0000000000237054

AUTHOR

Alexander Heger

0000-0002-3684-1325

showing 7 related works from this author

The chemical signature of jet-driven hypernovae

2020

Hypernovae powered by magnetic jets launched from the surface of rapidly rotating millisecond magnetars are one of the leading models to explain broad-lined Type Ic supernovae (SNe Ic-BL), and have been implicated as an important source of metal enrichment in the early Universe. We investigate the nucleosynthesis in such jet-driven hypernovae using a parameterised, but physically motivated, approach that analytically relates an artificially injected jet energy flux to the power available from the energy in differential rotation in the proto-neutron star. We find ejected $^{56}\mathrm{Ni}$ masses of $0.05\,\mathrm{M}_\odot - 0.45\,\mathrm{M}_\odot$ in our most energetic models with explosion…

High Energy Astrophysical Phenomena (astro-ph.HE)Physics010308 nuclear & particles physicsAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsType (model theory)01 natural sciencesInterstellar mediumSupernovaStars13. Climate actionSpace and Planetary ScienceNucleosynthesis0103 physical sciencesAstrophysics::Solar and Stellar AstrophysicsAstrophysics - High Energy Astrophysical PhenomenaHypernovaEjecta010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsEnergy (signal processing)Monthly Notices of the Royal Astronomical Society
researchProduct

Accretion in strong field gravity with eXTP

2019

In this paper we describe the potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission for studies related to accretion flows in the strong field gravity regime around both stellar-mass and supermassive black-holes. eXTP has the unique capability of using advanced 'spectral-timing-polarimetry' techniques to analyze the rapid variations with three orthogonal diagnostics of the flow and its geometry, yielding unprecedented insight into the inner accreting regions, the effects of strong field gravity on the material within them and the powerful outflows which are driven by the accretion process.

ACTIVE GALACTIC NUCLEIAccretionaccretion; black holes physics; X-ray; Physics and Astronomy (all)black holes physicAstronomyAstrophysics::High Energy Astrophysical PhenomenaBlack holes physicsPolarimetryFOS: Physical sciencesBLACK-HOLE SPINGeneral Physics and AstronomyStrong fieldAstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesX-rayPhysics and Astronomy (all)ELECTROMAGNETIC EMISSIONSettore FIS/05 - Astronomia e Astrofisicablack holes physicsaccretion0103 physical sciencesAstrophysics::Solar and Stellar Astrophysics010306 general physics010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)XMM-NEWTONPhysicsLENS-THIRRING PRECESSION[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]QUASI-PERIODIC OSCILLATIONS[SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]IRON KAccretion (astrophysics)X ray[SDU]Sciences of the Universe [physics]ULTRA-FAST OUTFLOWSAstrophysics::Earth and Planetary AstrophysicsSPECTRAL FEATURESAstrophysics - High Energy Astrophysical Phenomena[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]X-RAY BINARIESScience China Physics, Mechanics & Astronomy
researchProduct

The Large Observatory For x-ray Timing

2014

The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m 2 effective area, 2-30 keV, 240 eV spectral resolution, 1 deg collimated field of view) and a WideFi…

x-ray and γ-ray instrumentationcompact objects; microchannel plates; X-ray detectors; X-ray imaging; X-ray spectroscopy; X-ray timing; Electronic Optical and Magnetic Materials; Condensed Matter Physics; Computer Science Applications1707 Computer Vision and Pattern Recognition; Applied Mathematics; Electrical and Electronic EngineeringVisionX-ray timingObservatoriesField of view01 natural sciences7. Clean energyneutron starsObservatory010303 astronomy & astrophysicsPhysicsEquipment and servicesApplied MathematicsAstrophysics::Instrumentation and Methods for AstrophysicsSteradian[ SDU.ASTR.IM ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]Computer Science Applications1707 Computer Vision and Pattern RecognitionX-ray detectorsCondensed Matter Physicscompact objectsX-ray spectroscopyAstrophysics - Instrumentation and Methods for AstrophysicsX-ray detector[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]Cosmic VisionSpectral resolutionmicrochannel platesAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesNOmicrochannel platecompact objects; microchannel plates; X-ray detectors; X-ray imaging; X-ray spectroscopy; X-ray timing; Electronic Optical and Magnetic Materials; Condensed Matter Physics; Applied Mathematics; Electrical and Electronic EngineeringSettore FIS/05 - Astronomia e AstrofisicaX-rayscompact object0103 physical sciencesElectronicOptical and Magnetic MaterialsElectrical and Electronic EngineeringSpectral resolutionInstrumentation and Methods for Astrophysics (astro-ph.IM)dense hadronic matterSensors010308 nuclear & particles physicsX-ray imagingAstronomyAccretion (astrophysics)[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]Neutron star13. Climate actionx-ray and γ-ray instrumentation; neutron stars; dense hadronic matter[ PHYS.ASTR.IM ] Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]Gamma-ray burstastro-ph.IM
researchProduct

Stellar(n,γ)Cross Section ofNi62

2005

The 62Ni(n,gamma)63Ni(t(1/2)=100+/-2 yr) reaction plays an important role in the control of the flow path of the slow neutron-capture (s) nucleosynthesis process. We have measured for the first time the total cross section of this reaction for a quasi-Maxwellian (kT=25 keV) neutron flux. The measurement was performed by fast-neutron activation, combined with accelerator mass spectrometry to detect directly the 63Ni product nuclei. The experimental value of 28.4+/-2.8 mb, fairly consistent with a recent calculation, affects the calculated net yield of 62Ni itself and the whole distribution of nuclei with 62<A<90 produced by the weak s process in massive stars.

