Propeller effect in action: Unveiling quenched accretion in the transient X-ray pulsar 4U 0115+63

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Xiao, Hua, Tsygankov, Sergey S., Suleimanov, Valery F., Mushtukov, Alexander A., Ji, Long, Poutanen, Juri
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914057901047808
author Xiao, Hua
Tsygankov, Sergey S.
Suleimanov, Valery F.
Mushtukov, Alexander A.
Ji, Long
Poutanen, Juri
author_facet Xiao, Hua
Tsygankov, Sergey S.
Suleimanov, Valery F.
Mushtukov, Alexander A.
Ji, Long
Poutanen, Juri
contents The Be/X-ray pulsar 4U 0115+63 underwent a type II outburst in 2023. After the outburst, similar to the outbursts in 2015 and 2017, the source decayed into a quiescent state. Two out of three XMM-Newton observations conducted after the 2023 outburst confirmed the source to be in a low-luminosity state at a level of $L_{\rm X} \sim 10^{33}\,\rm erg\,s^{-1}$. X-ray pulsations were detected at $\approx$0.277 Hz in both observations with a pulsed fraction exceeding 50%. The power density spectra show no significant low-frequency red noise in both observations, suggesting that the radiation is not driven by accretion. The energy spectra in this state can be described by a single blackbody component, with an emitting area smaller than the typical size of the polar caps during the accretion phase. Based on the timing and spectral properties, we suggest that the propeller effect is active during the quiescent state, resulting in a total quenching of accretion. We discuss possible mechanisms for the generation of pulsations in this regime and consider the scenario of neutron star crust cooling.
format Preprint
id arxiv_https___arxiv_org_abs_2509_09860
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Propeller effect in action: Unveiling quenched accretion in the transient X-ray pulsar 4U 0115+63
Xiao, Hua
Tsygankov, Sergey S.
Suleimanov, Valery F.
Mushtukov, Alexander A.
Ji, Long
Poutanen, Juri
High Energy Astrophysical Phenomena
The Be/X-ray pulsar 4U 0115+63 underwent a type II outburst in 2023. After the outburst, similar to the outbursts in 2015 and 2017, the source decayed into a quiescent state. Two out of three XMM-Newton observations conducted after the 2023 outburst confirmed the source to be in a low-luminosity state at a level of $L_{\rm X} \sim 10^{33}\,\rm erg\,s^{-1}$. X-ray pulsations were detected at $\approx$0.277 Hz in both observations with a pulsed fraction exceeding 50%. The power density spectra show no significant low-frequency red noise in both observations, suggesting that the radiation is not driven by accretion. The energy spectra in this state can be described by a single blackbody component, with an emitting area smaller than the typical size of the polar caps during the accretion phase. Based on the timing and spectral properties, we suggest that the propeller effect is active during the quiescent state, resulting in a total quenching of accretion. We discuss possible mechanisms for the generation of pulsations in this regime and consider the scenario of neutron star crust cooling.
title Propeller effect in action: Unveiling quenched accretion in the transient X-ray pulsar 4U 0115+63
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2509.09860