Contemporaneous XMM-Newton investigation of a giant X-ray flare and quiescent state from a cool M-class dwarf in the local cavity

We report the serendipitous detection of a giant X-ray flare from the source 2XMM J043527.2-144301 during an XMM-Newton observation of the high latitude molecular cloud MBM20. The source has not been previously studied at any wavelength. The X-ray flux increases by a factor of more than 52 from quiescent state to peak of flare. A 2MASS counterpart has been identified (2MASS J04352724-1443017), and near-infrared colors reveal a spectral type of M8-M8.5 and a distance of (67\pm 13) pc, placing the source in front of MBM20. Spectral analysis and source luminosity are also consistent with this conclusion. The measured distance makes this object the most distant source (by about a factor of 4) at this spectral type detected in X-rays. The X-ray flare was characterized by peak X-ray luminosity of ~8.2E28 erg s-1 and integrated X-ray energy of ~2.3E32 erg. The flare emission has been characterized with a 2-temperature model with temperatures of ~10 and 46 MK (0.82 and 3.97 keV), and is dominated by the higher temperature component.Comment: 19 pages, 5 figures; Accepted for publication on Ap

The binary period and outburst behaviour of the SMC X-ray binary pulsar system SXP504

A probable binary period has been detected in the optical counterpart to the X-ray source CXOU J005455.6-724510 = RX J0054.9-7245 = AXJ0054.8-7244 = SXP504 in the Small Magellanic Cloud. This source was detected by Chandra on 04 Jul 2002 and subsequently observed by XMM-Newton on 18 Dec 2003. The source is coincident with an Optical Gravitational Lensing (OGLE) object in the lightcurves of which several optical outburst peaks are visible at ~ 268 day intervals. Timing analysis shows a period of 268.6 +/- 0.1 days at > 99% significance. Archival Rossi X-ray Timing Explorer (RXTE) data for the 504s pulse-period has revealed detections which correspond closely with predicted or actual peaks in the optical data. The relationship between this orbital period and the pulse period of 504s is within the normal variance found in the Corbet diagram.Comment: Accepted by MNRAS. 1 LATEX page. 4 figure

Hard X-ray lightcurves of High Mass X-ray binaries

Using the 9 years of continuous data now available from the Burst And Transient Source Experiment (BATSE) aboard CGRO, we have measured orbital periods and produced folded lightcurves for 8 High Mass X-ray Binaries (HMXB). Given the length of the datasets, our determinations are based on many more binary orbits than previous investigations. Thus our source detections have high statistical significance and we are able to follow long-term trends in X-ray output. In particular we focus on two systems: A0538-668 and EXO2030+375 both HMXBs exhibiting Type I outbursts.Comment: Accepted by MNRA

Testing the durability of limestone for Cathedral façade restoration

This research aimed to specify an optimum replacement stone for Truro Cathedral. A variety of petrographically and visually similar material to the original Bath stone was initially selected. The stones were subjected to three different durability tests; Sodium sulphate crystallisation and large scale testing with both accelerated and climatic freeze-thaw cyclic loading. The most suitable stone was determined as the one with the best performance characteristics overall

SPI/INTEGRAL observation of the Cygnus region

We present the analysis of the first observations of the Cygnus region by the SPI spectrometer onboard the Integral Gamma Ray Observatory, encompassing ${\sim}$ 600 ks of data. Three sources namely Cyg X-1, Cyg X-3 and EXO 2030+375 were clearly detected. Our data illustrate the temporal variability of Cyg X-1 in the energy range from 20 keV to 300 keV. The spectral analysis shows a remarkable stability of the Cyg X-1 spectra when averaged over one day timescale. The other goal of these observations is SPI inflight calibration and performance verification. The latest objective has been achieved as demonstrated by the results presented in this paper.Comment: 6 pages, 10 figures, accepted for publication in A&A (special INTEGRAL volume

Constraints in the Context of Induced-gravity Inflation

Constraints on the required flatness of the scalar potential $V(\phi)$ for a cousin-model to extended inflation are studied. It is shown that, unlike earlier results, Induced-gravity Inflation can lead to successful inflation with a very simple lagrangian and $\lambda \sim 10^{-6}$, rather than $10^{-15}$ as previously reported. A second order phase transition further enables this model to escape the \lq big bubble' problem of extended inflation, while retaining the latter's motivations based on the low-energy effective lagrangians of supergravity, superstring, and Kaluza-Klein theories.Comment: 19 pp; 3 figures (not included -- available from author). Plain LaTeX. In press in Physical Review