Detailed ROSAT X-ray Analysis of the AM Her Cataclysmic Variable VV Pup

TL;DR

This paper presents a detailed analysis of ROSAT X-ray data for the AM Her star VV Pup, including light curves, spectral fitting with multiple components, and phase-resolved spectral parameters to understand its accretion behavior.

Contribution

The study provides the first comprehensive phase-resolved spectral analysis of VV Pup using ROSAT data, incorporating multi-component spectral modeling and detailed light curve analysis.

Findings

X-ray light curves show variability with orbital phase.

Spectral fitting reveals a soft blackbody and hard bremsstrahlung components.

Phase-dependent spectral parameters highlight accretion dynamics.

Abstract

VV Pup is typical system of AM Her stars, where the main accreting pole rotates in and out of view during the orbital cycle. In the present paper we present ROSAT data analysis for the magnetic cataclysmic variable VV Pup. We obtained the X-ray light curves of VV Pup in high state, the PSPC count rate 0.1-2.0 keV is plotted as a function of time with bins of 10 sec and the count rate is folded over the orbital period of 100.4 min with bin size of 100 sec for individual observations. We calculate the mean best-fit PSPC spectrum, with a three-component spectral fit including a soft X-ray blackbody, hard X-ray bremsstrahlung, and Gaussian line covers the phase intervals, for a bright phase (phi_orb=0.9-1.1), the dip data (phi_orb=0.18-0.7), the egress from the dip (phi_orb=0.7-0.8), the phase interval phi = 0.1-0.18 and the mean best-fit spectrum for all data (phi_orb=0.0-1.0). We calculate spectral parameters, the hardness ratios, count rate and total integrated black body flux.