Structure of the accretion flow of IX Velorum as revealed by high-resolution spectroscopy

TL;DR

This study uses high-resolution spectroscopy to map the accretion flow and outflows in IX Vel, revealing complex structures including a disc wind and outflow near L3, and refining the system's orbital parameters.

Contribution

It provides detailed Doppler and temperature maps of IX Vel's accretion disc and outflows, highlighting features like the disc wind and outflow regions near L3, which are new insights.

Findings

Identification of irradiated secondary star face

Detection of high-temperature region in accretion disc

Evidence of accretion disc wind and outflow near L3

Abstract

Context: Several high-mass transfer cataclysmic variables show evidence for outflow from the system, which could play an important role in their evolution. We investigate the system IX Vel, which was proposed to show similar characteristics. Aims: We study the structure of the IX Vel system, particularly the structure of its accretion flow and accretion disc. Methods: We use high-resolution time-resolved spectroscopy to construct radial velocity curves of the components in IX Vel, we compute Doppler maps of the system which we use to estimate the temperature distribution maps. Results: We improve the spectroscopic ephemeris of the system and its orbital period P_orb = 0.19392793(3) d. We construct Doppler maps of the system based on hydrogen and helium emission lines and the Bowen blend. The maps show features corresponding to the irradiated face of the secondary star, the outer rim of the accretion disc, and low-velocity components located outside the accretion disc and reaching towards L3. We constructed a temperature distribution map of the system using the Doppler maps of Balmer lines. Apart from the features found in the Doppler maps, the temperature distribution map shows a region of high temperature in the accretion disc connecting the expected position of a bright spot and the inner parts of the disc. Conclusions: We interpret the low-velocity emission found in the Doppler map as emission originating in the accretion disc wind and in an outflow region located in the vicinity of the third Lagrangian point L3. This makes IX Vel a member of the RW Sex class of Cataclysmic Variables.