HR: 11:00h
AN: SH12A-03    [Abstracts]
TI: Millimeter-Interferometer Observations of Oscillations in the Solar Chromosphere
AU: * White, S M
EM: white@astro.umd.edu
AF: Department of Astronomy, University of Maryland, College Park, MD 20742 United States
AU: Loukitcheva, M
AF: Astronomical Institute, St Petersburg University, St Petersburg, 198504 Russian Federation
AU: Loukitcheva, M
AF: MPIS, Max-Planck-Institut fuer Sonnensystemforschung, Katlenburg-Lindau, D-37191 Germany
AU: Solanki, S K
AF: MPIS, Max-Planck-Institut fuer Sonnensystemforschung, Katlenburg-Lindau, D-37191 Germany
AB: The use of millimeter-interferometer data for the study of chromospheric structure and dynamics is tested using 85 GHz observations with the 10-element Berkeley-Illinois-Maryland Array (BIMA). Interferometer data have the advantage over single-dish data that they allow both high spatial resolution and dense temporal sampling simultaneously. However, snapshot imaging of the quiet solar atmosphere with a small number of dishes is challenging. We demonstrate that techniques are available to carry out this task successfully. We compare observations of quiet Sun, active region and coronal hole targets using images with 10 arcsec resolution at 15 second cadence. The brightest features in the images are typically 1500 K above the background level, with a snapshot noise level of order 100 K. We use extensive tests to determine whether oscillation power can be recovered from sequences of snapshot images and show that they can down to quite weak levels. Intensity oscillations with significant power in the frequency range 1.5-8.0 mHz are found in the quiet-Sun and active region targets. For the quiet-Sun region we use the spatially-resolved time series to investigate the properties of network boundaries and cell interiors (internetwork) separately. In agreement with investigations at other wavelengths, the millimeter data show that power in the network tends to be at periods of 5 minutes and longer while power in the internetwork is present also at shorter (3-minute) periods.
DE: 7507 Chromosphere
DE: 7534 Radio emissions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly