Query: rescigno 2163

title: An accurate strong lensing model of the Abell 2163 core
abstract: Abell 2163 at $z \simeq 0.201$ is one of the most massive galaxy clusters known, very likely in a post merging phase. Data from several observational windows suggest a complex mass structure with interacting subsystems, which makes the reconstruction of a realistic merging scenario very difficult. A missing key element in this sense is unveiling the cluster mass distribution at high resolution. We perform such a reconstruction of the cluster inner total mass through a strong lensing model based on new spectroscopic redshift measurements. We use data from the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) to confirm 12 multiple images of 4 sources with redshift values from 1.16 to 2.72. We also discover four new multiple images and identify 29 cluster members and 35 foreground and background sources. The resulting galaxy member and image catalogs are used to build five cluster total mass models. The fiducial model consists of 111 small scale subhalos plus a diffuse component, which is centered \sim2$ arcseconds away from the BCG belonging to the east Abell 2163 subcluster. We confirm that the latter is well represented by a single, large scale mass component. Its strong elongation towards a second (west) subcluster confirms the existence of a preferential axis, corresponding to the merging direction. From the fiducial model, we extrapolate the cumulative projected total mass profile and measure a value of $M(<300\$kpc$ 1.43^+0.07}_{ 0.06}\times 10^{14}$M$_{\odot} which has a significantly reduced statistical error compared with previous estimates, thanks to the inclusion of the spectroscopic redshifts. Our strong lensing results are very accurate: the model predicted positions of the multiple images are, on average, only $0.15$ arcseconds away from the observed ones.

title: AN ACCURATE MASS MODEL OF THE GALAXY CLUSTER ABELL 2163 VIA STRONG GRAVITATIONAL LENSING

title: Impact of preoperative anemia on outcomes in patients undergoing curative resection for gastric cancer: a single institution retrospective analysis of 2163 Chinese patients
abstract: We sought to evaluate whether preoperative anemia was an important determinant of survival in gastric cancer (GC) A single institution cohort of 2163 GC patients who underwent curative resection were retrospectively analyzed. Anemia was defined as a preoperative hemoglobin level <120 g/L in males and <110 g/L in females. Overall survival (OS) was analyzed using the Kaplan Meier method, and a multivariate Cox proportional hazards model was performed to identify the independent prognostic factor. Anemic patients had a poorer OS compared with nonanemic patients after resection for tumor nodes metastasis (TNM) stage III tumors (5 year OS rate: 32.2% vs. 45.7% P 0.001) but not stage I (P 0.480) or stage II (P 0.917) tumors. Multivariate analysis revealed that preoperative anemia was an independent prognostic factor in TNM stage III (hazard ratio [HR] 1.771; 95% CI, 1.040 3.015; P 0.035) In a stage stratified analysis, preoperative anemia was still independently associated with OS in TNM stages IIIa through IIIc (P 0.001, P 0.075, and P 0.012, respectively) though the association was only marginal in stage IIIb. Of note, preoperative mild anemia had a similar prognostic value in TNM stage III GC. Furthermore, preoperative anemia was significantly associated with more perioperative transfusions, postoperative complications and several nutritional based indices, including the prognostic nutritional index (PNI) preoperative weight loss and performance status (all P 0.05) Preoperative anemia, even mild anemia, was an important predictor of postoperative survival for TNM stage III GC.

title: Lopez Dahab based elliptic crypto processor (ECP) over GF(2163) for low area applications on FPGA
abstract: In this paper, a novel low area elliptic crypto processor (ECP) implementation over GF(2163) for point multiplication (PM) is presented on field programmable gate array (FPGA) using polynomial basis representation. The novel architecture is based on Lopez Dahab PM algorithm. A bit parallel hybrid karatsuba multiplier is used to reduce clock cycles (latency) and Itoh Tsujii inversion algorithm is used to reduce hardware resources. The proposed ECP architecture has been implemented on different Xilinx FPGA's i e. Virtex 4, Virtex 5, Virtex 6 and Virtex 7 devices. The performance of proposed ECP in terms of area to time product is analyzed by using slicesxk.P(s)/106. Our proposed ECP achieves the lower area (slices) with comparable speed and area to time product on Virtex 4 (6884 slices, 53.5 ms, 0.368) on Virtex 5 (3636 slices, 32.3 ms, 0.117) on Virtex 6 (3144 slices, 26.9 ms, 0.084) and on newer Virtex 7 (3657 slices, 25.3 ms, 0.092) Finally, the proposed ECP outperforms on Virtex 6 in terms of both area (slices) and area to time product (0.084) when compared with most relevant state of the art.

