J/A+A/646/A116 EG And Halpha line fluxes and radial velocities (Shagatova+ 2021)
Wind mass transfer in S-type symbiotic binaries.
III. Confirmation of a wind focusing in EG Andromedae from the nebular
[O III] lambda 5007 line.
Shagatova N., Skopal A., Shugarov S.Yu., Komzik R., Kundra E., Teyssier F.
<Astron. Astrophys. 646, A116 (2021)>
=2021A&A...646A.116S 2021A&A...646A.116S (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Spectroscopy ; Radial velocities
Keywords: binaries: symbiotic - scattering - stars: winds - stars: outflows -
stars: individual: EG And
Abstract:
Structure of the wind from the cool giants in symbiotic binaries
carries important information for understanding the wind mass transfer
to their white dwarf companions, its fuelling, and thus the path to
different phases of symbiotic-star evolution.
In this paper we indicate a non-spherical distribution of the neutral
wind zone around the red giant (RG) in the symbiotic binary star EG
And. In particular, its focusing towards the orbital plane and the
asymmetry alongside the orbital motion of the RG.
We achieved this aim by analysing the periodic orbital variations of
fluxes and radial velocities of individual components of the H_alpha
and [OIII] lambda 5007 lines observed on our high-cadence medium
(R∼11000) and high-resolution (R∼38000) spectra.
The asymmetric shaping of the neutral wind zone at the
near-orbital-plane region is indicated by:
(i) the asymmetric course of the Halpha core emission fluxes along
the orbit,
(ii) the presence of their secondary maximum around the orbital phase
phi=0.1 possibly caused by the refraction effect, and
(iii) the properties of the H_alpha broad wing emission originating by
Raman scattering on H0 atoms.
The wind is substantially compressed from polar directions to the
orbital plane as constrained by the location of the [OIII] lambda 5007
line emission zones in the vicinity of the RG at/around its poles. The
corresponding mass-loss rate from the polar regions of
≲10-8M☉/yr is a factor of ≳10 lower than the average rate of
∼10-7M☉/yr derived from nebular emission of the ionized wind
from the RG, and it is two orders of magnitude lower than that
measured in the near-orbital-plane region from Rayleigh scattering.
The startling properties of the nebular [OIII] lambda 5007 line in
EG And provides an independent indication of the wind focusing towards
the orbital plane -- the key to understanding the efficient wind mass
transfer in symbiotic binary stars.
Description:
Log of spectroscopic observations of S-type symbiotic star EG And
containing HJD, date, analysed spectral lines (Halpha, [OIII] or
both) and observatory are given. For Halpha line, measured fluxes and
radial velocities of core emission, wing emission and absorption
component with corresponding orbital phase are presented.
Objects:
-------------------------------------------
RA (2000) DE Designation(s)
-------------------------------------------
00 44 37.19 +40 40 45.7 EG And = HD 4174
-------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 67 120 Log of spectral observations of EG And
table2.dat 103 109 *Fluxes and radial velocities of Halpha line
profile components
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Note on table2.dat: Correction for interstellar extinction according to
Cardelli et al. (1989ApJ...345..245C 1989ApJ...345..245C) with E(B-V)=0.05
(Muerset et al., 1991A&A...248..458M 1991A&A...248..458M).
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See also:
J/AJ/152/1 : Spectroscopy of EG And over roughly 14 years (Kenyon+, 2016)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
6- 16 F11.3 d HJD Heliocentric Julian date
24- 37 A14 "date" Date Date (yyyy/mm/dd.ddd)
45- 59 A15 --- Line Analysed spectral lines (H_alpha, [OIII] or both)
64- 67 A4 --- Obs Observatory / Database (1)
--------------------------------------------------------------------------------
Note (1): Observatory/Database as follows:
G1 = Stara Lesna Observatory
SP = Skalnate Pleso Observatory
ARAS = Astronomical Ring for Access to Spectroscopy database
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
6- 19 A14 --- Date Date (yyyy/mm/dd.ddd)
26- 30 F5.3 --- Phase Orbital phase
36- 41 F6.3 10-14W/m2 Fce Flux in the core-emission component of the
Halpha line (in 10-11erg/cm2/s unit)
49- 53 F5.3 10-14W/m2 Fwe Flux in the wing-emission component of the
Halpha line (in 10-11erg/cm2/s unit)
59- 65 F7.3 10-14W/m2 Fa Flux in the absorption component of the
Halpha line (in 10-11erg/cm2/s unit)
72- 79 F8.3 km/s RVce Radial velocity of the core-emission
component of the Halpha line
84- 91 F8.3 km/s RVwe Radial velocity of the wing-emission
component of the Halpha line
96-103 F8.3 km/s RVa Radial velocity of the absorption
component of the Halpha line
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Acknowledgements:
Natalia Shagatova, nshagatova(at)ta3.sk
References:
Shagatova & Carikova, Paper I 2015A&A...573A...8S 2015A&A...573A...8S
Shagatova et al., Paper II 2016A&A...588A..83S 2016A&A...588A..83S
(End) Natalia Shagatova [AI SAS, Slovakia], Patricia Vannier [CDS] 11-Dec-2020