Beating the confusion limit: The necessity of high angular resolution for probing the physics of Sagittarius A* and its environment: Opportunities for LINC-NIRVANA (LBT), GRAVITY (VLTI) and and METIS (E-ELT)

TL;DR

High angular resolution imaging with advanced telescopes like LINC-NIRVANA, GRAVITY, and METIS is essential to overcome confusion limits and effectively study the variability and physics of Sagittarius A* and its environment.

Contribution

This paper emphasizes the importance of high angular resolution observations for probing SgrA*'s variability, highlighting how upcoming instruments will improve understanding beyond current confusion limits.

Findings

Confusion limits hinder the study of SgrA*'s low states.

Blending effects can create artificial sources lasting years.

High-resolution instruments will enable detailed variability analysis.

Abstract

The super-massive 4 million solar mass black hole (SMBH) SgrA* shows variable emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light curves allows us to address the accretion phenomenon in a statistical way. The analysis shows that the near-infrared flux density excursions are dominated by a single state power law, with the low states of SgrA* limited by confusion through the unresolved stellar background. We show that for 8-10m class telescopes blending effects along the line of sight will result in artificial compact star-like objects of 0.5-1 mJy that last for about 3-4 years. We discuss how the imaging capabilities of GRAVITY at the VLTI, LINC-NIRVANA at the LBT and METIS at the E-ELT will contribute to the investigation of the low variability states of SgrA*.