Aperiodic variability of low-mass X-ray binaries at very low frequencies

We have obtained discrete Fourier power spectra of a sample of persistent low-mass neutron-star X-ray binaries using long-term light curves from the All Sky Monitor on board the Rossi X-ray Timing Explorer. Our aim is to investigate their aperiodic variability at frequencies in the range 1 x 10^{-7}-5 x 10^{-6} Hz and compare their properties with those of the black-hole source Cyg X-1. We find that the classification scheme that divides LMXBs into Z and atoll sources blurs at very low frequencies. Based on the long-term (~ years) pattern of variability and the results of power-law fits (P ~ v^{-a}) to the 1 x 10^{-7}-5 x 10^{-6} Hz power density spectra, low-mass neutron-star binaries fall into three categories. Type I includes all Z sources, except Cyg X-2, and the atoll sources GX9+1 and GX13+1. They show relatively flat power spectra (a < 0.9) and low variability (rms < 20%). Type II systems comprise 4U 1636-53, 4U 1735-44 and GX3+1. They are more variable (20% < rms < 30%) and display steeper power spectra (0.9 < a < 1.2) than Type I sources. Type III systems are the most variable (rms > 30%) and exhibit the steepest power spectra (a > 1.2). The sources 4U 1705-44, GX354-0 and 4U 1820-30 belong to this group. GX9+9 and Cyg X-2 appear as intermediate systems in between Type I and II and Type II and III sources, respectively. We speculate that the differences in these systems may be caused by the presence of different types of mass-donor companions. Other factors, like the size of the accretion disc and/or the presence of weak magnetic fields, are also expected to affect their low-frequency X-ray aperiodic varibility.Comment: 9 pages, 6 figures. To be published in A&

The nature of 1WGA J1958.2+3232: a new intermediate polar

We present low and intermediate resolution spectroscopy of the optical counterpart to the recently discovered pulsating X-ray source 1WGA J1958.2+3232. The presence of strong HI , HeI and HeII emission lines together with the absence of absorption features rules out the possibility that the object is a massive star, as had recently been suggested. The observed X-ray and optical characteristics are consistent with the object being an intermediate polar. The double-peaked structure of the emission lines indicates that an accretion disc is present

Miguel Santos Molina. The internal exile of a socialist

A través de la biografia de Miguel Santos Molina, en primer lloc, podem resseguir el llarg procés de formació de la clase obrera castellonenca. En segon lloc, hi podem constatar el procés de desenganxament del moviment obrer del republicanisme de Fernando Gasset i de la seua funció tribunícia. Altrament, amb la persona de Miguel Santos es trenca el mite del «Castelló liberal» i s’imposa progressivament la realitat d’un Castelló de predomini socialista. A més a més, i com a conseqüència de la influència del republicanisme valencianista, una part de l’esquerra marxista acceptarà l’autonomia del País Valencià, tot trencant amb el model d’Estat centralista jacobí. A partir del 14 de juny de 1938, Miguel Santos sofrirà, en la seua persona, totes les característiques de la repressió franquista en la vessant de l’anomenat exili interior.Through the biography of Miguel Santos Molina, in the first place we can follow the long process of the formation of the working class of Castelló. Secondly, we can see the process of the detachment of the workers’ movement from the republicanism of Fernando Gasset and from its tribal function. In addition, the character of Miguel Santos breaks the myth of “liberal Castelló”, gradually imposing the reality of a predominantly socialist Castelló. In addition, and as a result of the influence of Valencianist republicanism, part of the Marxist Left would accept the autonomy of the Valencian region, breaking with the model of a centralist Jacobin State. After 14 June 1938, the person of Miguel Santos would suffer all the characteristics of the so-called internal exile aspect of Francoist repression

Enterrament de Jaume II a Santes Creus l'any 1327

In this document, the information about three important points pertaining tot the death of Jaume II (James II), King of Aragon and Count of Barcelona, has been collected, compared and examined under the light of historical criticism: the date of death, the habit wit which the corpse was clothed and the year of its final burial. The date of death can be found in the documents issued by the Royal House itself and which include the interesting detail that death occurred on the 2nd November 1327, shortly before the strike of what was know as the "Thieves Bell" (at sunset). The documents also state that the monarch was still alive on the 1st and 2nd of that month. Another version, to be found in Aragonese chronicles and written some time after the fact, claims that the King died on 31st October. As for the habit with which he was buried, the inscription on the tomb states that this was Ciestercian, which would be perfectly in keeping with the King’s devotion to the monastery of Santes Creus, run by Cistercian monks. However, a modern scholar concluded that the habit was Franciscan. Contemporany documents from the Royal House, from the See of Barcelona (published in its entirety in the appendices) and an account by a Cistercian monk, situate the burial as having taken place not long after the King’s death, on 19th November 1327 at the monastery of Santes Creus. However, historical works indicate the King was buried provisionally in Barcelona and was taken to this final resting place at the above mentioned monastery in 1410, based on estimations not corroborated in any texts