337 research outputs found
Lump solitons in a higher-order nonlinear equation in 2+1 dimensions
We propose and examine an integrable system of nonlinear equations that generalizes the nonlinear Schrodinger equation to 2 + 1 dimensions. This integrable system of equations is a promising starting point to elaborate more accurate models in nonlinear optics and molecular systems within the continuum limit. The Lax pair for the system is derived after applying the singular manifold method. We also present an iterative procedure to construct the solutions from a seed solution. Solutions with one-, two-, and three-lump solitons are thoroughly discussed
The nuclear and extended mid-infrared emission of Seyfert galaxies
We present subarcsecond resolution mid-infrared (MIR) images obtained with
8-10 m-class ground-based telescopes of a complete volume-limited (DL<40 Mpc)
sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog.
We use those MIR images to study the nuclear and circumnuclear emission of the
galaxies. Using different methods to classify the MIR morphologies on scales of
~400 pc, we find that the majority of the galaxies (75-83%) are extended or
possibly extended and 17-25% are point-like. This extended emission is compact
and it has low surface brightness compared with the nuclear emission, and it
represents, on average, ~30% of the total MIR emission of the galaxies in the
sample. We find that the galaxies whose circumnuclear MIR emission is dominated
by star formation show more extended emission (650+-700 pc) than AGN-dominated
systems (300+-100 pc). In general, the galaxies with point-like MIR
morphologies are face-on or moderately inclined (b/a~0.4-1.0), and we do not
find significant differences between the morphologies of Sy1 and Sy2. We used
the nuclear and circumnuclear fluxes to investigate their correlation with
different AGN and SF activity indicators. We find that the nuclear MIR emission
(the inner ~70 pc) is strongly correlated with the X-ray emission (the harder
the X-rays the better the correlation) and with the [O IV] lambda 25.89 micron
emission line, indicating that it is AGN-dominated. We find the same results,
although with more scatter, for the circumnuclear emission, which indicates
that the AGN dominates the MIR emission in the inner ~400 pc of the galaxies,
with some contribution from star formation.Comment: 27 pages, 12 figures, accepted by MNRA
The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245
We present subarcsecond resolution infrared (IR) imaging and mid-IR
spectroscopic observations of the Seyfert 1.9 galaxy NGC 2992, obtained with
the Gemini North Telescope and the Gran Telescopio CANARIAS (GTC). The N-band
image reveals faint extended emission out to ~3 kpc, and the PAH features
detected in the GTC/CanariCam 7.5-13 micron spectrum indicate that the bulk of
this extended emission is dust heated by star formation. We also report
arcsecond resolution MIR and far-IR imaging of the interacting system Arp 245,
taken with the Spitzer Space Telescope and the Herschel Space Observatory.
Using these data, we obtain nuclear fluxes using different methods and find
that we can only recover the nuclear fluxes obtained from the subarcsecond data
at 20-25 micron, where the AGN emission dominates. We fitted the nuclear IR
spectral energy distribution of NGC 2992, including the GTC/CanariCam nuclear
spectrum (~50 pc), with clumpy torus models. We then used the best-fitting
torus model to decompose the Spitzer/IRS 5-30 spectrum (~630 pc) in AGN and
starburst components, using different starburst templates. We find that,
whereas at shorter mid-IR wavelengths the starburst component dominates (64% at
6 micron), the AGN component reaches 90% at 20 micron. We finally obtained dust
masses, temperatures and star formation rates for the different components of
the Arp 245 system and find similar values for NGC 2992 and NGC 2993. These
measurements are within those reported for other interacting systems in the
first stages of the interaction.Comment: 20 pages, 12 figures, accepted by MNRA
Evaluación de calidad de agua en un sistema ribereño utilizado para riego agrÃcola de subsistencia
En la evaluación del impacto de la contaminación en el ambiente, existen diversas herramientas y técnicas que se aplican para conocer la calidad ambiental de los recursos naturales. El objetivo de este trabajo fue evaluar la calidad del agua en un sistema ribereño en San Luis PotosÃ, México asociado al impacto del uso agrÃcola, urbano e industrial. Fueron establecidos cinco puntos de muestreo asociado a diversos usos y descargas residuales en donde se evaluaron 28 muestras durante cuatro dÃas de muestro. Estas fueron distribuidas a los 20, 40, 60, 80, 100 y 120 minutos del trayecto determinando con un medidor multiparámetro los sólidos
disueltos totales (SDT), temperatura (T), conductividad eléctrica (CE), pH y oxÃgeno disuelto (OD). El resultado más destacado de las 28 muestras diarias y del total de 112 que los promedios oxÃgeno disuelto indican condición hipoxia que indica la desaparición de organismos y especies sensibles, concluyendo que el área ribereña requiere un constante monitoreo y diversificación de parámetros para evaluar su condición para actividades agrÃcolas.In the assessment of the impact of pollution on the environment, there are various tools and techniques that are applied to know the environmental quality of natural resources. The objective of this work was to evaluate water quality in a river system in San Luis PotosÃ, Mexico associated with the impact of agricultural, urban and industrial use. Five sampling points associated to various uses and residual discharges were established where 28 samples were evaluated during four days of sampling. The total dissolved solids (SDT), temperature (T), electrical conductivity (CE), pH and dissolved oxygen (OD) were distributed at 20, 40, 60, 80, 100 and 120 minutes of the path. The most outstanding result of the 28 daily samples and the total of 112 that dissolved oxygen averages indicate hypoxia condition indicating the disappearance of sensitive organisms and species, concluding that the riparian area requires constant monitoring and diversification of parameters to evaluate agricultural activities.Fil: Alcalá Jáuregui, J. A.
