Search results for "eclipse"

Accurate Period Determination of an Eclipsing Binary X-Ray Source in M33

1993

We have analyzed the time variability of one of the X-ray sources in M33 observed by both the ROSAT and Einstein Observatory telescopes. The light curve of M33 X-7 exhibits a variability pattern of high and low states, suggesting an eclipsing binary X-ray source. The data suggest a binary period P=1.78572 days (very close to that of Her X-1) and an eclipse duration of ∼0.4 days. The low phase lasts about one-fourth of the period as in Cen X-3

X-Ray Eclipse Time Delays in 4U2129+47

2007

4U 2129+47 was discovered in the early 80's and classified as an accretion disk corona source due to its broad and partial X-ray eclipses. The 5.24 hr binary orbital period was inferred from the X-ray and optical light curve modulation, implying a late K or M spectral type companion star. The source entered a low state in 1983, during which the optical modulation disappeared and an F8 IV star was revealed, suggesting that 4U 2129+47 might be part of a triple system. The nature of 4U 2129+47 has since been investigated, but no definitive conclusion has been reached. Here, we present timing and spectral analyses of two XMM-Newton observations of this source, carried out in May and June, 2005.…

The OpenUp Process

2014

The Open Unified Process (OpenUp) is an iterative design process that structures the project lifecycle into four phases: Inception, Elaboration, Construction, and Transition. It is part of the Eclipse Process Framework and embraces a pragmatic, agile philosophy that focuses on the collaborative nature of software development. It is a tools-agnostic, low-ceremony process that can be extended to address a broad variety of project types. The project lifecycle provides stakeholders and team members with visibility and decision points throughout the project and makes them able to manage their work through micro-increments.

Accretion onto Neutron Stars: spectral and timing investigation of Low Mass X-ray Binaries

2021

La città di Alphabet. Architettura per prosumers.

2021

Attraverso alcuni aspetti salienti dell’ideazione, della produzione e dell’opposizione al progetto del Toronto Quayside di Sidewalk labs, l’articolo discute l’influenza delle infrastrutture digitali per l’informazione sul progetto della casa e del quartiere. L’ampliamento delle attività svolte da remoto nello spazio domestico, enfatizzato dal quotidiano della pandemia da Covid 19, costituisce per gli oligopolisti planetari degli urban data come Alphabet un utile volano pubblicitario e un acceleratore. La fusione dei nuovi vessilli della tecnoemancipazione e della sostenibilità in ipotesi sperimentali che mirano a costruirsi sia per intero che per parti realizza un nuovo orizzonte in cui lo …

A possible solution of the puzzling variation of the orbital period of MXB 1659-298

2017

MXB 1659-298 is a transient neutron star Low-Mass X-ray binary system that shows eclipses with a periodicity of 7.1 hr. The source went to outburst in August 2015 after 14 years of quiescence. We investigate the orbital properties of this source with a baseline of 40 years obtained combining the eight eclipse arrival times present in literature with 51 eclipse arrival times collected during the last two outbursts. A quadratic ephemeris does not fit the delays associated with the eclipse arrival times and the addition of a sinusoidal term with a period of $2.31 \pm 0.02$ yr is required. We infer a binary orbital period of $P=7.1161099(3)$ hr and an orbital period derivative of $\dot{P}=-8.5(…

Els viatges de la física: perseguint ombres, mesurant meridians

2013

A partir del segle XVII l’estudi acurat i resolució de diversos problemes de la física, principalment relacionats amb l’astronomia i la forma de la Terra, però no sols, ha passat per realitzar mesures a diferents llocs i, per tant, per l’organització de viatges científics amb aquests objectius específics. Presentarem alguns d’aquests problemes i les solucions adoptades a l’època.

Critical proofreading of the book "Les derniers jours du siège d'Alésia"

2023

Was there a lunar eclipse that could have influenced the outcome of the Battle of Alesia? This is the argument developed in the book by Alain Deyber and David Romeuf, «Les Derniers Jours du Siège d'Alésia». Having verified the existence of an eclipse on the date given by the authors and based on the latest publications as well as on the scientific consensus, we conduct a critical study on the chronology of the siege and on the ethnological arguments, even ethno-astronomical of the authors.

Mobiilisovellusten siirrettävyys ja toteutuksen abstraktiotaso

2006

Verification of a commercial implementation of the Macro-Monte-Carlo electron dose calculation algorithm using the virtual accelerator approach.

2009

Abstract In this work, the accuracy of the implementation of the Macro Monte Carlo electron dose calculation algorithm into the radiation therapy treatment planning system Eclipse is evaluated. This implementation – called eMC – uses a particle source based on the Rotterdam Initial Phase-Space model. A three-dimensional comparison of eMC calculated dose to dose distributions resulting from full treatment head simulations with the Monte Carlo code package EGSnrc is performed using the ‘virtual accelerator’ approach. Calculated dose distributions are compared for a homogeneous tissue equivalent phantom and a water phantom with air and bone inhomogeneities. The performance of the eMC algorithm…