TIME Commissioning Observations: I. Mapping Dust and Molecular Gas in the Sgr A Molecular Cloud Complex at the Galactic Center
Abstract
We present the processing of an observation of Sagittarius A (Sgr A) with the Tomographic Ionized-carbon Mapping Experiment (TIME), part of the 2021-2022 commissioning run to verify TIME's hyperspectral imaging capabilities for future line-intensity mapping. Using an observation of Jupiter to calibrate detector gains and pointing offsets, we process the Sgr A observation in a purpose-built pipeline that removes correlated noise through common-mode subtraction with correlation-weighted scaling, and uses map-domain principal component analysis to identify further systematic errors. The resulting frequency-resolved maps recover strong 12CO(2-1) and 13CO(2-1) emission, and a continuum component whose spectral index discriminates free-free emission in the circumnuclear disk (CND) versus thermal dust emission in the 20 km s and 50 km s molecular clouds. Broadband continuum flux comparisons with the Bolocam Galactic Plane Survey (BGPS) show agreement to within 5% in high-SNR molecular clouds in the Sgr A region. From the CO line detections, we estimate a molecular hydrogen mass of between and , consistent with prior studies. These results demonstrate TIME's ability to recover both continuum and spectral-line signals in complex Galactic fields, validating its readiness for upcoming extragalactic CO and [C II] surveys.
Keywords
Cite
@article{arxiv.2511.09473,
title = {TIME Commissioning Observations: I. Mapping Dust and Molecular Gas in the Sgr A Molecular Cloud Complex at the Galactic Center},
author = {Selina F. Yang and Sophie M. McAtee and Benjamin J. Vaughan and Abigail T. Crites and Victoria L. Butler and Dongwoo T. Chung and Ryan P. Keenan and Dang Pham and Shwetha Prakash and James J. Bock and Charles M. Bradford and Tzu-Ching Chang and Yun-Ting Cheng and Audrey Dunn and Nicholas Emerson and Clifford Frez and Jonathon Hunacek and Chao-Te Li and Ian N. Lowe and King Lau and Daniel P. Marrone and Evan C. Mayer and Guochao Sun and Isaac Trumper and Anthony D. Turner and Ta-Shun Wei and Michael Zemcov},
journal= {arXiv preprint arXiv:2511.09473},
year = {2025}
}
Comments
17 pages + 5 pages of bibliography and appendices. 14 figures, 3 tables. To be submitted to ApJ