Journal article
The ALMaQUEST Survey. VIII. What causes the discrepancy in the velocity between the CO and H alpha rotation curves in galaxies?
- Abstract:
- We compare the CO(1-0) and Hα kinematics in 34 nearby galaxies, selected from the ALMaQUEST and EDGE-CALIFA surveys. We use 3D-Barolo, a 3D tilted-ring model, to derive the CO and Hα rotation curves. Before comparing rotation curves in the 34 nearby galaxies, we found systematics between the MaNGA and CALIFA data using eight MaNGA-CALIFA overlapping galaxies. We assume the rotation curves based on the MaNGA data are accurate and made the corresponding correction to the CALIFA data. Our result shows that ∼56% (19/34) of our galaxies present slower Hα rotation curves compared to the CO rotation curves, with a median value of 6.5 km s−1. The remaining galaxies (15/34) show consistent CO-Hα rotation velocity within uncertainties. As a result, the Hα rotation may underestimate the total dynamical mass by 6% for a circular velocity of 200 km s−1 (the median value in our sample). Furthermore, the difference in the velocity between the CO and Hα rotational velocity is found to correlate with the difference in velocity dispersion between CO and Hα, suggesting that gas pressure plays a role in the discrepancy in velocity. After incorporating the effect of pressure support due to the turbulent gas motion into our sample, the median value of the difference in the velocities decreases to 1.9 km s−1, which in turn reduces the underestimation of the dynamical mass to ∼2%. Finally, we also investigate the role that the extraplanar diffuse ionized gas plays in the discrepancy in the velocity of CO-Hα.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
Actions
Access Document
- Files:
-
-
(Preview, Version of record, pdf, 9.1MB, Terms of use)
-
- Publisher copy:
- 10.3847/1538-4357/ac77fd
Authors
- Publisher:
- American Astronomical Society
- Journal:
- Astrophysical Journal More from this journal
- Volume:
- 934
- Issue:
- 2
- Article number:
- 173
- Publication date:
- 2022-08-04
- Acceptance date:
- 2022-06-11
- DOI:
- EISSN:
-
1538-4357
- ISSN:
-
0004-637X
- Language:
-
English
- Keywords:
- Pubs id:
-
1272661
- Local pid:
-
pubs:1272661
- Deposit date:
-
2022-10-03
Terms of use
- Copyright holder:
- Su et al
- Copyright date:
- 2022
- Rights statement:
- © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
- Licence:
- CC Attribution (CC BY)
If you are the owner of this record, you can report an update to it here: Report update to this record