Radio jets in colliding galaxies: Testing the interaction-activity connection

The idea that galaxy interactions and merging are related to the generation of starburst and AGN activity in galactic nuclei has been the subject of intensive investigations over the past several years and is still a matter of lively debate. Peculiar morphologies, indicative of tidal interactions, have been detected in high-luminosity radio galaxies, in quasars, and in ultraluminous IRAS galaxies. In addition, low-luminosity radio and active galaxies show similar evidence for a recent merger or for nearby companions. In a recent CCD optical study of galaxies selected on the basis that they all contain well defined radio jets, it was found that almost half of the sample consists of pairs of elliptical galaxies. Many of these low-luminosity radio galaxies with companions show a well defined distorted radio jet structure at the VLA scale with an S- or C-shaped morphology. We have developed a general numerical simulation algorithm for ballistic radio jets with the intention of applying this model to the study of the bent jets seen in colliding pairs of galaxies and with the hope of testing the well documented interaction-activity connection. In our model the morphological evolution of the jets is determined by their response to the simple mechanical forces (i.e., gravity and ram pressure) imposed on them from both the host and the companion galaxies. Radiative losses, jet precession, magnetic effects, relativistic terms, and hydrodynamic instabilities have all been ignored. Starting with a previously derived collision model for the interacting pair of elliptical galaxies NGC 4782/4783, we have used our algorithm to simulate the specific two-sided jet morphology seen in the radio source 3C 278, associated with NGC 4782. This is the first time that such jet simulations have been produced for a galaxy pair whose relative orbit was determined independently from the jet modeling

VLT/VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies: 2D kinematic properties

We present and discuss the 2D kinematic properties of the ionized gas (Halpha) in a sample of 38 local (ultra) luminous infrared galaxies [(U)LIRGs] (31 LIRGs and 7 ULIRGs) observed with VIMOS at the VLT using integral field spectroscopy. This sample covers well the less studied LIRG luminosity range and includes isolated disks, interacting systems, and mergers. The majority of the galaxies have two main kinematically distinct components. One component (i.e., narrow or systemic) extends over the whole line-emitting region and is characterized by small to intermediate velocity dispersions (i.e., sigma from 30 to 160 km s^-1). It traces the overall velocity field. The second component (broad) has in general a larger velocity dispersion (up to 320 km s^-1), mainly found in the inner regions and generally blueshifted with respect to the systemic component. Most of the objects (76%) are dominated by rotation, more relevant in LIRGs than in ULIRGs. Isolated disks, interacting galaxies, and merging systems define a sequence of increasing mean velocity dispersion, and decreasing velocity field amplitude.The LIRGs classified as isolated disks have similar velocity amplitudes but larger mean velocity dispersions (44 vs. 24 km s^-1) than local spirals, implying a larger turbulence and thicker disks. Interacting systems and mergers have values closer to those of low velocity dispersion ellipticals/lenticular galaxies (E/SOs). The (U)LIRGs classified as mergers have kinematic properties similar to those shown by the Lyman break analogs (LBAs). The dynamical masses range from \sim 0.04 m* to 1.4 m* (i.e., m* = 1.4x10^{11} Msun), with ULIRGs (M{dyn} sim 0.5 +/- 0.2 m*) being more massive than LIRGs by, on average, a factor of about 2. The mass ratio of individual pre-coalescence galaxies is <2.5 for most of the systems, confirming that most (U)LIRG mergers involve sub-m* galaxies of similar mass.Comment: 66 pages, 5 figures plus 45 figures in App. A; accepted for publication in A&

Spitzer/IRS Mapping of Local Luminous Infrared Galaxies

We present results of our program Spitzer/IRS Mapping of local Luminous Infrared Galaxies (LIRGs). The maps cover the central 20"x20" or 30"x 30" regions of the galaxies, and use all four IRS modules to cover the full 5-38 microns spectral range. We have built spectral maps of the main mid-IR emission lines, continuum and PAH features, and extracted 1D spectra for regions of interest in each galaxy. The final goal is to fully characterize the mid-IR properties of local LIRGs as a first step to understanding their more distant counterparts.Comment: 4 pages, 5 figures. To appear in "Highlights of Spanish Astrophysics V", Proceedings of the VIII Scientific Meeting of the Spanish Astronomical Society (SEA) held in Santander, 7-11 July, 200

Ionized gas outflows and global kinematics of low-z luminous star forming galaxies

