A large misalignment between continuous jet and discrete ejecta in microquasar GRS 1915+105 during its obscured phase

TL;DR

This study reveals a significant and recurrent misalignment between continuous jets and discrete ejecta in GRS 1915+105, suggesting a warped accretion disk influences jet launching during obscured phases.

Contribution

It provides the first detailed observation of large, recurrent jet misalignments in GRS 1915+105, linking jet geometry changes to accretion disk warping during obscured states.

Findings

Discrete ejecta PA differs by about 41 degrees from continuous jet PA.

Lowest reported intrinsic ejecta velocity is approximately 0.35c.

Recurrent misalignment observed during separate flare events.

Abstract

We report a large misalignment between the continuous jet and the discrete ejecta in GRS 1915+105, detected in April 2023 with the East Asian VLBI network (EAVN). Two-sided ejecta are shown at 6.7 GHz images and central continuous jets are resolved at 43 GHz by EAVN quasi-simultaneously. While the continuous jet was aligned with the long-standing jet position angle (PA) of about 147 degree, the discrete ejecta appeared at a markedly different PA about 188 degree, with the lowest intrinsic velocity about 0.35 c ever reported. A similar misalignment of PA between discrete ejecta and continuous jet was independently detected in late September of 2023 during a consecutive flare event. The pronounced and recurrent angular deviations suggest a time-variable jet launching geometry, which, in conjunction with the observed X-ray obscuration, can be attributable to a warped accretion disk. Our result could offer new insight into the fundamental differences between continuous jet and discrete ejecta, and broadly provides a clue to understand the phenomena for transient black hole X-Ray binaries and changing-look active galactic nuclei during the X-ray obscured phase.