1RXS J180408.9-342058: an ultra compact X-ray binary candidate with a transient jet

We present a detailed NIR/optical/UV study of the transient low mass X-ray binary 1RXS J180408.9-342058 performed during its 2015 outburst, aimed at determining the nature of its companion star. We obtained three optical spectra at the 2.1 m San Pedro Martir Observatory telescope (Mexico). We performed optical and NIR photometric observations with both the REM telescope and the New Technology Telescope (NTT) in La Silla. We obtained optical and UV observations from the Swift archive. Finally, we performed optical polarimetry of the source by using the EFOSC2 instrument mounted on the NTT. The optical spectrum of the source is almost featureless since the hydrogen and He I emissions lines, typically observed in LMXBs, are not detected. Similarly, carbon and oxygen lines are neither observed. We marginally detect the He II 4686 AA emission line, suggesting the presence of helium in the accretion disc. No significant optical polarisation level was observed. The lack of hydrogen and He I emission lines in the spectrum implies that the companion is likely not a main sequence star. Driven by the tentative detection of the He II 4686 AA emission line, we suggest that the system could harbour a helium white dwarf. If this is the case, 1RXS J180408.9-342058 would be an ultra-compact X-ray binary. By combining an estimate of the mass accretion rate together with evolutionary tracks for a He white dwarf, we obtain a tentative orbital period of ~ 40 min. On the other hand, we also built the NIR-optical-UV spectral energy distribution (SED) of the source at two different epochs. One SED was gathered when the source was in the soft X-ray state, and it is consistent with the presence of a single thermal component. The second SED, obtained when the source was in the hard X-ray state, shows a thermal component together with a tail in the NIR, likely indicating the presence of a (transient) jet.Comment: 8 pages, 5 figures, 4 tables. Accepted for publication in Astronomy & Astrophysics (Section 7

A first look at equid “idols” from Tepecik-Ciftlik, southern Cappadocia, Turkey

Desde el año 2000, el profesor Erhan Biçakçi de la Universidad de Estambul, ha dirigido diversas campañas de excavación en el yacimiento arqueológico de Tepeçik-Çiftlik, en la región Niğde, al sur de la Capadocia. Allí se han podido documentar niveles pertenecientes al Neolítico Pre-cerámico, Neolítico Cerámico y Calcolítico Antiguo. Las excavaciones han sacado a la luz un rico conjunto de objetos de hueso datados en el Neolítico y Calcolítico. Una de las características más destacadas de este conjunto es la presencia de aproximadamente 250 “ídolos” de hueso. Estos objetos fueron realizados sobre la primera falange de équidos, aplanando la superficie dorsal y plantar/volar de ésta. Algunos de ellos incluso muestran una decoración mucho más elaborada. Las medidas tomadas en estos huesos indican que las falanges proximales de caballo salvaje (Equus ferus) e hydruntino (Equus hemionus hydruntinus) fueron empleadas para manufacturar estos objetos de hueso. Este artículo ilustrará cómo estos elementos óseos fueron realizados y cómo se distribuyen cronológicamente en el sitio.Excavation at the Pre-Pottery Neolithic, Pottery Neolithic, and Early Chalcolithic site of Tepecik-Çiftlik in the Niğde region of Southern Cappadocia, Turkey have been conducted since 2000 under the direction of Professor Erhan Biçakçi of Istanbul University. The excavations have yielded a rich assemblage of worked bone objects dating to the Neolithic and Chalcolithic Periods. One of the striking features of the assemblage is the presence of approximately 250 bone “idols”. These objects were made by flattening the dorsal and plantar/volar surfaces of equid first phalanges. Some also show more elaborate decoration. Measurements taken on these bones indicate that wild horse (Equus ferus) and hydruntine (Equus hemionus hydruntinus) proximal phalanges were used to produce these bone objects. This paper will illustrate how these how these bone objects were manufactured and how they were distributed chronologically within the site

The Brera Multi-scale Wavelet (BMW) ROSAT HRI source catalog. I: the algorithm

We present a new detection algorithm based on the wavelet transform for the analysis of high energy astronomical images. The wavelet transform, due to its multi-scale structure, is suited for the optimal detection of point-like as well as extended sources, regardless of any loss of resolution with the off-axis angle. Sources are detected as significant enhancements in the wavelet space, after the subtraction of the non-flat components of the background. Detection thresholds are computed through Monte Carlo simulations in order to establish the expected number of spurious sources per field. The source characterization is performed through a multi-source fitting in the wavelet space. The procedure is designed to correctly deal with very crowded fields, allowing for the simultaneous characterization of nearby sources. To obtain a fast and reliable estimate of the source parameters and related errors, we apply a novel decimation technique which, taking into account the correlation properties of the wavelet transform, extracts a subset of almost independent coefficients. We test the performance of this algorithm on synthetic fields, analyzing with particular care the characterization of sources in poor background situations, where the assumption of Gaussian statistics does not hold. For these cases, where standard wavelet algorithms generally provide underestimated errors, we infer errors through a procedure which relies on robust basic statistics. Our algorithm is well suited for the analysis of images taken with the new generation of X-ray instruments equipped with CCD technology which will produce images with very low background and/or high source density.Comment: 8 pages, 6 figures, ApJ in pres

