Detection of Intergalactic HeII Absorption at Redshift 3.5
W. Zheng, K. Chiu, S. F. Anderson, D. P. Schneider, C. J. Hogan, D. G. York, S. Burles, J. V. Brinkmann
Abstract
The large number of quasars found in the Sloan Digital Sky Survey has allowed searches for elusive, clear lines of sight towards HeII Ly-alpha absorption, a sensitive probe of the intergalactic medium. The few known systems indicate that HeII reionization occurs at z>3. We report the detection of a HeII Ly-alpha absorption edge in a quasar spectrum at z=3.50, the most distant such feature found to date. The candidate quasar was selected from a z~3 sample in the SDSS spectroscopic quasar survey and confirmed as part of an HST/STIS SNAP survey. We discuss the general characteristics of the absorption feature, as well as the probability for discovery of additional such objects.
Create a lesson
Related papers
On binary pulsars and the force of gravity
Davor Palle
Tidal torques. A critical review of some techniques
Michael Efroimsky, James G. Williams
Dynamics of a Spherical Accretion Shock with Neutrino Heating and Alpha-Particle Recombination
Rodrigo Fernández, Christopher Thompson
Asymptotically FRW black holes
J. T. Firouzjaee, Reza Mansouri
Reaction of Accretion Disks to Abrupt Mass Loss During Binary Black Hole Merger
Sean M. O'Neill, M. Coleman Miller, Tamara Bogdanovic et al.
A Gamma-Ray Burst/Pulsar for Cosmic-Ray Positrons with a Dark Matter-like Spectrum
Kunihito Ioka