Search results for "X-rays: individual: NGC 247 ULX-1"

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The Chameleon on the branches: spectral state transition and dips in NGC 247 ULX-1

2021

Soft Ultra-Luminous X-ray (ULXs) sources are a subclass of the ULXs that can switch from a supersoft spectral state, where most of the luminosity is emitted below 1 keV, to a soft spectral state with significant emission above 1 keV. In a few systems, dips have been observed. The mechanism behind this state transition and the dips nature are still debated. To investigate these issues, we obtained a long XMM-Newton monitoring campaign of a member of this class, NGC 247 ULX-1. We computed the hardness-intensity diagram for the whole dataset and identified two different branches: the normal branch and the dipping branch, which we study with four and three hardness-intensity resolved spectra, r…

High Energy Astrophysical Phenomena (astro-ph.HE)PhysicsPhotosphereAbsorption spectroscopy010308 nuclear & particles physicsAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesFluxAstronomy and AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysics01 natural sciencesOccultationX-rays: individual: NGC 247 ULX-1Spectral lineLuminosityX-rays: binariesSpace and Planetary Science0103 physical sciencesThermalBlack-body radiation[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]Astrophysics - High Energy Astrophysical Phenomena010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsMonthly Notices of the Royal Astronomical Society
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