Searching for galactic hidden gas through interstellar scintillation: the OSER project

Moniez, M ; Sharif University of Technology | 2008

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  1. Type of Document: Article
  2. DOI: 10.22323/1.064.0097
  3. Publisher: 2008
  4. Abstract:
  5. Considering the results of baryonic compact massive objects searches through microlensing [1], cool molecular hydrogen (H2 - He) clouds should now be seriously considered as a possible major component of the Galactic hidden matter. It has been suggested that a hierarchical structure of cold H 2 could fill the Galactic thick disk [8] or halo [3], providing a solution for the Galactic hidden matter problem. This gas should form transparent "clumpuscules" of ∼ 10 AU size, with a column density of 1024-25cm-2, and a surface filling factor smaller than 1%. The OSER project (Optical Scintillation by Extraterrestrial Refractors) is proposed to search for scintillation of extra-galactic sources through these Galactic - disk or halo - transparent H2 clouds. This project should allow one to detect (stochastic) transverse gradients of column density in cool Galactic molecular clouds of order of ∼ 3 × 10-5 g/cm2/ 10000km. We present the expectations from a complete simulation of the interstellar scintillation process. Test observations have been obtained through known nebulae to probe the concept in a controlled situation; we show preliminary results from their analysis
  6. Keywords:
  7. Column density ; Extra-galactic ; Filling factor ; Hierarchical structures ; Molecular clouds ; Molecular hydrogen ; Optical scintillation ; Scintillation process ; Galaxies ; Scintillation
  8. Source: Proceedings of Science, 18 August 2008 through 22 August 2008, Stockholm ; 2008 ; 18248039 (ISSN)
  9. URL: https://pos.sissa.it/064/097