A Medium-Resolution Search for Polarmetric Structure: Moderate Y Reddening Sightlines

Abstract

view Abstract Citations (69) References (28) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Medium-Resolution Search for Polarmetric Structure: Moderate Y Reddening Sightlines Wolff, Michael J. ; Nordsieck, Kenneth H. ; Nook, Mark A. Abstract Characterization of the interstellar polarization curve has made extensive use of broadband polarimetry measurements. Consequently, features or structure in the polarization curve of up to several hundred Angstroms in scale may exist undetected. Previous efforts to search for such structure have generally produced negative results. In an effort to investigate the report of polarimetric structure on a larger scale by Wolstencroft & Smith [MNRAS, 208, 461 (1984)], we present high signal-to-noise, multiepoch spectropolarimetric observations at the University of Wisconsin's Pine Bluff Observatory (PBO). Our sample, which consists of nine moderately reddened sightlines, is constructed to maximize the polarimetric signal-to-noise for a reasonably sized sample. We find the that there is no structure common to all sightlines down to a level of 1% of Pmax The individual sightlines show no convincing structure over the range 4000-7000 Å to a level of 4% of Pmax (to 2% for five of the sightlines). No evidence is seen for a polarimetric signature of very broadband structure (VBS), which implies that its carriers are at least two to four times less well aligned than the grains producing the continuum polarization. In addition, we find no corroboration for the claims of features (at or above the levels reported above) in the polarization curves of HD 36371, HD 149757, and HD 198478 by Wolstencroft and Smith. Publication: The Astronomical Journal Pub Date: February 1996 DOI: 10.1086/117833 Bibcode: 1996AJ....111..856W Keywords: EXTINCTION; DUST; POLARIZATION full text sources ADS | data products SIMBAD (19) MAST (1)