arXiv subjects

A. Domingo

Publications and source records attributed to A. Domingo.

22 records · Page 2Linked to original sources

arXiv2005

3A 0535+262 in outburst

The Be/X-ray binary 3A 0535+262 has the highest magnetic field determined by cyclotron line studies of all accreting X-ray pulsars, despite an open debate if the fundamental line was rather at ~50 or above 100 keV as observed by different instruments in past outbursts. The source went into quiescence for more than ten years since its last outbursts in 1994. Observing during a `normal' outburst August/September 2005 with Integral and RXTE we find a strong cyclotron line feature at ~45 keV and have for the first time since 1975 determined the low energy pulse profile.

astro-ph↗

arXiv2003

INTEGRAL timing and localization performance

In this letter we report on the accuracy of the attitude, misalignment, orbit and time correlation which are used to perform scientific analyses of the INTEGRAL data. The boresight attitude during science pointings has an accuracy of 3 arcsec. At the center of the field, the misalignments have been calibrated leading to a location accuracy of 4 to 40 arcsec for the different instruments. The spacecraft position is known within 10 meters. The relative timing between instruments could be reconstructed within 10 microsec and the absolute timing within 40 microsec.

astro-ph↗

arXiv2000

The luminosity calibration of the uvby-$β$ photometry

The ESA HIPPARCOS satellite has provided astrometry of unprecedented accuracy, allowing to reassess, improve and refine the pre-HIPPARCOS luminosity calibrations. We review the "classical" absolute magnitude calibrations with the Stroemgren-Crawford intermediate-band photometric system. A small zero point correction of about 2-4% seems necessary, as well as to refine the dependences on metallicity and projected rotational velocity. The need of a rigorous statistical treatment of the extremely precise HIPPARCOS to derive definite dependences of the luminosity on physical stellar parameters is emphasized.

astro-ph↗

arXiv1998

CP stars: Photometric calibrations of luminosity using Hipparcos data

The application of the Stromgren photometric luminosity calibrations to different types of CP stars is reexamined in the light of the new Hipparcos data. A first attempt is made to use the LM statistical parallax method (Luri et al., 1996) -- based on the maximum likelihood principle -- to obtain a calibration of the absolute magnitude as a function of two Stromgren colour indices, thus reflecting effective temperature and evolution. Its application to a sample of Si stars and to a sample of normal main sequence stars in the same spectral range allows us to compare the calibrations obtained and to discuss the position of Si stars in the HR diagram. Additionally, a sample of bonafide, spectroscopically selected Am stars together with normal main sequence stars are used to derive a new absolute magnitude calibration for late A-type main sequence stars, taking into account the effects of evolution, metallicity and stellar rotation.

astro-ph↗