An XMM-Newton view of Planetary Nebulae in the Small Magellanic Cloud. The X-ray luminous central star of SMP SMC 22

During an X-ray survey of the Small Magellanic Cloud, carried out with the XMM-Newton satellite, we detected significant soft X-ray emission from the central star of the high-excitation planetary nebula SMP SMC 22. Its very soft spectrum is well fit with a non local thermodynamical equilibrium model atmosphere composed of H, He, C, N, and O, with abundances equal to those inferred from studies of its nebular lines. The derived effective temperature of 1.5x10^5 K is in good agreement with that found from the optical/UV data. The unabsorbed flux in the 0.1-0.5 keV range is about 3x10^{-11} erg cm^-2 s^-1, corresponding to a luminosity of 1.2x10^37 erg/s at the distance of 60 kpc. We also searched for X-ray emission from a large number of SMC planetary nebulae, confirming the previous detection of SMP SMC 25 with a luminosity of (0.2-6)x10^35 erg/s (0.1-1 keV). For the remaining objects that were not detected, we derived flux upper limits corresponding to luminosity values from several tens to hundreds times smaller than that of SMP SMC 22. The exceptionally high X-ray luminosity of SMP SMC 22 is probably due to the high mass of its central star, quickly evolving toward the white dwarf's cooling branch, and to a small intrinsic absorption in the nebula itself.Comment: Accepted for publication on Astronomy and Astrophysic

An analysis of the FIR/RADIO Continuum Correlation in the Small Magellanic Cloud

The local correlation between far-infrared (FIR) emission and radio-continuum (RC) emission for the Small Magellanic Cloud (SMC) is investigated over scales from 3 kpc to 0.01 kpc. Here, we report good FIR/RC correlation down to ~15 pc. The reciprocal slope of the FIR/RC emission correlation (RC/FIR) in the SMC is shown to be greatest in the most active star forming regions with a power law slope of ~1.14 indicating that the RC emission increases faster than the FIR emission. The slope of the other regions and the SMC are much flatter and in the range of 0.63-0.85. The slopes tend to follow the thermal fractions of the regions which range from 0.5 to 0.95. The thermal fraction of the RC emission alone can provide the expected FIR/RC correlation. The results are consistent with a common source for ultraviolet (UV) photons heating dust and Cosmic Ray electrons (CRe-s) diffusing away from the star forming regions. Since the CRe-s appear to escape the SMC so readily, the results here may not provide support for coupling between the local gas density and the magnetic field intensity.Comment: 19 pages, 7 Figure

LMC X-1: A New Spectral Analysis of the O-star in the binary and surrounding nebula

We provide new observations of the LMC X-1 O star and its extended nebula structure using spectroscopic data from VLT/UVES as well as H$\alpha$ imaging from the Wide Field Imager on the Max Planck Gesellschaft / European Southern Observatory 2.2m telescope and ATCA imaging of the 2.1 GHz radio continuum. This nebula is one of the few known to be energized by an X-ray binary. We use a new spectrum extraction technique that is superior to other methods to obtain both radial velocities and fluxes. This provides an updated spatial velocity of $\simeq 21.0~\pm~4.8$ km s$^{-1}$ for the O star. The slit encompasses both the photo-ionized and shock-ionized regions of the nebula. The imaging shows a clear arc-like structure reminiscent of a wind bow shock in between the ionization cone and shock-ionized nebula. The observed structure can be fit well by the parabolic shape of a wind bow shock. If an interpretation of a wind bow shock system is valid, we investigate the N159-O1 star cluster as a potential parent of the system, suggesting a progenitor mass of $\sim 60$ M$_{\odot}$ for the black hole. We further note that the radio emission could be non-thermal emission from the wind bow shock, or synchrotron emission associated with the jet inflated nebula. For both wind and jet-powered origins, this would represent one of the first radio detections of such a structure.Comment: 7 Figures, 4 Table

