4 WEAK GRAVITATIONAL LENSING MEASUREMENTS OF THE MASSES OF CLUSTERS OF GALAXIES WILL PROVIDE A CRITICAL CONTRIBUTION TO WFIRST'S MEASUREMENT OF THE EVOLUTION OF DARK ENERGY. THESE MEASUREMENTS ARE COMPLEMENTARY WITH THOSE THAT INVOLVE LARGE SCALE STRUCTURE (WEAK LENSING SHEAR CORRELATIONS, BARYON ACOUSTIC OSCILLATIONS) OR THE EXPANSION HISTORY OF THE UNIVERSE (TYPE IA SUPERNOVAE). EXPLOITING THE POTENTIAL OF CLUSTER MASS MEASUREMENTS WITH WFIRST WILL REQUIRE VERY ACCURATE CALIBRATION OF THE DISTORTION OF THE BACKGROUND GALAXIES. DESPITE A DECADE OF WORK ON WEAK LENSING ALGORITHMS (MOST OF IT AIMED AT THE CALIBRATING SIGNAL EXTRACTION FOR SHEAR CORRELATION MEASUREMENTS), WE HAVE NOT YET REACHED THE 1% SYSTEMATIC UNCERTAINTY REQUIRED FOR GALAXY CLUSTERS TO COMPETITIVELY MEASURE DARK ENERGY. IN PART, THIS IS BECAUSE SIMULATIONS HAVE NOT BEEN OPTIMIZED TO REPRODUCE THE CONDITIONS THAT WILL BE ENCOUNTERED IN A SPACE-BASED WEAK LENSING SURVEY. WE PROPOSE TO UNDERTAKE A SERIES OF SIMULATIONS SPECIFICALLY DESIGNED TO CAPTURE THE ESSENTIAL FEATURES OF WFIRST (THE COLOR DEPENDENCE OF THE POINT SPREAD FUNCTION, THE EFFECTS OF DIFFUSION, AND THE HIGH RESOLUTION, BACKGROUND GALAXY DENSITY AND REDSHIFT). THESE SIMULATIONS WILL ALLOW US TO IMPROVE AND CALIBRATE TECHNIQUES FOR CLUSTER WEAK LENSING MASS MEASUREMENT, PROVIDE FEEDBACK INTO OPTIMAL DESIGN OF THE WFIRST WIDE SURVEY TO MINIMIZE ERRORS IN CLUSTER MASS MEASUREMENT, AND ALLOW THE FULL POTENTIAL OF WFIRST FOR COSMOLOGY TO BE REALIZED. Funding Only Action ($27) 6/22/18 3 WEAK GRAVITATIONAL LENSING MEASUREMENTS OF THE MASSES OF CLUSTERS OF GALAXIES WILL PROVIDE A CRITICAL CONTRIBUTION TO WFIRST'S MEASUREMENT OF THE EVOLUTION OF DARK ENERGY. THESE MEASUREMENTS ARE COMPLEMENTARY WITH THOSE THAT INVOLVE LARGE SCALE STRUCTURE (WEAK LENSING SHEAR CORRELATIONS, BARYON ACOUSTIC OSCILLATIONS) OR THE EXPANSION HISTORY OF THE UNIVERSE (TYPE IA SUPERNOVAE). EXPLOITING THE POTENTIAL OF CLUSTER MASS MEASUREMENTS WITH WFIRST WILL REQUIRE VERY ACCURATE CALIBRATION OF THE DISTORTION OF THE BACKGROUND GALAXIES. DESPITE A DECADE OF WORK ON WEAK LENSING ALGORITHMS (MOST OF IT AIMED AT THE CALIBRATING SIGNAL EXTRACTION FOR SHEAR CORRELATION MEASUREMENTS), WE HAVE NOT YET REACHED THE 1% SYSTEMATIC UNCERTAINTY REQUIRED FOR GALAXY CLUSTERS TO COMPETITIVELY MEASURE DARK ENERGY. IN PART, THIS IS BECAUSE SIMULATIONS HAVE NOT BEEN OPTIMIZED TO REPRODUCE THE CONDITIONS THAT WILL BE ENCOUNTERED IN A SPACE-BASED WEAK LENSING SURVEY. WE PROPOSE TO UNDERTAKE A SERIES OF SIMULATIONS