2012/11/02 by Anthony L. Piro, S. R. Kulkarni · 43 citations
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Dynamo #Ejecta #Gamma-ray bursts and supernovae #Magnetar #Magnetic field #Neutron star #Pulsar #Pulsars and Gravitational Waves Research #Stellar rotation #Supernova #White dwarf #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.1088/2041-8205/762/2/l17
published in The Astrophysical Journal Letters 762(2), L17 (IOP Publishing) · Submitted for publication in The Astrophysical Journal Letters, 4 pages, 2 figures
arxiv created 2012/11/02 · openalex publication_date 2012/12/13 · arxiv updated 2015/06/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
It has long been expected that in some scenarios when a white dwarf (WD) grows to the Chandrasekhar limit, it can undergo an accretion-induced collapse (AIC) to form a rapidly rotating neutron star. Nevertheless, the detection of such events has so far evaded discovery, likely because the optical, supernova-like emission is expected to be dim and short-lived. Here we propose a novel signature of AIC: a transient radio source lasting for a few months. Rapid rotation along with flux freezing and dynamo action can grow the WD's magnetic field to magnetar strengths during collapse. The spin-down of this newly born magnetar generates a pulsar wind nebula (PWN) within the ∼10 −3 –10 −1 M ☉ of ejecta surrounding it. Our calculations show that synchrotron emission from the PWN may be detectable in the radio, even if the magnetar has a rather modest magnetic field of ∼2 × 10 14 G and an initial spin period of ∼10 ms. An all-sky survey with a detection limit of 1 mJy at 1.4 GHz would see ∼4( f /10 −2 ) above threshold at any given time, where f is the ratio of the AIC rate to Type Ia supernova rate. A similar scenario may result from binary neutron stars if some mergers produce massive neutron stars rather than black holes. We conclude with a discussion of the detectability of these types of transient radio sources in an era of facilities with high mapping speeds.