Calibration Requirements for Detecting the EoR Power Spectrum N. - PowerPoint PPT Presentation

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Calibration Requirements for Detecting the EoR Power Spectrum N. Barry Department of Physics University of Washington December 8th, 2016 Science at Low Frequencies III N. Barry 1

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations The 2D Power Spectrum EoR Window n o w z i e r o i v h f o d l e fi y r a m i r p Foreground Wedge Intrinsic Foregrounds By Bryna Hazelton N. Barry 2

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Looking at the 2D Power Spectrum N. Barry 3

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Dirty, calibrated (6950 sources) N. Barry 4

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Model, 72% flux (4000 sources) N. Barry 5

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Residual, 28% flux (2950 sources) N. Barry 6

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Residual, 28% flux (2950 sources) N. Barry 7

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Residual PS N. Barry 8

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Residual PS N. Barry 9

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Residual PS "perfect calibration" = no calibration errors N. Barry 10

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Difference – per freq, per pol, per antenna calibration N. Barry 11

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Difference – per freq, per pol, per antenna calibration N. Barry 12

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Difference – per freq, per pol, per antenna calibration N. Barry 13

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations ◮ Entire window is saturated by as much as 10 7 , or an order of magnitude above the EoR ◮ Foreground wedge have been over fit ◮ Measurement of the EoR impossible! N. Barry 14

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations N. Barry 15

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Modulation h ( ν ) = f ( ν ) (1 + ∆ g cos η 0 ν ) (1) The modulation theorem results in the Fourier transform H ( η ) = ∆ g 2 F ( η − η 0 ) + ∆ g 2 F ( η + η 0 ) + F ( η ) (2) An order of magnitude estimate of the positive power spectrum of this modified signal is �� 2 � ∆ g � O ( | H ( η ) | 2 ) ≈ O ( | F ( η ) | 2 ) + O � � 2 F ( η ± η 0 ) (3) � � � � N. Barry 16

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Final 1D comparison N. Barry 17

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations Recommendations ◮ No frequency structure faster than 8 MHz (125 ns) in instrument ◮ Frequency structure needs to be lower than 1 part in 10 5 ◮ Validation of calibration techniques ◮ in the space of the measurement ◮ using incomplete models N. Barry 18

Power Spectrum Space Calibration Sim Setup Traditional Cal Recommendations For more information... ◮ Barry N., Hazelton B., Sullivan, I. Morales M. F., Pober J. C., 2016 , MNRAS, doi:10.1093/mnras/stw1380 ◮ Trott C. M. and Wayth R. B., 2016, PASA, 33, e019 doi:10.1017/pasa.2016.18. ◮ Patil A. H., Yatawatta S., Zaroubi S., Koopmans L. V. E., de Bruyn A. G., Jelić V., Ciardi B., Iliev I. T., Mevius M., Pandey V. N., Gehlot B. K., 2016, MNRAS, doi:10.1093/mnras/stw2277 N. Barry 19