SPECIFICALLY DESIGNED TO CAPTURE THE ESSENTIAL FEATURES OF WFIRST (THE COLOR DEPENDENCE OF THE POINT SPREAD FUNCTION, THE EFFECTS OF DIFFUSION, AND THE HIGH RESOLUTION, BACKGROUND GALAXY DENSITY AND REDSHIFT). THESE SIMULATIONS WILL ALLOW US TO IMPROVE AND CALIBRATE TECHNIQUES FOR CLUSTER WEAK LENSING MASS MEASUREMENT, PROVIDE FEEDBACK INTO OPTIMAL DESIGN OF THE WFIRST WIDE SURVEY TO MINIMIZE ERRORS IN CLUSTER MASS MEASUREMENT, AND ALLOW THE FULL POTENTIAL OF WFIRST FOR COSMOLOGY TO BE REALIZED. Other Administrative Action $0 6/22/18 Not listed WEAK GRAVITATIONAL LENSING MEASUREMENTS OF THE MASSES OF CLUSTERS OF GALAXIES WILL PROVIDE A CRITICAL CONTRIBUTION TO WFIRST'S MEASUREMENT OF THE EVOLUTION OF DARK ENERGY. THESE MEASUREMENTS ARE COMPLEMENTARY WITH THOSE THAT INVOLVE LARGE SCALE STRUCTURE (WEAK LENSING SHEAR CORRELATIONS BARYON ACOUSTIC OSCILLATIONS) OR THE EXPANSION HISTORY OF THE UNIVERSE (TYPE IA SUPERNOVAE). EXPLOITING THE POTENTIAL OF CLUSTER MASS MEASUREMENTS WITH WFIRST WILL REQUIRE VERY ACCURATE CALIBRATION OF THE DISTORTION OF THE BACKGROUND GALAXIES. DESPITE A DECADE OF WORK ON WEAK LENSING ALGORITHMS (MOST OF IT AIMED AT THE CALIBRATING SIGNAL EXTRACTION FOR SHEAR CORRELATION MEASUREMENTS) WE HAVE NOT YET REACHED THE 1% SYSTEMATIC UNCERTAINTY REQUIRED FOR GALAXY CLUSTERS TO COMPETITIVELY MEASURE DARK ENERGY. IN PART THIS IS BECAUSE SIMULATIONS HAVE NOT BEEN OPTIMIZED TO REPRODUCE THE CONDITIONS THAT WILL BE ENCOUNTERED IN A SPACE-BASED WEAK LENSING SURVEY. WE PROPOSE TO UNDERTAKE A SERIES OF SIMULATIONS SPECIFICALLY DESIGNED TO CAPTURE THE ESSENTIAL FEATURES OF WFIRST (THE COLOR DEPENDENCE OF THE POINT SPREAD FUNCTION THE EFFECTS OF DIFFUSION AND THE HIGH RESOLUTION BACKGROUND GALAXY DENSITY AND REDSHIFT). THESE SIMULATIONS WILL ALLOW US TO IMPROVE AND CALIBRATE TECHNIQUES FOR CLUSTER WEAK LENSING MASS MEASUREMENT PROVIDE FEEDBACK INTO OPTIMAL DESIGN OF THE WFIRST WIDE SURVEY TO MINIMIZE ERRORS IN CLUSTER MASS MEASUREMENT AND ALLOW THE FULL POTENTIAL OF WFIRST FOR COSMOLOGY TO BE REALIZED. $0 6/22/18 Not listed WEAK GRAVITATIONAL LENSING MEASUREMENTS OF THE MASSES OF CLUSTERS OF GALAXIES WILL PROVIDE A CRITICAL CONTRIBUTION TO WFIRST'S MEASUREMENT OF THE EVOLUTION OF DARK ENERGY. THESE MEASUREMENTS ARE COMPLEMENTARY WITH THOSE THAT INVOLVE LARGE SCALE STRUCTURE (WEAK LENSING SHEAR CORRELATIONS BARYON ACOUSTIC OSCILLATIONS) OR THE EXPANSION HISTORY OF THE UNIVERSE (TYPE IA SUPERNOVAE). EXPLOITING THE POTENTIAL OF CLUSTER MASS MEASUREMENTS WITH WFIRST WILL REQUIRE VERY ACCURATE CALIBRATION