D'Arcangelo, F. D., Marscher, A. P., Jorstad, S. G., Smith, P. S., Larionov, V. M., Hagen-Thorn, V. A., Kopatskaya, E. N., Williams, G. G., Gear, W. K. 2007 Rapid Multiwaveband Polarization Variability in the Quasar PKS 0420-014 ApJ 659, L107 (Extragalactic) Smith, P. S., Williams, G. G., Schmidt, G. D., Diamond-Stanic, A. M., Means, D. L. 2007 Highly Polarized Optically Selected BL Lacertae Objects ApJ 663, 118 (Extragalactic) Jorstad, S. G., Marscher, A. P., Stevens, J. A., Smith, P. S., Forster, J. R., Gear, W. K., Cawthorne, T. V., Lister, M. L., Stirling, A. M., Gomez, J. L., Greaves, L. S., Robson, E. I. 2007 Multiwaveband Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Correlated Polarization Behavior AJ 134, 799 (Extragalactic) Banerjee, D. P. K., Misselt, K. A., Su, K. Y. L., Ashok, N. M., Smith, P. S. 2007 Spitzer Observations of V4332 Sagittarii: Detection of Alumina Dust ApJ 666, L25 (Stellar/Galactic) Schmidt, G. D., Smith, P. S., Hines, D. C., Tremonti, C. A., Low, F. J. 2007 Multiple Scattered Sight Lines to the Red QSO 2MASX J10494334+5837501 ApJ 666, 784 (Extragalactic) Shi, Y., Ogle, P., Rieke, G. H., Antonucci, R., Hines, D. C., Smith, P. S., Low, F. J., Bouwman, J., Willmer, C. 2007 Aromatic Features in AGNs: Star-forming Infrared Luminosity Function of AGN Host Galaxies ApJ 669, 841 (Extragalactic) Holman, M., Gredel, R., Milne, P., Bouche, N., Buschkamp, P., Smith, P., Grazian, A., Trilling, D. E. 2007 Minor Planet Observations Minor Planet Circular 61425, 1 (Solar System)
P.S. Smith, C.W. Engelbracht, along with several members of the University of Arizona's Spitzer/MIPS instrument team and the Spitzer Science Center have completed the calibration of the Spectral Energy Distribution (SED) observing mode of the Multi-band Imaging Photometer for Spitzer. This observing capability provides very low-resolution spectroscopy from 53-99 microns suitable for determining the IR continuum shape of targets observed by the Spitzer Space Telescope. (Instrumentation) P.S. Smith, F.J. Low, and D.C. Hines (SSI) are continuing their investigation into the properties of QSOs selected by their red near-IR colors from the Two-Micron All Sky Survey (2MASS) and the optically selected QSOs of the Palomar-Green (PG) survey. This study makes use of data from the Chandra X-Ray Observatory, Hubble Space Telescope ultraviolet data, ground-based optical, 2MASS, and Spitzer Space Telescope IR photometry and spectroscopy. The Spitzer observations include photometry at 25, 70, and 160 microns for all objects. (Extragalactic) P.S. Smith, and G.G. Williams (MMTO), along with an international collaboration led by A. Marscher (Boston U.) have reported instances of correlated optical-radio polarization variations in two blazars. In the highly polarized quasar, PKS 0420-014, the optical polarization position angle rotated by a large amount over a 12-day period and this rotation was also seen in the VLBI radio core. This behavior implies that the polarized flux in both wavelength regimes is produced in the same region of the relativistic jet. In addition, unprecedented optical and VLBI monitoring of BL Lacertae during the same period has isolated the highly variable polarized flux from a radio component in a region where it is believed to be accelerating outward from the central engine (not detected in radio images) and the first shock front in the jet flow (coincident with radio "core"). The smooth rotation of the optical polarization position angle suggests a toroidal magnetic field that collimates the jet and accelerates the plasma away from its point of origin very close to the supermassive black hole. Details can be found in an April 24, 2008 issue of Nature. (Extragalactic) P.S. Smith, G.D. Schmidt, and G.G. Williams (MMTO) continue their long-term polarization survey of BL Lacertae candidates selected spectroscopically from the Sloan Digital Sky Survey. Preliminary results were published with the help of A.M. Diamond-Stanic and D.L. Means and showed that a majority of the candidates are highly polarized at optical wavelengths. The polarization sample now includes over 100 objects and clearly shows the subsamples in the SDSS that are polarized and those that are not (i.e., objects not likely to be BL Lac objects). (Extragalactic)