Download presentation
Presentation is loading. Please wait.
Published byJasmin Wiggins Modified over 9 years ago
1
The KAT/SKA project and Related Research Catherine Cress (UKZN/KAT/UWC)
2
The Square Kilometer Array (SKA) radio telescope for 2020+ 1000's of dishes spread over 1500km+ 1 km 2 collecting area 0.1-22GHz? US$1 billion+ 17 countries will be built in South Africa or Australia SA demonstrator projects: KAT, meerKAT, BigKAT > R800million committed Other demonstrators: xNTD, ATA, LOFAR, etc
3
SKA Science * Galaxy Evolution, Cosmology and dark energy * Reionisation epoch (time of first stars and quasars) * Pulsars, Black Holes and Gravitational Waves SKA will find large number of binary pulsar systems: good for testing GR in strong fields: see effects of QG? * Planet Formation and SETI * Cosmic Magnetism www.ska.ac.za
4
SKA layout and site
7
Survey figure of merit: Field-of-view*(collecting area/system temp) 2 *bandwidth
8
KAT Now: * first dish being made at Hartrao * >20 Engineers at KAT office in Cape Town+ team of ~8 in JHB * Postgrad bursary program of over 25 students – (engineering & science)
9
SKA/KAT-related research at UKZN(/UWC?) * Science for SKA: eg. measuring sound speed of dark energy (Torres-Rodriguez, Cress) * Clustering of HI-detected galaxies (Passmoor, Cress) * HI-studies with KAT – z-distributions, configurations etc. * Radio Galaxy/optical cross-correlations to measure bias (relationship between dark and luminous matter) (Nhanombe, Elbouchefry, Passmoor, Harpaul, Cress) * N-body simulations for galaxy evolution studies (Bryan, Cress) * Detecting background of gravitational waves with pulsar array (Moodley, Warne)
10
SKA/KAT-related research at UKZN(/UWC?)- Results * Science for SKA: eg. measuring sound speed of dark energy dark energy sound speed potentially distinguishable: test quintessence hypothesis * Clustering of HI-detected galaxies: HI galaxies antibiased wrt DM * Radio Galaxy/optical cross-correlations * N-body simulations for galaxy evolution: coherent figure rotation over long periods
11
SKA/KAT-related research at UKZN(/UWC?) - Results HI observations with (meer)KAT
12
HI observations with KAT: M31 at z=0.001 with 2km, 500m and 200m baselines Large beams: confusion, even in redshift space
13
SKA/KAT related research at other institutions * see UCT talks * pulsars, masers – UJ, Wits, UNISA, Hartrao * Rhodes – instrumentation, masers with VLBI?
14
Other Research at UKZN Atacama Cosmology Telescope project New generation CMB experiment from WMAP group (members from Princeton, UPenn, Rutgers, others & UKZN) mm telescope being built in Chile Will discover many cluster of galaxies through sunyaev-zeldovich effect Much optical follow-up required in South to measure redshifts and masses of clusters Perfect high-profile project for SALT Project goals: * Identify ~1000 clusters of galaxies though Sunyaev-Zeldovich effect to constrain w to +/-10% (w in dark energy equation of state) and limit neutrino mass to 0.1ev * Get CMB fluctuations in the 200<l<10000 range => info on primordial spectrum to constrain physics generating initial density fluctuations,(&) study reionisation, gravitational lensing of CMB
15
Other research at UKZN (with Kavi Moodley and students) Atacama Cosmology Telescope: - SALT observations - simulations to study cluster identification with clustered point sources - Blanco Cosmology Survey (deep optical, 50 sq deg in south) - theory Spanish Planck collaboration - simulations to study cluster identification (with optical info) - SALT observations? Galaxy Evolution simulations CMB theory
16
the KAT/SKA project viewed from just outside the project team in 2005: in 2007: * funding * people development (see 2006 bursary conference) * site * first dish production * strong international support – SKADS etc.
17
MBAC on ACT 1.7’ beam w/ 2X noise High-Res SZ Simulations Planck (2008) Sunyaev-Zeldovich effect: Hot gas (10 7 K) in environment of clusters of galaxies. CMB photons upscattered to higher frequencies by inverse Compton effect (hot e-’s give up energy to radio photons =>in direction of clusters get hole in CMB sky at radio ’s, bright patch at mm ’s. Optical Xray
18
Effect of varying w (in equation of state of dark energy) on number density of clusters over a given SZ detection threshold Top to bottom at peak: w= -1, -0.6, -0.3, 0 Haiman et al (2001)
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.