Sánchez-Menguiano, L;
Sánchez, SF;
Kawata, D;
Chemin, L;
Pérez, I;
Ruiz-Lara, T;
Sánchez-Blázquez, P;
... Gómez, FA; + view all
(2016)
Evidence of ongoing radial migration in NGC 6754: Azimuthal variations of the gas properties.
The Astrophysical Journal Letters
, 830
(2)
, Article L40. 10.3847/2041-8205/830/2/L40.
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Abstract
Understanding the nature of spiral structure in disk galaxies is one of the main, and still unsolved questions in galactic astronomy. However, theoretical works are proposing new testable predictions whose detection is becoming feasible with recent development in instrumentation. In particular, streaming motions along spiral arms are expected to induce azimuthal variations in the chemical composition of a galaxy at a given galactic radius. In this letter we analyse the gas content in NGC 6754 with VLT/MUSE data to characterise its 2D chemical composition and H$\alpha$ line-of-sight velocity distribution. We find that the trailing (leading) edge of the NGC 6754 spiral arms show signatures of tangentially-slower, radially-outward (tangentially-faster, radially-inward) streaming motions of metal-rich (poor) gas over a large range of radii. These results show direct evidence of gas radial migration for the first time. We compare our results with the gas behaviour in a $N$-body disk simulation showing spiral morphological features rotating with a similar speed as the gas at every radius, in good agreement with the observed trend. This indicates that the spiral arm features in NGC 6754 may be transient and rotate similarly as the gas does at a large range of radii.
| Type: | Article |
|---|---|
| Title: | Evidence of ongoing radial migration in NGC 6754: Azimuthal variations of the gas properties |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/2041-8205/830/2/L40 |
| Publisher version: | http://dx.doi.org/10.3847/2041-8205/830/2/L40 |
| Language: | English |
| Additional information: | This is the published version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | galaxies: abundances, galaxies: evolution, galaxies: ISM, galaxies: spiral, H II regions, techniques: imaging spectroscopy |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1521332 |
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