Resolving the 2024 Outburst of Magnetar 1E 1841-045 from its host Supernova Remnant with EP-FXT

TL;DR

This paper reports on the 2024 outburst of magnetar 1E 1841-045, analyzing its timing, spectral evolution, and pulse profile changes using Einstein Probe data, highlighting the importance of high-resolution observations.

Contribution

First detailed timing and spectral analysis of the 2024 outburst of magnetar 1E 1841-045 with high spatial resolution data from Einstein Probe.

Findings

20% flux increase after outburst

Pulse profile shows phase shifts and energy-dependent changes

Spectral hardening correlates with pulse phase

Abstract

The magnetar 1E 1841-045 exhibited a new active episode starting on August 20, 2024, marked by X-ray bursts and enhanced persistent emission. Using data from the Einstein Probe (EP), we report on the timing and spectral results following the onset of this outburst. The pulse profile displays a multi-peaked structure, with notable phase shifts in the secondary peak. Energy-resolved pulse profile analysis indicates a transition in the dominant peak of the pulse profile above 5.8 keV. The 0.5-10 keV X-ray spectrum is well-modeled by a combined blackbody and power-law (BB+PL) model, showing a $\sim 20\%$ flux increase following the outburst. Phase-resolved spectroscopy indicates a correlation between BB temperature and pulse profile intensity, along with spectral hardening at a specific pulse phase. The high spatial resolution of EP enables effective separation of the supernova remnant emission, which is crucial for measuring the intrinsic pulse emission of the source. These findings underscore the intricate relationship between magnetar outbursts, pulse profile evolution, and spectral characteristics.