Phase diagram for a Cubic Consistent-Q Interacting Boson Model Hamiltonian: signs of triaxiality

An extension of the Consistent-Q formalism for the Interacting Boson Model that includes the cubic QxQxQ term is proposed. The potential energy surface for the cubic quadrupole interaction is explicitly calculated within the coherent state formalism using the complete chi-dependent expression for the quadrupole operator. The Q-cubic term is found to depend on the asymmetry deformation parameter gamma as a linear combination of cos(3gamma) and cos^2(3\gamma) terms, thereby allowing for triaxiality. The phase diagram of the model in the large N limit is explored, it is described the order of the phase transition surfaces that define the phase diagram, and moreover, the possible nuclear equilibrium shapes are established. It is found that, contrary to expectations, there is only a very tiny region of triaxiality in the model, and that the transition from prolate to oblate shapes is so fast that, in most cases, the onset of triaxiality might go unnoticed.Comment: 18 pages, 19 figure

Sub-continental transport mechanisms and pathways during two ozone episodes in northern Spain

International audienceTwo ozone episodes (occurring in June 2001 and June 2003) in the air quality monitoring network of the Basque Country (BC) are analyzed. The population information threshold was exceeded in many stations (urban, urban-background and rural). During this type of episodes, forced by a blocking anticyclone over the British Isles, ozone background concentrations over the area increase after the import of pollution from both, the continental Europe and the western Mediterranean areas (Gangoiti et al., 2002). For the present analysis, emphasis is made in the search for transport mechanisms, pathways and area sources contributing to the build-up of the episodes. Contributions from a selection of 17 urban and industrial conglomerates in the western European Atlantic (WEA) and the western Mediterranean (WM) are shown after the results of a coupled RAMS-HYPACT modelling system. Meteorological simulations are tested against both the high-resolution wind data recorded at the BC coastal area by a boundary layer wind-profiler radar (Alonso et al., 1998) and the wind soundings reported by the National Centres of Meteorology at a selection of European and north-African sites. Results show that during the accumulation phase of the episodes, background ozone concentrations increase in the whole territory as a consequence of transport from the Atlantic coast of France and the British Channel. For the peak phase, intrusions from new sources, located at the Western Mediterranean, Southern France, Ebro Valley, and, occasionally, the area of Madrid are added, resulting in a further increase in the ozone concentrations. Direct day and night transport within the north-easterly winds over the sea from the WEA source region, and night-time transport within the residual layer over continental areas (southern France, the Ebro Valley, and central Iberia) modulate the import sequence of pollutants and the local increase of ozone concentrations. The alternative direct use of low resolution meteorological data for the estimation of back-trajectories shows a more simple transport scheme with no contributions neither from the Western Mediterranean nor from the Madrid area

Turning light into a liquid via atomic coherence

We study a four level atomic system with electromagnetically induced transparency with giant $\chi^{(3)}$ and $\chi^{(5)}$ susceptibilities of opposite signs. This system would allow to obtain multidimensional solitons and light condensates with surface tension properties analogous to those of usual liquids

Use of water troughs by wild rabbits (Oryctolagus cuniculus) in a farmland area of north–west Spain

