Nn. Somov et al., DISCOVERY OF MONOCHROMATIC OSCILLATIONS IN OPTICAL-SPECTRUM OF THE INTERMEDIATE POLAR RE0751+14, Astronomy and astrophysics, 332(2), 1998, pp. 526-540
We report the results of optical dynamic spectroscopy and spectropolar
imetry of the intermediate polar RE 0751+14 which were obtained with t
he help of the multichannel photon-counting system (scanner) in a high
time resolution mode(32 ms) at the 6 m telescope (BTA) from February
1993 to March 1996. The dependences of the power of oscillations on th
e wavelengths (3900-5200 Angstrom, 1 Angstrom/channel) and periods of
pulsations in the region 300-2000 a with a mean resolution along the p
eriod 10 s have been ivestigated. The statistically significant (the p
robability of random signal is till 10(-3)) perturbations of spectral
composition of the photoelectron noise in the narrow wavelength passba
nds (1 Angstrom) were discovered. Power spectra have revealed strong (
amplitude up to 40%), circularly polarized (dominating in one polariza
tion) monochromatic (FWHM in Fewer spectra 2-3 Angstrom) oscillations
with periods of 13.3-15.2 min in the vicinity of the spin period of th
e white dwarf (13.9 min) mainly in the profiles of emission lines with
the time of life 3000-5000 s. The wavelengths of the oscillations cor
respond to the solutions of the Schrodinger equation in strong resonan
ce magnetic fields (quadratic Zeeman effect). The equation for calcula
tions of resonance magnetic fields for a transitions is the equality o
f the wavelength shifts due to the linear and quadratic terms of the Z
eeman effect. As a result of the detection of the oscillations corresp
onding to sigma - transitions, the resonance magnetic fields equal for
strongest transitions of H delta approximate to 4 MGs and for H gamma
approximate to 9 MGs were measured. The strong magnetic fields indica
te that the sources of radiation causing the oscillations are in the a
ccretion column of the white dwarf. On the basis of analysis of proper
ties of the oscillations we conclude that the physical nature of the s
ources of the oscillations and its radiation cannot be explained in fr
ame of a conventional physics.