A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the

The power spectrum of more than 630 days of full-disk solar velocity data, provided by the GOLF spectrophotometer aboard the Solar and Heliospheric Observatory, has revealed the presence of modelike structure well beyond the acoustic cutoff frequency for the solar atmosphere ( nu _{{ac}}~5.4 mHz). Similar data produced by full-disk instruments

We present two-dimensional spectroscopy of the 125×125 pc2 circumnuclear region of M31, obtained using two optical fiber systems, INTEGRAL and 2D-FIS, installed at the 4.2 m William Herschel Telescope at the Roque de los Muchachos Observatory on the island of La Palma, Spain. We present continuum and emission-line maps, emission-line quotients, and

The first results of a program of observations designed to probe the structure and kinematics of the Local Interstellar Medium (LISM) using the Queen's University of Belfast Echelle Spectrograph (QUBES) on the 4.2 m William Herschel Telescope are reported. The observations show the potential of the instrument for measuring small column densities

We present deep Ka-band (ν~ 33 GHz) observations of the cosmic microwave background (CMB) made with the extended Very Small Array (VSA). This configuration produces a naturally weighted synthesized FWHM beamwidth of ~11 arcmin, which covers an l range of 300 to 1500. On these scales, foreground extragalactic sources can be a major source of

Observations of three post-Main-Sequence nebulae, taken with an intermediate dispersion spectrograph mounted on the 2.5 m Isaac Newton Telescope (La Palma, Spain), are presented. The results reveal evidence for high-velocity outflows of about 100 km/s in the primary shells, and very much greater velocities in the cores, while in one unique source