Young pre-low-mass X-ray binaries in the propeller phase

Abstract

Context. Discovery of the 6.7-h periodicity in the X-ray source 1E 161348-5055 in RCW 103 has led to investigations of the nature of this periodicity. Aims. To explore a model for 1E 161348-5055 wherein a fast-spinning neutron star with a magnetic field ∼10 12 G in a young prelow-mass X-ray Binary (pre-LMXB) with an eccentric orbit of period 6.7 h operates in the "propeller" phase. Methods. The 6.7-h light curve of 1E 161348-5055 is modeled in terms of orbitally-modulated mass transfer through a viscous accretion disk and subsequent propeller emission. Formation of eccentric binaries in supernovae and their subsequent tidal evolution are studied.Results. The light curve of 1E 161348-5055 can be quantitatively accounted for by models of propeller torques of both IllarionovSunyaev type and Romanova-Lovelace et al. type, and spectral and other properties are also in agreement. Formation and evolution of model systems are shown to be in accordance both with standard theories and with X-ray observations of 1E 161348-5055. Conclusions. The pre-LMXB model for 1E 161348-5055 and similar sources agrees with observation. Distinguishing features between this model and the recently-proposed magnetar model need to be explored.

CHANDRAOBSERVATIONS OF SNR RCW 103

“…Note that many stellar evolution and SN models, including Heger et al (2003), assume an isolated, non-rotating star. A binary system is a major ingredient in many of the proposed explanations for the CCO's strange variability (e.g., Pizzolato et al 2008;Bhadkamkar & Ghosh 2009), and binary interactions could have played a role in the mass loss of the progenitor, affecting both the CSM and the final progenitor mass. RCW 103 is an unusual system.…”

“…Such a binary scenario is also one of the two leading hypotheses for explaining the strange nature of the CCO (Pizzolato et al 2008;Bhadkamkar & Ghosh 2009). Unfortunately, the superposition of CSM and metal-rich ejecta emission throughout the remnant, along with the variations in absorbing column density, make a reliable estimate of the shocked CSM mass very difficult in the current data.…”

“…Visible only in the X-ray and with a periodicity of 6.68 hr (Esposito et al 2011), the nature of this CCO is still being debated (Reynoso et al 2004;Li 2007;De Luca et al 2008;Pizzolato et al 2008;Bhadkamkar & Ghosh 2009;Esposito et al 2011;Ikhsanov et al 2013). X-ray observations also reveal a nearly circular shell ∼8′ in diameter, similar in morphology to the diffuse radio emission.…”

X-ray emission from isolated neutron stars

“…The periodicity, if interpreted as an orbital motion, suggests a low mass binary [20,10], but the deep optical limits pose severe constraints on the companion star [22]. Models involving magnetars, isolated or in a synchronous binary, and fall-back disks have also been proposed [129,89].…”

Progenitors and explosion properties of supernova remnants hosting central compact objects: I. RCW 103 associated with the peculiar source 1E 161348−5055

“…Past X-ray studies focused on the unusual compact object, 1E1613, at the remnant's centre. This compact object, classified as a Central Compact Object (CCO), displays strong X-ray variability (Gotthelf et al 1997) and a periodicity of 6.67 hr (De Luca et al 2006) The long ∼6.7 hr periodicity suggested several possibilities: an accreting binary system, such as a young pre-low-mass X-ray binary system with an eccentric orbit operating in the 'propeller' phase (Bhadkamkar & Ghosh 2009;Reynoso et al 2004;De Luca et al 2007), a magnetar born in a low-mass binary system (Pizzolato et al 2008), or an isolated highly magnetized neutron star accreting material from a fossil disk resulting from fallback after the neutron star's birth and slowing it down to an extremely slow period (Li 2007;Ikhsanov et al 2013;De Luca et al 2007). Recently, 1E1613 went into a period of bursting activity detected by Swift/BAT and followed up by telescopes in X-rays (Chandra, NuSTAR and Swift) and in the optical/NIR (Rea et al 2016;D'Aì et al 2016;Tendulkar et al 2017).…”