Summary of Data Analysis: Low-Band 2, East-West Antenna, With Balun Shield

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1 LOCO EDGES REPORT #18 Summary of Data Analysis: Low-Band 2, East-West Antenna, With Balun Shield Raul A. Monsalve CASA, University of Colorado Boulder SESE, Arizona State University August 31, 217 Here we show results for the analysis of data from the Low-Band 2 instrument with the antenna in the E-W orientation, with the balun shield installed. Equivalent reports for other Low-Band datasets can be found here: Nominal choices and calibration settings: 1. Dates: to Sun cut: none 3. Moon cut: none 4. Receiver calibration S11 file: s11 calibration low band LNA25degC txt 5. Receiver parameter polynomial terms: Nfit=6, Wfit=5 6. Antenna S11 file: S11 blade low band INPIT.txt 7. Antenna S11 modeling: 9 polynomial terms after removal of delay 8. Balun loss correction: yes 9. Ground loss correction: yes,.5% 1. Beam correction: yes, using beam file newniv rotated to AZ = +87, and Haslam sky map scaled to 76 MHz using β =

2 The results are summarized in the following figures. The first seven figures (after Figure 1 described below) provide a overview of the data. Figure 2: daily residuals to 7-term polynomial over 5-1 MHz, for all days considered. The GHA range is -24 hr. Figure 3: residuals for 4-hr GHA averages, to 7-term polynomial over 5-1 MHz. Figure 4: residuals for 6-hr GHA averages, to 6-term polynomial over MHz. Figure 5: residuals for 6-hr GHA averages, to 6-term polynomial plus 21-cm signature, over MHz. The signature center and duration are not fixed, but found by maximizing the SNR. Figure 6: amplitude of 21-cm signature as a function of GHA for 6-hour averages, in parallel to the total sky temperature. The signature center and duration, different from case to case, are shown at the bottom. Figure 7: residuals and model for average over GHA -24 hr, to 1) 6-term polynomial over 5-1 MHz; 2) 6-term polynomial over MHz; 3) 6-term polynomial plus 21-cm signature over MHz. Figure 8: residuals and model for average over GHA 9-15 hr, to 1) 6-term polynomial over 5-1 MHz; 2) 6-term polynomial over MHz; 3) 6-term polynomial plus 21-cm signature over MHz. The next three figures show the results for the nominal data average, and compare them with those obtained for different data cuts and calibrations. All the cases correspond to data averages over GHA 9-15 hr and MHz, modeled with a 6-term polynomial plus a 21-cm signature. In these cases, the frequency and duration of the 21-cm signature, as well as its amplitude, are found by maximizing the ratio SNR = a 21 /σ 21. Figure 9: residuals and 21-cm signature for three alternative receiver calibrations: 1) Nfit=6, Wfit=5, at 23 C, 2) Nfit=6, Wfit=5, at 27 C, and 3) Nfit=7, Wfit=7, at 25 C. Figure 1: residuals and 21-cm signature for three alternative antenna S11: 1) (before balun measurement), 2) (after balun measurement), 3) (VNA in hut, not inside pit). Figure 11: residuals and 21-cm signature for two alternative corrections: 1) applying no ground loss correction, and 2) applying no beam correction. Finally, Table 1 presents the amplitude estimates for the different data cuts and calibration alternatives, and Figure 1 shows the values. 2

3 Table 1: Signature amplitude estimates for all the cases considered. In all cases, the GHA range is 9-15 hr. The frequency range is MHz and, in addition to the signature, the fit model includes six polynomial terms. Case Description Amplitude estimate [mk] Nominal 434 ± 13 1 recv cal217, Nfit=6, Wfit=5, 23 C 433 ± 16 2 recv cal217, Nfit=6, Wfit=5, 27 C 42 ± 13 3 recv cal217, Nfit=7, Wfit=7, 25 C 428 ± (before balun measurement) 353 ± (after balun measurement) 376 ± (VNA in hut, not inside pit) 398 ± 13 7 No ground loss correction 45 ± 99 8 No beam correction 369 ± a21 [mk] case number Figure 1: Signature amplitude for the cases of Table 1. 3

4 day of year 217 [1 K per division] mk 179 mk 256 mk 26 mk 223 mk 212 mk 198 mk 223 mk 21 mk 212 mk 237 mk 225 mk 166 mk 185 mk 185 mk Figure 2: Daily residuals to 7-term polynomial over 5-1 MHz, for all days considered. The GHA range is -24 hr. 4

5 7 polynomial terms RMS: 186 mk GHA [.5 K per division] RMS: 182 mk RMS: 76 mk RMS: 88 mk RMS: 11 mk RMS: 173 mk Figure 3: Residuals for 4-hr GHA averages, to 7-term polynomial over 5-1 MHz. 6 polynomial terms RMS: 146 mk GHA [.5 K per division] RMS: 68 mk RMS: 78 mk Figure 4: Residuals for 6-hr GHA averages, to 6-term polynomial over MHz. 5

