Double-nucleus elliptical MCG-01-12-005 in an X-ray emitting cluster of galaxies

The scenario of galaxy formation is believed to follow a structure that builds up from the bottom, with large galaxies being formed by several merging episodes of smaller ones. In this scenario a number of galaxies can be expected to be seen in the merging phase, with their external regions already mixed, while their nuclei, with stronger self-gravitation, are still recognizable as such. During a photometric monitoring of AGNs in the field of a long-exposure INTEGRAL pointing, we serendipitously found an elliptical galaxy in the center of the X-ray cluster (EXO 0422-086) with two nuclei. We performed surface photometry on our images and those of the SDSS archive and obtained slit spectra of both nuclei. Aperture photometry of the two stellar-like nuclei showed very similar colors in the SDSS image and in our Johnson BVRI images, which is typical of an elliptical galaxy nucleus. The spectra of the nuclei showed the typical absorption lines of an elliptical galaxy without appreciable emission lines. The redshifts derived from each nucleus were equal and fully consistent with the literature value (0.0397). We can therefore exclude the possibility that one of the nuclei is a foreground star or a background AGN and consider this elliptical galaxy as a bona fide example of a galaxy merger.Comment: 4 pages, 3 figures. Accepted on Astronomy and Astrophysic

Questioni di lessico politico tra traduzioni di testi latini e trasmissione della Politica di Aristotele: libertas e liberté nelle traduzioni di Oresme, Foulechat e del Songe du Vergier

In order to show the complexity of translating from Latin to French in Middle-Ages, this article focuses on the term libertas. The pivotal question for medieval translators is how to render the different meanings (theological, ethical, political) of libertas. Three medieval authors as Denis Foulechat, Evrart de Tremaugon and Nicole Oresme find personal solutions, handling the French of their own age. But are their personal choices consistent with the meaning of the word that they are translating? A creative translator can help his readers and enrich the language they speak, but he can also alter what he is translating

Climate Responsive Design and the Milam Residence

Energy conservation and efficiency is an essential area of focus in contemporary building design. The perception that the designers of buildings during the Modernist period of architecture ignored these principles is a false one. The present study, an examination of Paul Rudolph’s Milam Residence, a masterpiece of American residential architecture, is part of a larger project endeavoring to create a knowledge base of the environmental performance of iconic modernist homes. A critical examination of the Milam House allows insight into specific design characteristics that impact energy efficiency and conservation. Located in Ponte Vedra Beach, Florida, the Milam Residence was constructed in 1962. It was the last of a series of Florida residences designed by Rudolph, Chairman of the Department of Architecture at Yale University (1958–1965). The structure’s form is strongly related to its location on a subtropical beachfront. This paper presents a detailed analysis of the building’s solar responsiveness. Specifically, we examine design strategies such as orientation and sunscreening and their effect on daylighting, shading, and heat gain. The analysis is based on parametric energy modeling studies using Autodesk’s Ecotect, an environmental analysis tool that allows simulation of building performance. While the initial target of the program was early design, the program allows the input of complex geometries and detailed programming of zones, materials, schedules, etc. The program\u27s excellent analyses of desired parameters are augmented by visualizations that make it especially valuable in communicating results. Our findings suggest that the building, as built and situated on the site, does take advantage of daylighting and solar shading and does so in both expected and unexpected ways

The 17 min orbital period in the Ultra Compact X-ray Binary 4U 0513-40

The ultracompact low-mass X-ray binary 4U 0513-40 in the globular cluster NGC1851 exhibits large amplitude X-ray flux variations with spectral changes from low/hard to high/soft states which have not been reported previously in other ultracompact X-ray binaries. Using BeppoSAX, CHANDRA and XMM Newton archival data together with recent INTEGRAL observations, we reveal a clear sinusoidal periodic signal with a period of ~17 minutes when the source is in a typical high/soft state with a dominant soft thermal component. The periodicity disappears when the source is in a low/hard state and the thermal soft component is not required any more to model the data. These properties indicate the orbital nature of the detected signal and imply an high inclination angle of the binary system (>80{\deg}).Comment: accepted MNRAS 201

