microlensing in wide-field surveys

Transcript

1. Identifying Microlenses in Wide-field, Non-uniformly Sampled Surveys Adrian Price-Whelan Marcel Agüeros Amanda Fournier (UCSB) Rachel Street (LCOGT) May 2012 1 Tuesday, May 29, 12
2. May 2012 Will wide-field, time-domain surveys aid microlensing event discovery? 2 Tuesday, May 29, 12
3. What is microlensing, and why is it interesting? Can we model the expected microlensing signal in synoptic surveys? How should we identify microlensing events in single-color, photometric data? May 2012 3 Tuesday, May 29, 12
4. What is microlensing, and why is it interesting? May 2012 4 Tuesday, May 29, 12
5. May 2012 ✓E = q GM c2 DS DL DS DL = q GM c2 Drel 5 Tuesday, May 29, 12
6. Microlensing May 2012 ✓E 6 Tuesday, May 29, 12
7. Microlensing May 2012 ✓E tE = ✓E µrel / p M p Drel 6 Tuesday, May 29, 12
8. 7 Tuesday, May 29, 12
9. Why is it interesting? Exoplanets Galactic structure Stellar abundances Compact objects / dwarfs May 2012 8 Tuesday, May 29, 12
10. What is microlensing, and why is it interesting? Can we model the expected microlensing signal in synoptic surveys? How should we identify microlensing events in single-color, photometric data? May 2012 9 Tuesday, May 29, 12
11. Modelling To predict the microlensing signal, we need a Galactic model and some measure of the detection efficiency May 2012 10 Tuesday, May 29, 12
12. Galactic Model Lensing rate / nSD2 S nLD2 L 2✓E µrel Pre-2008 (Peale et al. 1998): Uniform densities, uniform velocity distribution Han et al. 2008: More realistic model with disk-like distributions 11 Tuesday, May 29, 12
13. Galactic Model Our model (Amanda Fournier): - Galactic disk (no bulge) - Main sequence sources (0.07 to 12 ) - Scale heights dependent on age - SFD dust maps - Flat rotation velocity + 3D dispersion M 12 Tuesday, May 29, 12
14. Galactic Model Next steps: - Apply to a single cluster (Rup 147) - Update velocity distribution - Add bulge - Add dwarfs / stellar remnants 13 Tuesday, May 29, 12
15. May 2012 Will wide-field, time-domain surveys aid microlensing event discovery? 14 Tuesday, May 29, 12
16. Detection Efficiency OGLE, MACHO, MOA (1990’s - present) Limited coverage: LMC, SMC, Bulge PTF, Pan-STARRs, LSST (present / future) Wide-field cameras Extremely irregular sampling May 2012 15 Tuesday, May 29, 12
17. Keck NIR WFC3 OGLE IV May 2012 16 Tuesday, May 29, 12
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20. Detection Efficiency Depends on survey sampling baseline photometric errors detection algorithm Previous studies used matched filters We aim to combine this with statistical variability indices May 2012 19 Tuesday, May 29, 12
21. What is microlensing, and why is it interesting? Can we model the expected microlensing signal in synoptic surveys? How should we identify microlensing events in single-color, photometric data? May 2012 20 Tuesday, May 29, 12
22. Variability Indices σ / μ : root variance / mean magnitude η : mean square successive difference / sample variance J : large for potentially variable sources K : kurtosis Δχ2 : difference in chi-square for Gaussian vs. straight line fit May 2012 21 Tuesday, May 29, 12
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26. May 2012 25 Tuesday, May 29, 12
27. Issues: Blending May 2012 26 Tuesday, May 29, 12
28. Issues: Blending May 2012 26 Tuesday, May 29, 12
29. Issues: Blending May 2012 26 Tuesday, May 29, 12
30. Issues: Pipeline May 2012 27 Tuesday, May 29, 12
31. Future Develop selection criteria on all variability indices to pick out microlensing events Run Amanda’s code for a single cluster, compare to observations Predict microlensing signal in PTF, then run our code on the entire archive Real-time identifier? LSST? May 2012 28 Tuesday, May 29, 12