[Paper Review] R2-D2: Roman and Rubin -- From Data to Discovery

Suvi Gezari, Misty C. Bentz+29 more|arXiv (Cornell University)|Feb 24, 2022

Astronomy and Astrophysical Research4 citations

TL;DR

This paper proposes a synergistic framework for combining data from the NASA Nancy Grace Roman Space Telescope and the Vera C. Rubin Observatory to unlock transformative discoveries in general astrophysics beyond cosmology. By coordinating survey fields, joint coverage of the Galactic plane and ecliptic, and enabling shared data products, transient alerts, and joint analysis tools, the synergy enhances photometric redshifts, weak-lensing measurements, and the study of small bodies, stellar streams, and dark matter on small scales.

ABSTRACT

The NASA Nancy Grace Roman Space Telescope (Roman) and the Vera C. Rubin Observatory Legacy Survey of Space and Time (Rubin), will transform our view of the wide-field sky, with similar sensitivities, but complementary in wavelength, spatial resolution, and time domain coverage. Here we present findings from the AURA Roman+Rubin Synergy Working group, charged by the STScI and NOIRLab Directors to identify frontier science questions in General Astrophysics, beyond the well-covered areas of Dark Energy and Cosmology, that can be uniquely addressed with Roman and Rubin synergies in observing strategy, data products and archiving, joint analysis, and community engagement. This analysis was conducted with input from the community in the form of brief (1-2 paragraph) "science pitches" (see Appendix), and testimony from "outside experts" (included as co-authors). We identify a rich and broad landscape of potential discoveries catalyzed by the combination of exceptional quality and quantity of Roman and Rubin data, and summarize implementation requirements that would facilitate this bounty of additional science with coordination of survey fields, joint coverage of the Galactic plane, bulge, and ecliptic, expansion of General Investigator and Target of Opportunity observing modes, co-location of Roman and Rubin data, and timely distribution of data, transient alerts, catalogs, value-added joint analysis products, and simulations to the broad astronomical community.

Motivation & Objective

• Address frontier astrophysics questions beyond dark energy and cosmology that require the combined capabilities of Roman and Rubin.
• Overcome limitations in current surveys by leveraging Roman’s diffraction-limited near-infrared imaging and spectroscopy with Rubin’s wide-area, deep, multi-band optical imaging and high-cadence time-domain coverage.
• Enable community-wide discovery by coordinating survey fields, joint data products, and timely distribution of alerts and value-added catalogs.
• Facilitate advanced data analysis by providing co-located data, simulations, and joint analysis tools tailored for the unique strengths of both missions.
• Expand observing modes to include General Investigator and Target of Opportunity programs that leverage the synergy for transient and rare object studies.

Proposed method

• Coordinate observing strategies between Roman and Rubin to ensure overlapping coverage of key regions such as the Galactic plane, bulge, and ecliptic.
• Integrate Roman’s high-resolution, diffraction-limited near-infrared imaging and prism/grism spectroscopy with Rubin’s seeing-limited, wide-field optical imaging and regular cadence.
• Develop joint data products including co-located catalogs, photometric redshifts, and deblended lensed arc measurements using machine learning and joint deconvolution techniques.
• Enable real-time transient alert distribution with cross-mission identification and follow-up capabilities, especially for high-cadence events.
• Create shared simulation frameworks and data analysis pipelines to prepare the community for handling the unprecedented data volume and complexity.
• Establish community engagement through science pitches and expert testimony to identify high-impact, cross-mission science cases.

Experimental results

Research questions

• RQ1 How can the combination of Roman’s diffraction-limited NIR imaging and Rubin’s wide-field optical imaging improve the characterization of small bodies in the solar system, including interstellar objects and trans-Neptunian objects?
• RQ2 What is the role of joint photometry and spectroscopy from Roman and Rubin in refining photometric redshifts and weak-lensing shear measurements for cosmological probes?
• RQ3 How can the synergy enhance the detection and study of stellar streams, halo substructures, and ultra-faint dwarf galaxies beyond the Local Group?
• RQ4 In what ways can joint high-resolution imaging and spectroscopy from Roman and deep optical surveys from Rubin improve constraints on dark matter distribution on small scales?
• RQ5 How can machine learning and joint deblending techniques applied to Rubin’s strong lensing candidates and Roman’s high-resolution follow-up improve lens modeling and time-delay measurements?

Key findings

• The synergy between Roman and Rubin enables the detection and detailed characterization of extreme small solar system bodies, including interstellar objects like 1I/Oumuamua, through high-precision photometry and spectroscopy.
• Joint analysis improves photometric redshift accuracy and weak-lensing shear measurements, enhancing cosmological constraints beyond what either survey can achieve alone.
• Roman’s spectroscopic capabilities at 1.6 µm and 2.0 µm enable the identification of water ice absorption features in comets and asteroids, as demonstrated in the spectrum of 9P/Tempel 1.
• The combination allows for improved orbit determination of near-Earth objects on impact trajectories, leveraging Roman’s space-based vantage point and faint limiting magnitude.
• The synergy supports the discovery and study of proto-clusters at z > 2 and massive galaxies with relic structures, using Rubin’s wide-field imaging and Roman’s targeted spectroscopic follow-up.
• Co-located data and joint analysis tools significantly enhance the detection and modeling of strongly lensed arcs, enabling strong lensing tomography and improved time-delay measurements.