Universidad Autónoma de San Luis PotosÃ. Facultad de AgronomÃaFil: Acosta Doporto Geiler, A.
Instituto Tecnológico Superior de los RÃos de Balancan (México)Fil: RodrÃguez Ortiz, J.C.
Universidad Autónoma de San Luis PotosÃ. Facultad de AgronomÃaFil: Hernández Montoya, A.
Universidad Autónoma de San Luis PotosÃ. Facultad de AgronomÃaFil: MartÃnez Carretero, Eduardo.
Consejo Nacional de Investigaciones CientÃficas y TécnicasFil: Filippini, Maria Flavia.
Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: DÃaz Flores, P. E.
Universidad Autónoma de San Luis PotosÃ. Facultad de AgronomÃaFil: Lara Mireles, J. L.
Universidad Autónoma de San Luis PotosÃ. Facultad de AgronomÃ
Banco de La Concepción: A new Natura 2000 Marine Site off Canary Islands
The main objective of the LIFE+ INDEMARES project is to contribute to the protection and sustainable
use of the biodiversity in the Spanish seas through the identification of valuable areas for the Natura 2000
Network. The Spanish Institute of Oceanography (IEO) has been in charge of implementing scientific
surveys to map sensitive habitats of seven of the ten INDEMARES areas, and to determine the fisheries
footprint over these areas.
Banco de La Concepci´on is one of the areas chosen to be depicted in the frame of INDEMARES project.
Located at 71 km to the NE of Lanzarote, at the coordinates 29º 55’ Latitude N and 12º 45’ Longitude
W, Banco de la Concepci´on raises from 2,541 m up to its summit at 170 m deep.
The biological richness of Banco de la Concepci´on is very influenced by the deep water up-welling
phenomena, which create a high productivity, attracting a multitude of pelagic species, such as cetaceans,
turtles, sharks, and tunas looking for food. In its vicinity, fishery resources such as goraz, anglerfish, and
hakes, are abundant, and a rich invertebrate fauna cohabits in their bottoms. Banco de la Concepci´on is
a traditional fishing area of oceanic pelagic species, and very good to catch demersal fish; it is highly
visited by Galician and Portuguese drifters and long liners that fish in Mauritania, and mainly by the
Andalusian longliners. In general, its main impacts are related to uncontrolled fishing pressure. The
available information on the anthropogenic impact of the area was scarce, and its level of research was
very poor as well, before INDEMARES project.
Methodology approach complies with a multidisciplinary perspective, having described the area from
geological, oceanographic, biological and fisheries points of view. Several surveys have taken place since
2009 to 2013 at Banco de La Concepci´on waters. Traps, longlines, beam trawls, benthic dredges and box
corers have been used to sample benthic fauna. These last two, plus EM 3002 multibeam echosounder,
PS 18 parametric sub bottom profiler, EA600 monobeam sounder, Seapath 200 positioning sensor and
SV Plus sound velocity calibration sensor were used to make a geophysical study which provides a range
of environmental factors. CTD was used to depict physical conditions of the water column. Finally,
Remote Operated Vehicle Liropus 2000 and different photogrammetric tugged sleds were used to make
a great effort of visual sampling.
Data from VMS (Vessel Monitoring System) were used, combined with interviews to users (fishers), to
describe the fishery uses in the area.
Results from all this field work provide enough information for the administrations to establish a new
Natura 2000 area, trying to reconcile protection of biodiversity and artisanal local economic activities.
This establishment should take place at the end of a process of public consultation to stakeholders which
is taking place in the present and which will help to shape the future Management Plan which will give
details about permitted and prohibited uses
Sensitive Habitats and fishing footprint off Canary Islands seamounts Amanay and El Banquete
The main objective of the LIFE+ INDEMARES project is to contribute to the protection and sustainable
use of the biodiversity in the Spanish seas through the identification of valuable areas for the Natura 2000
Network. The Spanish Institute of Oceanography (IEO) has been in charge of implementing scientific
surveys to map sensitive habitats of seven of the ten INDEMARES areas, and to determine the fisheries
footprint over these areas.
