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Probing Individual Sources during Reionization and Cosmic Dawn using Square Kilometre Array HI 21-cm Observations
- Source :
- Journal of Astrophysics and Astronomy
- Publication Year :
- 2016
-
Abstract
- Detection of individual luminous sources during the reionization epoch and cosmic dawn through their signatures in the HI 21-cm signal is one of the direct approaches to probe the epoch. Here, we summarize our previous works on this and present preliminary results on the prospects of detecting such sources using the SKA1-low experiment. We first discuss the expected HI 21-cm signal around luminous sources at different stages of reionization and cosmic dawn. We then introduce two visibility based estimators for detecting such signal: one based on the matched filtering technique and the other relies on simply combing the visibility signal from different baselines and frequency channels. We find that that the SKA1-low should be able to detect ionized bubbles of radius $R_b \gtrsim 10$ Mpc with $\sim 100$ hr of observations at redshift $z \sim 8$ provided that the mean outside neutral Hydrogen fraction $ x_{\rm HI} \gtrsim 0.5$. We also investigate the possibility of detecting HII regions around known bright QSOs such as around ULASJ1120+0641 discovered by Mortlock et al. 2011. We find that a $5 \sigma$ detection is possible with $600$ hr of SKA1-low observations if the QSO age and the outside $ x_{\rm HI} $ are at least $\sim 2 \times 10^7$ Myr and $\sim 0.2$ respectively. Finally, we investigate the possibility of detecting the very first X-ray and Ly-$\alpha$ sources during the cosmic dawn. We consider mini-QSOs like sources which emits in X-ray frequency band. We find that with a total $\sim 1000$ hr of observations, SKA1-low should be able to detect those sources individually with a $\sim 9 \sigma$ significance at redshift $z=15$. We summarize how the SNR changes with various parameters related to the source properties.
- Subjects :
- QSOS
Cosmology: cosmic reionization
Epoch (astronomy)
REDSHIFT
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Astronomy & Astrophysics
QUASAR
01 natural sciences
square kilometre array
DETECTING IONIZED BUBBLES
LY-ALPHA EMITTERS
Ionization
0103 physical sciences
MAPS
010303 astronomy & astrophysics
Reionization
21-cm signal
Physics
EPOCH
COSMIC cancer database
Science & Technology
010308 nuclear & particles physics
Astronomy and Astrophysics
Radius
FLUCTUATIONS
Redshift
EVOLUTION
GALAXIES
0201 Astronomical And Space Sciences
PROSPECTS
13. Climate action
Space and Planetary Science
Physical Sciences
astro-ph.CO
Subjects
Details
- ISSN :
- 02506335
- Database :
- OpenAIRE
- Journal :
- Journal of Astrophysics and Astronomy
- Accession number :
- edsair.doi.dedup.....db8a0382e7ce1d01e1604fdcc861282d
- Full Text :
- https://doi.org/10.1007/s12036-016-9405-x