Work

Hydrodynamical models of the outer ejecta of η Carinae: shock dynamics and X-ray emission

Year: 2026

Type: article

Abstract: ABSTRACT In this work, we present an analytical study and two-dimensional axisymmetric hydrodynamical simulations of the outer ejecta surrounding $\eta$ Carinae. This extended elliptical structure, considerably larger than the well-known Homunculus produced during the 1890s eruption, provides evidence for multiple mass-ejection episodes between the 13th and 17th centuries. We explore the hypothesis that a major eruption in the 1500s led to the formation of the observed elliptical layer extending up to $\sim 0.7$ pc along the symmetry axis of the Homunculus. We modelled this structure as the result of shocks driven by this eruptive event into the ambient stellar wind. After 520 yr of evolution, our models predict a projected size of $\sim 0.73$ pc and an expansion velocity of $\simeq 1400\ \mathrm{km\ s^{-1}}$, in good agreement with observations of the outer ejecta. In addition, we modelled the expected X-ray emission and obtained results consistent with recent X-ray observations of this astrophysical object.

Source: Monthly Notices of the Royal Astronomical Society

DOI: 10.1093/mnras/stag1208

Authors: K M Vargas-Rojas, R F González, P F Velázquez, J C Toledo-Roy

Institution: Universidad Nacional Autónoma de México

Language: English

Topic: Stellar, planetary, and galactic studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,046

Funders: Universidad Nacional Autónoma de México, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México