Sur y Oriente de Fuerteventura y Lanzarote is one of the areas chosen to be depicted in the frame of
INDEMARES project, although the study about benthic habitats and fishery footprint carried by IEO
has restricted to Amanay and El Banquete Seamounts. El Banquete really is the extension of southern
continental shelf while Amanay seamount is located at 25 km from Jand´ıa Lighthouse (S of Fuerteventura)
and 55 km from Las Palmas de Gran Canaria, at the coordinates 28º 07’ Latitude N and 14º 44’
LongitudeW, both volcanic buildings raise from more than 2,000 m up to their summits at 25-30 m deep,
separated by a 1.500 m deep channel.
The biological richness of Amanay and El Banquete seamounts is very influenced by the deep water
up-welling phenomena, which create a high productivity, attracting a multitude of pelagic species, such
as cetaceans, turtles, sharks, and tunas looking for food. There is also a high influence from Saharian
up-welling. Both the seamounts tops and their vicinities are often visited by a large artisanal local fishing
fleet which profits of their fishery resources; also a rich invertebrate fauna cohabits in their bottoms. In
general, its main impacts are related to uncontrolled fishing pressure, and maritime navigation. The
available information on the anthropogenic impact of the area was scarce, and its level of research was
very poor as well, before INDEMARES project.
Methodology approach complies with a multidisciplinary perspective, having described the area from
geological, oceanographic, biological and fisheries points of view. Several surveys have taken place
since 2009 to 2013 at Amanay and El Banquete waters. Traps, longlines, beam trawls, benthic dredges
and box corers have been used to sample benthic fauna. These last two, plus EM 3002 multibeam
echosounder, PS 18 parametric sub bottom profiler, EA600 monobeam sounder, Seapath 200 positioning
sensor and SV Plus sound velocity calibration sensor were used to make a geophysical study which
provides a range of environmental factors. CTD was used to depict physical conditions of the water
column. Finally, different photogrammetric tugged sleds were used to make a great effort of visual
sampling. Data from VMS (Vessel Monitoring System) were used, combined with interviews to users
(fishers), landing samplings and scientific observation onboard, to describe the fishery uses in the area
\b{eta}-delayed three-proton decay of 31Ar
The beta decay of 31Ar, produced by fragmentation of a 36Ar beam at 880
MeV/nucleon, was investigated. Identified ions of 31Ar were stopped in a
gaseous time projection chamber with optical readout allowing to record decay
events with emission of protons. In addition to \b{eta}-delayed emission of one
and two protons we have clearly observed the beta-delayed three-proton branch.
The branching ratio for this channel in 31Ar is found to be 0.07(2)%.Comment: 5 pages, 3 figures, submitted to Physical Rev.
The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245
We present subarcsecond resolution infrared (IR) imaging and mid-IR (MIR) spectroscopic observations of the Seyfert 1.9 galaxy NGC 2992, obtained with the Gemini North Telescope and the Gran Telescopio CANARIAS (GTC). The N-band image reveals faint extended emission out to ∼3 kpc, and the polycyclic aromatic hydrocarbon features detected in the GTC/CanariCam 7.5–13 μm spectrum indicate that the bulk of this extended emission is dust heated by star formation. We also report arcsecond resolution MIR and far-IR imaging of the interacting system Arp 245, taken with the Spitzer Space Telescope and the Herschel Space Observatory. Using these data, we obtain nuclear fluxes using different methods and find that we can only recover the nuclear fluxes obtained from the subarcsecond data at 20–25 μm, where the active galactic nuclei (AGN) emission dominates. We fitted the nuclear IR spectral energy distribution of NGC 2992, including the GTC/CanariCam nuclear spectrum (∼50 pc), with clumpy torus models. We then used the best-fitting torus model to decompose the Spitzer/IRS 5–30 μm spectrum (∼630 pc) in AGN and starburst components, using different starburst templates. We find that, whereas at shorter MIR wavelengths the starburst component dominates (64 per cent at 6 μm), the AGN component reaches 90 per cent at 20 μm. We finally obtained dust masses, temperatures and star formation rates for the different components of the Arp 245 system and find similar values for NGC 2992 and NGC 2993. These measurements are within those reported for other interacting systems in the first stages of the interaction.IGB acknowledges financial support from the Instituto de AstrofÃsica de Canarias through Fundacion La Caixa. This research was partly supported by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme
(PIEF-GA-2012-327934). CRA and IGB acknowledge financial support from the Spanish Ministry of Science and Innovation (MICINN) through project PN AYA2013-47742-C4-2-P.
AAH acknowledges funding from the Spanish Ministry of Economy and Competitiveness under grant AYA2012-31447, which is party funded by the FEDER program. PE acknowledges support from the Spanish Plan Nacional de AstronomÃa y AstrofÃsica
under grant AYA2012-31277. OGM acknowledges support from grant AYA2012-39168-C03-01. TDS was supported by ALMA-CONICYT grant number 31130005.Peer Reviewe
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