|
Description
The work is aimed at studying the circumstellar disk of the bright classical binary Be star pi Aqr. We analysed variations of a double-peaked profile of the Halpha emission line in the spectrum of pi Aqr that was observed in many phases during ~40 orbital cycles in 2004-2013. We applied the discrete Fourier transform (DFT) method to search for periodicity in the peak intensity ratio (V/R). Doppler tomography was used to study the structure of the disk around the primary. The dominant frequency in the power spectrum of the Halpha V/R ratio is 0.011873d^-1^, which corresponds to a period of 84.2(2) days and agrees with the earlier determined orbital period of the system P_orb_=84.1d. The V/R shows a sinusoidal variation that is phase-locked with the orbital period. Doppler maps of all our spectra show a non-uniform structure of the disk around the primary: a ring with the inner and outer radii at V_in_~450km/s and V_out_~200km/s, respectively, along with an extended stable region (spot) at V_x_~225km/s and Vy~100km/s. The disk radius of ~65R_{sun}_=0.33AU was estimated by assuming Keplerian motion of a particle on a circular orbit at the disk's outer edge.
|
