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Paper: |
A Transit Search for Highly Redshifted HI |
Volume: |
156, Highly Redshifted Radio Lines |
Page: |
34 |
Authors: |
Weintroub, J.; Horowitz, P.; Avruch, I. M.; Burke, B. F. |
Abstract: |
An experiment to detect protoclusters at high redshift is described. We attempt to observe these objects in the 1420 MHz line from neutral atomic hydrogen in the redshift range 4.7 <= z <= 5.5 (219 <= nu <= 251 MHz). The expected signal strength is very weak so we need a large aperture and a long integration time for a detection to be feasible. This is achieved by building a dedicated and specialized instrument, which allows the experiment to run continuously, in the background, at the Arecibo radio-telescope. We scan the same declination strip each day and co-add the data from successive sidereal days to achieve long integration times. The search volume is 1.8 times10^8 h^{-3} Mpc^3 and the beamwidth is about 0.75^circ, corresponding to a drift time of about three minutes. Strong time-variable RFI is a serious problem in the search band. We continue to gather more data but so far we have failed to detect a protocluster. |
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