Related papers: Silicate Extinction Profile Based on the Stellar S…

We investigate the occurrence of crystalline silicates in oxygen-rich evolved stars across a range of metallicities and mass-loss rates. It has been suggested that the crystalline silicate feature strength increases with increasing…

A precise measure of the mid-infrared interstellar extinction law is crucial to the investigation of the properties of interstellar dust, especially of the grains in the large size end. Based on the stellar parameters derived from the…

Depletion studies provide a way to understand the chemical composition of interstellar dust grains. We here examine 23 gamma-ray bursts (GRB) optical afterglow spectra (spanning 0.6<z<5.0) and compare their silicon and iron dust-phase…

We present an analysis of archival Spitzer InfraRed Spectrograph (IRS) observations of the recurrent nova RS Ophiuchi obtained on several occasions, beginning about 7 months after the outburst in 2006. These data show atomic emission lines,…

The purpose of the investigation is to probe the dust properties inside a molecular cloud, how particle grow and how the presence of ice coatings may change the overall shape of the extinction curve. Field stars can be used to probe the…

We present evidence of a >10-sigma detection of the 10 micron silicate dust absorption feature in the spectrum of the gravitationally lensed quasar PKS 1830-211, produced by a foreground absorption system at redshift 0.886. We have examined…

We report the detection and successful modeling of the unusual 9.7\mum Si--O stretching silicate emission feature in the type 1 (i.e. face-on) LINER nucleus of M81. Using the Infrared Spectrograph (IRS) instrument on Spitzer, we determine…

Recent ground-based mid-infrared spectra of 29 late-type stars, most with substantial dust shells, are compared to ground-based spectra of these stars from the 1960s and 1970s and to IRAS-LRS spectra obtained in 1983. The spectra of about…

Infrared spectra of a number of evolved O-rich stars have been obtained with the Short- and Long- Wavelength spectrometers on board the Infrared Space Observatory. The very broad wavelength coverage (2.4-197 micron) obtained by combining…

Using \emph{Spitzer} Infrared Spectrograph observations of G0--M4 III stars behind dark clouds, I construct $5-20\mu$m empirical extinction curves for $0.3\leq A_K<7$, which is equivalent to $A_V$ between $\approx$ 3 and 50. For $A_K<1$ the…

Silicates are an important component of interstellar dust and the structure of these grains -- amorphous versus crystalline -- is sensitive to the local physical conditions. We have studied the infrared spectra of a sample of ultra-luminous…

For decades ever since the early detection in the 1990s of the emission spectral features of crystalline silicates in oxygen-rich evolved stars, there is a long-standing debate on whether the crystallinity of the silicate dust correlates…

The dust extinction curve is a critical component of many observational programs and an important diagnostic of the physics of the interstellar medium. Here we present new measurements of the dust extinction curve and its variation towards…

We present a sample of low-resolution 5-38um Spitzer IRS spectra of the inner few square kiloparsecs of 59 nearby galaxies spanning a large range of star formation properties. A robust method for decomposing mid-infrared galaxy spectra is…

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.)…

We determine the mid-infrared (MIR, $\sim$5~\mu m--22~\mu m) extinction towards the Galactic center using MIRI/MRS integral field unit (IFU) observations of the central $3''\times3''$ region (near 5~\mu m) to $7''\times7''$ region (near…

This is the first paper in a series of three where we present the first comprehensive inventory of solid state emission bands observed in a sample of 17 oxygen-rich circumstellar dust shells surrounding evolved stars. The data were taken…

We present polarisation spectra of seven stars in the lines-of-sight towards the Sco OB1 association. Our spectra were obtained within the framework of the Large Interstellar Polarization Survey carried out with the FORS instrument of the…

Infrared ~5--35 um spectra for 40 solar-mass T Tauri stars and 7 intermediate-mass Herbig Ae stars with circumstellar disks were obtained using the Spitzer Space Telescope as part of the c2d IRS survey. This work complements prior…

Modern data of the extinction curve from the ultraviolet to the near infrared are revisited to study the property of dust grains in the Milky Way (MW) and the Small Magellanic Cloud (SMC). We confirm that the graphite-silicate mixture of…