Volume 412, Number 1, December II 2003
|Page(s)||105 - 120|
|Section||Galactic structure, stellar clusters, and populations|
|Published online||25 November 2003|
Does transparent hidden matter generate optical scintillation?
Laboratoire de l'Accélérateur Linéaire, IN2P3-CNRS, Université de Paris-Sud, BP 34, 91898 Orsay Cedex, France
Corresponding author: email@example.com
Accepted: 4 September 2003
Stars twinkle because their light goes through the atmosphere. The same phenomenon is expected when the light of extra-galactic stars goes through a Galactic – disk or halo – refractive medium. Because of the large distances involved here, the length and time scales of the optical intensity fluctuations resulting from the wave distortions are accessible to current technology. In this paper, we discuss the different possible scintillation regimes and we focus on the so-called strong diffractive regime that is likely to produce large intensity contrasts. The critical relationship between the source angular size and the intensity contrast in optical wavelengths is also discussed in detail. We propose to monitor small extra-galactic stars every ~10 s to search for intensity scintillation produced by molecular hydrogen clouds. We discuss means to discriminate such hidden matter signals from the foreground effects on light propagation. Appropriate observation of the scintillation process described here should allow one to detect column density stochastic variations in Galactic molecular clouds of the order of ~, that is per ~ transverse distance.
Key words: cosmology: dark matter / Galaxy: disk / Galaxy: halo / ISM: clouds / ISM: molecules
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.