Parametric SED Modelling of Protoplanetary Discs: Validation and Application to an Unstudied YSO

TL;DR

This paper introduces a Bayesian SED modelling framework for deriving stellar and disc parameters from broadband photometry, validated on known systems and applied to an unstudied YSO.

Contribution

It combines a parametrized disc model with Bayesian inference, enabling self-consistent constraints on disc properties from broadband data.

Findings

Successfully reproduces literature properties of 49 Cet

Characterizes a new YSO as a Class II object

Shows robustness of extinction parameters against R_V variations

Abstract

We present a physically motivated spectral energy distribution (SED) modelling framework for deriving stellar and circumstellar disc parameters from broadband photometry. The model combines a parametrized disc structure, dust opacity, and interstellar extinction within a Bayesian Markov Chain Monte Carlo (MCMC) inference scheme, allowing correlated parameters to be constrained self-consistently. Initial parameter estimates are obtained via non-linear least-squares fitting and subsequently refined through MCMC sampling. The method is first validated using the well-studied debris disc system 49 Cet, for which the model successfully reproduces key literature properties. It is then applied to the previously uncharacterised young stellar object (YSO) candidate 2MASS J02512618+6012576, using photometric measurements compiled from multiple surveys. The resulting fit indicates a late-type pre-main-sequence star surrounded by a substantial circumstellar disc consistent with a moderately embedded Class II object. We further assess the sensitivity of the inferred parameters to the adopted extinction law and find that the high reddening required by the model is robust against variations in $R_V$. This work demonstrates that physically meaningful constraints on disc structure can be obtained from broadband SED modelling when extinction and distance are treated within a statistically consistent framework.