One-sided jet at milliarcsecond scales in LS I +61˚ 303

We present Very Long Baseline Interferometry (VLBI) observations of the high mass X-ray binary LS I +61˚303, carried out with the European VLBI Network (EVN). Over the 11 hour observing run, performed ~10 days after a radio outburst, the radio source showed a constant flux density, which allowed sensitive imaging of the emission distribution. The structure in the map shows a clear extension to the southeast. Comparing our data with previous VLBI observations we interpret the extension as a collimated radio jet as found in several other X-ray binaries. Assuming that the structure is the result of an expansion that started at the onset of the outburst, we derive an apparent expansion velocity of 0:003 c, which, in the context of Doppler boosting, corresponds to an intrinsic velocity of at least 0:4 c for an ejection close to the line of sight. From the apparent velocity in all available epochs we are able to establish variations in the ejection angle which imply a precessing accretion disk. Finally we point out that LS I +61˚303, like SS 433 and Cygnus X-1, shows evidence for an emission region almost orthogonal to the relativistic jet

Hints for a fast precessing relativistic radio jet in LS I + 61° 303

Here we discuss two consecutive MERLIN observations of the X-ray binary LS I +61° 303 . The first observation shows a double-sided jet extending up to about 200 AU on both sides of a central source. The jet shows a bent S-shaped structure similar to the one displayed by the well-known precessing jet of SS 433 . The precession suggested in the first MERLIN image becomes evident in the second one, showing a one-sided bent jet significantly rotated with respect to the jet of the day before. We conclude that the derived precession of the relativistic (beta=0.6) jet explains puzzling previous VLBI results. Moreover, the fact that the precession is fast could be the explanation of the never understood short term (days) variability of the associated gamma-ray source 2CG 135+01 / 3EG J0241+6103

La Quarta millor biblioteca universitària

Amb la posada en marxa de la segona fase de la biblioteca de Montilivi, la Universitat de Girona (UdG) completa un cicle que es va iniciar quinze anys enrere i que ha estat un repte constant en l'agenda dels successius equips de govern: definir quin havia de ser el millor model de biblioteca per a la universitat per al seu territori i, alhora, donar un servei de valor afegit a les persones. La Biblioteca de la UdG és avui la quarta entre les millors biblioteques universitàries espanyoles, i en la inauguració d'aquest nou equipament la Dra. Anna Maria Geli, rectora de la UdG, va manifestar que "millorarem posicions i, perquè no pensar a ser els primers?"

L'Associació de teixidors de Vic

Es presenten les conclusions sobre la composició social de les associacions de teixidors de Vic al segle XIX en el marc de la fabricació de teixits de cotó i en comparació amb altres assosciacions existents