SPHERE/ZIMPOL observations of the symbiotic system R Aquarii. II. Dynamics of the dust in the Mira wind and the Halpha gas in the jet

@misc{schmid2026spherezimpol,
  title = {{SPHERE/ZIMPOL observations of the symbiotic system R Aquarii. II. Dynamics of the dust in the Mira wind and the Halpha gas in the jet}},
  author = {H. M. Schmid and E. Lagadec and J. Milli and C. Tschudi and J. Ma and N. Engler and J. L. Beuzit and A. Boccaletti and G. Chauvin and R. Claudi and S. Desidera and K. Dohlen and M. Feldt and R. Gratton and Th. Henning and M. Kasper and M. Langlois and F. Ménard and D. Mouillet and A. Vigan},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.05118},
  eprint = {2610.05118},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.05118},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - SPHERE/ZIMPOL observations of the symbiotic system R Aquarii. II. Dynamics of the dust in the Mira wind and the Halpha gas in the jet
AU  - H. M. Schmid
AU  - E. Lagadec
AU  - J. Milli
AU  - C. Tschudi
AU  - J. Ma
AU  - N. Engler
AU  - J. L. Beuzit
AU  - A. Boccaletti
AU  - G. Chauvin
AU  - R. Claudi
AU  - S. Desidera
AU  - K. Dohlen
AU  - M. Feldt
AU  - R. Gratton
AU  - Th. Henning
AU  - M. Kasper
AU  - M. Langlois
AU  - F. Ménard
AU  - D. Mouillet
AU  - A. Vigan
PY  - 2026
DA  - 2026/10/04
PB  - arXiv
DO  - 10.48550/arxiv.2610.05118
UR  - https://arxiv.org/abs/2610.05118
AB  - R Aqr is a resolved symbiotic Mira binary and a prototype target for the study of complex hydrodynamic processes including dust-driven mass loss, mass transfer, accretion, and jet outflows and the formation of strongly asymmetric structures. We investigate for R Aqr the central Halpha emission from the ionized gas and the polarization from scattering dust based on SPHERE/ZIMPOL maps with a resolution of about 25 mas (5 AU). Data for four epochs were taken, including the dust eclipse around 2021, to follow structural changes. The central Halpha gas traces the orbital motion of the hot component. The polarization from scattering dust shows interaction effects near the binary (<60 AU), including a flattened distribution in the orbital plane, corotating dust, and a reduction of the scattering signal during the dust eclipse. The polarization shows at >60 AU a steady outflow with about a dozen dust clouds, a few of which have a comet-like core and tail features. The dust velocity is about 20 km/s, and this is faster than for the CO gas measured with ALMA. Several prominent Halpha clouds also show scattering polarization because they are just partly ionized dust clouds from the Mira wind. We also found small faster-moving transient Halpha clouds, pointing to outflow instabilities and shocks. The observed angular shift of Halpha during the dust eclipse, can be explained by strong illumination changes from the hot component. At larger separation, the Hα clouds move faster (>100 km/s), in agreement with previous studies. This acceleration is probably a result of gas heating by photoionization and shocks, and the produced overpressure gives rise to the two well-known jet-like features expanding in polar directions. The presented R Aqr data are very useful to clarify the complex hydrodynamics taking place in AGB binaries.
ER  -