The ion-acoustic instability in a dusty negative ion plasma is investigated, focusing on the parameter regime in which the negative ion density is much larger than the electron density. The dynamics of the massive dust grains are neglected, but collisions of electrons and ions with dust grains in addition to other collisional processes are taken into account. The presence of a population of cha...

Simulations are reported to investigate solid superheating and liquid supercooling of two-dimensional systems with a Yukawa interparticle potential. Motivated by experiments where a dusty plasma is heated and then cooled suddenly, we track particle motion using a simulation with Langevin dynamics. Hysteresis is observed when the temperature is varied rapidly in a heating and cooling cycle. As i...

In this paper, we examine the combined effects of thermal radiation, buoyancy force and magnetic field on oscillatory flow of a conducting optically thin dusty fluid through a vertical channel filled with a saturated porous medium. The governing partial differential equations are obtained and solved analytically by variable separable method. Numerical results depicting the effects of various em...

We determined abundances of O, Ca, Fe, Ba and Y for a sample of dusty and dust-free A stars, taken from the list of Cheng et al. (1992). Five of the stars have an infrared-excess due to circumstellar dust. Ongoing accretion from their circumstellar surroundings might have modified the abundances in the photospheres of these stars, but our results clearly show, that there is no difference in the...

Order-disorder transitions take place in many physical systems, but observing them in detail in real materials is difficult. In two- or quasi-two-dimensional systems, the transition has been studied by computer simulations and experimentally in electron sheets, dusty plasmas, colloidal and other systems. Here I show the different stages of defect formation in the vortex lattice of a superconduc...

We present the discovery of strongly variable emission lines from a gaseous disc around the DA white dwarf SDSS J1617+1620, a star previously found to have an infrared excess indicative of a dusty debris disc formed by the tidal disruption of a rocky planetary body. Time series spectroscopy obtained during the period 2006–2014 has shown the appearance of strong double-peaked Ca II emission line...

We discuss recent advances in the study of dusty, massive galaxies at z > 1 arising from the first extensive spectroscopic surveys.

Recent far-infrared and submillimetre waveband observations revealed huge amount of Ultraluminous Infrared Galaxies (ULIGs) with infrared luminosities > 10 L⊙. These sources are proposed to lie at redshift above one, and normally interacting systems with very dusty environments. We discussed in a previous paper that a population of fast evolving infrared burst phase triggered by gas rich merger...

We have carried out a multiwavelength observational campaign demonstrating some of the remarkable properties of the infrared-bright variable star BP Psc. Surrounded by a compact dusty, gaseous disk, this little-studied late G (or early K) type star emits about 75% of its detected energy flux at infrared wavelengths. Evidence for accretion of gas in conjunction with narrow bipolar jets andHerbig...

I discuss Spitzer GO programs aimed at studying the mid-IR spectral properties of IR-luminous galaxies at high z. I present the IRS lowresolution, mid-IR spectra of a sample of 52 sources from our GO1 medium size program. We found that ∼ 75% of the sample are at z ∼ 1.5−2.6, with redshifts determined based on features including PAH emission and silicate absorption in the mid-IR spectra. This da...