arXiv subjects

J. Mikolajewska

Publications and source records attributed to J. Mikolajewska.

41 records · Page 3Linked to original sources

arXiv2001

Mm/submm observations of symbiotic binary stars: implications for the mass loss and mass exchange

We discuss mm/submm spectra of a sample of symbiotic binary systems, and compare them with popular models proposed to account for their radio emission. We find that radio emission from quiescent S-type systems originates from a conical region of the red giant wind ionized by the hot companion (the STB model), whereas more complicated models involving winds from both components and their interaction are required to account for radio emission of active systems. We also find that the giant mass-loss rates derived from our observations are systematically higher than those for single cool giants. This result is in agreement with conclusions derived from IRAS observations and with requirements of models for the hot component.

astro-ph↗

arXiv2001

On the radio spectrum of CI Cygni: a test of popular models for symbiotic stars

We have determined the spectral energy distribution at wavelengths between 6 cm and 0.85 mm for the proto-typical S(stellar)-type symbiotic star, CI Cygni, during quiescence. Data were obtained simultaneously with the Very Large Array and the SCUBA sub-millimetre (sub-mm) camera on the James Clerk Maxwell Telescope. The data have allowed us to determine the free-free turnover frequency of the ionised component, facilitating a model-dependent estimate of the binary separation to compare with the known orbital parameters of CI Cug and to critically test the known models for radio emission from symbiotic stars. In particular, our data rule out the two most popular models: ionization of the giant wind by Lyman continuum photons from its hot companion and emission resulting from the interaction of winds from the two binary components.

astro-ph↗

arXiv2000

A catalogue of symbiotic stars

We present a new catalogue of symbiotic stars. In our list we include 188 symbiotic stars as well as 28 objects suspected of being symbiotic. For each star, we present basic observational material: coordinates, V and K magnitudes, ultraviolet (UV), infrared (IR), X-ray and radio observations. We also list the spectral type of the cool component, the maximum ionization potential observed, references to finding charts, spectra, classifications and recent papers discussing the physical parameters and nature of each object. Moreover, we present the orbital photometric ephemerides and orbital elements of known symbiotic binaries, pulsational periods for symbiotic Miras, Hipparcos parallaxes and information about outbursts and flickering.

astro-ph↗

arXiv1998

Recurrent Novae at Quiescence: Systems with Giant Secondaries

Spectroscopic and photometric behaviour of the class of recurrent novae with giant secondaries (T Coronae Borealis, RS Ophiuchi, V3890 Sagittarii and V745 Scorpii) at quiescence are presented in this study. The hot component in these systems is variable, with the variability manifesting as variability in the ultraviolet luminosity, the ultraviolet and optical emission line fluxes and in the UBV/visual magnitudes. The variations are uncorrelated with the binary orbital motion. The observed ultraviolet+optical spectral characteristics of the hot component in these systems can be explained by a white dwarf+accretion disc embedded in an envelope of wind from the M giant secondary. We suggest the observed variations are a result of (a) fluctuations in the mass accretion rate; (b) changes in the column density of the absorbing, optically thick, wind envelope.

astro-ph↗

arXiv1998

New binary parameters for the symbiotic recurrent nova T Coronae Borealis

The amplitude of the ellipsoidal variability, the mass function, and the evolutionary limits on the component masses have been used to constrain the binary system parameters. Contrary to all previous studies, our analysis shows that the mass ratio of T CrB q(M_giant/M_hot)=0.6, which implies a low mass binary system, with the stellar masses M_giant=0.7 solar mass, and M_hot=1.2 solar mass. This result strongly supports the thermonuclear runaway model for this recurrent nova, and solves all controversies about the nature of the hot component and the physical causes of its eruptions.

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