OF THE DISTORTION OF THE BACKGROUND GALAXIES. DESPITE A DECADE OF WORK ON WEAK LENSING ALGORITHMS (MOST OF IT AIMED AT THE CALIBRATING SIGNAL EXTRACTION FOR SHEAR CORRELATION MEASUREMENTS) WE HAVE NOT YET REACHED THE 1% SYSTEMATIC UNCERTAINTY REQUIRED FOR GALAXY CLUSTERS TO COMPETITIVELY MEASURE DARK ENERGY. IN PART THIS IS BECAUSE SIMULATIONS HAVE NOT BEEN OPTIMIZED TO REPRODUCE THE CONDITIONS THAT WILL BE ENCOUNTERED IN A SPACE-BASED WEAK LENSING SURVEY. WE PROPOSE TO UNDERTAKE A SERIES OF SIMULATIONS SPECIFICALLY DESIGNED TO CAPTURE THE ESSENTIAL FEATURES OF WFIRST (THE COLOR DEPENDENCE OF THE POINT SPREAD FUNCTION THE EFFECTS OF DIFFUSION AND THE HIGH RESOLUTION BACKGROUND GALAXY DENSITY AND REDSHIFT). THESE SIMULATIONS WILL ALLOW US TO IMPROVE AND CALIBRATE TECHNIQUES FOR CLUSTER WEAK LENSING MASS MEASUREMENT PROVIDE FEEDBACK INTO OPTIMAL DESIGN OF THE WFIRST WIDE SURVEY TO MINIMIZE ERRORS IN CLUSTER MASS MEASUREMENT AND ALLOW THE FULL POTENTIAL OF WFIRST FOR COSMOLOGY TO BE REALIZED. ($27) 6/22/18 Not listed WEAK GRAVITATIONAL LENSING MEASUREMENTS OF THE MASSES OF CLUSTERS OF GALAXIES WILL PROVIDE A CRITICAL CONTRIBUTION TO WFIRST'S MEASUREMENT OF THE EVOLUTION OF DARK ENERGY. THESE MEASUREMENTS ARE COMPLEMENTARY WITH THOSE THAT INVOLVE LARGE SCALE STRUCTURE (WEAK LENSING SHEAR CORRELATIONS BARYON ACOUSTIC OSCILLATIONS) OR THE EXPANSION HISTORY OF THE UNIVERSE (TYPE IA SUPERNOVAE). EXPLOITING THE POTENTIAL OF CLUSTER MASS MEASUREMENTS WITH WFIRST WILL REQUIRE VERY ACCURATE CALIBRATION OF THE DISTORTION OF THE BACKGROUND GALAXIES. DESPITE A DECADE OF WORK ON WEAK LENSING ALGORITHMS (MOST OF IT AIMED AT THE CALIBRATING SIGNAL EXTRACTION FOR SHEAR CORRELATION MEASUREMENTS) WE HAVE NOT YET REACHED THE 1% SYSTEMATIC UNCERTAINTY REQUIRED FOR GALAXY CLUSTERS TO COMPETITIVELY MEASURE DARK ENERGY. IN PART THIS IS BECAUSE SIMULATIONS HAVE NOT BEEN OPTIMIZED TO REPRODUCE THE CONDITIONS THAT WILL BE ENCOUNTERED IN A SPACE-BASED WEAK LENSING SURVEY. WE PROPOSE TO UNDERTAKE A SERIES OF SIMULATIONS SPECIFICALLY DESIGNED TO CAPTURE THE ESSENTIAL FEATURES OF WFIRST (THE COLOR DEPENDENCE OF THE POINT SPREAD FUNCTION THE EFFECTS OF DIFFUSION AND THE HIGH RESOLUTION BACKGROUND GALAXY DENSITY AND REDSHIFT). THESE SIMULATIONS WILL ALLOW US TO IMPROVE AND CALIBRATE TECHNIQUES FOR CLUSTER WEAK LENSING MASS MEASUREMENT PROVIDE FEEDBACK INTO OPTIMAL DESIGN OF THE WFIRST WIDE SURVEY TO MINIMIZE ERRORS IN CLUSTER MASS MEASUREMENT AND ALLOW THE FULL POTENTIAL OF WFIRST FOR COSMOLOGY TO BE REALIZED. $30.9k 8/25/17