High-energy emission from NGC 5506, the brightest hard X-ray Narrow Line Seyfert 1 galaxy

We present results on the hard X-ray emission of NGC 5506, the brightest narrow line Seyfert 1 galaxy above 20 keV. All the recent observations by INTEGRAL, Swift and Suzaku have been analysed and spectral analysis during nine separated time periods has been performed. While flux variations by a factor of 2 were detected during the last 7 years, only moderate spectral variations have been observed, with the hint of a hardening of the X-ray spectrum and a decrease of the intrinsic absorption with time. Using Suzaku observations it is possible to constrain the amount of Compton reflection to R = 0.6-1.0, in agreement with previous results on the source. The signature of Comptonisation processes can also be found in the detection of a high-energy cut-off during part of the observations, at Ec = 40-100 keV. When a Comptonisation model is applied to the Suzaku data, the temperature and the optical depth of the Comptonising electron plasma are measured at kT = 60-80 keV and tau = 0.6-1.0, respectively. The properties inferred for NGC 5506 in this study agree with those based on other data sets for the same AGN, and fit the picture of NLS1 having in general lower high-energy cut-offs at hard X-rays than their broad line equivalent.Comment: 8 pages, 3 figures, 1 table. Proceedings of the Workshop "Narrow-Line Seyfert 1 Galaxies and Their Place in the Universe", Milano, April 4-6, 2011 (Proceedings of Science, http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=126

The Hard X-ray Emission of Cen A

The radio galaxy Cen A has been detected all the way up to the TeV energy range. This raises the question about the dominant emission mechanisms in the high-energy domain. Spectral analysis allows us to put constraints on the possible emission processes. Here we study the hard X-ray emission as measured by INTEGRAL in the 3-1000 keV energy range, in order to distinguish between a thermal and non-thermal inverse Compton process. The hard X-ray spectrum of Cen A shows a significant cut-off at energies Ec = 434 (+106 -73) keV with an underlying power law of photon index 1.73 +- 0.02. A more physical model of thermal Comptonisation (compPS) gives a plasma temperature of kT = 206+-62 keV within the optically thin corona with Compton parameter y = 0.42 (+0.09 -0.06). The reflection component is significant at the 1.9 sigma level with R = 0.12 (+0.09 -0.10), and a reflection strength R>0.3 can be excluded on a 3 sigma level. Time resolved spectral studies show that the flux, absorption, and spectral slope varied in the range f(3-30 keV) = (1.2 - 9.2)e-10 erg/cm**2/s, NH = (7 - 16)e22 1/cm**2, and photon index 1.75 - 1.87. Extending the cut-off power law or the Comptonisation model to the gamma-ray range shows that they cannot account for the high-energy emission. On the other hand, also a broken or curved power law model can represent the data, therefore a non-thermal origin of the X-ray to GeV emission cannot be ruled out. The analysis of the SPI data provides no sign of significant emission from the radio lobes and gives a 3 sigma upper limit of f(40-1000 keV) < 0.0011 ph/cm**2/s. While gamma-rays, as detected by CGRO and Fermi, are caused by non-thermal (jet) processes, the main process in the hard X-ray emission of Cen A is still not unambiguously determined, being either dominated by thermal inverse Compton emission, or by non-thermal emission from the base of the jet.Comment: 8 pages, 6 figures, accepted for publication in A&

The Neutron Halo in Heavy Nuclei Calculated with the Gogny Force

The proton and neutron density distributions, one- and two-neutron separation energies and radii of nuclei for which neutron halos are experimentally observed, are calculated using the self-consistent Hartree-Fock-Bogoliubov method with the effective interaction of Gogny. Halo factors are evaluated assuming hydrogen-like antiproton wave functions. The factors agree well with experimental data. They are close to those obtained with Skyrme forces and with the relativistic mean field approach.Comment: 13 pages in Latex and 17 figures in ep