title: ALMA CO Clouds and Young Star Complexes in the Interacting Galaxies IC 2163 and NGC 2207
abstract: Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Debra Meloy Elmegreen, et al, 'ALMA CO Clouds and Young Star Complexes in the Interacting Galaxies IC 2163 and NGC 2207' The Astrophysical Journal, 841:43 (10pp) 22 May 2017,

title: High star formation rates in turbulent atomic dominated gas in the interacting galaxies IC 2163 and NGC 2207
abstract: CO observations of the interacting galaxies IC 2163 and NGC 2207 are combined with HI, Halpha and 24 microns to study the star formation rate (SFR) surface density as a function of the gas surface density. More than half of the high SFR regions are HI dominated. When compared to other galaxies, these HI dominated regions have excess SFRs relative to their molecular gas surface densities but normal SFRs relative to their total gas surface densities. The HI dominated regions are mostly located in the outer part of NGC 2207, where the HI velocity dispersion is high, 40 50 km/s. We suggest that the star forming clouds in these regions have envelopes at lower densities than normal, making them predominantly atomic, and cores at higher densities than normal because of the high turbulent Mach numbers. This is consistent with theoretical predictions of a flattening in the density probability distribution function for compressive, high Mach number turbulence.

title: SPIRITS 15c and SPIRITS 14buu: Two Obscured Supernovae in the Nearby Star Forming Galaxy IC 2163
abstract: SPIRITS SPitzer InfraRed Intensive Transients Survey is an ongoing survey of nearby galaxies searching for infrared (IR) transients with Spitzer/IRAC. We present the discovery and follow up observations of one of our most luminous $M_{[4.5] 17.1\pm0.4$ mag, Vega) and red [3.6] [4.5] 3.0 \pm 0.2$ mag) transients, SPIRITS 15c. The transient was detected in a dusty spiral arm of IC 2163 $D\approx35.5$ Mpc) Pre discovery ground based imaging revealed an associated, shorter duration transient in the optical and near IR (NIR) NIR spectroscopy showed a broad \approx 8400$ km s$ 1} double peaked emission line of He I at $1.083 \mu$m, indicating an explosive origin. The NIR spectrum of SPIRITS 15c is similar to that of the Type IIb SN 2011dh at a phase of \approx 200$ days. Assuming $A_V 2.2$ mag of extinction in SPIRITS 15c provides a good match between their optical light curves. The IR light curves and the extreme [3.6] [4.5] color cannot be explained using only a standard extinction law. Another luminous $M_{4.5} 16.1\pm0.4$ mag) event, SPIRITS 14buu, was serendipitously discovered in the same galaxy. The source displays an optical plateau lasting \gtrsim 80$ days, and we suggest a scenario similar to the low luminosity Type IIP SN 2005cs obscured by $A_V \approx 1.5$ mag. Other classes of IR luminous transients can likely be ruled out in both cases. If both events are indeed SNe, this may suggest \gtrsim 18\ of nearby core collapse SNe are missed by currently operating optical surveys.

title: Ocular Shock Front in the Colliding Galaxy IC 2163
abstract: ALMA observations in the CO 1 0 line of the interacting galaxies IC 2163 and NGC 2207 at 2" x 1.5" resolution reveal how the encounter drives gas to pile up in narrow, 1 kpc wide, "eyelids" in IC 2163. IC 2163 and NGC 2207 are involved in a grazing encounter, which has led to development in IC 2163 of an eye shaped (ocular) structure at mid radius and two tidal arms. The CO data show that there are large velocity gradients across the width of each eyelid, with a mixture of radial and azimuthal streaming of gas at the outer edge of the eyelid relative to its inner edge. The sense of the radial streaming in the eyelids is consistent with the idea that gas from the outer part of IC 2163 flows inward until its radial streaming slows down abruptly and the gas piles up in the eyelids. The radial compression at the eyelids causes an increase in the gas column density by direct radial impact and also leads to a high rate of shear. We find a strong correlation between the molecular column densities and the magnitude of dv/dR across the width of the eyelid at fixed values of azimuth. Substantial portions of the eyelids have high velocity dispersion in CO, indicative of elevated turbulence there.

title: Dark matter distribution in the merging cluster Abell 2163
abstract: The cluster Abell 2163 is a merging system of several subclusters with complex dynamics. It presents exceptional X rays properties (high temperature and luminosity) suggesting that it is a very massive cluster. Recent 2D analysis of the gas distribution has revealed a complex and multiphase structure. This paper presents a wide field weak lensing study of the dark matter distribution in the cluster in order to provide an alternative vision of the merging status of the cluster. The 2D mass distribution is built and compared to the galaxies and gas distributions. A Bayesian method, implemented in the Im2shape software, was used to fit the shape parameters of the faint background galaxies and to correct for PSF smearing. A careful color selection on the background galaxies was applied to retrieve the weak lensing signal. Shear signal was measured out to more than 2 Mpc ~12' from the center) The radial shear profile was fit with different parametric mass profiles. The 2D mass map is built from the shear distribution and used to identify the different mass components. The 2D mass map agrees with the galaxy distribution, while the total mass inferred from weak lensing shows a strong discrepancy to the X ray deduced mass. Regardless of the method used, the virial mass M200 falls in the range 8 to 14 10^14 Msol inside the virial radius 2.0 Mpc) a value that is two times less than the mass deduced from X rays. The central mass clump appears bimodal in the dark matter distribution, with a mass ratio ~3:1 between the two components. The infalling clump A2163 B is detected in weak lensing as an independent entity. All these results are interpreted in the context of a multiple merger seen less than 1Gyr after the main crossover.

title: NGC 2207/IC 2163: A GRAZING ENCOUNTER WITH LARGE SCALE SHOCKS
abstract: Radio continuum, Spitzer infrared, optical, and XMM Newton X ray and ultraviolet observations (UVW1 and UVM2) are used to study large scale shock fronts, young star complexes, and the galactic nuclei in the interacting galaxies NGC 2207/IC 2163. There are two types of large scale shock fronts in this galaxy pair. The large scale shock front along the rim of the ocular oval in IC 2163 has produced vigorous star formation in a dusty environment, bright in the Spitzer 8 {mu}m and 24 {mu}m images. In the outer part of the companion side of NGC 2207, a large scale front attributed to halo scraping is particularly bright in the {lambda}6 cm and {lambda}20 cm radio continuum but not in any tracers of recent star formation (H{alpha} 8 {mu}m, 24 {mu}m, or ultraviolet emission) or in X rays. This radio continuum front may be from compression of the halo magnetic field on the back side of NGC 2207, between the two galaxies. The X ray emission sets an upper limit to the gas density in the halo. Values of the flux density ratio S{sub {nu}(8 {mu}m)/S{sub {nu}(6 cm) of prominent, kiloparsec size, Spitzer/IRAC star forming clumps in NGC 2207/IC 2163 are compared with those of giant radio H II regions in M81.more For the bright clumps in NGC 2207, the mean value of this ratio is the same as for the M81 H II regions, whereas for the bright clumps on the rim of the IC 2163 ocular oval, the mean value is nearly a factor of two greater. Possible explanations for this are discussed. The galaxy pair has global values of the ratios of infrared to radio continuum flux density in the Spitzer 8 {mu}m, 24 {mu}m, and 70 {mu}m bands, and the IRAS FIR significantly below the medians/means for large samples of galaxies. Feature i, a mini starburst on an outer arm of NGC 2207 on its anti companion side, is the most luminous 8 {mu}m, 24 {mu}m, 70 {mu}m, radio continuum, and H{alpha} source in the galaxy pair. We find evidence that a radio supernova was present in the core of feature i in 2001. X ray emission is detected from the nucleus of NGC 2207 and from nine discrete sources whose X ray luminosities make them possible candidates for Ultraluminous X ray sources. One of these corresponds with the Type Ib SN 1999ec, which is also bright in the ultraviolet, and another may be a radio supernova or a background quasar. The X ray luminosity of the NGC 2207 nucleus is log L{sub 0.3 10.0keV} 40.6 erg s{sup 1} which, together with its X ray spectrum, suggests that this is a highly absorbed, low luminosity, active galactic nucleus.