Extending the M33 Extinction Map with Radio and Far-Infrared Gas Observations
Abstract
As the third-largest galaxy in the Local Group, M33 requires high-precision, wide-area extinction maps to recover the intrinsic luminosity and enable accurate studies, yet the available maps remain limited in coverage. In this work, we extend the stellar-based extinction map within the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) footprint to the outer disk by calibrating empirical AV-H\,\textsc{i} and AV-total hydrogen relations in the PHATTER overlap region. Within the PHATTER footprint, we retain the stellar-based map at 6′′ resolution, and outside the area covered by the stellar-based extinction map we produce an extended map at ≈ 12′′ resolution. The resulting map preserves a continuous morphology across the PHATTER boundary and reveals clear spiral-arm and interarm contrast and patchy dust substructures across a broader area. The median and maximum extinction values, median(AV)≈ 0.91 mag and AV,max ≈ 2.62 mag, are consistent with the high-extinction range reported by previous M33 studies, while naturally reflecting differences in tracers and spatial coverage. The extinction map provides a practical, publicly available dataset for galaxy-wide extinction correction and for further studies in M33.
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BibTeX
@misc{wang2026extending,
title = {{Extending the M33 Extinction Map with Radio and Far-Infrared Gas Observations}},
author = {Yuxi Wang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26571},
eprint = {2610.26571},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26571},
}
RIS
TY - UNPB
TI - Extending the M33 Extinction Map with Radio and Far-Infrared Gas Observations
AU - Yuxi Wang
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26571
UR - https://arxiv.org/abs/2610.26571
AB - As the third-largest galaxy in the Local Group, M33 requires high-precision, wide-area extinction maps to recover the intrinsic luminosity and enable accurate studies, yet the available maps remain limited in coverage. In this work, we extend the stellar-based extinction map within the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) footprint to the outer disk by calibrating empirical A_V-H\,\textsc{i} and A_V-total hydrogen relations in the PHATTER overlap region. Within the PHATTER footprint, we retain the stellar-based map at 6^′′ resolution, and outside the area covered by the stellar-based extinction map we produce an extended map at ≈ 12^′′ resolution. The resulting map preserves a continuous morphology across the PHATTER boundary and reveals clear spiral-arm and interarm contrast and patchy dust substructures across a broader area. The median and maximum extinction values, median(A_V)≈ 0.91 mag and A_V,max ≈ 2.62 mag, are consistent with the high-extinction range reported by previous M33 studies, while naturally reflecting differences in tracers and spatial coverage. The extinction map provides a practical, publicly available dataset for galaxy-wide extinction correction and for further studies in M33.
ER -