Extreme flux states of NGC 4151 observed with INTEGRAL

We present a comprehensive spectral analysis of all INTEGRAL data obtained so far for the X-ray-bright Seyfert galaxy NGC 4151. We also use all contemporaneous data from RXTE, XMM-Newton, Swift and Suzaku. We find a linear correlation between the medium- and hard-energy X-ray fluxes measured by INTEGRAL, which indicates an almost constant spectral index over 6 yr. The majority of INTEGRAL observations were made when the source was either at a very bright or very dim hard-X-ray state. We find that thermal Comptonization models applied to the bright state yields the plasma temperature of ≃50-70 keV and its optical depth of ≃1.3-2.6, depending on the assumed source geometry. For the dim state, these parameters are in the ranges of ≃180-230 keV and ≃0.3-0.7, respectively. The Compton parameter is for all the spectra, indicating a stable geometry. Using this result, we can determine the reflection effective solid angles associated with the close and distant reprocessing media as and , respectively. The plasma energy balance, the weak disc reflection and a comparison of the UV fluxes illuminating the plasma to the observed ones are all consistent with an inner hot accretion surrounded by an outer cold disc. The disc truncation radius can be determined from an approximate equipartition between the observed UV and X-ray emission, and from the fitted disc blackbody model, as ∼15 gravitational radii. Alternatively, our results can be explained by a mildly relativistic coronal outflo

Development of computational models for the prediction of the toxicity of nanomaterials

Extended abstrac

Evaluation of aqueous flare after Descemet’s stripping endothelial keratoplasty and penetrating keratoplasty

Purpose: Evaluation of aqueous flare in patients after Descemet's Stripping Endothelial Keratoplasty (DSEK) and Penetrating Keratoplasty (PK) performed of various indications. Material and methods: In a prospective study 17 eyes in 16 patients were examined. First group consisted of 8 eyes after DSEK, second: 9 eyes after PK. The first procedure was performed of Fuch’s dystrophy - 4 eyes, bullous keratopathy – 4 eyes. The indications in the second were as follows: keratoconus – 2 eyes, corneal cicatrix without neovascularization – 3 eyes, endangering corneal perforation – 4 eyes. Examined group mean age was respectively 67 and 69 years. The overall examining time was six months after the surgery. In the paperaqueous flare was evaluated in the anterior chamber in 1st, 3rd and 6th month after keratoplasty in FM-600 Laser Flare Kowa. Abovementioned device function is based on emission and detection of light produced by diode laser. Keratoplasty was performed in general (No 9) or in local peribulbar (No 8) anaesthesia. Results: Mean aqueous flarein 1st, 3rd, and 6th month after keratoplasty is significantly lower after DSEK (14,46 +/- 4,70 ph/ms; 10,64 +/- 2,91 ph/ms; 5,98 +/- 2,53 ph/ms) in comparison with PK (18,50 +/- 5,82 ph/ms; 15,04 +/- 6,38 ph/ms; 10,68 +/- 3,83 ph/ms). In 6 months observation the mean flare value in DSEK was decreased twice in comparison with PK. Considering indication for keratoplasty mean flare measurements were respectively in 1st, 3rd and 6th month for first group: Fuchs’ dystrophy: 11,85 +/- 5,46 ph/ms; 8,28 +/- 1,80 ph/ms; 4,93 +/- 0,95 ph/ms; bullous keratopathy: 17,08 +/- 1,89 ph/ms; 13,00 +/- 1,27 ph/ms; 7,03 +/- 3,32 ph/ms. In second group respectively: keratoconus: 15,15 +/- 1,34 ph/ms; 11,95 +/- 0,49 ph/ms; 11,25 +/- 0,64 ph/ms; corneal cicatrix without neovascularization: 16,40 +/- 9,27 ph/ms; 12,13 +/- 9,85 ph/ms; 6,87 +/- 4,20 ph/ms; endangering corneal perforation: 21,75 +/- 2,54 ph/ms; 18,78 +/- 3,21 ph/ms; 13,25 +/- 1,92 ph/ms. In the analysis of indications for keratoplasty the lowest mean aqueous flare in 1st, 3rd, and 6th month after procedure was observed in the Fuchs’ dystrophy. In endangering corneal perforation mean flare values were the highest. Conclusions: Our results indirectly indicate that in examined patients after DSEK post-operative inflammatory reaction is lower than in PK. Furthermore flare values might depend on the indications for keratoplasty. The study was performed in group with various indications for keraoplasty. Further studies including protein concentration in AH after DSEK and PK performed in equal indications are needed