"Hiccup" accretion in the swinging pulsar IGR J18245-2452

IGR J18245-2452 is the fifteenth discovered accreting millisecond X-ray pulsar and the first source of this class showing direct evidence for transition between accretion and rotational powered emission states. These swing provided the strongest confirmation of the pulsar recycling scenario available so far. During the two XMM-Newton observations that were carried out while the source was in outburst in April 2013, IGR J18245-2452 displayed a unique and peculiar variability of its X-ray emission. In this work, we report on a detailed analysis of the XMM- Newton data and focus in particular on the timing and spectral variability of the source. IGR J18245-2452 continuously switches between lower and higher intensity states, with typical variations in flux up to a factor of about 500 in time scales as short as few seconds. These variations in the source intensity are sometimes associated to a dramatic spectral hardening, during which the power-law photon index of the source changes from Gamma=1.7 to Gamma=0.9. The pulse profiles extracted at different count rates and energies show a complex variability. These phenomena are not usually observed in accreting millisecond X-ray pulsars, at least not on such a short time scale. Fast variability was also found in the ATCA radio observations carried out for about 6 hours during the outburst at a frequency of 5.5 and 9 GHz. We interpret the variability observed from IGR J18245-2452 in terms of a "hiccup" accretion phase, during which the accretion of material from the inner boundary of the Keplerian disk is reduced by the onset of centrifugal inhibition of accretion, possibly causing the launch of strong outflows. Changes across accretion and propeller regimes have been long predicted and reproduced by MHD simulations of accreting millisecond X-ray pulsars but never observed to produce an extreme variability as that shown by IGR J18245-2452.Comment: A&A in press. Revised versio

0103-72.6: A New Oxygen-Rich Supernova Remnant in the Small Magellanic Cloud

0103$-$72.6, the second brightest X-ray supernova remnant (SNR) in the Small Magellanic Cloud (SMC), has been observed with the {\it Chandra X-Ray Observatory}. Our {\it Chandra} observation unambiguously resolves the X-ray emission into a nearly complete, remarkably circular shell surrounding bright clumpy emission in the center of the remnant. The observed X-ray spectrum for the central region is evidently dominated by emission from reverse shock-heated metal-rich ejecta. Elemental abundances in this ejecta material are particularly enhanced in oxygen and neon, while less prominent in the heavier elements Si, S, and Fe. We thus propose that 0103$-$72.6 is a new ``oxygen-rich'' SNR, making it only the second member of the class in the SMC. The outer shell is the limb-brightened, soft X-ray emission from the swept-up SMC interstellar medium. The presence of O-rich ejecta and the SNR's location within an H{\small II} region attest to a massive star core-collapse origin for 0103$-$72.6. The elemental abundance ratios derived from the ejecta suggest an $\sim$18 M$_{\odot}$ progenitor star.Comment: 6 pages (ApJ emulator format), including 5 figures and 2 tables. For high quality Figs.1,2, & 3, contact [email protected]. Accepted by the ApJ Letter

The XMM-Newton survey of the Small Magellanic Cloud: The X-ray point-source catalogue

Local-Group galaxies provide access to samples of X-ray source populations of whole galaxies. The XMM-Newton survey of the Small Magellanic Cloud (SMC) completely covers the bar and eastern wing with a 5.6 deg^2 area in the (0.2-12.0) keV band. To characterise the X-ray sources in the SMC field, we created a catalogue of point sources and sources with moderate extent. Sources with high extent (>40") have been presented in a companion paper. We searched for point sources in the EPIC images using sliding-box and maximum-likelihood techniques and classified the sources using hardness ratios, X-ray variability, and their multi-wavelength properties. The catalogue comprises 3053 unique X-ray sources with a median position uncertainty of 1.3" down to a flux limit for point sources of ~10^-14 erg cm^-2 s^-1 in the (0.2-4.5) keV band, corresponding to 5x10^33 erg s^-1 for sources in the SMC. We discuss statistical properties, like the spatial distribution, X-ray colour diagrams, luminosity functions, and time variability. We identified 49 SMC high-mass X-ray binaries (HMXB), four super-soft X-ray sources (SSS), 34 foreground stars, and 72 active galactic nuclei (AGN) behind the SMC. In addition, we found candidates for SMC HMXBs (45) and faint SSSs (8) as well as AGN (2092) and galaxy clusters (13). We present the most up-to-date catalogue of the X-ray source population in the SMC field. In particular, the known population of X-ray binaries is greatly increased. We find that the bright-end slope of the luminosity function of Be/X-ray binaries significantly deviates from the expected universal high-mass X-ray binary luminosity function.Comment: 32 pages, 18 figures, accepted for publication in A&A, catalog will be available at CD

