This thesis presents radio, IR and X-ray observations to determine the physical properties of dust in local, and extra-galactic environments. I show 1.4 and 5 GHz observations taken with the Very Large Array (VLA) and 250 GHz obtained with the Max-Planck millimeter bolometer (MAMBO) at the IRAM 30 m telescope, of optically luminous quasars at high (z ≥ 5) and medium (z ∼ 2) redshifts. For three of the ten high redshift sources I find that the (sub)mm flux densities for these three sources are much larger than their 1.4 GHz flux densities. The rapidly rising spectra into the (rest frame) far IR argue that the observed mm emission is likely thermal emission from warm dust, although more exotic possibilities cannot be precluded. The implied IR luminosities for these objects are between 10¹² and 10¹³ [special characters omitted]. If the dust is heated by star formation, the implied massive star formation rates are between 200 and 1000 [special characters omitted] year^-1.

Sixteen z∼ 2 sources were observed in a similar fashion, eight of these are bright at 250 or 350 GHz while the other half were not detected at mm wavelengths; the former QSOs were detected at 1.4 GHz, in most cases at high significance (S/N ≥ 7), but only three of the latter sources were detected at radio frequencies, and only at lower significance (S/N ∼ 3). The data are consistent with a correlation between the mm and radio fluxes indicating a physical connection between the mechanisms responsible for the radio and mm emission. However, this conclusion is based on data including many upper limits, and deeper data are clearly needed to verify this correlation. All eight mm detected QSOs are detected in the radio continuum, with radio flux densities consistent with the radio-to-FIR correlation for low z star forming galaxies. However, four of these have flatter spectral indices than is typical for star forming galaxies (i.e. greater than -0.5) suggesting that radiation from the central AGN dominates the observed radio emission. All the sources detected at 1.4 GHz are spatially unresolved, with the size limits typically < 1" = 6 kpc. High star formation rate galaxies at low redshift are typically nuclear starbursts, with sizes < 1 kpc. Hence, the current radio size limits are insufficient to constrain the emission model (AGN or starburst). An investigation of a sample of Mid-IR selected quasars suggests that the spectral energy distributions (SEDs) and star-formation properties of AGN detected on the basis of their broad-band MIR colors are well described by a clumpy torus model, as developed by Nenkova et al. (2002) and that the majority of our sources have similar FIR to radio properties as star-forming galaxies. X-ray studies complement well longer wavelength investigations. I present the results of a search for an intergalactic X-ray dust scattering halo in a deep observation of the bright, high-redshift quasar QSO 1508+5714 with the Chandra X-Ray Observatory. I do not detect such a halo. This result implies an upper limit on the density of diffuse, large-grained intergalactic dust of Omegad ≤< 2 × 10^-6, assuming a characteristic grain size of ∼ 1 μm. This work demonstrates the sensitivity of this technique for detecting very small amounts of intergalactic dust, which are very hard to detect otherwise. It allow us to put important constraints on systematic effects induced by extinction on the interpretation of the Hubble diagram for Type Ia supernovae, as well as on the amount and properties of cosmological dust being expelled into the intergalactic medium at early (z ≥ 2) times. I also show an investigation on the solid state properties of interstellar grains by attempting an X-ray Crystallography experiment on Interstellar dust. I was unable to determine any signatures for X-Ray absorption structure due to both the superposition in the ISM of different silicates types, and also structure in the response of the instruments which we have not yet fully characterized.