Blazar SED modeling: SSC, EIC and lepto-hadronic models

Compute the broadband SED of a blazar jet for the parameters you give, or fit a model to an SED from MMDC or to your own data.

About the modeling tool

Three models are available: synchrotron self-Compton (SSC), external inverse Compton (EIC) scattering of disk, broad-line region and torus photons, and a lepto-hadronic model with protons in the emitting region. Each is a convolutional neural network trained on a physical model; the SSC and EIC ones include self-consistent electron cooling and pair creation–annihilation (Bégué et al. 2024, ApJ 963, 71; Sahakyan et al. 2024, ApJ 971, 70). A model curve takes seconds instead of a full numerical run.

• Input: the redshift, optional EBL absorption, and the parameters of the emitting region, the electrons, the external photon fields (EIC) or the protons (hadronic), each with its allowed range.
• Output: the model SED drawn over your data points.
• Fit: upload a CSV of frequency, νFν and its error (the CSV from the SED builder works as it is). The fit runs with MultiNest in the background and gives the posterior of every parameter and a corner plot; the result is sent by email. It usually takes from 15 seconds (SSC) to about 2 minutes (hadronic).

The parameters and their meaning are described in the modeling guide, the fit and its file format in Fitting your SED.