Testenina od spelte

Spelt wheat is suitable organic raw material for pasta production with modified nutritional characteristics. This paper investigates the rheological quality of wholemeal spelt as raw material for the production of pasta as well as eggs influence on technological quality and texture of pasta. Data point at good indicators of technological quality and textural characteristics of spelt pasta with eggs. Additions of eggs improve the technological quality of pasta. Pasta obtained from wholemeal spelt flour may contribute to variety organic safe products at the market.U proizvodnji organske hrane spelta pšenice je pogodna sirovina za proizvodnju testenine sa izmenjenim nutritivnim karakteristikam. U ovom radu je ispitan reološki kvalitet integralnog brašna od spelte kao sirovine za proizvodnju testenine i uticaj jaja na tehnološki kvalitet i teksturu testenine. Rezultati ispitivanja pokazuju da se može proizvesti testenina od spelte dobrog kvaliteta i teksture pri čemu dodatk jaja utiče na poboljšanje tehnološkog kvaliteta testene. Testenina dobijena od integrlanog brašna spelte može predstavljati nov organski bezbedan proizvod na našem tržištu

Induction of Crystallization of Calcium Oxalate Dihydrate in Micellar Solutions of Anionic Surfactants

Calcium oxalate dihydrate (CaC2O4.(2+x)H2O; COD; x ≤ 0.5) does not readily crystallize from electrolytic solutions but appears as a component in crystalluria. In this paper, we review in vitro studies on the factors responsible for its nucleation and growth with special attention given to the role of surfactants. The following surfactants were tested: dodecyl ammonium chloride (cationic), octaethylene monohexadecylether (non-ionic), sodium dodecyl sulfate (SOS, anionic), dioctyl sulphosuccinate (AOT, anionic), and sodium cholate (NaC, anionic). The cationic and some of the anionic surfactants (SOS, AOT) induced different habit modifications of growing calcium oxalate crystals by preferential adsorption at different crystal faces. In addition, the anionic surfactants effectively induced crystallization of COD at the expense of COM, the proportion of COD in the precipitates abruptly increasing above a critical surfactant concentration, close to, but not necessarily identical with the respective CMC. A mechanism is proposed, whereby crystallization of COD in the presence of surfactants is a consequence of the inhibition of COM by preferential adsorption of surfactant hemimicelles (two-dimensional surface aggregates) at the surfaces of growing crystals

Роль фактора некроза опухоли-альфа в прогнозировании тяжести и исхода сепсиса у пациентов неотложного отделения с системным воспалением

Aim of the study was to determine whether the TNF-a levels, proximal inflammatory mediator, in septic patients presenting to the emergency department (ED) and admitted to the intensive care unit (ICU) are associated with progression to severe sepsis, septic shock or death. Material and methods. A retrospective observational study was performed on a sample of one hundred adult subjects presenting to the ED with systemic inflammatory response syndrome of 2 etiologies: presumed (and later confirmed in the ICU and/or operating room) severe acute pancreatitis or generalized peritonitis. Blood TNF-a samples measurements were taken shortly after ED admission. TNF-a was measured by commercial ELISA test in plasma. Results. Mean values of TNF-a on admission (day zero, in ED) were 191,5-fold lower in group with septic shock compared to severe sepsis group and were 63-fold higher in survivors (p<0.01). The area under the curve (AUC) for the TNF-a plots for severity of clinical status was 0.813 and for outcome 0.834. Patients with TNF-a levels lower than 7.95 pg/mL had a 3.2-fold higher probability of septic shock development than those with higher values, at the cutoff level sensitivity was 83,9% and specificity 72,5%. Patients with TNF-a levels higher than 10.5 pg/mL had a 4.8-fold higher probability to survive than those with lower values, at the cutoff level sensitivity was 83,0% and specificity 77,4%. Conclusion: Decreasing in TNF-a concentration leads to the septic shock development and fatal outcome. TNF-a is very good predictor of sepsis severity and outcome. Key words: sepsis, tumor necrosis factor-alpha, emergency medical services, survival rate, severity of illness index.Цель исследования — определить, связаны ли уровни ФНО-a, ключевого медиатора воспаления, у пациентов с сепсисом, поступающих в отделение неотложной помощи и переводящихся в отделение реанимации, с прогрессированием его до тяжелого сепсиса, септического шока и смерти. Материал и методы. Ретроспективное обсервационное исследование было выполнено на выборке в 100 взрослых человек, поступивших в неотложное отделение с признаками системного воспаления двух возможных этиологий: тяжелый острый панкреатит (предполагаемый, а затем подтвержденный в отделении реанимации и/или операционной) или общий перитонит. Производили измерения ФНО-a в крови сразу после поступления. ФНО-a измеряли коммерчески доступным ELISA-методом в плазме крови. Результаты. Средние уровни ФНО-a при поступлении (день 0, в неотложном отделении) были в 191,5 раз ниже в группе с септическим шоком по сравнению с группой тяжелого сепсиса и в 63 раза выше у выживших (