Monitoring dusty sources in the vicinity of Sgr A*

TL;DR

This study tracks dusty infrared sources near SgrA* using VLT data from 2002 to 2018, revealing spectroscopic features and potential links to X-ray structures, enhancing understanding of the galactic center's environment.

Contribution

It provides new spectroscopic observations of dusty sources near SgrA*, identifying unique emission lines and their possible connection to X-ray features, expanding knowledge of the galactic center's dust and gas dynamics.

Findings

Detection of Doppler-shifted Br_gamma and HeI lines.

Exclusive [FeIII] emission in dusty sources west of SgrA*.

Correlation between Br_gamma-bar emission and X-ray bubble structure.

Abstract

We trace several dusty infrared sources on their orbit around the supermassive black hole (SMBH) SgrA* in the center of our galaxy. We give an overview of known and unknown sources in the direct vicinity of our SMBH in a radius of around 0.04pc. For that, we are using NACO (K- and L'-band) and SINFONI (H+K-band) data (VLT, Chile/Paranal) between 2002 and 2018. Our spectroscopic analysis reveals a Doppler-shifted line emission of Br_gamma and HeI. Additionally, we report the detection of [FeIII] lines that are found exclusively in the investigated dusty sources west of SgrA*. We speculate, that the known [FeIII] emission in the GC is partially generated due to the line emission of the Dusty sources investigated in this work. However, we extend our analysis of the GC by taking the bright Br_gamma-bar close (< 120 mas) to SgrA* into account. The finding of this feature is in line with a reported SgrA* X-ray bubble that consists of an open side towards G359.945-0.044 (North-West-West direction). The location of the open side of this X-ray bubble coincides with the emission of the bright Br_gamma-bar detected in our SINFONI data-cubes.