Uso de bebederos por parte del conejo de monte (Oryctolagus cuniculus) en un paisaje agrícola en el noroeste de EspañaEn la península Ibérica, los bebederos son una herramienta de gestión de hábitat muy frecuente para incrementar las densidades de especies de caza menor, aunque el comportamiento de ingestión de agua de las especies “diana” no se ha estudiado en profundidad, como es el caso del conejo de monte (Oryctolagus cuniculus). Estudiamos el uso de bebederos por parte de conejos de monte durante 228 períodos de una semana en tres períodos consecutivos (junio–octubre) de 2008, 2009 y 2010 en un paisaje agrícola de noroeste de España, utilizando cámaras de fototrampeo. Los conejos utilizaron el 43% de los bebederos y se observó un número significativamente mayor de conejos bebiendo en bebederos rodeados por cobertura vegetal en comparación con bebederos situados en campos abiertos sin dicha cobertura vegetal. La mayoría de los conejos que bebieron fueron fotografiados de julio a septiembre (98%), si bien la utilización de bebederos no se relacionó claramente con la climatología. Los conejos bebieron principalmente durante la mañana (52% de los conejos) no tanto durante la tarde y noche, y raramente durante el mediodía. Los conejos se fotografiaron junto con perdices rojas (Alectoris rufa) en el 6% de las fotografías. Estos hallazgos sugieren que los bebederos son útiles para el conejo y otras especies con necesidades hídricas similares y que debieran ser colocados cerca de zonas con cobertura vegetal arbustiva.Installation of water troughs is a common approach to increase densities of small game species in the Iberian peninsula but little is known about the watering patterns of target species, such as the wild rabbit (Oryctolagus cuniculus). Using camera trapping, we monitored the use of water troughs by wild rabbits over 228 weeks in three consecutive periods, from June to October in 2008, 2009 and 2010, on farmland in north–west Spain. Wild rabbits used 43% of the water troughs. A significantly higher number of rabbits were observed drinking at troughs surrounded by shrub cover than at those in open fields. Most drinking events were recorded from July to September (98%), though the use of water troughs was not clearly related to weather. Wild rabbits drank mainly during the morning (52% of rabbits), less so in the evening and at night, and rarely in the afternoon. Wild rabbits were photographed together with red–legged partridges (Alectoris rufa) in 6% of photographs. These findings suggest water troughs are useful for species such as wild rabbits and should be allocated close to shrub areas.Uso de bebederos por parte del conejo de monte (Oryctolagus cuniculus) en un paisaje agrícola en el noroeste de EspañaEn la península Ibérica, los bebederos son una herramienta de gestión de hábitat muy frecuente para incrementar las densidades de especies de caza menor, aunque el comportamiento de ingestión de agua de las especies “diana” no se ha estudiado en profundidad, como es el caso del conejo de monte (Oryctolagus cuniculus). Estudiamos el uso de bebederos por parte de conejos de monte durante 228 períodos de una semana en tres períodos consecutivos (junio–octubre) de 2008, 2009 y 2010 en un paisaje agrícola de noroeste de España, utilizando cámaras de fototrampeo. Los conejos utilizaron el 43% de los bebederos y se observó un número significativamente mayor de conejos bebiendo en bebederos rodeados por cobertura vegetal en comparación con bebederos situados en campos abiertos sin dicha cobertura vegetal. La mayoría de los conejos que bebieron fueron fotografiados de julio a septiembre (98%), si bien la utilización de bebederos no se relacionó claramente con la climatología. Los conejos bebieron principalmente durante la mañana (52% de los conejos) no tanto durante la tarde y noche, y raramente durante el mediodía. Los conejos se fotografiaron junto con perdices rojas (Alectoris rufa) en el 6% de las fotografías. Estos hallazgos sugieren que los bebederos son útiles para el conejo y otras especies con necesidades hídricas similares y que debieran ser colocados cerca de zonas con cobertura vegetal arbustiva

A novel approach for adapting the standard addition method to single particle-ICP-MS for the accurate determination of NP size and number concentration in complex matrices; 35414390

This paper presents a novel approach, based on the standard addition method, for overcoming the matrix effects that often hamper the accurate characterization of nanoparticles (NPs) in complex samples via single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). In this approach, calibration of the particle size is performed by two different methods: (i) by spiking a suspension of NPs standards of known size containing the analyte, or (ii) by spiking the sample with ionic standards; either way, the measured sensitivity is used in combination with the transport efficiency (TE) for sizing the NPs. Moreover, such transport efficiency can be readily obtained from the data obtained via both calibration methods mentioned above, so that the particle number concentration can also be determined. The addition of both ionic and NP standards can be performed on-line, by using a T-piece with two inlet lines of different dimensions. The smaller of the two is used for the standards, thus ensuring a constant and minimal sample dilution. As a result of the spiking of the samples, mixed histograms including the signal of the sample and that of the standards are obtained. However, the use of signal deconvolution approaches permits to extract the information, even in cases of signal populations overlapping. For proofing the concept, characterization of a 50 nm AuNPs suspension prepared in three different media (i.e., deionized water, 5% ethanol, and 2.5% tetramethyl ammonium hydroxide-TMAH) was carried out. Accurate results were obtained in all cases, in spite of the matrix effects detected in some media. Overall, the approach proposed offers flexibility, so it can be adapted to different situations, but it might be specially indicated for samples for which the matrix is not fully known and/or dilution is not possible/recommended. © 2022 The Author

