Spatially resolved X-ray study of supernova remnants that host magnetars: Implication of their fossil field origin

Abstract

Magnetars are regarded as the most magnetized neutron stars in the Universe. Aiming to unveil what kinds of stars and supernovae can create magnetars, we have performed a state-of-the-art spatially resolved spectroscopic X-ray study of the supernova remnants (SNRs) Kes 73, RCW 103, and N49, which host magnetars 1E 1841−045, 1E 161348−5055, and SGR 0526−66, respectively. The three SNRs are O-and Ne-enhanced and are evolving in the interstellar medium with densities of > 1-2 cm −3 . The metal composition and dense environment indicate that the progenitor stars are not very massive. The progenitor masses of the three magnetars are constrained to be < 20 M (11-15 M for Kes 73, 13 M for RCW 103, and ∼ 13-17 M for N49). Our study suggests that magnetars are not necessarily made from very massive stars, but originate from stars that span a large mass range. The explosion energies of the three SNRs range from 10 50 erg to ∼ 2 × 10 51 erg, further refuting that the SNRs are energized by rapidly rotating (millisecond) pulsars. We report that RCW 103 is produced by a weak supernova explosion with significant fallback, as such an explosion explains the low explosion energy (∼ 10 50 erg), small observed metal masses (M O ∼ 4 × 10 −2 M and M Ne ∼ 6 × 10 −3 M ), and sub-solar abundances of heavier elements such as Si and S. Our study supports the fossil field origin as an important channel to produce magnetars, given the normal mass range (M ZAMS < 20 M ) of the progenitor stars, the low-to-normal explosion energy of the SNRs, and the fact that the fraction of SNRs hosting magnetars is consistent with the magnetic OB stars with high fields.

Periodicity in recurrent fast radio bursts and the origin of ultralong period magnetars

“…The late-time accretion of supernova ejecta through a fallback disk 11 (Michel 1988) and its resulting torque on the central neutron star has long been considered a promising mechanism to explain the ULP of 1E 161348-5055 (Li 2007;Tong et al 2016;Ho & Andersson 2017;Xu & Li 2019), although most previous works on this subject make a number of overly simplistic assumptions. Spectroscopic calorimetry of RCW 103 with blast-wave models provide evidence for a subenergetic supernova explosion (Braun et al 2019;Zhou et al 2019), consistent with a significant quantity of fallback material. Metzger et al (2018) presented a model for fallback accretion onto millisecond magnetars, assuming that the magnetic field is aligned with the spin vector and taking into account the angular momentum and energy coupling between the disk and the magnetar, and focusing on the situation in which the fallback radius and the outer edge of the disk, are larger than the other characteristic radii in the problem.…”

Localized Fast Radio Bursts Are Consistent with Magnetar Progenitors Formed in Core-collapse Supernovae

“…In an explosion driven by a millisecond magnetar engine, excess kinetic energy would be injected into the SNR from the spin down of the magnetar, which would be observable at late times. However, the population of SNRs associated with magnetars does not appear different than the general population of SNRs in the Milky Way (Zhou et al 2019). The millisecond magnetar hypothesis also predicts large kick velocities of order 10 3 km s −1 (Duncan & Thompson 1992).…”

“…However, the distribution of magnetar kick velocities is similar to that of the general NS population (Deller et al 2012;Tendulkar 2014;Ding et al 2020). In addition, there is evidence that the stellar progenitors of magnetars span a wide range of masses (Muno et al 2006;Davies et al 2009;Zhou et al 2019), while the progenitors of engine-driven explosions are likely more massive than a typical CCSN (Blanchard et al 2020).…”

A Spectroscopic Study of Supernova Remnants with the Infrared Space Observatory

“…N49 -Bilikova et al (2007) estimated regional expansion velocities up to ∼ 500 km s -1 based on echelle spectra of Hα and [N II] emission lines, while X-ray observations indicate that N49 is enriched in Si and S (Park et al 2003(Park et al , 2012, as well as O and Ne (Zhou et al 2019). We find marginal evidence for a broad [O III] 88 μm line (a 3 σ detection, Group C, Table 2).…”