Redshift Search Receiver tour page1 2 3 4 5
Back to the Instrumentation Page
Back to the FCRAO Home Page
Back to the Astronomy Dept. Home Page
Send mail to the Webmaster
Last Modified: Monday, 12-December-05 1:05:31 PM EDT
This material is based on work supported by the National Science Foundation under Grant AST-0096854.
Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of the National Science Foundation.
- Unique, ultra-wideband receiver designed to search for highly redshifted spectral lines from very distant galaxies
- Covers 74-110.5 GHz bandwidth with a receiver/spectrometer system yielding 31 MHz resolution
- Two dual polarization feeds with full band ortho-mode transitions (effectively four separate receivers)
- High speed Faraday rotation beam switch to minimize 1/f noise
- Back-end spectrometer is an analog autocorrelator with 6.5 GHz bandwidth per section and 6 sections per receiver, which provides 146 GHz total bandwidth!
Redshift Search Strategy
- The early universe is indicated by highly redshifted galaxies.
- These galaxies are easy to identify using bolometers, but bolometers provide no redshift (Z) information.
- The strongest spectral lines are from CO (N x 115 GHz) and C (492 GHz, 810 GHz). This receiver will search the entire band simultaneously for these and other lines of interest.
- High Z galactic spectral lines are expected to be quite weak, therefore there is no reason to search at frequencies of high absorption.
- The 74-110.5 GHz bandwidth lends a high probability of detecting one line from galaxies with Z > 1.1, and two lines from galaxies with Z > 3.
System noise temp with Trcvr= 60 K and 2 and 5 mm PWV.
Block diagram of the front end.
Blue components are at 20K, red at room temperature outside the dewar.
Continue the REDSHIFT tour...