2003/02/28 by M. Moniez · 1 citation
Physics and Astronomy · #Angular diameter #Astronomy #Astrophysics #Dark Matter and Cosmic Phenomena #Dark matter #Detector #Galaxy #Gamma-ray bursts and supernovae #Halo #Intensity (physics) #Optics #Physics #Scintillation #Stars #Stellar, planetary, and galactic studies #Wavelength #astro-ph
paper · pdf · doi:10.1051/0004-6361:20031478
published as Astron.Astrophys.412:105-120,2003 · 16 pages, 10 eps figures. Accepted for publication in A&A. Minor changes/additions : temporal coherence aspects; scintillation of a quasar in tables 1 (reorganized) and 4; further details on the Local Interstellar Medium
arxiv created 2003/09/22 · openalex publication_date 2003/11/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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.