The XMM-Newton Slew view of IGRJ17361-4441: a transient in the globular cluster NGC 6388

IGRJ17361-4441 is a hard transient recently observed by the INTEGRAL satellite. The source, close to the center of gravity of the globular cluster NGC 6388, quickly became the target of follow-up observations conducted by the Chandra, Swift/XRT and RXTE observatories. Here, we concentrate in particular on a set of observations conducted by the XMM-Newton satellite during two slews, in order to get the spectral information of the source and search for spectral variations. The spectral parameters determined by the recent XMM-Newton slew observations were compared to the previously known results. The maximum unabsorbed $X$-ray flux in the 0.5-10 keV band as detected by the XMM-Newton slew observations is $\simeq 4.5\times 10^{-11}$ erg cm$^{-2}$ s$^{-1}$, i.e. consistent with that observed by the Swift/XRT satellite 15 days earlier. The spectrum seems to be marginally consistent ($\Gamma\simeq 0.93-1.63$) with that derived from the previous high energy observation.Comment: Accepted for publication on New Astronomy, 2012. A sentence about the globular cluster 47 Tuc was partially rewritten to avoid confusio

A well-monitored, X-ray selected, tidal disruption event

We report on a candidate tidal disruption event detected in the XMM-Newton slew survey from the nucleus of SDSS J120136.02+300305.5 (z = 0.146; hereafter SDSS J1201+30). The source, monitored by Swift and XMM-Newton, was highly variable on timescales of a week, reaching a peak X-ray luminosity of 3 × 1044 ergs/s. The light curve is reminiscent of the variations seen in SWIFT J1644+57, although in this case the absence of radio flux rules out a jet mechanism for the emission. The X-ray spectrum is steep, (spectral index = 3–5) and softens with diminishing flux. It is inconsistent with a single or multi-temperature black-body model but may be fit with Bremsstrahlung or comptonised thermal emission

Tidal disruption events from the first XMM-Newton slew survey

Observations over the past decade have revealed that supermassive black holes (SMBHs) likely reside at the centres of most or all bulge galaxies. Confirmation of their dormant presence in non-active galaxies is difficult to obtain. An unavoidable consequence of the existence of remnant SMBHs is the detection of a tidal disruption event. This is discovered as flaring radiation produced when a star is tidally disrupted and subsequently accreted by the black hole. Two of these exceptional events have been discovered by XMM-Newton in the first slew catalogue, NGC 3599 and SDSS J132341.97+482701.3. Here we show their evolution up to four years after the peak of the outburst including a detailed analysis of NGC 3599, for which novel follow-up observations are presented here

A well-monitored, X-ray selected, tidal disruption event

We report on a candidate tidal disruption event detected in the XMM-Newton slew survey from the nucleus of SDSS J120136.02+300305.5 (z = 0.146; hereafter SDSS J1201+30). The source, monitored by Swift and XMM-Newton, was highly variable on timescales of a week, reaching a peak X-ray luminosity of 3 × 1044 ergs/s. The light curve is reminiscent of the variations seen in SWIFT J1644+57, although in this case the absence of radio flux rules out a jet mechanism for the emission. The X-ray spectrum is steep, (spectral index = 3–5) and softens with diminishing flux. It is inconsistent with a single or multi-temperature black-body model but may be fit with Bremsstrahlung or comptonised thermal emission

In vitro effects of hydrochloric and lactic acids on bioelectric properties of equine gastric squamous mucosa

Reasons for performing study: Volatile fatty acids, byproducts of carbohydrate fermentation by resident bacteria, have been implicated in causing nonglandular (NG) gastric ulcers. Lactic acid (LA), also produced by stomach bacteria, may cause gastric ulcers when exposed to the equine NG mucosa. Objectives: To investigate the in vitro effects of LA on equine NG mucosa bioelectric properties, sodium transport and tissue resistance. Methods: Gastric tissues obtained from 13 mature horses were studied in Ussing chambers. Short-circuit current (Isc) and potential difference (PD) were measured, and electrical resistance (R) and conductance (G) calculated for tissues after addition of HCl and LA (5, 10, 20 and 40 mmol/l) in normal Ringer's solution (NRS). Results: Mucosa exposed to HCl or LA (5, 10 and 20 mmol/l) in NRS (pH 1.5 and to a lesser extent pH 4.0) had a significant decrease in Isc and PD. Mucosa exposed to a high concentration of LA (40 mmol/l) in NRS (LRS) at pH 1.5 showed an increased G, but this increase was not significant. Values returned to baseline after solutions were returned to pH 7.0. Histological changes were consistent with HCl-induced (p