Scattering and absorption properties at optical and ultraviolet wavelengths are calculated for an interstellar dust model consisting of carbonaceous grains and amorphous silicate grains. Polarization as a function of scattering angle is calculated for selected wavelengths from the infrared to the vacuum ultraviolet. The widely-used Henyey-Greenstein phase function provides a good approximation ...

In an attempt to assess the physical realism of the plage flux tube model derived by Bellot Rubio, Ruiz Cobo & Collados (1997, 1998) we extend its predictions to the Stokes V zero-crossing shifts of a number of Fe ii lines. For this analysis, accurate Fe ii central wavelengths are required. We have devised a procedure for bringing the available Fe ii laboratory wavelengths to the system of accu...

High resolution VLA observations of the Arches cluster near the Galactic center show evidence of continuum emission at λ3.6, 6, 20 and 90cm. The continuum emission at λ90cm is particularly striking because thermal sources generally become optically thick at longer wavelengths and fall off in brightness whereas non-thermal sources increase in brightness. It is argued that the radio emission from...

We present critical, long-wavelength observations of η Carinae in the submillimetre using SCUBA on the JCMT at 850 and 450 μm to confirm the presence of a large mass of warm dust around the central star. We fit a two-component blackbody to the IR-submm spectral energy distribution (SED) and estimate between 0.3− 0.7 M⊙ of dust exists in the nebula depending on the dust absorption properties and...

The absolute photoelectron quantum yield spectra for benzo[a]pyrene and dimethylbenzanthracene are presented in the wavelength range 180--230 nm. These polycyclic aromatic carcinogens have photoelectron quantum yields of approximately 2 x 10(-3) electrons per incident photon at 180 nm. The quantum yields fall off quickly and monotonically at wavelengths longer than 210 nm (5.9 eV). Threshold va...

We investigated vapor bubbles generated upon irradiation of gold nanoparticles with nanosecond laser pulses. Bubble formation was studied both with optical and acoustic means on supported single gold nanoparticles and single nanoparticles in suspension. Formation thresholds determined at different wavelengths indicate a bubble formation efficiency increasing with the irradiation wavelength. Vap...