Il ruolo dell’evergetismo aristocratico nella costruzione degli edifici di culto cristiani nell’hinterland di Roma

Studio delle committenze laiche degli edifici di culto cristiani del Lazio, con particolare riguardo al territorio rurale. L'evergetismo aristocratico si impone come fondamentale nella costruzione di una rete di chiese con cura di anime, sia nelle città che nelle campagn

X-ray spectral evolution of V404 Cygni in the initial phase of the 2015 outburst

The black hole binary GS 2023+338 exhibited an unprecedently bright outburst on June 2015. Since June 17th, the high energy instruments on board INTEGRAL detected an extremely variable emission during both bright and low luminosity phases, with dramatic variations of the hardness ratio on time scales of ~seconds. The analysis of the IBIS and SPI data reveals the presence of hard spectra in the brightest phases, compatible with thermal Comptonization with temperature kTe ~ 40 keV. The seed photons temperature is best fit by kT0 ~ 7 keV, that is too high to be compatible with blackbody emission from the disk. This result is consistent with the seed photons being provided by a different source, that we hypothesize to be a synchrotron driven component in the jet. During the brightest phase of flares, the hardness shows a complex pattern of correlation with flux, with a maximum energy released in the range 40-100 keV. The hard X-ray variability for E > 50 keV is correlated with flux variations in the softer band, showing that the overall source variability cannot originate entirely from absorption, but at least part of it is due to the central accreting source.Comment: 5 pages, 4 figures, accepted for publication in Astrophysical Journal Letter

XMM-Newton observations of unidentified INTEGRAL/IBIS sources

About 30% of the sources in the 4th INTEGRAL-IBIS catalogue are unidentified in that they lack an optical counterpart. To be able to classify them, X-ray observations are of crucial importance as they can place tighter constraints on the high energy error box, which is usually of the order of a few arcminutes, and allow their broad band spectrum to be studied. To this aim we have cross-correlated the list of all unidentified IBIS sources in the fourth catalogue with the archive of all XMM-Newton pointings, finding a set of 6 objects with archival data. For 1 of them, IGR J17331-2406, no X-ray source is detected by XMM inside the IBIS error box, most likely due to the fact that it is a transient object. In the case of IGR J17445-2747 two possible X-ray counterparts are found inside the IBIS error box: one is very weak while the other is bright but only detected once. In each of the remaining 4 cases: IGR J155359-5750, AX J1739.3-2923, AX J1740.2-2903 and IGR J18538-0102, we find instead a convincing association for which we provide an improved X-ray position and information on the optical/infrared counterpart. We also performed a detailed analysis of their XMM-IBIS spectra and on the basis of all information acquired we suggest that IGR J155359-5750 is an AGN of intermediate type, AX J1739.3-2923 and AX J1740.2-2903 are High Mass X-ray Binary systems, IGR J17331-2406 and IGR J17445-2747 are Galactic transient sources and IGR J18538-0102 could be a background AGN.Comment: 9 pages, 10 figures, accepted for publication on MNRAS main journa

Can Twitter be a source of information on allergy? Correlation of pollen counts with tweets reporting symptoms of allergic rhinoconjunctivitis and names of antihistamine drugs

Pollen forecasts are in use everywhere to inform therapeutic decisions for patients with allergic rhinoconjunctivitis (ARC). We exploited data derived from Twitter in order to identify tweets reporting a combination of symptoms consistent with a case definition of ARC and those reporting the name of an antihistamine drug. In order to increase the sensitivity of the system, we applied an algorithm aimed at automatically identifying jargon expressions related to medical terms. We compared weekly Twitter trends with National Allergy Bureau weekly pollen counts derived from US stations, and found a high correlation of the sum of the total pollen counts from each stations with tweets reporting ARC symptoms (Pearson's correlation coefficient: 0.95) and with tweets reporting antihistamine drug names (Pearson's correlation coefficient: 0.93). Longitude and latitude of the pollen stations affected the strength of the correlation. Twitter and other social networks may play a role in allergic disease surveillance and in signaling drug consumptions trends