High resolution spectroscopy of symbiotic stars

Schild, Hans H.; Dumm, T.; Mürset, U.; Nussbaumer, H.; Schmid, H. M.; Schmutz, W.

doi:10.1051/0004-6361:20000338

Cited by 22 publications

(41 citation statements)

References 20 publications

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“…AR Pav: during epochs 59−63 (1987-1995) of its historical light curve, Skopal et al (2000) estimated R e /A = 0.05 ± 0.02 (see Fig. 1 there), which for A = 419 R (Schild et al 2001) implies R d = 21±8 R . AX Per: recently, Skopal et al (2011) derived R d = 27 ± 2 R from the 2009 eclipse, which developed during the 2007−10 active phase.…”

Section: Column Density Of the Neutral Hydrogenmentioning

confidence: 95%

Ionization structure of hot components in symbiotic binaries during active phases

Cariková

Skopal

2012

A&A

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Context. During active phases of symbiotic binaries, an optically thick medium in the form of a flared disk develops around their hot stars. During quiescent phases, this structure is not evident. Aims. We propose the formation of a flared neutral disk-like structure around the rotating white dwarf (WD) in symbiotic binaries. Methods. We applied the wind compression model and calculated the ionization boundaries in the compressed wind from the WD using the equation of photoionization equilibrium. Results. During active phases, the compression of the enhanced wind from the rotating WD can form a neutral disk-like zone at the equatorial plane, while the remainder of the sphere above/below the disk is ionized. The hydrogen column density throughout the neutral zone and the emission measure of the ionized fraction of the wind, calculated for the mass loss rate from the WD, M = 2 × 10 −6 M yr −1 with v ∞ = 2000 km s −1 , are consistent with those derived from observations. During quiescent phases, the neutral disk-like structure cannot be created because of insufficient mass loss rate. Conclusions. Formation of the neutral disk-like zone at the equatorial plane is connected with the enhanced wind from the rotating WD, observed during active phases of symbiotic binaries. This probably represents a common origin of warm pseudophotospheres, indicated in the spectrum of active symbiotic binaries with a high orbital inclination.

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Section: Column Density Of the Neutral Hydrogenmentioning

confidence: 95%

Ionization structure of hot components in symbiotic binaries during active phases

Cariková

Skopal

2012

A&A

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“…With the parameters adopted above the orbital velocities of the two stellar components with respect to the center of mass are v rg = 4.6 km s −1 for the red giant and v hc = 13.8 km s Schild et al 2001) yields a mean radial velocity of 36.7 km s −1 with a scatter of σ = 1.1 km s −1 for 16 measurements taken between April 1992 and December 1997. Our FEROS spectra provide daily radial velocities for the red giant.…”

Section: Parameters For Mwc 560 Binary Systemmentioning

confidence: 99%

Spectroscopic monitoring of the jet in the symbiotic star MWC 560

Schmid¹,

Kaufer

Camenzind³

et al. 2001

A&A

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Abstract. We present the results of an intensive monitoring program of the jet absorptions in the symbiotic system MWC 560, obtained with the FEROS echelle spectrograph at the ESO 1.5 m Telescope. MWC 560 is a unique jet source because the line of sight lies practically parallel to the jet axis so that the outflowing gas is seen as absorption in the continuum of the accreting object, in the emission line spectrum of the accretion disk and temporary also in the spectrum of the red giant companion. Highly variable, blue-shifted jet absorption components, due to H i, He i, Na i, Ca ii and Fe ii are observed, which are detached from the undisplaced, narrow emission line components. The allowed emission lines from neutral and singly ionized heavy elements vary simultaneously with the strongly variable continuum emission. Therefore they can be attributed to the irradiated (chromospheric) layers of the neutral part of the accretion disk. The fluxes of forbidden emission lines are practically constant because they originate in a much larger volume. The structure and variability of the jet absorptions indicate the presence of three distinct outflow regions along the jet axis: i. An initial acceleration region above the disk with low velocities <600 km s −1 which covers only partly the central continuum source; ii. A highly variable outflow region covering the continuum source and up to about half of the line emission from the disk. This region shows repeatedly high velocity components ≈1800−2500 km s −1 which are decelerated to <1500 km s −1 within one to a few days. The appearance of high velocity components is anti-correlated and therefore closely related to the low velocity absorptions of region i. The life time of the high velocity components suggests that region ii extends to about one to a few AU from the jet source; iii. A steady flow at an intermediate velocity of ≈900−1300 km s −1 at a distance of the order ∼10 AU from the jet source. This component covers the hot continuum source and the entire narrow line region of the accretion disk. At the beginning of our campaign region iii covers also the extended red giant companion with two absorption components at 1250 km s −1 and 1140 km s −1 , which can be considered as terminal velocities v∞ of the jet outflow. The components disappear during the following several weeks as expected for the end of an occultation phase of the red giant by the collimated jet occuring probably regularly once per binary orbit. Several fast moving (1300−1700 km s −1 ), narrow absorptions are present in the Ca ii resonance lines. The high speed, low column density, and the long life time (∼months) suggest that these are radiative bow shocks in the jet cocoon generated by the collision of the transient high velocity components with slower moving jet material. A geometric model for the jet outflow in MWC 560 is presented. System parameters are derived based on our spectroscopic data and previous studies. Beside other parameters a binary separation of the order 4 AU, a jet inclination of <16•...

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“…It was suggested that "symbiotic dust" carries as much information as symbiotic emission lines (Angeloni et al 2007c), and the unique CH Cyg mid-IR spectra recorded by the ISO satellite (Schild et al 1999) complicated furthermore the system overall picture. Multiple dust shells, mixed grain chemistry, equilibrium between grain formation and destruction processes in the turbulent nebulae (Angeloni et al 2007a) are worth investigating with the new era of mm-IR facilities, such as ALMA and Herschel.…”

Section: Observational Progressmentioning

confidence: 99%

“…Regarding the infrared range, it is worth reminding some results of 1997 ISO observations, unfortunately still no fully exploited. Schild et al (1999), who did a preliminary analysis of the spectra, found no strong emission lines but [OI]63 µm, and strong OH and weak H 2 O molecular emission on top of a rapidly decreasing continuum. This continuum can be fitted by a single dust shell model (T d ∼ 1000K, Fig.…”

Section: -1997 Transition Phase: the Contribution Of Radio Synchrmentioning

confidence: 99%

The symbiotic system CH Cygni: An analysis of the shocked nebulae at different epochs

Contini¹,

Angeloni

Rafanelli

2009

Astron Nachr

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Context. We analyse the line and continuum spectra of the symbiotic system CH Cygni. Aims. To show that the colliding-wind model is valid to explain this symbiotic star at different phases. Methods. Peculiar observed features such as flickering, radio variation, X-ray emission, as well as the distribution of the nebulae and shells throughout the system are investigated by modelling the spectra at different epochs. The models account consistently for shock and photoionization and are constrained by absolute fluxes. Results. We find that the reverse shock between the stars leads to the broad lines observed during the active phases, as well as to radio and hard X-ray emission, while the expanding shock is invoked to explain the data during the transition phases.

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High resolution spectroscopy of symbiotic stars

Cited by 22 publications

References 20 publications

Ionization structure of hot components in symbiotic binaries during active phases

Ionization structure of hot components in symbiotic binaries during active phases

Spectroscopic monitoring of the jet in the symbiotic star MWC 560

The symbiotic system CH Cygni: An analysis of the shocked nebulae at different epochs

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