Neutron halos in heavy nuclei -- relativistic mean field approach

Assuming a~simple spherical relativistic mean field model of the nucleus, we estimate the width of the antiproton--neutron annihilation ($\Gamma_n$) and the width of antiproton--proton ($\Gamma_p$) annihilation, in an antiprotonic atom system. This allows us to determine the halo factor $f$, which is then discussed in the context of experimental data obtained in measurements recently done on LEAR utility at CERN. Another quantity which characterizes the deviation of the average nuclear densities ratio from the corresponding ratio of the homogeneous densities is introduced too. It was shown that it is also a good indicator of the neutron halo. The results are compared to experimental data as well as to the data of the simple liquid droplet model of the nuclear densities. The single particle structure of the nuclear density tail is discusssed also.Comment: revtex, 12 pages + 6 postscript figure

Recurrent mutations of BRCA1, BRCA2 and PALB2 in the population of breast and ovarian cancer patients in Southern Poland

Background Mutations in the BRCA1, BRCA2 and PALB2 genes are well-established risk factors for the development of breast and/or ovarian cancer. The frequency and spectrum of mutations in these genes has not yet been examined in the population of Southern Poland. Methods We examined the entire coding sequences of the BRCA1 and BRCA2 genes and genotyped a recurrent mutation of the PALB2 gene (c.509_510delGA) in 121 women with familial and/or early-onset breast or ovarian cancer from Southern Poland. Results A BRCA1 mutation was identified in 11 of 121 patients (9.1 %) and a BRCA2 mutation was identified in 10 of 121 patients (8.3 %). Two founder mutations of BRCA1 accounted for 91 % of all BRCA1 mutation carriers (c.5266dupC was identified in six patients and c.181 T > G was identified in four patients). Three of the seven different BRCA2 mutations were detected in two patients each (c.9371A > T, c.9403delC and c.1310_1313delAAGA). Three mutations have not been previously reported in the Polish population (BRCA1 c.3531delT, BRCA2 c.1310_1313delAAGA and BRCA2 c.9027delT). The recurrent PALB2 mutation c.509_510delGA was identified in two patients (1.7 %). Conclusions The standard panel of BRCA1 founder mutations is sufficiently sensitive for the identification of BRCA1 mutation carriers in Southern Poland. The BRCA2 mutations c.9371A > T and c.9403delC as well as the PALB2 mutation c.509_510delGA should be included in the testing panel for this population

INTEGRAL hard X-ray spectra of the cosmic X-ray background and Galactic ridge emission

We derive the spectra of the cosmic X-ray background (CXB) and of the Galactic ridge X-ray emission (GRXE) in the ~20-200 keV range from the data of the IBIS instrument aboard the INTEGRAL satellite obtained during the four dedicated Earth-occultation observations of early 2006. We analyse the modulation of the IBIS/ISGRI detector counts induced by the passage of the Earth through the field of view of the instrument. Unlike previous studies, we do not fix the spectral shape of the various contributions, but model instead their spatial distribution and derive for each of them the expected modulation of the detector counts. The spectra of the diffuse emission components are obtained by fitting the normalizations of the model lightcurves to the observed modulation in different energy bins. The obtained CXB spectrum is consistent with the historic HEAO-1 results and falls slightly below the spectrum derived with Swift/BAT. A 10% higher normalization of the CXB cannot be completely excluded, but it would imply an unrealistically high albedo of the Earth. The derived spectrum of the GRXE confirms the presence of a minimum around 80 keV with improved statistics and yields an estimate of ~0.6 M_Sun for the average mass of white dwarfs in the Galaxy. The analysis also provides updated normalizations for the spectra of the Earth's albedo and the cosmic-ray induced atmospheric emission.Comment: 13 pages, 13 figures, minor changes to text, A&A in pres