Ultraviolet Spectral Behavior of TVCol During and After Flaring Activity

Resumo

We studied the intermediate polar TVCol during and after its flare in November 1982 observed in the ultraviolet range with the International Ultraviolet Explorer. Two spectra revealing the variations of emission lines at different times are presented. We have estimated a new value of the reddening from the 2200 Å absorption feature, E (B − V ) = 0.12 ± 0.02, and calculated the line fluxes of C IV and He II emission lines produced in the outer accretion disk. The average ultraviolet luminosity of emitting region during and after the flare is approximately 4 × 10³² erg s⁻¹ and 9 × 10³⁰ erg s⁻¹, the corresponding average mass accretion rate is nearly 3 × 10¹⁵ erg s⁻¹ (4.76 × 10⁻¹¹M_⊙ yr⁻¹) and 5 × 10¹³ erg s⁻¹ (7.9³ × 10⁻¹³M_⊙ yr⁻¹), and the average temperature of the emitting region during and after flare is estimated to be of about 3.5 × 10³ K and 2 × 10³ K. We attribute this flare to a sudden increase in the mass accretion rate leading to the outburst activity.