Application of calibration masks to TV vidicon tube

Photographic application method devised for overlaying test pattern masks on TV camera vidicon tubes prints the mask within 0.0076 cm of the vertical and horizontal center lines of the tube face. Entire process, including mask fabrication and alignment procedure, requires less than 10 minutes

XMM-Newton observations of two transient millisecond X-ray pulsars in quiescence

We report on XMM-Newton observations of two X-ray transient millisecond pulsars (XRTMSPs). We detected XTE J0929-314 with an unabsorbed luminosity of \~7x10^{31} erg/s. (0.5-10 keV) at a fiducial distance of 10 kpc. The quiescent spectrum is consistent with a simple power law spectrum. The upper limit on the flux from a cooling neutron star atmosphere is about 20% of the total flux. XTE J1807-294 instead was not detected. We can put an upper limit on the source quiescent 0.5-10 keV unabsorbed luminosity <4x10^{31} erg/s at 8 kpc. These observations strenghten the idea that XRTMSPs have quiescent luminosities significantly lower than classical neutron star transients.Comment: 4 pages including 1 figures. Accepted for publication in A&A Letter

Two fast X-ray transients in archival Chandra data

We present the discovery of two new X-ray transients in archival Chandra data. The first transient, XRT 110103, occurred in January 2011 and shows a sharp rise of at least three orders of magnitude in count rate in less than 10 s, a flat peak for about 20 s and decays by two orders of magnitude in the next 60 s. We find no optical or infrared counterpart to this event in preexisting survey data or in an observation taken by the SIRIUS instrument at the Infrared Survey Facility 2.1 yr after the transient, providing limiting magnitudes of J>18.1, H>17.6 and Ks>16.3. This event shows similarities to the transient previously reported in Jonker et al. which was interpreted as the possible tidal disruption of a white dwarf by an intermediate mass black hole. We discuss the possibility that these transients originate from the same type of event. If we assume these events are related a rough estimate of the rates gives 1.4*10^5 per year over the whole sky with a peak 0.3-7 keV X-ray flux greater than 2*10^-10 erg cm^-2 s^-1 . The second transient, XRT 120830, occurred in August 2012 and shows a rise of at least three orders of magnitude in count rate and a subsequent decay of around one order of magnitude all within 10 s, followed by a slower quasi-exponential decay over the remaining 30 ks of the observation. We detect a likely infrared counterpart with magnitudes J=16.70+/-0.06, H=15.92+/-0.04 and Ks=15.37+/-0.06 which shows an average proper motion of 74+/-19 milliarcsec per year compared to archival 2MASS observations. The JHKs magnitudes, proper motion and X-ray flux of XRT 120830 are consistent with a bright flare from a nearby late M or early L dwarf.Comment: Accepted for publication in MNRAS, 6 pages, 5 figure

LOFT as a discovery machine for jetted Tidal Disruption Events

This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of jetted tidal disruption events. For a summary, we refer to the paper.Comment: White Paper in Support of the Mission Concept of the Large Observatory for X-ray Timin

The optical counterpart of IGR J00291+5934 in quiescence

The recent (December 2004) discovery of the sixth accretion-powered millisecond X-ray pulsar IGR J00291+5934 provides a very good chance to deepen our knowledge of such systems. Although these systems are well studied at high energies, poor informations are available for their optical/NIR counterparts during quiescence. Up to now, only for SAX J1808.4-3658, the first discovered system of this type, we have a secure multiband detection of its optical counterpart in quiescence. Among the seven known system IGR J00291+5934 is the one that resembles SAX J1808.4-3658 more closely. With the Italian 3.6 m TNG telescope, we have performed deep optical and NIR photometry of the field of IGR J00291+5934 during quiescence in order to look for the presence of a variable counterpart. We present here the first multiband ($VRIJH$) detection of the optical and NIR counterpart of IGR J00291+5934 in quiescence as well as a deep upper limit in the $K-$band. We obtain an optical light curve that shows variability consistent with a sinusoidal modulation at the known 2.46 hr orbital period and present evidence for a strongly irradiated companion.Comment: 6 pages, 5 figures. Accepted for publication in Astronomy and Astrophysic

