Powerful flare phenomena in water vapor maser lines in the emerging protostellar system with protoplanetary disks IRAS 16293-2422

TL;DR

This study reports the detection of powerful, short-lived water maser flares in IRAS 16293-2422, revealing new configurations of maser spots and confirming activation mechanisms related to amplification length increases.

Contribution

It presents the first experimental discovery of multiple maser spots aligned along the line of sight, advancing understanding of water maser activation in protostellar systems.

Findings

Detection of year-long maser phenomena near 6 and 8 km/s

Confirmation of multiple maser spots along the line of sight

Establishment of saturation states of different maser flares

Abstract

Based on the long-term monitoring data of the water maser since 2019.0 to 2021.0 allowed us detecting in IRAS 16293-2422 two powerful phenomena lasted about year at radial velocities near 6 and 8 km s$^{-1}$. In both cases, powerful short flares were located on the tops of less powerful, but more prolonged ones (2.5 and 0.5 kJy), radiation of which initiated the emission of more powerful flares. For the first time, configurations of several emitting maser spots located at the line of sight to the observer were discovered experimentally. This made it possible to confirm the hypothesis of activation of the water maser, based on an increase in the amplification length of the maser due to several maser condensations located at the line of sight to the observer. The unsaturated state of the most powerful and shortest maser flares, as well as the saturated state of the weak, has been established. New important parameters of the water maser and the assumed location of the maser spots have been obtained.