Key technologies for CO intensity mapping
Lead Research Organisation:
University of Oxford
Department Name: Oxford Physics
Abstract
Intensity mapping is a new concept in observational cosmology in which low resolution but high brightness sensitivity instruments are used to map out not individual objects, but their large-scale distribution. Several instruments have been proposed to measure the large-scale structure of protogalaxies in the early universe via the HI line of hydrogen, by imaging on angular scales corresponding to the large-scale structure (arcminutes) rather than the individual galaxies (arcseconds); this is one of the goals of the Square Kilometre Array. Other radio lines can also be used in principle in the same way; wheras HI traces neutral hydrogen that has not yet collapsed in to stars, carbon monoxide (CO) traces the molecular gas that is the direct precursor of star formation, and is thus complementary to HI, mapping out the densest parts of protogalaxies.
This project is to develop the key technologies necessary for a CO intensity mapping experiment. The CO lines have rest frequencies of multiples of 115 GHz; at the redshift of early galaxy formation these are redshifted in to the centimetre regime. The key requirements of a CO intensity mapping telescope are high efficiency, low-sidelobe telescope optics; multi-feed cryogenic receivers with broad (~2:1) bandwidth; and a high bandwidth (>10 GHz) digital signal processing system. The student will investigate all three of these areas, via simulation, laboratory experiments, and demonstration on a prototype telescope, and will aim to demonstrate sufficient performance to allow a first-generation CO mapper to be built.
Similar technology and techniques are also used in the mapping of diffuse foregrounds for use in CMB intensity and polarization measurements. The student will gain experience in actual observations by reducing data from C-BASS, an existing single-pixel intensity mapping experiment.
This project is to develop the key technologies necessary for a CO intensity mapping experiment. The CO lines have rest frequencies of multiples of 115 GHz; at the redshift of early galaxy formation these are redshifted in to the centimetre regime. The key requirements of a CO intensity mapping telescope are high efficiency, low-sidelobe telescope optics; multi-feed cryogenic receivers with broad (~2:1) bandwidth; and a high bandwidth (>10 GHz) digital signal processing system. The student will investigate all three of these areas, via simulation, laboratory experiments, and demonstration on a prototype telescope, and will aim to demonstrate sufficient performance to allow a first-generation CO mapper to be built.
Similar technology and techniques are also used in the mapping of diffuse foregrounds for use in CMB intensity and polarization measurements. The student will gain experience in actual observations by reducing data from C-BASS, an existing single-pixel intensity mapping experiment.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| ST/N504233/1 | 01/10/2015 | 31/03/2021 | |||
| 1659479 | Studentship | ST/N504233/1 | 01/10/2015 | 30/09/2019 | Jaz Hill-Valler |
| Description | Stargazing - University of Oxford/ Curiosity Carnival - Oxford |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Public/other audiences |
| Results and Impact | I have taken part in experiments with children demonstrating the spectrum of light, this involved making spectrometers out of CD's and black card along with demonstrating how radio receivers work. In more recent years, I have run my own astronomy themed art activities, these involved scientific colouring in which I drew myself along with making different type of telescope hats with younger children. This is important because it shows children and parents that science attracts creative and unconventional people also, I had a lot of interest from parents that were pleased to know that I also enjoy art, not just science. It takes away the threatening 'isolated genius' stereotype that is associated with Physics and allows conversation about science in a relaxed and creative environment. My colleagues were pleasantly surprised and it was refreshing for them to say they enjoyed seeing the hats around department, some even came down to make their own! |
| Year(s) Of Engagement Activity | 2015,2017,2018 |
| Description | Teddy Talk - NextBASS: Observing Cosmic Microwave Background Foregrounds |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Undergraduate students |
| Results and Impact | I gave a talk at St. Edmund Hall College Research Expo which was open to the general public and friends of the college. I spoke about my research and the day in the life of a Radio Astronomer. I received a lot of wonderful feedback from the general public that I spoke with clarity and they asked me further questions about the science I was discussing. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://www.seh.ox.ac.uk/news/research-expo-2017 |