Radio Transients from the Accretion Induced Collapse of White Dwarfs

Дата и время публикации : 2012-11-02T20:00:08Z

Авторы публикации и институты :
Anthony L. Piro (Caltech)
S. R. Kulkarni (Caltech)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: Submitted for publication in The Astrophysical Journal Letters, 4 pages, 2 figures
Первичная категория: astro-ph.HE

Все категории : astro-ph.HE, astro-ph.SR

Краткий обзор статьи: 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 spindown of this newly born magnetar generates a pulsar wind nebula (PWN) within the ~0.001-0.1Msun 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 radio sources in an era of facilities with high mapping speeds.

Category: Physics