Whelan, E. T. and Pascucci, I. and Gorti, U. and Edwards, S. and Alexander, R. D. and Sterzik, M. F. and Melo, C.
(2021)
Evidence for an MHD Disk Wind via Optical Forbidden Line Spectroastrometry*.
The Astrophysical Journal, 913 (1).
p. 43.
ISSN 0004-637X
Abstract
Spectroastrometry is used to investigate the low-velocity component (LVC) of the optical forbidden emission from
the T Tauri stars RU Lupi and AS 205 N. Both stars also have high-velocity forbidden emission, which is tracing a
jet. For AS 205 N, analysis reveals a complicated outflow system. For RU Lupi, the [O I] λ6300 and [S II]
λλ6716,6731 LV narrow component (NC) is offset along the same position angle (PA) as the high-velocity
component but with a different velocity gradient than the jet, in that displacement from the stellar position along
the rotation axis is decreasing with increasing velocity. From the LVC, NC, PA, and velocity gradient, it is inferred
that the NC is tracing a wide-angled magnetohydrodynamic (MHD) disk wind. A photoevaporative wind is ruled
out. This is supported by a comparison with a previous spectroastrometric study of the CO fundamental line. The
decrease in offset with increasing velocity is interpreted as tracing an increase in the height of the wind with
increasing disk radius. This is one of the first measurements of the spatial extent of the forbidden emission line LVC NC (∼40 au, 8 au for RU Lupi in the [S II] λ6731 and [O I] λ6300 lines) and the first direct confirmation that the LVC narrow component can trace an MHD disk wind.
| Item Type: |
Article
|
| Additional Information: |
Cite as: Whelan, E.T., Pascucci, I., Gorti, U., Edwards, S., Alexander, R.D., Sterzik, M.F. & Melo, C. 2021, "Evidence for an MHD Disk Wind via Optical Forbidden Line Spectroastrometry", The Astrophysical journal, vol. 913, no. 1, pp. 43. |
| Keywords: |
Emission analysis;
Emission lines;
Emissions;
Fluid flow;
Magnetohydrodynamics;
T Tauri stars;
Tracing;
Velocity;
Velocity gradient;
Wind; |
| Academic Unit: |
Faculty of Science and Engineering > Experimental Physics |
| Item ID: |
17615 |
| Identification Number: |
https://doi.org/10.3847/1538-4357/abf55e |
| Depositing User: |
Emma Whelan
|
| Date Deposited: |
28 Sep 2023 11:03 |
| Journal or Publication Title: |
The Astrophysical Journal |
| Publisher: |
IOP Publishing |
| Refereed: |
Yes |
| URI: |
|
| Use Licence: |
This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available
here |
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