Early Science with AMI Jonathan Zwart

19 March 2006Jonathan Zwart, Cavendish Astrophysics2 Overview Case Study: Abell 1914 Observing strategy & science goals –Early cluster targets –Survey plans

19 March 2006Jonathan Zwart, Cavendish Astrophysics3 A1914: 228 Hours with Ryle

19 March 2006Jonathan Zwart, Cavendish Astrophysics4 A1914: 34 Hours with AMI Long baselinesShort baselines (after radio sources removed)

19 March 2006Jonathan Zwart, Cavendish Astrophysics5

19 March 2006Jonathan Zwart, Cavendish Astrophysics6 Only 7 (/10) antennas 18 point sources subtracted Need for source subtraction astro-ph/ (MNRAS accepted)

19 March 2006Jonathan Zwart, Cavendish Astrophysics7 Observing Strategy Known clusters Initial blind surveys Surveys of equatorial fields (need LA) Joint fields (AMiBA, SZA, UKIDSS…)

19 March 2006Jonathan Zwart, Cavendish Astrophysics8 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 2006Jonathan Zwart, Cavendish Astrophysics9 NORAS-Selected Clusters Selection criteria: –L X > 6.8×10 44 erg s -1 –z > 0.1 Calibrate scaling relations L–T, M, etc +X-ray g, H 0 A263: 10 hours; z = 0.3; (Natasha Hurley-Walker)

19 March 2006Jonathan Zwart, Cavendish Astrophysics10 MACS-Selected Clusters Selection criteria: –L X > erg s -1 –z > 0.5 Evolution of scaling relations with z +X-ray g (z), H 0, q 0 MACS : 8 hours; z = 0.545

19 March 2006Jonathan Zwart, Cavendish Astrophysics11 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 2006Jonathan Zwart, Cavendish Astrophysics12 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 2006Jonathan Zwart, Cavendish Astrophysics13 Other Science CMB power spectrum at high angular scales ( > 3000, cf VSA) Other non-Gaussian features, e.g. cosmic strings, ionization regions

19 March 2006Jonathan Zwart, Cavendish Astrophysics14 Summary AMI has started obs of known clusters (astro-ph/ ) Shallow blind survey of optical fields begins summer 2006 Deep survey as soon as LA commissioned Open to guest observers