We study the kinematic properties of the ambient ionized ISM and ionized gas outflows in a large and representative sample of local luminous and ultraluminous infrared galaxies (U/LIRGs) (58 systems, 75 galaxies), on the basis of integral field spectroscopy (IFS)-based high S/N integrated spectra at galactic and sub-galactic, i.e. star forming (SF) clumps, scales. Ambient ionized gas. The velocity dispersion of the ionized ISM in U/LIRGs ( ~ 70 kms-1) is larger than in lower luminosity local star forming galaxies ( ~ 25 kms-1). While for isolated disc LIRGs star formation appears to sustain turbulence, gravitational energy release associated to interactions and mergers plays an important role driving sigma in the U/LIRG range. We also find that the impact of an AGN in ULIRGs is strong, increasing sigma by a factor 1.5 on average. The observed weak dependency of sigma with SFR surface density for local U/LIRGs is in very good agreement with that measured in some high-z samples. Ionized outflows. The presence of ionized gas outflows in U/LIRGs seems universal based on the detection of a broad, usually blueshifted, Halpha line. AGNs in U/LIRGs are able to generate faster (x2) and more massive (x1.4) ionized gas outflows than pure starbursts. The derived ionized mass loading factors are in general below one, with only a few AGNs above this limit. Only a small fraction of the ionized material from low mass LIRGs (log(Mdyn/Msun) < 10.4) could reach the intergalactic medium, with more massive galaxies retaining the gas. The observed average outflow properties in U/LIRGs are similar to high-z galaxies of comparable SFR. In the bright SF clumps found in LIRGs, ionized gas outflows appear to be very common. For a given SFR surface density, outflows in LIRG clumps would be about one to two orders of magnitude less energetic than those launched by clumps in high-z SF galaxies.Comment: 36 pages, 20 figures, 6 tables. Accepted for publication in A&

Detection of a Super Star Cluster as the Ionizing Source in the Low Luminosity AGN NGC 4303

HST UV STIS imaging and spectroscopy of the low luminosity AGN (LLAGN) NGC 4303 have identified the previously detected UV-bright nucleus of this galaxy, as a compact, massive and luminous stellar cluster. The cluster with a size (FWHM) of 3.1 pc, and an ultraviolet luminosity log L (1500 A}(erg/s/A)= 38.33 is identified as a nuclear super star cluster (SSC) like those detected in the circumnuclear regions of spirals and starburst galaxies. The UV spectrum showing the characteristic broad P Cygni lines produced by the winds of massive young stars, is best fitted by the spectral energy distribution of a massive cluster of 1e5 Msol generated in an instantaneous burst 4 Myr ago. No evidence for an additional non-thermal ionizing source associated with an accreting black hole is detected in the ultraviolet. We hypothesize that at least some LLAGNs in spirals could be understood as the result of the combined ionizing radiation emitted by an evolving SSC and a black hole (BH) accreting with low radiative efficiency, coexisting in the inner few parsecs region.Comment: 4 figure

Soluciones espurias o extrañas y como determinarlas en el proceso de resolución de problemas de ecuaciones irracionales de índice n = 2

El presente trabajo pretende justificar las definiciones de soluciones espurias o extrañas y las transformaciones que las generan en el proceso de resolución de problemas de una ecuación irracional, que por lo general, los libros de textos no explican de donde surgen estas soluciones y otros la excusan superficialmente. La investigación se orienta hacia los docentes de matemática a los fines de que aborden las definiciones y justificaciones usando planes de resolución de problemas de Polya y Schoenfeld, por medio de la nueva algebra que propone Picciotto y Wah, y así facilitar el proceso de enseñanza-aprendizaje de manera estimulante en el pensamiento crítico y la metacognición

The Geographical Distribution of the Personal Networks of People Living in Catalonia : a dual society

Background of INCASI Project H2020-MSCA-RISE-2015 GA 691004. WP1: CompilationBased on a survey concerning personal networks of a sample of 416 people living in Catalonia we address two questions: First, are there differences between native-born and foreign-born residents in terms of the geographical repartition of their personal networks? Second, regarding active contacts providing support, where do they live? Our data show that on average 70% of the active contacts of native-born residents live in the same city whereas immigrants have more than 50% of their active contacts living in another city or country, regardless of the length of residence in Catalonia. Natives and immigrants also differ in the location of supportive network contacts, mostly non-locals in the latter case. With regard to the social interactions among nationals and immigrants, our results bring us to characterize the Catalan society as a "dual society", with a social divide between the two groups. We suggest that this situation can be applicable to most of the countries where a "sub-functional class" is working in a dual labour market

The establishment of Aceratoneuromyia indica (Hymenoptera: Eulophidae) in three biogeographical regions of Argentina

Specimens of the eulophid Aceratoneuromyia indica (Silvestri) were recovered from fruit fly pupae collected in three Argentinian biogeographical regions. A total of 11 A. indica specimens was obtained from pupae of the tephritid Anastrepha fraterculus (Wiedemann) in Las Yungas and Paranaense subtropical rain forest regions, and 10 A. indica specimens were recovered from pupae of the tephritid Ceratitis capitata (Wiedemann) in Chacoan subtropical dry forest region.Thus, A. indica was recovered approximately 38 years after its first release in Argentina.Fil: Ovruski Alderete, Sergio Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Schliserman, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: De Coll, Olga R.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Peñaloza, Claudia. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Oroño, Luis Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Colina, Carolina del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin