Overview
SED Grid is a modern, interactive tool for exploring precomputed spectral energy distribution (SED) grids from advanced stellar population synthesis (SPS) models. Designed for researchers, students, and enthusiasts, it helps you intuitively visualize how model SEDs change across physical parameter spaces.
The current implementation is powered by Prospector, with support for BAGPIPES planned in future versions.
Note: When loading for the first time, it might take some time to plot the SEDs, depending on your internet connection.
Key Features
- Visualizes large SED grids from SPS models (e.g., Prospector)
- Parameter selection via intuitive dropdowns (Age, Metallicity, Dust, etc.)
- Dynamic filtering and plotting of SEDs based on your selections.
- Compact summary panel for selected parameters.
- Handles partial selections and displays multiple curves as needed.
- Fully browser-based — no backend required.
Model Parameters
The SEDs are sampled over a 7D parameter grid:
tage— Stellar population age (Gyr)logzsol— Metallicity (log solar units)dust2— Dust attenuation (optical depth)imf_type— IMF choice (e.g., Chabrier, Salpeter)mass— Stellar mass (log₁₀ M☉)sfh— Star formation history model (e.g., delayed-τ)tau— τ timescale (Gyr) for SFH
How It Works
The tool loads a compressed JSON grid of SEDs directly in your browser. Each SED matches a unique set of model parameters. Select parameter values via dropdowns; if any are set to All, all matching SEDs are shown. A single SED appears only when all parameters are fixed. The idea is to allow you to explore the parameter space interactively, making it easier to understand how different parameters affect the SED.
Underlying Models
The current SED grids are generated using Prospector, an open-source Bayesian inference framework for fitting SEDs with flexible stellar population models. It builds upon FSPS and is widely used for interpreting galaxy spectra and photometry.
Future versions of SED Grid aim to integrate BAGPIPES, offering users the ability to compare and interact with models across different population synthesis codes.
Data & Technical Notes
- SED grid generated with Prospector SPS framework
- Uses Plotly.js for interactive plots and fflate.js for decompression
- Runs entirely in your browser — no external dependencies beyond JS libraries
Planned Extensions
- User photometry upload for visual comparison (multi band).
- Support for BAGPIPES and other SPS engines.
- Interactive fitting against observed SEDs.
- On-hover inspection and parameter brushing.
- Expanded grid: nebular emission, AGN components, and finer parameter sampling.