2014/04/08 by S. Campana, F. Brivio, N. Degenaar +6 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Exponential decay #Flux (metallurgy) #Galaxy #High-pressure geophysics and materials #Luminosity #Neutron star #Nuclear physics #Physics #Pulsars and Gravitational Waves Research #X-ray binary #astro-ph.HE
paper · pdf · doi:10.1093/mnras/stu709
MNRAS accepted (4 figures and 6 tables)
arxiv created 2014/04/08 · openalex publication_date 2014/05/15 · arxiv updated 2015/06/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Aql X-1 is the most prolific low-mass X-ray binary transient hosting a neutron star. In this paper we focus on the return to quiescence following the 2010 outburst of the source. This decay was monitored thanks to 11 pointed observations taken with XMM–Newton, Chandra and Swift. The decay from outburst to quiescence is very fast, with an exponential decay characteristic time-scale of ∼2 d. Once in quiescence the X-ray flux of Aql X-1 remained constant, with no further signs of variability or decay. The comparison with the only other well-monitored outburst from Aql X-1 (1997) is tale-telling. The luminosities at which the fast decay starts are fully compatible for the two outbursts, hinting at a mechanism intrinsic to the system and possibly related to the neutron star rotation and magnetic field (i.e. the propeller effect). In addition, for both outbursts, the decay profiles are also very similar, likely resulting from the shut-off of the accretion process on to the neutron star surface. Finally, the quiescent neutron star temperatures at the end of the outbursts are well consistent with one another, suggesting a hot neutron star core dominating the thermal balance. Small differences in the quiescent X-ray luminosity among the two outbursts can be attributed to a different level of the power-law component.