Water Fountain Sources Monitored in FLASHING
Paper in proceeding, 2022
We have investigated the spectral evolutions of H2O and SiO masers associated with 12 water fountain sources in our FLASHING (Finest Legacy Acquisitions of SiO-/H2O-maser Ignitions by Nobeyama Generation) project. Our monitoring observations have been conducted using the Nobeyama 45 m telescope every 2 weeks-2 months since 2018 December except during summer seasons. We have found new extremely high velocity H2O maser components, breaking the records of jet speeds in this type of sources. Systematic line-of-sight velocity drifts of the H2O maser spectral peaks have also been found, indicating acceleration of the entrained material hosting the masers around the jet. Moreover, by comparing with previous spectral data, we can find decadal growths/decays of H2O maser emission. Possible periodic variations of the maser spectra are further being inspected in order to explore the periodicity of the central stellar system (a pulsating star or a binary). Thus we expect to see the real-time evolution/devolutions of the water fountains over decades.
outflows
stars: AGB and post-AGB
stars: mass loss
masers
stars: winds
Author
Hiroshi Imai
Kagoshima University
Kei Amada
Kagoshima University
J. F. Gomez
Institute of Astrophysics of Andalusia (IAA)
L. Uscanga
Universidad de Guanajuato
Daniel Tafoya
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Keisuke Nakashima
Kagoshima University
K. Y. Shum
Kagoshima University
Yuhki Hamae
Kagoshima University
R. A. Burns
RIKEN
National Astronomical Observatory of Japan
Yosuke Shibata
Kagoshima University
Rina Kasai
Kagoshima University
Miki Takashima
Kagoshima University
G. Orosz
Joint Institute for VLBI in Europe (JIVE)
Proceedings of the International Astronomical Union
1743-9213 (ISSN) 1743-9221 (eISSN)
Vol. 18 333-337Subject Categories
Physical Chemistry
Water Engineering
Astronomy, Astrophysics and Cosmology
Oceanography, Hydrology, Water Resources
DOI
10.1017/S1743921323001916