The X-ray Pulse Profile of BG CMi

TL;DR

This study analyzes X-ray data of BG CMi, revealing four distinct peaks in its pulse profile and energy-dependent flux variations, providing insights into the pulsar's emission mechanisms.

Contribution

It presents the first detailed analysis of BG CMi's X-ray pulse profile with multiple peaks and energy-dependent flux changes, enhancing understanding of magnetic cataclysmic variables.

Findings

Four peaks in X-ray pulse profile, unlike optical.

Flux of major pulses is 2-5 times larger than minor pulses.

Pulsed flux fraction varies significantly with energy.

Abstract

We present an analysis of the X-ray data of a magnetic cataclysmic variable, BG CMi, obtained with ROSAT in March 1992 and with ASCA in April 1996. We show that four peaks clearly exist in the X-ray pulse profile, unlike a single peak found in the optical profile. The fluxes of two major pulses are $\sim 2 - 5$ times larger than those of two minor pulses. The fraction of the total pulsed flux increases from 51% to 85% with increasing energy in 0.1 $-$ 2.0 keV, whereas it decreases from 96% to 22% in 0.8 $-$ 10 keV. We discuss the implications of our findings for the origin of the pulse profile and its energy dependence.