MSFC Relativistic Astrophysics
Multi-Messenger Astrophysics Community Tools and Support
Motivation
The Astro2020 Decadal Survey recommended, as its highest-priority sustaining activity, that NASA establish a Time Domain Astronomy and Multi-messenger program (TDAMM)
“...to realize and sustain the necessary suite of space-based electromagnetic capabilities required to study transient and time variable phenomena, and to follow-up multi-messenger events.”
To meet this goal, NASA’s Internal Scientist Funding Model (ISFM) program has tapped the expertise of the Relativistic Astrophysics team at MSFC to support TDAMM astrophysics by extending analysis tools and techniques developed for the Fermi Gamma-ray Burst Monitor (GBM) to enable and support current and future TDAMM missions.
Table of Contents
- Title
- Multi-Messenger Astrophysics Community Tools and Support
- Contact
- P.I. Dr. Colleen Wilson-Hodge
- Outline
- Motivation
- MSFC Leadership
- TDAMM Supporting Activities
- Points of Contact
- Products and Deliverables
- Citations
- Additional Resources
MSFC Leadership in TDAMM Astrophysics
The Gamma-ray Burst Monitor (GBM) onboard the Fermi Gamma-ray Space Telescope has been one of NASA’s premiere facilities for the detection of gamma-ray transients. The GBM team at MSFC has been at the forefront of TDAMM science and helped facilitate the joint detection of GW/GRB 170817. The team provides NASA leadership to the GW-GRB working group, a long-standing collaboration between NASA and LIGO Scientific Collaboration that has helped facilitate the joint analysis of sub-threshold GW signals, the development of infrastructure to promptly report joint localizations, and the pursuit of joint science investigations. The team also has a strong relationship with the IceCube & Neil Gehrels Swift Observatory teams, including performing follow-up analysis of IceCube neutrino detections and helping facilitate a unique low-latency trigger of the Burst Alert Telescope (BAT) on Swift. The team is also helping to transition the Interplanetary Network (IPN) operations to from Berkeley to LSU.
TDAMM Support Activities
The Relativistic Astrophysics team’s current (FY23-25) ISFM program to support TDAMM missions, and TDAMM astronomy more broadly, includes the following activities:
Developing Standard Software Toolkits for Gamma-ray Missions
The Relativistic Astrophysics team’s current (FY23-25) ISFM program to support TDAMM missions, and TDAMM astronomy more broadly, includes the following activities:
The Astro2020 Decadal Review stated that the “Highest priority sustaining activity is a space-based time-domain and multi-messenger program of small and medium-scale missions.” [Summary (p. S-3)]. To support this priority, the team is working to create standardized gamma-ray mission toolkits based on existing Fermi GBM software that harnesses the unique knowledge and 30+ years of experience of the MSFC Relativistic Astrophysics Team. These mission toolkits include a standardized multi-mission gamma-ray analysis software, on-board and ground-based detection algorithms, localization and classification toolkits, as well as standard detector responses and atmospheric scattering models. All tools will be developed as open-source software and released to the community
USRA recently released the Gamma-ray Data Tools (GDT) 2.0 via Github and PyPi. The Gamma-ray Data Tools serves as a Standard multi-mission data analysis suite for gamma-ray missions, much as X-Spec has for x-ray missions. The software package is built on the GBM data tools and establishes a standard framework to handle data from generic gamma-ray instruments, as well as Swift and several specific legacy instruments. The Glowbug, BurstCube, and StarBurst data processing pipelines are all based on the GDT.
You can learn more about the GDT here, and access to the software on the USRA GitHub repo here.
Figure 1: Example interactive light curve selection and spectral model fitting via GDT 2.0.
Modernizing Interplanetary Network IPN Localizations
The IPN consists of group of spacecrafts equipped with high-energy detectors used to localize gamma-ray transients. The IPN has contributed to the studies of various astrophysical gamma ray transients, most notably SGRs and GRBs since the 1976, and can provide arcminute localization of these sources through an arrival time “triangulation”. Louisiana State University LSU recently took over the operations of the IPN and initiated a modernization effort, including automating and modernizing IPN operations and notifications and issuing IPN localizations using the HEALPix data format. The ISFM funding supports these ongoing IPN modernization efforts as well as the development of an IPN toolkit, which would provide a framework to assess localization capabilities of new missions participating in the network. This task directly supports NASA’s efforts to modernization and support critical infrastructure for the success of TDAMM science.
Base classes for localization annuli and generic orbit handling have been incorporated into the GDT v2.0. These classes establish the framework on which to build the modernized IPN. A separate IPN toolkit will be released to the public next year, which will include simulation software, cross correlation algorithms, and localization annuli generation. These additions will help missions assess their contribution to, and more easily participate in, the IPN.
Figure 2: IPN annulus and localization construction using the IPN toolkit.
Developing Multi-mission Sub-threshold Gamma-ray Targeted Search
Joint GBM-LIGO observations motivated the development of methods to search for sub-threshold gamma-ray transients at a specific time. These searches would be able to employ much more sophisticated analysis than what is capable by onboard flight software detection algorithms. The GBM sub-threshold search coherently combine the statistical likelihood of signals from separate detectors, treating each one as an independent experiment and examining the probability of a signal in each detector originating from a consistent location on the sky. The ISFM funding supports a re-write of the GBM sub-threshold search for use with generic gamma-ray missions through the use of the GDT. The ultimate goal of this effort will be the development of a multi-mission search that would coherently search data from instruments on multiple spacecraft.
A re-write of the GBM targeted search using the GDT v2.0 has been completed and an open-source public release of the new Gamma-ray Targeted Search (GTS) is forthcoming. The BurstCube team is already working on incorporating the GTS into their science operations pipeline for the analyze of their untriggered data.
Figure 3: The GBM sub-threshold search being applied to GBM data of GRB 170817.
Products and Deliverables
- Product: Gamma-ray Data Tools
- Latest Version: 2.0
- Release Date: 03-01-2024;
- Documenation: ReadTheDocs
- Code: GitHub
- Product: Generalized Targeted Search; Release Date: TBD
- Product: IPN Toolkit; Release Date: TBD
Points of Contact:
Dr. Colleen Wilson-Hodge
Dr. Michelle Hui
Dr. Cori Fletcher
Dr. Daniel Kocevski
Dr. Joshua Wood