0000000000643344

AUTHOR

Ralph Neuhäuser

showing 2 related works from this author

Properties of the isolated neutron star RX J185635-3754

2004

Abstract Despite improved observational capabilities, the surface properties of neutron stars remain uncertain. In principle, multiwavelength spectra can reveal their compositions and angular diameters and constrain the interior equation of state. The Chandra LETG spectrum of the brightest isolated neutron star is a featureless continuum. The X-ray blackbody fit underpredicts the observed optical fluxes, but the spectral energy distribution can be fit with a two blackbody model. No pulsations are seen. We discuss model atmosphere fits. We conclude there is no need to invoke exotic physics: RX J185635-3754 is likely a 0.5 × 10 6 years old pulsar.

PhysicsAtmospheric ScienceEquation of stateAstrophysics::High Energy Astrophysical PhenomenaContinuum (design consultancy)Aerospace EngineeringAstronomy and AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsSpectral lineAtmosphereNeutron starGeophysicsPulsarSpace and Planetary ScienceAstrophysics::Solar and Stellar AstrophysicsGeneral Earth and Planetary SciencesSpectral energy distributionBlack-body radiationAdvances in Space Research
researchProduct

XMM-Newton spectroscopy of the metal depleted T Tauri star TWA 5

2005

We present results of X-ray spectroscopy for TWA 5, a member of the young TW Hydrae association, observed with XMM-Newton. TWA~5 is a multiple system which shows Halpha emission, a signature typical of classical T Tauri stars, but no infrared excess. From the analysis of the RGS and EPIC spectra, we have derived the emission measure distribution vs. temperature of the X-ray emitting plasma, its abundances, and the electron density. The characteristic temperature and density of the plasma suggest a corona similar to that of weak-line T Tauri stars and active late-type main sequence stars. TWA 5 also shows a low iron abundance (~0.1 times the solar photospheric one) and a pattern of increasin…

PhysicsInfrared excessAstrophysics (astro-ph)FOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsAstrophysicsCoronaSpectral lineAccretion (astrophysics)StarsT Tauri starSettore FIS/05 - Astronomia E AstrofisicaSpace and Planetary ScienceTW HydraeX-rays: stars techniques: spectroscopic stars: activity stars: abundances stars: pre-main sequence stars: individual: TWA 5Main sequenceAstronomy & Astrophysics
researchProduct