On the Detectability of the Hydrogen 3-cm Fine Structure Line from the EoR

Details On the Detectability of the Hydrogen 3-cm Fine Structure Line from the EoR On the Detectability of the Hydrogen 3-cm Fine Structure Line from the EoR

2008-09-24

arxiv.org/abs/0809.4279v2

Astronomy and Astrophysics

Astrophysics

7 pages, 4 figures, MNRAS in press; v2. some typos fixed

Scientific paper

10.1111/j.1365-2966.2008.13680.x

A soft ultraviolet radiation field, 10.2 eV < E <13.6 eV, that permeates neutral intergalactic gas during the Epoch of Reionization (EoR) excites the 2p (directly) and 2s (indirectly) states of atomic hydrogen. Because the 2s state is metastable, the lifetime of atoms in this level is relatively long, which may cause the 2s state to be overpopulated relative to the 2p state. It has recently been proposed that for this reason, neutral intergalactic atomic hydrogen gas may be detected in absorption in its 3-cm fine-structure line (2s_1/2 -> 2p_3/2) against the Cosmic Microwave Background out to very high redshifts. In particular, the optical depth in the fine-structure line through neutral intergalactic gas surrounding bright quasars during the EoR may reach tau~1e-5. The resulting surface brightness temperature of tens of micro K (in absorption) may be detectable with existing radio telescopes. Motivated by this exciting proposal, we perform a detailed analysis of the transfer of Lyman beta,gamma,delta,... radiation, and re-analyze the detectability of the fine-structure line in neutral intergalactic gas surrounding high-redshift quasars. We find that proper radiative transfer modeling causes the fine-structure absorption signature to be reduced tremendously to tau< 1e-10. We therefore conclude that neutral intergalactic gas during the EoR cannot reveal its presence in the 3-cm fine-structure line to existing radio telescopes.

Affiliated with

Also associated with

No associations

Rating

On the Detectability of the Hydrogen 3-cm Fine Structure Line from the EoR does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with On the Detectability of the Hydrogen 3-cm Fine Structure Line from the EoR, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Detectability of the Hydrogen 3-cm Fine Structure Line from the EoR will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-181214