The Open mulTiwavelength Transient Event Repository (OTTER): Infrastructure Release and Tidal Disruption Event Catalog

TL;DR

OTTER delivers an open, API-first infrastructure and catalog for multiwavelength transient metadata and photometry, addressing prior fragmentation by storing data from radio to X-ray in a flexible, JSON-based schema within a scalable ArangoDB backend. The initial release focuses on tidal disruption events, aggregating ≳118,000 photometric observations for 240 TDE candidates and enabling end-to-end access via a web app and Python REST API, with robust data provenance through ADS bibcodes and a multi-tier classification flagging system. Four example analyses illustrate OTTER's utility: constraining UV/optical–X-ray delays, linking ECLE host dust properties to TDE environments, facilitating straightforward MOSFiT modeling, and validating Rubin-era photometric classifiers. The platform is designed for future expansion to additional transient classes, deeper integration with modeling tools, and eventual inclusion of spectra, aiming to become a long-lasting, scalable hub for time-domain astrophysics data and analyses.

Abstract

Multiwavelength analyses of astrophysical transients are essential for understanding the physics of these events. To make such analyses more efficient and effective, we present the Open mulTiwavelength Transient Event Repository (OTTER), a publicly available catalog of published transient event metadata and photometry. Unlike previous efforts, our data schema is optimized for the storage of multiwavelength photometric datasets spanning the entire electromagnetic spectrum from multiple published sources. Open source software, including an application programming interface (API) and web application, are available for viewing, accessing, and analyzing the dataset. For the initial release of OTTER, we present the largest ever photometric archive of tidal disruption event (TDE) candidates, including $\gtrsim 118,000$ observations of 240 TDE candidates spanning from radio to X-ray wavelengths. We demonstrate the power of this infrastructure through four example analyses of the TDE population. We plan to maintain this dataset as more TDE candidates are proposed in the future and encourage other users to contribute by uploading newly published data via our web application. The infrastructure was built with the goal of archiving additional transient data (supernovae, gamma-ray bursts, fast blue optical transients, fast radio bursts, etc.) in the future. The web application is available at https://otter.idies.jhu.edu and the API documentation is available at https://astro-otter.readthedocs.io.

Figures (16)

• Figure 1: Diagram of the OTTER infrastructure. The infrastructure is made up of a front end web application (bottom right), application programming interface (API; top right), and backend database (left). The different colored arrows show different workflows, two of which are for users (red and yellow) and one for administrators (blue). All of the infrastructure is containerized using docker and deployable on a kubernetes cluster.
• Figure 2: A decision tree showing our process for flagging classifications in OTTER. The classification confidence is a keyword for each individual classification associated with each transient and is then used to apply higher level flags to the classification. The flags are defined in the text and in Table \ref{['tab:conf-flag']}.
• Figure 3: Distribution of the maximum confidence flag we assign to a classification in each transient. Most transient events in OTTER are classified with at least one optical spectrum.
• Figure 4: The OTTER home page with the sky map and table of objects. The objects in OTTER are spread relatively uniformly across the sky. There is a slight bias towards the nothern hemisphere due to the high TDE discovery rate of the Zwicky Transient Facility.
• Figure 5: Sample transient page for the TDE Sw J1644+57 2011Natur.476..425Z2011Sci...333..199L2012ApJ...748...36B2012MNRAS.421.1942W2013ApJ...767..152Z2016ApJ...819...51L2016MNRAS.462L..66Y2017ApJ...838..149A2018ApJ...854...86E2021ApJ...908..125C. The quick look image is from ALADIN 2000AAS..143...33B2014ASPC..485..277B2022ASPC..532....7B. These individual transient pages provide basic metadata information on the transient and show the available photometry stored in OTTER. The photometry is displayed with both a light curve (top) split by wavelength regimes and a spectral energy distribution (SED) with tunable hyperparameters. The SED hyperparameters include a $\Delta t$ (used for binning and colorizing the data), a maximum and minimum time to plot, and an X-axis version (Frequency in GHz or Wavelength in nm).