This is about 6 years out of date - replacement coming soon...

Thermal dust as a CMBR foreground
The SFD98 dust map is also useful as a tracer of thermal (blackbody) emission from dust grains at frequencies above 100 GHz. In 1999, we published an emission model based on DIRBE column densities and temperatures for each line of sight, and constrained at long wavelengths with FIRAS. This should be a very useful dust template for CMBR anisotropy work. Data from MAT (140 GHz) and Viper (450 GHz) will soon be used to test these predictions.

Spinning dust as a CMBR foreground
Electric dipole emission from rapidly rotating dust grains is predicted to be a substantial component of ISM emission at frequencies from ~10-40 GHz (Draine and Lazarian 1998). We scanned a dozen dust filaments at 5-10 GHz using the Green Bank 140 foot telescope in June, 1999, and detected the predicted emission in one object. Using the MAT (30,40 GHz) data and other data sets we hope to pursue a more detailed analysis of spinning dust emission in the near future.

The cosmic infrared background
In the course of the above work, FIR backgrounds in excess of those expected from interplanetary dust and interstellar dust were found in the DIRBE data at 140 and 240 microns (SFD 1998). More recently, we have undertaken a much more thorough analysis of the DIRBE data and detected excess emission at 60 and 100 microns as well. If this emission is extragalactic in origin, then the implications are astounding: heavily enshrouded AGN would be the main energy source in the universe - not stellar fusion. Also, TeV gamma ray measurements would have to be reinterpreted. We are still in the process of contemplating this exciting result.

Tests of the SFD98 dust map
The SFD98 reddening map is already in wide use (150 citations as of Nov, 1999) but more accuracy checks need to be done. We have used the APM galaxy counts to test the SFD98 reddening map at high Galactic latitude, and hope to perform more detailed tests using counts and colors from DPOSS and SDSS. Also, we have 16 nights of data from CTIO to constrain the dust map in the southern hemisphere. Special attention will be paid to regions of unusual dust temperature, to verify that temperature variations have been handled properly.

Dust and starlight polarization
With Carl Heiles and Dick Treffers, I am observing small patches of sky with the automated telescope at Lick to measure optical light polarization on strategically chosen dust filaments. This probes both the Galactic magnetic field and the physical mechanism for dust filament formation.

K-band photometry of Tully-Fisher galaxies
In 1996, with David Schlegel (Princeton) and Lexi Moustakas (Oxford), I obtained K-band photometry for ~40 of the Tully-Fisher galaxies used in Schlegel's thesis. This work was done with the 40 inch Nickel telescope at Lick Observatory. pretty pictures