Abundance Patterns in the Interstellar Medium of the S0 Galaxy NGC 1316 (Fornax A) Revealed with Suzaku

TL;DR

This study uses Suzaku X-ray observations to analyze the metal abundance patterns in the interstellar medium of the S0 galaxy NGC 1316, revealing near-solar elemental ratios and insights into its chemical enrichment history.

Contribution

First measurement of multiple metal abundances in NGC 1316's ISM using Suzaku, showing a near-solar pattern and implications for galaxy evolution.

Findings

Abundance pattern close to solar values for O, Ne, Mg, Si, Fe.

ISM shows enhanced alpha/Fe ratio similar to elliptical galaxies.

Supports chemical enrichment from Type Ia supernovae.

Abstract

The Suzaku X-ray satellite observed the nearby S0 galaxy NGC 1316, a merger remnant aged 3 Gyr. The total good exposure time was 48.7 ksec. The spectra were well represented by a two-temperature thermal model for the interstellar medium (ISM) plus a power-law model. The cool and hot temperatures of the thermal model were 0.48 +/- 0.03 and 0.92 +/- 0.04 keV, respectively. The excellent spectral sensitivity of Suzaku enables for the first time to measure the metal abundances of O, Ne, Mg, Si, and Fe in the ISM. The resultant abundance pattern of O, Ne, Mg, Si, and Fe is close to that of the new solar abundance determined by Lodders (2003). The measured abundance pattern is compared with those of elliptical galaxies and an S0 galaxy, observed with Suzaku. Considering the metal-enrichment from present Type Ia supernovae, the near-solar abundance pattern of the ISM in NGC~1316 indicates an enhanced {\alpha}/Fe ratio of stellar materials in the entire galaxy, like in giant elliptical galaxies.