6 6 polynomial terms + signature RMS: 137 mk GHA [.5 K per division] RMS: 43 mk RMS: 76 mk Figure 5: Residuals for 6-hr GHA averages, to 6-term polynomial plus 21-cm signature, over MHz. The signature center and duration are not fixed, but found by maximizing the SNR polynomial terms + signature a21 [mk] Tsky [K] 4 2 νr = 79.2 MHz νr = 76. MHz νr = 78.6 MHz νr = 79.8 MHz ν = 16.8 MHz ν = 21.6 MHz ν = 19.4 MHz ν = 15. MHz GHA [hr] 1 Figure 6: Amplitude of 21-cm signature as a function of GHA for 6-hour averages, in parallel to the total sky temperature at the frequency of the signature center. The signature center and duration are shown at the bottom. 6

7 -24 GHA RMS: 86 mk [.5 K per division] + signature RMS: 49 mk a 21 = 341 +/- 88 mk ν r = 78.2 MHz ν = 19. MHz Figure 7: Residuals for average over -24 GHA, to 1) 6-term polynomial over 5-1 MHz (blue); 2) 6-term polynomial over MHz (green); 3) 6-term polynomial plus 21-cm signature over MHz (red). Also shown (cyan) is the best fit 21-cm signature over MHz GHA RMS: 94 mk [.5 K per division] + signature a 21 = 434 +/- 13 mk ν = 19.4 MHz Figure 8: Residuals for average over 9-15 GHA, to 1) 6-term polynomial over 5-1 MHz (blue); 2) 6-term polynomial over MHz (green); 3) 6-term polynomial plus 21-cm signature over MHz (red). Also shown (cyan) is the best fit 21-cm signature over MHz. 7

8 Nominal a 21 = 434 +/- 13 mk ν = 19.4 MHz Calibration 217, Nfit6 - Wfit5, Receiver at 23 C RMS: 65 mk RMS: 57 mk a 21 = 433 +/- 16 mk ν r = 78.4 MHz ν = 19.6 MHz Calibration 217, Nfit6 - Wfit5, Receiver at 27 C RMS: 63 mk RMS: 56 mk a 21 = 42 +/- 13 mk ν = 19. MHz Calibration 217, Nfit7 - Wfit7, Receiver at 25 C RMS: 56 mk a 21 = 428 +/- 15 mk ν r = 78.4 MHz ν = 19.6 MHz Figure 9: Residuals and 21-cm signature for three alternative receiver calibrations: 1) Nfit=6, Wfit=5, 23 C, 2) Nfit=6, Wfit=5, 27 C, and 3) Nfit=7, Wfit=7, 25 C. Top panel is the nominal case. 8

9 Nominal a 21 = 434 +/- 13 mk ν = 19.4 MHz Antenna S RMS: 6 mk RMS: 54 mk a 21 = 353 +/- 96 mk ν r = 79. MHz ν = 17.8 MHz Antenna S RMS: 63 mk RMS: 56 mk a 21 = 376 +/- 1 mk ν r = 79. MHz ν = 18. MHz Antenna S RMS: 63 mk RMS: 56 mk a 21 = 398 +/- 13 mk ν = 19. MHz Figure 1: Residuals and 21-cm signature for three alternative antenna S11: 1) (before balun measurement), 2) (after balun measurement), 3) (VNA in hut, not inside pit). Top panel is the nominal case. 9

10 Nominal a 21 = 434 +/- 13 mk ν = 19.4 MHz No Ground Loss Correction RMS: 62 mk RMS: 54 mk a 21 = 45 +/- 99 mk ν r = 78.4 MHz ν = 19.2 MHz No Beam Correction RMS: 63 mk RMS: 57 mk a 21 = 369 +/- 1 mk ν r = 79. MHz ν = 18. MHz Figure 11: Residuals and 21-cm signature for two alternative corrections: 1) applying no ground loss correction, and 2) applying no beam correction. Top panel is the nominal case. 1

Updates from EDGES. Judd D. Bowman (Arizona State University), Raul Monsalve, Alan Rogers, Tom Mozdzen, and Nivedita Mahesh

Updates from EDGES. Judd D. Bowman (Arizona State University), Raul Monsalve, Alan Rogers, Tom Mozdzen, and Nivedita Mahesh Updates from EDGES Judd D. Bowman (Arizona State University), Raul Monsalve, Alan Rogers, Tom Mozdzen, and Nivedita Mahesh in collaboration with CSIRO February 8, 2018 EDGES (since 2012) Goal - Detect/constrain