Confronting feedback simulations with observations of hot gas in elliptical galaxies

TL;DR

This paper investigates the discrepancy between observed hot gas properties and theoretical feedback models in elliptical galaxies, aiming to improve interpretation of X-ray data and understand galaxy evolution.

Contribution

It develops a new model to interpret X-ray observations of hot gas, linking feedback processes with galaxy outflows and evolution.

Findings

Identifies the discrepancy between observed and expected hot gas properties.

Proposes a model to interpret X-ray data in the context of feedback and outflows.

Enhances understanding of galaxy evolution through feedback analysis.

Abstract

Elliptical galaxies comprise primarily old stars, which collectively generate a long-lasting feedback via stellar mass-loss and Type Ia SNe. This feedback can be traced by X-ray-emitting hot gas in and around such galaxies, in which little cool gas is typically present. However, the X-ray-inferred mass, energy, and metal abundance of the hot gas are often found to be far less than what are expected from the feedback, particularly in so-called low L_X/L_B ellipticals. This "missing" stellar feedback is presumably lost in galaxy-wide outflows, which can play an essential role in galaxy evolution (e.g., explaining the observed color bi-modality of galaxies). We are developing a model that can be used to properly interpret the X-ray data and to extract key information about the dynamics of the feedback and its interplay with galactic environment.