Nuclear physicsPhysicsCross section (physics)StarsNucleosynthesisNeutron fluxYield (chemistry)General Physics and AstronomyAtomic physicss-processMass spectrometryAccelerator mass spectrometryPhysical Review Letters
researchProduct

Nucleosynthesis of proton-rich nuclei. Experimental results on the rp-process

2009

Experience NSCL; International audience; We report in this study the nuclear properties of proton-rich isotopes located along the rp-process path. The experiments have recently been performed at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The level properties above the proton separation energy of the nuclei 30S, 36K and 37Ca were measured with precision of < 10 keV. This will allow a reduction in the determination of the astrophysical (p, ) reaction rate under rp-process conditions.

Nuclear reactionPhysicsHistoryProton010308 nuclear & particles physics[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]Nuclear TheoryCyclotronrp-process[PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]7. Clean energy01 natural sciencesComputer Science ApplicationsEducationlaw.inventionNuclear physicsIsotopes of potassiumlawNucleosynthesis0103 physical sciencesr-processAtomic physics010306 general physicsNuclear ExperimentRadioactive decay
researchProduct

Observatory science with eXTP

2019

Disponible preprint en: arXiv:1812.04023v1 [astro-ph.HE] [v1] Mon, 10 Dec 2018 19:00:52 UTC (4,376 KB)

cataclysmic binariesAstronomyFIELD CAMERAS OBSERVATIONSspace research instruments nuclear astrophysics flare stars accretion and accretion disks mass loss and stellar winds cataclysmic binaries X-ray binaries supernova remnants active galactic nuclei X-ray bursts gamma-ray bursts gravitational wavesGeneral Physics and Astronomygamma-ray burstspace research instrument01 natural sciencesGamma ray burstsObservatoryAccretion and accretion disksAstrophysics::Solar and Stellar Astrophysics010303 astronomy & astrophysicsgravitational waveaccretion and accretion diskPhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)supernova remnants[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph][SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]flare starsgamma-ray burstsAstrophysics::Instrumentation and Methods for Astrophysicsaccretion and accretion disks; active galactic nuclei; cataclysmic binaries; flare stars; gamma-ray bursts; gravitational waves; mass loss and stellar winds; nuclear astrophysics; space research instruments; supernova remnants; X-ray binaries; X-ray bursts; Physics and Astronomy (all)Space research instrumentsX ray burstSupernovaX-ray binariesgravitational wavesaccretion and accretion disksQUIETHigh massX-ray binarieMass loss and stellar windsNuclear astrophysicsGamma-ray burstsspace research instrumentsAstrophysics - High Energy Astrophysical PhenomenaPULSAR-WIND NEBULAEFAST RADIO-BURSTSAstrofísica nuclearActive galactic nucleusTIDAL DISRUPTIONSupernova remnantsAstrophysics::High Energy Astrophysical Phenomenanuclear astrophysicsPolarimetryFOS: Physical sciencesAstrophysics::Cosmology and Extragalactic AstrophysicsACCRETING NEUTRON-STARSaccretion and accretion disks; active galactic nuclei; cataclysmic binaries; flare stars; gamma-ray bursts; gravitational waves; mass loss and stellar winds; nuclear astrophysics; space research instruments; supernova remnants; X-ray binaries; X-ray burstsGravitational wavesPhysics and Astronomy (all)cataclysmic binarieSettore FIS/05 - Astronomia e AstrofisicaSUPERMASSIVE BLACK-HOLES0103 physical sciences010306 general physicsX-ray burstAstrophysics::Galaxy AstrophysicsCataclysmic binariesActive galactic nucleiflare starAstronomyWhite dwarfFlare starsStarssupernova remnantQB460-466 Astrophysics[SDU]Sciences of the Universe [physics]mass loss and stellar wind:Física::Astronomia i astrofísica [Àrees temàtiques de la UPC]active galactic nucleiX-RAYX-ray burstsSupernova remmantsmass loss and stellar windsX ray binaries[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]SEYFERT 1 GALAXYnuclear astrophysic
researchProduct

Dense matter with eXTP

2019

In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics o…

GAMMA-RAY PULSARSdense matterAstrophysics::High Energy Astrophysical PhenomenaPolarimetryGeneral Physics and AstronomyFOS: Physical sciencesAstrophysicsNeutronBRIGHTNESS OSCILLATIONS7. Clean energy01 natural sciencesINNER ACCRETION DISKSSpectral lineX-raydense matter; equation of state; neutron; X-rays; Physics and Astronomy (all)Physics and Astronomy (all)Equacions d'estatneutronPulsar0103 physical sciencesMILLISECOND PULSARSX-raysNEUTRON-STARRADIUS CONSTRAINTS010306 general physics010303 astronomy & astrophysicsRELATIVISTIC IRON LINEequation of statePhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)LIGHT CURVESNeutronsEquation of stateQUASI-PERIODIC OSCILLATIONSX-RaysStarke Wechselwirkung und exotische Kerne – Abteilung BlaumAstrophysics::Instrumentation and Methods for AstrophysicsEQUATION-OF-STATEAccretion (astrophysics)Neutron star:Física::Astronomia i astrofísica [Àrees temàtiques de la UPC]Raigs XAstrophysics::Earth and Planetary AstrophysicsAstrophysics - High Energy Astrophysical PhenomenaDense matterDense matter
researchProduct