GBT20A-432

High-Fidelity HI 21cm Imaging of M83 with GBT+VLA

Abstract

We propose an On-the-Fly mapping of the whole HI disk of the nearby barred spiral galaxy M83 (1.5deg x 1.2deg region) with the GBT.
In conjunction with the archival, yet unpublished, JVLA data, the new GBT data will provide the highest fidelity HI image of this galaxy at an unprecedented ~6" (130pc) resolution without the missing flux problem.
The HI data will be used for three goals:
(1) To investigate the evolution of the atomic/molecular gas phase across spiral arms and interarm regions in the main optical disk, by comparing this atomic gas data with a brand-new ALMA CO(1-0) image of this galaxy;
(2) to investigate the extent and structure of the large outer atomic gas disk around this galaxy; and
(3) to demonstrate the performance of the new technique and software that we developed for combining single-dish and interferometer data in uv space (Koda et al. 2019).
The VLA and ALMA data are already at hand, and their calibrations were completed just recently.
In terms of data volume, the GBT data is relatively small, but is extremely important in measuring total flux, in identifying extended HI emission, and for filling in the information that VLA cannot provide.

Investigators

Name	Institution
Jin Koda *	New York at Stony Brook, State University of

* indicates the PI