Suzaku observations of two diffuse hard X-ray source regions, G22.0+0.0 and G23.5+0.1

TL;DR

This study uses Suzaku X-ray observations to analyze two diffuse hard X-ray sources, G22.0+0.0 and G23.5+0.1, identifying their spectral properties and potential as old pulsar wind nebulae.

Contribution

First detailed spectral analysis of G22.0+0.0 and G23.5+0.1 using Suzaku, suggesting they are old PWNe and clarifying their emission components.

Findings

G22.0+0.0 is a largely extended emission with complex spectral components.

G23.5+0.1 is an extended source with properties consistent with old PWNe.

Spectral analysis indicates different origins for thermal and non-thermal components.

Abstract

G22.0+0.0 and G23.5+0.1 are diffuse hard X-ray sources discovered in the ASCA Galactic Plane Survey. We present Suzaku results of spectral analysis for these sources. G22.0+0.0 is confirmed to be a largely extended emission. The spectra were represented by a highly absorbed power-law model with a photon index of 1.7+/-0.3 and a moderately absorbed thermal emission with a temperature of 0.34^{+0.11}_{-0.08} keV. The difference in the N_{H} values between the two components suggests that the thermal component is unrelated with the power-law component and is a foreground emission located in the same line-of-sight. G23.5+0.1 is an extended source with a size of 3'.5. The spectra were fitted with an absorbed power-law model with a photon index of 2.4^{+0.5}_{-0.4}. The spatial and spectral properties show that both are candidates of old pulsar wind nebulae (PWNe). In addition to the extended sources, we analyzed spectra of three point sources found in the observed fields. Based on the spectral features, we discuss origin of the sources.