NASA | GSFC | Fermi | 2014 Oct 21
NASA's Fermi Gamma-ray Space Telescope detected a rapid-fire "storm" of high-energy blasts from a highly magnetized neutron star, also called a magnetar, on Jan. 22, 2009. Now astronomers analyzing this data have discovered underlying signals related to seismic waves rippling throughout the magnetar.
A rupture in the crust of a highly magnetized neutron star, shown here in an artist's
rendering, can trigger high-energy eruptions. Fermi observations of these blasts
include information on how the star's surface twists and vibrates, providing new
insights into what lies beneath. (Credit: NASA/GSFC/SVS/S. Wiessinger)
Such signals were first identified during the fadeout of rare giant flares produced by magnetars. Over the past 40 years, giant flares have been observed just three times -- in 1979, 1998 and 2004 -- and signals related to starquakes, which set the neutron stars ringing like a bell, were identified only in the two most recent events.
"Fermi's Gamma-ray Burst Monitor (GBM) has captured the same evidence from smaller and much more frequent eruptions called bursts, opening up the potential for a wealth of new data to help us understand how neutron stars are put together," said Anna Watts, an astrophysicist at the University of Amsterdam in the Netherlands and co-author of a new study about the burst storm. "It turns out that Fermi's GBM is the perfect tool for this work." ...
Quasi-Periodic Oscillations in Short Recurring Bursts of the Soft-Gamma Repeater J1550-5418 - Daniela Huppenkothen et al
- Astrophysical Journal 787(2) 128 (2014 Jun 01) DOI: 10.1088/0004-637X/787/2/128
arXiv.org > astro-ph > arXiv:1404.2756 > 10 Apr 2014
- Astrophysical Journal 768(1) 87 (2013 May 01) DOI: 10.1088/0004-637X/768/1/87
arXiv.org > astro-ph > arXiv:1212.1011 > 05 Dec 2012 (v1), 06 Mar 2013 (v2)