The structure of the X-ray absorber in Mrk 915 revealed by Swift

In this paper we present the results obtained with a monitoring programme (23 days long) performed with Swift-XRT on the local Seyfert galaxy Mrk 915. The light-curve analysis shows a significant count rate variation (about a factor of 2-3) on a time-scale of a few days, while the X-ray colours show a change in the spectral curvature below 2 keV and the presence of two main spectral states. From the spectral analysis we find that the observed variations can be explained by the change of the intrinsic nuclear power (about a factor of 1.5) coupled with a change of the properties of an ionized absorber. The quality of the data prevents us from firmly establishing if the spectral variation is due to a change in the ionization state and/or in the covering factor of the absorbing medium. The latter scenario would imply a clumpy structure of the ionized medium. By combining the information provided by the light curve and the spectral analyses, we can derive some constraints on the location of the absorber under the hypotheses of either homogeneous or clumpy medium. In both cases, we find that the absorber should be located inside the outer edge of an extended torus and, in particular, under the clumpy hypothesis, it should be located near, or just outside, to the broad emission line region.Comment: 8 pages, 6 figures, 1 table. Accepted for publication on MNRA

An examination of the psychometric properties of Brazilian Portuguese translations of the Drive for Muscularity Scale, the Swansea Muscularity Attitudes Questionnaire, and the Masculine Body Ideal Distress Scale

The aim of this study was to translate into Brazilian Portuguese three scales for the assessment of men's body image, namely the Drive for Muscularity Scale (DMS), the Swansea Muscularity Attitudes Questionnaire (SMAQ), and the Male Body Ideal Distress Scale (MBIDS), and to evaluate the factor structure of each of these translated scales. A sample of 878 men completed translated versions of each of the scales, a previously translated Portuguese version of the Body Appreciation Scale, and demographic measures. Confirmatory factor analysis, using unweighted least square estimation and listwise deletion, was used to determine the scales' factorial structures. Results showed that the Portuguese DMS and MBIDS had similar factor structures as their parent versions, whereas the SMAQ had a three-factor structure that diverged from its parent scale. Adequate internal reliability coefficients and evidence of construct validity was established for all three scales. These translated scales provide useful tools for quantitative investigations of men's body image in the Brazilian context and expand the possibility of future cross-cultural research

A multi-objective DIRECT algorithm for ship hull optimization

The paper is concerned with black-box nonlinear constrained multi-objective optimization problems. Our interest is the definition of a multi-objective deterministic partition-based algorithm. The main target of the proposed algorithm is the solution of a real ship hull optimization problem. To this purpose and in pursuit of an efficient method, we develop an hybrid algorithm by coupling a multi-objective DIRECT-type algorithm with an efficient derivative-free local algorithm. The results obtained on a set of “hard” nonlinear constrained multi-objective test problems show viability of the proposed approach. Results on a hull-form optimization of a high-speed catamaran (sailing in head waves in the North Pacific Ocean) are also presented. In order to consider a real ocean environment, stochastic sea state and speed are taken into account. The problem is formulated as a multi-objective optimization aimed at (i) the reduction of the expected value of the mean total resistance in irregular head waves, at variable speed and (ii) the increase of the ship operability, with respect to a set of motion-related constraints. We show that the hybrid method performs well also on this industrial problem

XMM-Newton and NuSTAR joint observations of Mrk 915: a deep look into the X-ray properties

We report on the X-ray monitoring programme (covering slightly more than 11 days) carried out jointly by XMM-Newton and NuSTAR on the intermediate Seyfert galaxy Mrk 915. The light curves extracted in different energy ranges show a variation in intensity but not a significant change in spectral shape. The X-ray spectra reveal the presence of a two-phase warm absorber: a fully covering mildly ionized structure [log xi/(erg cm/s)~2.3, NH~1.3x10^21 cm-2] and a partial covering (~90 per cent) lower ionized one [log xi/(erg cm/s)~0.6, NH~2x10^22 cm-2]. A reflection component from distant matter is also present. Finally, a high-column density (NH~1.5x10^23 cm-2) distribution of neutral matter covering a small fraction of the central region is observed, almost constant, in all observations. Main driver of the variations observed between the datasets is a decrease in the intrinsic emission by a factor of ~1.5. Slight variations in the partial covering ionized absorber are detected, while the data are consistent with no variation of the total covering absorber. The most likely interpretation of the present data locates this complex absorber closer to the central source than the narrow line region, possibly in the broad line region, in the innermost part of the torus, or in between. The neutral obscurer may either be part of this same stratified structure or associated with the walls of the torus, grazed by (and partially intercepting) the line of sight.Comment: 14 pages, 10 figures, 4 tables. Accepted for publication in MNRA

COMPARING THE RESPECTIVE EFFECTS OF THREE TYPES OF WARM-UP ON THE COUNTERMOVEMENT JUMP: AN ANALYSIS OF NON-ATHLETE COLLEGE STUDENTS

The purpose of this study was to examine and compare the respective effects of traditional, dynamic, and plyometric warm-ups on non-athlete college students’ performance of the countermovement jump (CMJ). Forty-seven male non-athlete college students were respectively allocated to three separate groups: the traditional warm-up group (TG), dynamic warm-up group (DG), and the plyometric warm-up group (PG). The DG and PG showed statistically significant improvements in push-off, force, and power (p\u3c0.001) when compared to the TG. No statistically significant differences were observed in jump height, flight time and velocity, and the effect sizes were small. The findings of this study showed that dynamic and plyometric warm-up protocols could influence CMJ performance among non-athlete college students