Low X-Ray Luminosity Galaxy Clusters: Main goals, sample selection, photometric and spectroscopic observations

We present the study of nineteen low X-ray luminosity galaxy clusters (L$_X \sim$ 0.5--45 $\times$ $10^{43}$ erg s$^{-1}$), selected from the ROSAT Position Sensitive Proportional Counters (PSPC) Pointed Observations (Vikhlinin et al. 1998) and the revised version of Mullis et al. (2003) in the redshift range of 0.16 to 0.7. This is the introductory paper of a series presenting the sample selection, photometric and spectroscopic observations and data reduction. Photometric data in different passbands were taken for eight galaxy clusters at Las Campanas Observatory; three clusters at Cerro Tololo Interamerican Observatory; and eight clusters at the Gemini Observatory. Spectroscopic data were collected for only four galaxy clusters using Gemini telescopes. With the photometry, the galaxies were defined based on the star-galaxy separation taking into account photometric parameters. For each galaxy cluster, the catalogues contain the PSF and aperture magnitudes of galaxies within the 90\% completeness limit. They are used together with structural parameters to study the galaxy morphology and to estimate photometric redshifts. With the spectroscopy, the derived galaxy velocity dispersion of our clusters ranged from 507 km~s$^{-1}$ for [VMF98]022 to 775 km~s$^{-1}$ for [VMF98]097 with signs of substructure. Cluster membership has been extensively discussed taking into account spectroscopic and photometric redshift estimates. In this sense, members are the galaxies within a projected radius of 0.75 Mpc from the X-ray mission peak and with cluster centric velocities smaller than the cluster velocity dispersion or 6000 km~s$^{-1}$, respectively. These results will be used in forthcoming papers to study, among the main topics, the red cluster sequence, blue cloud and green populations; the galaxy luminosity function and cluster dynamics.Comment: 13 pages, 6 tables, 9 figures. Uses emulateapj. Accepted for publication in The Astronomical Journal. Some formatting errors fixe

The globular cluster system of the nearest Seyfert II galaxy Circinus

Context. The globular cluster (GC) system of Circinus galaxy has not been probed previously partly because of the location of the galaxy at - 3.8$^\circ$ Galactic latitude which suffers severely from interstellar extinction, stellar crowding, and Galactic foreground contamination. However, the deep near-infrared (NIR) photometry by the VISTA Variables in the Via L\'actea Extended Survey (VVVX) in combination with the precise astrometry of Gaia EDR3 allow us to map GCs in this region. Aims. Our long-term goal is to study and characterise the distributions of GCs and Ultra-compact dwarfs of Circinus galaxy which is the nearest Seyfert II galaxy. Here we conduct the first pilot search for GCs in this galaxy. Methods. We use NIR VVVX photometry in combination with Gaia EDR3 astrometric features such as astrometric excess noise and BP/RP excess factor to build the first homogeneous catalogue of GCs in Circinus galaxy. A robust combination of selection criteria allows us to effectively clean interlopers from our sample. Results. We report the detection of$\sim$ 70 GC candidates in this galaxy at a 3 $\sigma$ confidence level. They show a bimodal colour distribution with the blue peak at (G-Ks)$_0$ = 0.985$\pm$0.127 mag with a dispersion of 0.211$\pm$0.091 mag and the red peak at (G-Ks)$_0$ = 1.625$\pm$0.177 mag with a dispersion of 0.482$\pm$0.114 mag. A GC specific frequency (S$_N$) of 1.3$\pm$0.2 was derived for the galaxy, and we estimated a total population of 120$\pm$40 GCs. Based on the projected radial distribution it appears that Circinus has a different distribution of GC candidates than MW and M31. Conclusions. We demonstrate that Circinus galaxy hosts a sizeable number of cluster candidates. This result is the first leap towards understanding the evolution of old stellar clusters in this galaxy.Comment: 15 pages, 12 figure

Phase diagram and influence of defects in the double perovskites

The phase diagram of the double perovskites of the type Sr_{2-x} La_x Fe Mo O_6 is analyzed, with and without disorder due to antisites. In addition to an homogeneous half metallic ferrimagnetic phase in the absence of doping and disorder, we find antiferromagnetic phases at large dopings, and other ferrimagnetic phases with lower saturation magnetization, in the presence of disorder.Comment: 4 pages, 3 postscript figures, some errata correcte