Fermi GBM detects pulsations from Swift J0243.6+6124
ATel #10812; P. Jenke (UAH), C. A. Wilson-Hodge (NASA)
on 3 Oct 2017; 19:04 UT
Credential Certification: Peter Jenke (email@example.com)
Subjects: Gamma Ray, Binary, Neutron Star, Transient, Pulsar
On October 1, 2017, blind searches of Fermi GBM data detected strong pulsations from an unknown source with a pulse period of 4.927 seconds. Upon the Swift discovery of the new 9.86 second accreting NS, Swift J0243.6+6124 (ATeL #10809), the GBM pulsar project performed a dedicated search for pulsations around the pulse period of 9.86 seconds from the direction of Swift J0243.6+6124 starting September 01 through October 2, 2017. Very significant pulsations were found on October 1 and October 2 with both the pulse frequency and pulsed flux increasing. The pulse frequency on October 2 was 101.4603 +/- 0.0003 mHz (9.8661 +/- 0.0003 seconds) and the pulsed flux (12-25 keV) was 0.20 +/- 0.02 keV cm-2 s-1.
Dedicated searches were also performed around periods equal to half and twice the reported period, 4.93 and 19.71 seconds, respectively. Pulsations were also detected at a slightly reduced significance for the pulse period of 4.928 seconds. No significant pulsations were detected around 19.71 seconds.
The Fermi GBM Pulsar Project