An optical spectroscopic and polarimetric study of the microquasar binary system SS 433. (arXiv:2007.09615v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Picchi_P/0/1/0/all/0/1">P. Picchi</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Shore_S/0/1/0/all/0/1">S. N. Shore</a> (1 and 2) ((1) Dipartimento di Fisica ''Enrico Fermi'', Università di Pisa, (2) INFN- Sezione Pisa, Pisa, Italy)
We present a study of the mass transfer and wind outflows of SS433, focusing
on the so-called stationary lines based on archival high and medium resolution
optical spectra, and new optical multifilter polarimetry and low resolution
optical spectra spanning an interval of a decade and a broad range of
precessional and orbital phases. We derive $text{E(B-V)}=0.86pm0.10$ and
revised UV and U band polarizations and polarization angles that yield the same
position angle as the optical. The polarization wavelength dependence is
consistent with optical-dominating electron scattering with a Rayleigh
component in U and the UV filters; no polarization changes were observed during
a flare event. Using profile orbital and precessional modulation of multiple
lines we derive properties for the accretion disk, present evidence for a
strong disk wind, determine its velocity structure, and demonstrate its
variability on timescales unrelated to the orbit. We derive a mass ratio
$q=0.37pm0.04$, and masses $text{M}_X=4.2pm0.4 text{M}_odot$,
$text{M}_A=11.3pm 0.6 text{M}_odot$, and show that the A star fills its
Roche surface. The O I 7772 r{A} and 8446 r{A} lines show different but
related orbital modulation and no evidence for a circumbinary disk component.
Instead, the spectral line profile variability can be understood with an
ionization stratified outflow predicted by thermal wind modeling, which also
accounts for an extended equatorial structure detected at long wavelength.
We present a study of the mass transfer and wind outflows of SS433, focusing
on the so-called stationary lines based on archival high and medium resolution
optical spectra, and new optical multifilter polarimetry and low resolution
optical spectra spanning an interval of a decade and a broad range of
precessional and orbital phases. We derive $text{E(B-V)}=0.86pm0.10$ and
revised UV and U band polarizations and polarization angles that yield the same
position angle as the optical. The polarization wavelength dependence is
consistent with optical-dominating electron scattering with a Rayleigh
component in U and the UV filters; no polarization changes were observed during
a flare event. Using profile orbital and precessional modulation of multiple
lines we derive properties for the accretion disk, present evidence for a
strong disk wind, determine its velocity structure, and demonstrate its
variability on timescales unrelated to the orbit. We derive a mass ratio
$q=0.37pm0.04$, and masses $text{M}_X=4.2pm0.4 text{M}_odot$,
$text{M}_A=11.3pm 0.6 text{M}_odot$, and show that the A star fills its
Roche surface. The O I 7772 r{A} and 8446 r{A} lines show different but
related orbital modulation and no evidence for a circumbinary disk component.
Instead, the spectral line profile variability can be understood with an
ionization stratified outflow predicted by thermal wind modeling, which also
accounts for an extended equatorial structure detected at long wavelength.
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