A Direct Upper Limit on the Density of Cosmological Dust from the Absence of an X-ray Scattering Halo around the z=4.3 QSO 1508+5714

Abstract

We report on the results of a search for an intergalactic X-ray dust scattering halo in a deep observation of the bright, high-redshift quasar QSO 1508+5714 with the Chandra X-ray Observatory. We do not detect such a halo. Our result implies an upper limit on the density of diffuse, large-grained intergalactic dust of Omega_ dust < 2 x 10^-6, assuming a characteristic grain size of 1micron. The result demonstrates the sensitivity of this technique for detecting very small amounts of intergalactic dust which are very hard to detect otherwise. This will allow us to put important constraints on systematic effects induced by extinction on the interpretation of the SN Ia Hubble Diagram, as well as on the amount and properties of cosmological dust being expelled into the intergalactic medium at early z~2 times.

14 pages, 2 figures. to appear in ApJ, vol. 651, Nov. 2006

Cited by in corpus (4)

• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• X-ray Scattering Echoes and Ghost Halos from the Intergalactic Medium: Relation to the nature of AGN variability
• Cosmological nanolensing by dense gas clouds