Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dark ages reionization & galaxy formation simulation XII: Bubbles at
  dawn   Direct detection of regions of ionized hydrogen (HII) has been suggested as a
promising probe of cosmic reionization. Observing the redshifted 21-cm signal
of hydrogen from the epoch of reionization (EoR) is a key scientific driver
behind new-generation, low-frequency radio interferometers. We investigate the
feasibility of combining low-frequency observations with the Square Kilometre
Array and near infra-red survey data of the Wide-Field Infrared Survey
Telescope to detect cosmic reionization by imaging HII bubbles surrounding
massive galaxies during the cosmic dawn. While individual bubbles will be too
small to be detected, we find that by stacking redshifted 21-cm spectra centred
on known galaxies, it will be possible to directly detect the EoR at $z \sim
9-12$, and to place qualitative constraints on the evolution of the spin
temperature of the intergalactic medium (IGM) at $z \geq 9$. In particular,
given a detection of ionized bubbles using this technique, it is possible to
determine if the IGM surrounding them is typically in absorption or emission.
Determining the globally-averaged neutral fraction of the IGM using this method
will prove more difficult due to degeneracy with the average size of HII
regions.

16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg