Wahhabism is often understood as a radical version of Islam responsible for inspiring and motivating Islamic terrorism. In contrast to the existing literature that treats Wahhabism as a historical ...phenomenon or a monolithic theological ideology, a literature often written by authors keen to promote geopolitical interests or with ideological axes to grind, Western Imaginings: The Intellectual Contest to Define Wahhabism considers Wahhabism as a discursive construct crafted and popularized by a Western intellectual elite. This comprehensive study speaks to how and why Western intellectuals have chosen to represent Wahhabism in specific ways.
ABSTRACT
We present the study of the internal dynamics of the intriguing galaxy cluster Abell 1703, a system hosting a probable giant radio halo whose dynamical status is still controversial. Our ...analysis is based on unpublished spectroscopic data acquired at the Italian Telescopio Nazionale Galileo and data publicly available in the literature. We also use photometric data from the Sloan Digital Sky Survey. We select 147 cluster members and compute the cluster redshift 〈z〉 ∼ 0.277 and the global line-of-sight velocity dispersion σv ∼ 1300 km s−1. We infer that Abell 1703 is a massive cluster: M200 ∼ 1–2 × 1015 M⊙. The results of our study disagree with the picture of an unimodal, relaxed cluster as suggested by previous studies based on the gravitational lensing analysis and support the view of a perturbed dynamics proposed by recent works based on Chandra X-ray data. The first strong evidence of a dynamically disturbed cluster comes from the peculiarity of the BCG velocity with respect to the first moment of the velocity distribution of member galaxies. Moreover, several statistical tests employed to study the cluster galaxies kinematics find significant evidence of substructure, being Abell 1703 composed by at least two or three subclumps probably caught after the core–core passage. In this observational scenario, the suspected existence of a radio halo in the centre of this cluster is not surprising and well agrees with the theoretical models describing diffuse radio sources in clusters.
The first results of a new survey, which explores the second data release of the ESA‐Gaia mission, are reported in order to search for stellar companions of (Community) TESS Objects of Interest and ...to characterize their properties. In total, 193 binary and 15 hierarchical triple star systems are presented, detected among 1,391 target stars, which are located at distances closer than about 500 pc around the Sun. The companions and the targets are equidistant and share a common proper motion, as is expected for gravitationally bound stellar systems, proven with their accurate Gaia astrometry. The companions exhibit masses in the range between about 0.08 M⊙ and 3M⊙ and are most frequently found in the mass range between 0.13 and 0.6M⊙. The companions are separated from the targets by about 40 up to 9,900 au, and their frequency continually decreases with increasing separation. While most of the detected companions are late K to mid M dwarfs, also five white dwarf companions were identified in this survey, whose true nature is revealed by their photometric properties.
Properties of dark matter haloes can be probed observationally and numerically, and comparing both approaches provides ways to constrain cosmological models. When it comes to the inner part of galaxy ...cluster scale haloes, interaction between the baryonic and the dark matter component is an important issue that is far from being fully understood. With this work, we aim to initiate a program coupling observational and numerical studies to probe the inner part of galaxy clusters. In this article, we apply strong lensing techniques on Abell 1703, a massive X-ray luminous galaxy cluster at $z = 0.28$. Our analysis is based on imaging data from both the space and ground in 8 bands, complemented by a spectroscopic survey. Abell 1703 is rather circular from the general shape of its multiply imaged systems and is dominated by a giant elliptical cD galaxy in its centre. This cluster exhibits a remarkable bright central ring formed by 4 images at zspec = 0.888 only 5–13″ away from the cD centre. This unique feature offers a rare lensing constrain for probing the central mass distribution. The stellar contribution from the cD galaxy (${\sim}$1.25 $\times$ 1012 $M_{\sun}$ within 30 kpc) is accounted for in our parametric mass modelling, and the underlying smooth dark matter component distribution is described using a generalized nfw profile parametrized with a central logarithmic slope α. The rms of our mass model in the image plane is equal to 1.4″. We find that within the range where observational constraints are present (from ~20 kpc to ~210 kpc), α is equal to $1.09^{+0.05}_{-0.11}$ (3σ confidence level). The concentration parameter is equal to c200 ~ 3.5, and the scale radius is constrained to be larger than the region where observational constraints are available (rs =$730^{\rm +15}_{-75}$ kpc). The 2D mass is equal to ${M}$ (210 kpc) = 2.4 $\times$ 1014 $M_{\sun}$. However, we cannot draw any conclusions on cosmological models at this point since we lack results from realistic numerical simulations containing baryons to make a proper comparison. We advocate the need for a large sample of well observed (and well constrained) and simulated unimodal relaxed galaxy clusters in order to make reliable comparisons and to potentially provide a test of cosmological models.
The article aims to find out how the census of 1701–1703 took place in the Kolomna diocese and to establish who took part in the practical conduct of the census events organized by the Monastery ...Order during the initial stage of the church reform of Peter I. The main attention is paid to the study of entries on the sheets of the census books of the Kolomna Episcopal House and monasteries of the Kolomna diocese.
Context. Strong gravitational lensing is a unique tool that can be used to accurately model the inner mass distribution of massive galaxy clusters. In particular, clusters with large Einstein radii ...provide a wealth of multiply imaged systems in the cluster core. Measuring the redshift of these multiple images provides strong constraints for precisely determining the shape of the central dark matter profile. Aims. This paper presents a spectroscopic survey of strongly lensed galaxies in the massive cluster lens Abell 1703, which displays a large Einstein radius (28´´ at $z=2.8$) and numerous strongly-lensed systems including a central ring-like configuration. Methods. We used the LRIS spectrograph on Keck to target multiple images and lensed galaxy candidates, and used the measured spectroscopic redshifts to constrain the mass distribution of the cluster using a parametric model. Results. The spectroscopic data enable us to measure accurate redshifts for 7 sources at $z>2$ , all of which are in good agreement with their photometric redshifts. We update the identification of multiply imaged systems by discovering 3 new systems and identifying a radial counter image. We also report the discovery of a remarkably bright ~3.6 L* i-band dropout at $z=5.827$ in our mask and it is only moderately magnified by the cluster ($\mu\sim3.0\pm0.08$). The improved parametric mass model, including 16 multiple systems with 10 spectroscopic redshifts, further constrains the smooth cluster-scale mass distribution with a generalized NFW profile of best-fit logarithmic slope $\alpha=0.92\pm0.04$, concentration $c_{200}=4.72\pm0.40$ and scale radius $r_{\rm s} =476\pm45$ kpc. The overall rms in the image plane is 1.3´´. Conclusions. Our strong-lensing model allows us to predict a large-scale shear signal that is consistent with weak-lensing measurements inferred from Subaru data out to 4 Mpc h-1. Also considering the strong-lensing modeling requires a single dark matter clump, this suggests that Abell 1703 is a relaxed, unimodal cluster. This unique cluster could be probed further using deep X-ray, SZ, and dynamics analysis for a detailed study of the physics in a relaxed cluster.
SAX J1818.6–1703 has been characterized as a supergiant fast X-ray transient system on the basis of several INTEGRAL/IBIS detections since the original BeppoSAX Wide Field Camera detection. Using ...IBIS/ISGRI, Swift/BAT and archival observations, we show that, in fact, SAX J1818.6–1703 exhibits emission on a period of 30 ± 0.1 d, with a high degree of recurrence. SAX J1818.6–1703 is therefore the second supergiant fast X-ray transient shown to exhibit periodic outbursts, but with a considerably shorter period than the other known system, IGR J11215–5952.
Weak lensing work can be badly compromised by unlensed foreground and cluster members which dilute the true lensing signal. We show how the lensing amplitude in multicolour space can be harnessed to ...securely separate cluster members from the foreground and background populations for three massive clusters, A1703 (z= 0.258), A370 (z= 0.375) and RXJ1347−11 (z= 0.451) imaged with Subaru. The luminosity functions of these clusters when corrected for dilution show similar faint-end slopes, α≃− 1.0, with no marked faint-end upturn to our limit of MR≃− 15.0, and only a mild radial gradient. In each case, the radial profile of the mass-to-light ratio (M/L) peaks at intermediate radius, ≃ 0.2rvir, at a level of 300–500(M/LR)⊙, and then falls steadily towards ∼ 100(M/LR)⊙ at the virial radius, similar to the mean field level. This behaviour is likely due to the relative paucity of central late-type galaxies, whereas for the E/S0 sequence only a mild radial decline in M/L is found for each cluster. We discuss this behaviour in the context of detailed simulations where predictions for tidal stripping may now be tested accurately with observations.
We present the results of a 30 ks XMM-Newton observation of the supergiant fast X-ray transient (SFXT) SAX J1818.6-1703 -- the first in-depth soft X-ray study of this source around periastron. ...INTEGRAL observations shortly before and after the XMM-Newton observation show the source to be in an atypically active state. Over the course of the XMM-Newton observation, the source shows a dynamic range of -100 with a luminosity greater than 1 x 10 super( 35) erg s super( -1) for the majority of the observation. After an ~6 ks period of low-luminosity (~10 super( 34) erg s super( -1)) emission, SAX J1818.6-1703 enters a phase of fast flaring activity, with flares ~250 s long, separated by ~2 ks. The source then enters a larger flare event of higher luminosity and ~8 ks duration. Spectral analysis revealed evidence for a significant change in spectral shape during the observation with a photon index varying from ... ~ 2.5 during the initial low-luminosity emission phase, to ... ~1.9 through the fast flaring activity, and a significant change to ... ~ 0.3 during the main flare. The intrinsic absorbing column density throughout the observation (n sub( H) ~ 5 x 10 super( 23) cm super( -2)) is among the highest measured from an SFXT, and together with the XMM-Newton and INTEGRAL luminosities, consistent with the neutron star encountering an unusually dense wind environment around periastron. Although other mechanisms cannot be ruled out, we note that the onset of the brighter flares occurs at 3 x 10 super( 35) erg s super( -1), a luminosity consistent with the threshold for the switch from a radiative-dominated to Compton cooling regime in the quasi-spherical settling accretion model. (ProQuest: ... denotes formulae/symbols omitted.)
Many of the urban settlements in Central Italy are placed nearby active faults and, consequently, the ground motion evaluation and seismic site effects under near-fault earthquakes are noteworthy ...issues to be investigated. This paper presents the results of site investigations, the seismic site characterization, and the local seismic response for assessing the effects induced by the Mw 6.7 2 February 1703, near-fault earthquake at the Madonna delle Fornaci site (Pizzoli, Central Italy) in which notable ground failure phenomena were observed, as witnessed by several coeval sources. Even though recent papers described these phenomena, the geological characteristics of the site and the failure mechanism have never been assessed through in-situ investigations and numerical modeling. Within a project concerning the assessment of soil liquefaction potential and co-seismic ground failure, deep and shallow continuous core drilling, geophysical investigations and in-hole tests have been carried out. Subsequently, the geotechnical model has been defined and the numerical quantification of the different hypotheses of failure mechanisms has been evaluated. Analyses showed that liquefaction did not occur, and the excess pore water pressure induced by the shaking was not the source of the ground failure. Therefore, it was hypothesized that the sinkhole was likely caused by earthquake-induced gas eruption.
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