A burst in a wind bubble and the impact on baryonic ejecta: high-energy gamma-ray flashes and afterglows from fast radio bursts and pulsar-driven supernova remnants

Abstract

Tenuous wind bubbles, which are formed by the spin-down activity of central compact remnants, are relevant in some models of fast radio bursts (FRBs) and superluminous supernovae. We study their high-energy signatures, focusing on the role of pair-enriched bubbles produced by young magnetars, rapidly-rotating neutron stars, and magnetized white dwarfs. (i) First, we study the nebular properties and the conditions allowing for escape of high-energy gamma-rays and radio waves, showing that their escape is possible for nebulae with ages of 10 − 100 yr. In the rapidly-rotating neutron star scenario, we find that radio emission from the quasi-steady nebula itself may be bright enough to be detected especially at sub-mm frequencies, which is relevant as a possible counterpart of pulsar-driven SNe and FRBs. (ii) Second, we consider the fate of bursting emission in the nebulae. We suggest that an impulsive burst may lead to a highly relativistic flow, which would interact with the nebula. If the shocked nebula is still relativistic, pre-existing non-thermal particles in the nebula can be significantly boosted by the forward shock, leading to short-duration (maybe millisecond or longer) high-energy gamma-ray flashes. Possible dissipation at the reverse shock may also lead to gamma-ray emission. (iii) After such flares, interactions with the baryonic ejecta may lead to afterglow emission with a duration of days to weeks. In the magnetar scenario, this burst-in-bubble model leads to the expectation that nearby ( 10 − 100 Mpc) high-energy gamma-ray flashes may be detected by the High-Altitude Water Cherenkov Observatory and the Cherenkov Telescope Array, and the subsequent afterglow emission may be seen by radio telescopes such as the Very Large Array. (iv) Finally, we discuss several implications specific to FRBs, including constraints on the emission regions and limits on soft gamma-ray counterparts.

The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102

“…Marcote et al (2017) have shown that the bursts and the persistent radio source are co-located to within a linear projected separation of 40 pc, suggesting that the two emission sources should be physically related, though not necessarily the same source. The radio source properties are consistent with a low-luminosity AGN or a young (<1000 year) supernova remnant (SNR) powered by an energetic neutron star (e.g., Murase et al 2016).…”

Large Host-galaxy Dispersion Measure of Fast Radio Bursts

“…Lorimer et al 2007;Keane et al 2012;Thornton et al 2013;Deng & Zhang 2014;Gao et al 2014;Murase et al 2016a), i.e.…”

The Repeating Fast Radio Burst FRB 121102 as Seen on Milliarcsecond Angular Scales

“…However, neither the SFR of M 240 1000 yr 1 - -nor the size of the region of 250-360 pc of Arp220 (Anantharamaiah et al 2000) agrees with the properties of the persistent source associated with FRB121102 ( M 0.4 yr 1 - and 0.7 pc  ). Murase et al (2016) and Piro (2016) discuss the properties of a young ( 1000 years < ) SNR that is powered by the spin-down power of a neutron star or white dwarf. The SNR expands into the surrounding medium and evacuates an ionized region that can be seen as a luminous synchrotron nebula.…”