physics in an extreme parameter regime. In this paper we investigate a sample of 29 well-characterized brown dwarfs and very low mass stars, for which Herschel…
Spitzer Space Telescope spectra reveal 10 micron silicate emission from circumstellar dust orbiting six externally-polluted white dwarfs. Micron-size glasses with an olivine stoichiometry can account for the distinctively broad wings that…
We examine the positions of substellar objects in mid-infrared color-magnitude and color-color diagrams to distinguish between cloudy and cloud-free atmospheres. Using Spitzer mid-infrared spectra of 113 M5-T9 ultracool dwarfs, we derive…
Although numerous white dwarf stars host dusty debris disks, the temperature distribution of these stars differs significantly from the white dwarf population as a whole. Dusty debris disks exist exclusively around white dwarfs cooler than…
Using the SDSS DR7 spectroscopic catalog, we searched the WISE AllWISE catalog to investigate the occurrence of warm dust, as inferred from IR excesses, around field M dwarfs (dMs). We developed SDSS/WISE color selection criteria to…
The dusty interstellar medium (ISM) of the Milky Way is distributed in a complex, cloudy structure. It is fundamental to the radiation balance within the Milky Way, provides a reaction surface to form complex molecules, and is the feedstock…
Mid-infrared spectra of planet-forming discs commonly show prominent silicate emission, whose spectral shape is sensitive to the disc temperature distribution as well as its mineralogical composition. We report new James Webb Space…