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Title: Probing the Physics of Dark Energy with LSST: Large Scale Structure and Supernovae

Abstract

The Large Synoptic Survey Telescope (LSST) will make a huge leap forward in understanding the mysterious “dark energy” that drives the accelerating Universe. Its unprecedented combination of sky area and depth allows for multiple, independent probes to address fundamental questions: Is dark energy consistent with Einstein’s cosmological constant? Does it change with space or time? Does modified gravity provide a better explanation of cosmic acceleration? The LSST design is advanced but leaves significant freedom in the cadence of when a given field on the sky will be observed in each filter as well as the specific dithering pattern used to obtain more uniform sky coverage. Because the LSST Project plans to finalize this survey strategy shortly, we pursued a golden but short-lived opportunity to optimize it for dark energy studies. The P.I.s served as co-convenors for the Large Scale Structure and Supernova Analysis Working Groups of DESC, respectively, with Gawiser later serving as DESC Deputy Spokesperson, and our activities involved coordination of those working groups as well as research on specific Key Projects identified in the LSST Dark Energy Science Collaboration (DESC) 2015 Science Roadmap. Overview of Gawiser’s Research: We tested dithering strategies (both the timescale and the pattern ofmore » telescope pointing shifts) on the DESC Data Challenges to measure resulting systematics for large-scale structure. This work informed the DESC Science Requirements Document (SRD)'s systematics error budget. We then recommended to the LSST Project observing strategies for both the main survey and the Deep Drilling Fields that are optimized for dark energy studies. Overview of Jha’s Research: We studied the LSST cadence and observing strategy for the main survey and deep-drilling fields to optimize the scientific return on dark energy physics from LSST observations of type-Ia supernovae (SN Ia). We also developed the next generation of SN Ia light-curve fitters, software tools that turn observed photometry into cosmological distances necessary for understanding the nature of dark energy. We made fundamental improvements in the methods used, incorporating new results regarding SN Ia intrinsic color variations, reddening/extinction by dust, and environmental dependencies to SN Ia luminosity, building upon a training set based on new, large SN Ia samples. The tools developed will be critical in reducing astrophysical systematic uncertainties that would otherwise limit the precision and accuracy of dark energy parameter constraints from LSST supernova cosmology.« less

Authors:
ORCiD logo [1];  [1]
  1. Rutgers Univ., New Brunswick, NJ (United States)
Publication Date:
Research Org.:
Rutgers Univ., New Brunswick, NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
Contributing Org.:
Large Synoptic Survey Telescope (LSST) Dark Energy Science Collaboration
OSTI Identifier:
1580563
Report Number(s):
DOE-RUTGERS-SC0011636-1
DOE Contract Number:  
SC0011636
Resource Type:
Technical Report
Resource Relation:
Related Information: 2019arXiv191107832A2019BAAS...51g.268J2019AAS...23338302D2018arXiv181200514F2018arXiv181200516S2018arXiv181200515L2018arXiv181000001T2017arXiv170804058L2015arXiv150107897J
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; dark energy; large-scale structure; Type Ia supernovae

Citation Formats

Gawiser, Eric, and Jha, Saurabh. Probing the Physics of Dark Energy with LSST: Large Scale Structure and Supernovae. United States: N. p., 2019. Web. doi:10.2172/1580563.
Gawiser, Eric, & Jha, Saurabh. Probing the Physics of Dark Energy with LSST: Large Scale Structure and Supernovae. United States. doi:10.2172/1580563.
Gawiser, Eric, and Jha, Saurabh. Sun . "Probing the Physics of Dark Energy with LSST: Large Scale Structure and Supernovae". United States. doi:10.2172/1580563. https://www.osti.gov/servlets/purl/1580563.
@article{osti_1580563,
title = {Probing the Physics of Dark Energy with LSST: Large Scale Structure and Supernovae},
author = {Gawiser, Eric and Jha, Saurabh},
abstractNote = {The Large Synoptic Survey Telescope (LSST) will make a huge leap forward in understanding the mysterious “dark energy” that drives the accelerating Universe. Its unprecedented combination of sky area and depth allows for multiple, independent probes to address fundamental questions: Is dark energy consistent with Einstein’s cosmological constant? Does it change with space or time? Does modified gravity provide a better explanation of cosmic acceleration? The LSST design is advanced but leaves significant freedom in the cadence of when a given field on the sky will be observed in each filter as well as the specific dithering pattern used to obtain more uniform sky coverage. Because the LSST Project plans to finalize this survey strategy shortly, we pursued a golden but short-lived opportunity to optimize it for dark energy studies. The P.I.s served as co-convenors for the Large Scale Structure and Supernova Analysis Working Groups of DESC, respectively, with Gawiser later serving as DESC Deputy Spokesperson, and our activities involved coordination of those working groups as well as research on specific Key Projects identified in the LSST Dark Energy Science Collaboration (DESC) 2015 Science Roadmap. Overview of Gawiser’s Research: We tested dithering strategies (both the timescale and the pattern of telescope pointing shifts) on the DESC Data Challenges to measure resulting systematics for large-scale structure. This work informed the DESC Science Requirements Document (SRD)'s systematics error budget. We then recommended to the LSST Project observing strategies for both the main survey and the Deep Drilling Fields that are optimized for dark energy studies. Overview of Jha’s Research: We studied the LSST cadence and observing strategy for the main survey and deep-drilling fields to optimize the scientific return on dark energy physics from LSST observations of type-Ia supernovae (SN Ia). We also developed the next generation of SN Ia light-curve fitters, software tools that turn observed photometry into cosmological distances necessary for understanding the nature of dark energy. We made fundamental improvements in the methods used, incorporating new results regarding SN Ia intrinsic color variations, reddening/extinction by dust, and environmental dependencies to SN Ia luminosity, building upon a training set based on new, large SN Ia samples. The tools developed will be critical in reducing astrophysical systematic uncertainties that would otherwise limit the precision and accuracy of dark energy parameter constraints from LSST supernova cosmology.},
doi = {10.2172/1580563},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {12}
}