0000000000451418

AUTHOR

Nuria Huélamo

showing 3 related works from this author

Search for Low-mass Companions to X-ray Emitting A-type Stars

2007

There is no obvious theory that would explain X-ray emission from main-sequence A-type stars. Therefore, the X-ray emission identified with these stars on basis of low spatial resolution X-ray observations is usually attributed to magnetic activity from unknown late-type companion stars. We systematically study the literature and public 2MASS data in search for binaries among A stars. This way, we identify new candidate counterparts for the X-ray sources in at least 60% of the A-type stars claimed to be detected in the ROSAT All-Sky Survey. There is marginal evidence that this fraction decreases from early to late A spectral type, possibly indicating the onset of intrinsic X-ray emission fo…

PhysicsAstrophysics::High Energy Astrophysical PhenomenaAstronomyAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsA-type main-sequence starStarsDynamo theoryROSATAstrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary AstrophysicsLow MassAstrophysics::Galaxy AstrophysicsVisual binary
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Testing the companion hypothesis for the origin of the X-ray emission from intermediate-mass main-sequence stars

2006

There is no straightforward explanation for intrinsic X-ray emission from intermediate-mass main-sequence stars. Therefore the observed emission is often interpreted in terms of (hypothesized) late-type magnetically active companion stars. We use Chandra imaging observations to spatially resolve in X-rays a sample of main-sequence B-type stars with recently discovered companions at arcsecond separation. We find that all spatially resolved companions are X-ray emitters, but seven out of eleven intermediate-mass stars are also X-ray sources. If this emission is interpreted in terms of additional sub-arcsecond or spectroscopic companions, this implies a high multiplicity of B-type stars. Firm …

PhysicsSpatially resolvedAstrophysics::High Energy Astrophysical PhenomenaAstrophysics (astro-ph)FOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsStarsSpace and Planetary ScienceAstrophysics::Solar and Stellar AstrophysicsAstrophysics::Earth and Planetary AstrophysicsMultiplicity (chemistry)Main sequenceAstrophysics::Galaxy Astrophysics
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Recent GRBs observed with the 1.23m CAHA telescope and the status of its upgrade

2010

We report on optical observations of Gamma-Ray Bursts (GRBs) followed up by our collaboration with the 1.23m telescope located at the Calar Alto observatory. The 1.23m telescope is an old facility, currently undergoing upgrades to enable fully autonomous response to GRB alerts. We discuss the current status of the control system upgrade of the 1.23m telescope. The upgrade is being done by our group based on the Remote Telescope System, 2nd Version (RTS2), which controls the available instruments and interacts with the EPICS database of Calar Alto. (Our group is called ARAE (Robotic Astronomy & High-Energy Astrophysics) and is based on members of IAA (Instituto de Astrofísica de Andalucía). …

High Energy Astrophysical Phenomena (astro-ph.HE)Article Subjectlcsh:AstronomyComputer scienceAstronomyFOS: Physical sciencesAstronomy and AstrophysicsBOOTESlaw.inventionlcsh:QB1-991TelescopeUpgradeSpace and Planetary ScienceObservatorylawAstrophysics - Instrumentation and Methods for AstrophysicsAstrophysics - High Energy Astrophysical PhenomenaGamma-ray burstInstrumentation and Methods for Astrophysics (astro-ph.IM)
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