NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Reionization of the Universe and the Photoevaporation of Cosmological MinihalosThe first sources of ionizing radiation to condense out of the dark and neutral Intergalactic Medium (IGM) sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and photoevaporating them. This feedback effect of universal reionization on cosmic structure formation is demonstrated here for the case of a cosmological minihalo of dark matter and baryons exposed to an external source of ionizing radiation with a quasar-like spectrum, just after the passage of the global ionization front created by the source. We model the pre-ionization minihalo as a truncated, nonsingular isothermal sphere in hydrostatic equilibrium following its collapse out of the expanding background universe and virialization. Results are presented of the first, gas dynamical simulations of this process, including radiative transfer. A sample of observational diagnostics is also presented, including the spatially-varying ionization levels of C, N, and O in the flow if a trace of heavy elements is present and the integrated column densities of H I, He I and He II, and C IV through the photoevaporating gas at different velocities, which would be measured in absorption against a background source like that responsible for the ionization.
Document ID
20000090662
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Shapiro, Paul R.
(Texas Univ. Austin, TX United States)
Raga, Alejandro C.
(Universidad Nacional Autonoma de Mexico Mexico City, Mexico)
Date Acquired
August 19, 2013
Publication Date
May 1, 2000
Publication Information
Publication: Astrophysical Plasmas: Codes, Models, and Observations
Volume: 9
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: NSF ASC-95-04046
CONTRACT_GRANT: TARP-3658-0624-1999
CONTRACT_GRANT: NAG5-7821
CONTRACT_GRANT: NAG5-7363
CONTRACT_GRANT: NAG5-2785
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available