140 likes | 266 Views
Jonathan Zwart jtlz2@mrao.cam.ac.uk. Early Science with AMI. Overview. Case Study: Abell 1914 Observing strategy & science goals Early cluster targets Survey plans. 19 March 2006. Jonathan Zwart, Cavendish Astrophysics. 2. A1914: 228 Hours with Ryle. 19 March 2006.
E N D
Jonathan Zwart jtlz2@mrao.cam.ac.uk Early Science with AMI
Overview • Case Study: Abell 1914 • Observing strategy & science goals • Early cluster targets • Survey plans 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 2
A1914: 228 Hours with Ryle 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 3
A1914: 34 Hours with AMI Long baselines Short baselines (after radio sources removed) 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 4
19 March 2006 Jonathan Zwart, Cavendish Astrophysics 5
Only7 (/10) antennas • 18 point sources subtracted Need for source subtraction • astro-ph/0509215 (MNRAS accepted) 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 6
Observing Strategy • Known clusters • Initial blind surveys • Surveys of equatorial fields (need LA) • Joint fields (AMiBA, SZA, UKIDSS…) 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 7
Early Cluster Targets • Abell (optical) & NORAS (X-ray) • MACS (X-ray, Ebeling et al. 2000) • High-z candidates Ryle source survey (2004–): 4 days for each of ~ 100 ‘lucky’ targets 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 8
NORAS-Selected Clusters Selection criteria: • LX > 6.8×1044 erg s-1 • z > 0.1 • Calibrate scaling relations L–T, M, etc +X-ray g,H0 A263: 10 hours; z = 0.3; (Natasha Hurley-Walker) 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 9
MACS-Selected Clusters Selection criteria: • LX > 1045 erg s-1 • z > 0.5 • Evolution of scaling relations with z +X-ray g (z),H0, q0 MACS 0717+37: 8 hours; z = 0.545 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 10
Blind Surveys • ‘Wedding cake’: • 10 □° deep survey (1 year) • 100 □° shallow survey (6 months) • Evolution of cluster population, N(m,z) • Some experimenting with z from SZ alone • But for now obtain redshifts independently… 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 11
Deep Survey – Optical Fields • ~ 10 sq. deg. on CFHT • R = 24.5, z’ = 23.5 (AB) • WFCAM K = 21.0 (AB) • Clusters out to z ~ 1.5 • Feedback on SZ selection function • Red Cluster Sequence (e.g. Gladders & Yee) • Voronoi tessellation (Culverhouse) • Full Bayesian analysis (Zwart & Hobson) • Spectroscopy 0.96° 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 12
Other Science • CMB power spectrum at high angular scales (ℓ > 3000, cf VSA) • Other non-Gaussian features, e.g. cosmic strings, ionization regions 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 13
Summary • AMI has started obs of known clusters (astro-ph/0509215) • Shallow blind survey of optical fields begins summer 2006 • Deep survey as soon as LA commissioned • Open to guest observers 19 March 2006 Jonathan Zwart, Cavendish Astrophysics 14