NICER Detects a Soft X-Ray Kilohertz Quasi-periodic Oscillation in 4U 0614+09

Peter Bult , Diego Altamirano , Zaven Arzoumanian , Edward M. Cackett , Deepto Chakrabarty , John Doty , Teruaki Enoto , Keith C. Gendreau , Sebastien Guillot (1, 2) , Jeroen Homan , Gaurava K. Jaisawal , Frederick K. Lamb , Renee M. Ludlam , Simin Mahmoodifar , Craig Markwardt , Takashi Okajima , Sam Price , Tod E. Strohmayer , Luke Winternitz

1 IRAP - Institut de recherche en astrophysique et planétologie
2 CNES - Centre National d'Études Spatiales [Toulouse]

We report on the detection of a kilohertz quasi-periodic oscillation (QPO) with the Neutron Star Interior Composition Explorer (NICER). Analyzing approximately 165 ks of NICER exposure on the X-ray burster 4U 0614+09, we detect multiple instances of a single-peak upper kHz QPO, with centroid frequencies that range from 400 to 750 Hz. We resolve the kHz QPO as a function of energy, and measure, for the first time, the QPO amplitude below 2 keV. We find the fractional amplitude at 1 keV is on the order of 2% rms, and discuss the implications for the QPO emission process in the context of Comptonization models.

Mots clés: accretion; accretion disks; stars: neutron; X-rays: binaries; X-rays: individual

Domaines: Astrophysique [astro-ph]

Peter Bult, Diego Altamirano, Zaven Arzoumanian, Edward M. Cackett, Deepto Chakrabarty, et al.. NICER Detects a Soft X-Ray Kilohertz Quasi-periodic Oscillation in 4U 0614+09. Astrophys.J.Lett., 2018, 860 (1), pp.L9. ⟨10.3847/2041-8213/aac893⟩. ⟨hal-01817878⟩