Discovery of an Accretion-rate Independent Absolute RMS Amplitude of Millihertz Quasi-periodic Oscillations in 4U 1636-53
Autor: | Mariano Mendez, G. C. Mancuso, Ming Lyu, Guobao Zhang, Diego Altamirano |
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Přispěvatelé: | Astronomy |
Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
010504 meteorology & atmospheric sciences
Astrophysics::High Energy Astrophysical Phenomena Ciencias Físicas BINARIES [X-RAYS] FOS: Physical sciences Binary number Astrophysics 01 natural sciences purl.org/becyt/ford/1 [https] Accretion rate stars: neutron X-rays: binaries DATA ANALYSIS Position (vector) 0103 physical sciences NEUTRON [STARS] 010303 astronomy & astrophysics 0105 earth and related environmental sciences High Energy Astrophysical Phenomena (astro-ph.HE) Physics Astronomy and Astrophysics purl.org/becyt/ford/1.3 [https] methods: data analysis Astronomía Amplitude Space and Planetary Science Physics::Accelerator Physics Quasi periodic Astrophysics - High Energy Astrophysical Phenomena CIENCIAS NATURALES Y EXACTAS |
Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET The Astrophysical Journal, 885(1):5. IOP PUBLISHING LTD |
ISSN: | 0004-637X |
Popis: | We investigate the frequency and amplitude of the millihertz quasi-periodic oscillations (mHz QPOs) in the neutron-star low-mass X-ray binary (NS LMXB) 4U 1636-53 using Rossi X-ray Timing Explorer observations. We find that no mHz QPOs appear when the source is in the hard spectral state. We also find that there is no significant correlation between the frequency and the fractional rms amplitude of the mHz QPOs. Notwithstanding, for the first time, we find that the absolute RMS amplitude of the mHz QPOs is insensitive to the parameter Sa, which measures the position of the source in the colour-colour diagram and is usually assumed to be an increasing function of mass accretion rate. This finding indicates that the transition from marginally stable burning to stable burning or unstable burning could happen very rapidly since, before the transition, the mHz QPOs do not gradually decay as the rate further changes. Comment: Accepted for publication in ApJ, 9 pages, 8 figures |
Databáze: | OpenAIRE |
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