A JWST/NIRSpec Catalog of Low-Mass Candidates toward NGC 2024 from Multi-component Spectral Modeling
Abstract
Young low-mass objects in crowded, highly obscured star-forming regions are difficult to characterize. Deriving reliable physical parameters requires separating photospheric emission from complex extinction and circumstellar emission. We apply a multi-component spectral-modeling framework to JWST/NIRSpec PRISM spectra toward NGC 2024, obtaining adopted fits for 78 sources. The framework incorporates atmospheric models, dust and ice opacities, and optional thermal emission. Most spectra favor additional large-H2O-ice opacity over the baseline small-grain model, while a smaller subset requires additional gray opacity, potentially arising from large refractory grains. Some spectra also require a thermal component to reproduce the long-wavelength continuum. The parameters inferred with this framework, together with the NGC 2024 distance, yield radii and bolometric luminosities. Comparison with evolutionary models for young low-mass and substellar objects provides mass estimates and identifies 46 candidate members, 27 sources classified as background, and five uncertain sources. Candidate members show lower fitted surface gravities than likely background stars. Of the candidate members, 23 lie above the youngest available isochrones, plausibly reflecting the cluster's youth and uncertainties in model initial conditions. The resulting catalog provides a uniform characterization of the NGC 2024 sample and establishes a framework for treating complex extinction and circumstellar emission in JWST spectra of other obscured star-forming regions.
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BibTeX
@misc{huang2026jwstnirspec,
title = {{A JWST/NIRSpec Catalog of Low-Mass Candidates toward NGC 2024 from Multi-component Spectral Modeling}},
author = {Haomiao Huang and Shu Wang and Xiaodian Chen and Zhijun Tu and Jifeng Liu},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.00970},
eprint = {2611.00970},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.00970},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A JWST/NIRSpec Catalog of Low-Mass Candidates toward NGC 2024 from Multi-component Spectral Modeling
AU - Haomiao Huang
AU - Shu Wang
AU - Xiaodian Chen
AU - Zhijun Tu
AU - Jifeng Liu
PY - 2026
DA - 2026/11/01
PB - arXiv
DO - 10.48550/arxiv.2611.00970
UR - https://arxiv.org/abs/2611.00970
AB - Young low-mass objects in crowded, highly obscured star-forming regions are difficult to characterize. Deriving reliable physical parameters requires separating photospheric emission from complex extinction and circumstellar emission. We apply a multi-component spectral-modeling framework to JWST/NIRSpec PRISM spectra toward NGC 2024, obtaining adopted fits for 78 sources. The framework incorporates atmospheric models, dust and ice opacities, and optional thermal emission. Most spectra favor additional large-H_2O-ice opacity over the baseline small-grain model, while a smaller subset requires additional gray opacity, potentially arising from large refractory grains. Some spectra also require a thermal component to reproduce the long-wavelength continuum. The parameters inferred with this framework, together with the NGC 2024 distance, yield radii and bolometric luminosities. Comparison with evolutionary models for young low-mass and substellar objects provides mass estimates and identifies 46 candidate members, 27 sources classified as background, and five uncertain sources. Candidate members show lower fitted surface gravities than likely background stars. Of the candidate members, 23 lie above the youngest available isochrones, plausibly reflecting the cluster's youth and uncertainties in model initial conditions. The resulting catalog provides a uniform characterization of the NGC 2024 sample and establishes a framework for treating complex extinction and circumstellar emission in JWST spectra of other obscured star-forming regions.
ER -