Warm Molecular Hydrogen in Metal-poor Compact Galaxies: A Uniform JWST/MIRI Archival Analysis
- 1University of Science and Technology Beijing
- 2Chinese Academy of Sciences
- 3University of Chinese Academy of Sciences
Abstract
Pure-rotational H ₂ lines trace warm molecular gas, but they do not determine the total molecular reservoir. We uniformly reanalyze public JWST/MIRI/MRS spectroscopy of I Zw 18, Leo P, SBS 0335-052 E, and CGCG 007-025. The analysis distinguishes reproducible product-level warm-H ₂ measurements from multiphase inferences that require a common spatial footprint. We calibrate line-flux uncertainties and detection S/N from local residuals while accounting for positive spectral autocorrelation and test that calibration with residual-preserving injections. A machine-readable decision table records 32 target–transition outcomes: five accepted X1D detections, 24 clean empirical upper limits, and three quality-control cases retained for review and quality assurance. No target retains three transitions; we therefore report upper-level populations without fitting an excitation slope or inferring a warm-H ₂ mass. For Leo P, VLA data give a beam-scale H i detection, but the broad-beam test has insufficient MIRI coverage and the better-covered smaller-beam test does not yield a statistically significant H i signal. Neither branch meets the joint requirements for a source-matched H i mass, so no numerical warm-H ₂ /H i ratio is reported. The quality-controlled inventory, local-noise calibration, and footprint audit provide a reproducible foundation for future source-matched multiphase observations.
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BibTeX
@article{liu2026warm,
title = {{Warm Molecular Hydrogen in Metal-poor Compact Galaxies: A Uniform JWST/MIRI Archival Analysis}},
author = {Siqi Liu and Xucheng Yin and A-Li Luo and Bo Qiu},
journal = {The Astrophysical Journal},
year = {2026},
month = nov,
doi = {10.3847/1538-4357/aea292},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aea292},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Warm Molecular Hydrogen in Metal-poor Compact Galaxies: A Uniform JWST/MIRI Archival Analysis
AU - Siqi Liu
AU - Xucheng Yin
AU - A-Li Luo
AU - Bo Qiu
PY - 2026
DA - 2026/11/02
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aea292
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aea292
AB - Pure-rotational H ₂ lines trace warm molecular gas, but they do not determine the total molecular reservoir. We uniformly reanalyze public JWST/MIRI/MRS spectroscopy of I Zw 18, Leo P, SBS 0335-052 E, and CGCG 007-025. The analysis distinguishes reproducible product-level warm-H ₂ measurements from multiphase inferences that require a common spatial footprint. We calibrate line-flux uncertainties and detection S/N from local residuals while accounting for positive spectral autocorrelation and test that calibration with residual-preserving injections. A machine-readable decision table records 32 target–transition outcomes: five accepted X1D detections, 24 clean empirical upper limits, and three quality-control cases retained for review and quality assurance. No target retains three transitions; we therefore report upper-level populations without fitting an excitation slope or inferring a warm-H ₂ mass. For Leo P, VLA data give a beam-scale H i detection, but the broad-beam test has insufficient MIRI coverage and the better-covered smaller-beam test does not yield a statistically significant H i signal. Neither branch meets the joint requirements for a source-matched H i mass, so no numerical warm-H ₂ /H i ratio is reported. The quality-controlled inventory, local-noise calibration, and footprint audit provide a reproducible foundation for future source-matched multiphase observations.
SN - 1538-4357
SN - 0004-637X
ER -