Formation of the planet around the millisecond pulsar J1719-1438

Context. Recently the discovery of PSR J1719-1438, a 5.8 ms pulsar with a companion in a 2.2 hr orbit, was reported. The combination of this orbital period and the very low mass function is unique. The discoverers, Bailes et al., proposed an ultracompact X-ray binary (UCXB) as the progenitor system. However, the standard UCXB scenario would not produce this system as the time required to reach this orbital period exceeds the current estimate of the age of the Universe. The detached state of the system aggravates the problem. Aims. We want to understand the evolutionary history of PSR J1719-1438, and determine under which circumstances it could have evolved from an UCXB. Methods. We model UCXB evolution varying the donor size and investigate the effect of a wind mass loss from the donor, and compare the results with the observed characteristics of PSR J1719-1438. Results. An UCXB can reach a 2.2 hr orbit within the age of the Universe, provided that 1) the millisecond pulsar can significantly heat and expand the donor by pulsar irradiation, or 2) the system loses extra orbital angular momentum, e.g. via a fast wind from the donor. Conclusions. The most likely scenario for the formation of PSR J1719-1438 is UCXB evolution driven by angular momentum loss via the usual gravitational wave emission, which is enhanced by angular momentum loss via a donor wind of ~3x10^-13 Msun/yr. Depending on the size of the donor during the evolution, the companion presently probably has a mass of ~1-3 Jupiter masses, making it a very low mass white dwarf as proposed by Bailes et al. Its composition can be either helium or carbon-oxygen. A helium white dwarf companion makes the long (for an UCXB) orbital period easier to explain, but the required inclination makes it a priori less likely than a carbon-oxygen white dwarf.Comment: 5 pages, 4 figures. Accepted for publication in Astronomy and Astrophysics. v2: Updated a referenc

Autistic disorder:Current psychopharmacological treatments and areas of interest for future developments

O transtorno autista e o grupo de condições relacionadas definidas como transtornos invasivos do desenvolvimento são transtornos de neurodesenvolvimento crônicos que começam na infância precoce e afetam um número significativo de crianças e suas famílias. Ainda que as causas e muito da fisiopatologia do transtorno sejam desconhecidas, em anos recentes, vários tratamentos medicamentosos disponíveis têm sido identificados como contendo a promessa de aliviar alguns dos comportamentos mal-adaptativos mais comprometedores associados aos transtornos invasivos do desenvolvimento. No entanto, esses tratamentos não enfocam os sintomas nucleares da enfermidade e, geralmente, seus efeitos colaterais excedem os benefícios. Portanto, há uma necessidade substancial de novas medicações que sejam mais seguras e mais eficazes em tratar os sintomas comportamentais do autismo. O objetivo desta revisão é o de destacar as farmacoterapias correntes disponíveis e aquelas emergentes e que tenham potencial de melhorar as opções de tratamento de pacientes com transtornos invasivos do desenvolvimento.Autistic disorder and the group of related conditions defined as pervasive developmental disorders are chronic neurodevelopmental disorders starting in early childhood and affecting a significant number of children and families. Although the causes and much of the pathophysiology of the disorder remain unknown, in recent years a number of available medication treatments have been identified as holding promise in alleviating some of the most disabling maladaptive behaviors, associated with pervasive developmental disorders. However these treatments do not address the core symptoms of the disease and oftentimes their side effects outweigh their benefits. Therefore there is substantial need for new medications that are safer and more effective in addressing the behavior symptoms of autism. The aim of this review is to highlight the available current pharmacotherapies and those emerging treatments with potential to enhance the treatment options of patients with pervasive developmental disorders