Lensing by Lyman-limit systems

• Verfasst von: Maller, Ariyeh H. [VerfasserIn]
• Verfasst von: Bartelmann, Matthias [VerfasserIn]
• Titel: Lensing by Lyman-limit systems
• Titelzusatz: determining the mass-to-gas ratio
• Verf.angabe: Ariyeh H. Maller and Tsafrir S. Kolatt, Matthias Bartelmann and George R. Blumentha
• Umfang: 11 S.
• Fussnoten: Gesehen am 27.09.2017
• Titel Quelle: Enthalten in: The astrophysical journal / 1
• Jahr Quelle: 2002
• Band/Heft Quelle: 569(2002), 1, S. 72-82
• ISSN Quelle: 1538-4357
• DOI: doi:10.1086/339262
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1563846802

Abstract

We present a new method for determining the total mass-to-neutral gas ratio ##IMG## [http://ej.iop.org/icons/Entities/Upsi.gif] Upsilon H I in Lyman-limit absorption systems. The method exploits the relation between the neutral hydrogen column density and the magnification of background sources due to weak gravitational lensing by these systems. Since weak lensing does not measure the mass directly, this relation must be inverted in a statistical sense to solve for the average ##IMG## [http://ej.iop.org/icons/Entities/Upsi.gif] Upsilon H I and its distribution. We demonstrate the feasibility of this approach by using a detailed mock catalog of quasars (sources) and Lyman-limit systems (lenses) and by showing our ability to recover the parameter ##IMG## [http://ej.iop.org/icons/Entities/Upsi.gif] Upsilon H I . This mock catalog also allows us to check for systematics in the method and to sketch its limitations. For a universal constant ##IMG## [http://ej.iop.org/icons/Entities/Upsi.gif] Upsilon H I and a sample of n QSO quasars, we obtain an unbiased estimate of ##IMG## [http://ej.iop.org/icons/Entities/Upsi.gif] Upsilon H I with 95% confidence levels of ±140(10 5 / n QSO ) 1/2 , where the error bars are independent of ##IMG## [http://ej.iop.org/icons/Entities/Upsi.gif] Upsilon H I .