3,893 research outputs found
Astronomical Site Ranking Based on Tropospheric Wind Statistics
We present comprehensive and reliable statistics of high altitude wind speeds
and the tropospheric flows at the location of five important astronomical
observatories. Statistical analysis exclusively of high altitude winds point to
La Palma as the most suitable site for adaptive optics, with a mean value of
22.13 m/s at the 200 mbar pressure level. La Silla is at the bottom of the
ranking, with the largest average value 200 mbar wind speed(33.35 m/s). We have
found a clear annual periodicity of high altitude winds for the five sites in
study. We have also explored the connection of high to low altitude atmospheric
winds as a first approach of the linear relationship between the average
velocity of the turbulence and high altitude winds (Sarazin & Tokovinin 2001).
We may conclude that high and low altitude winds show good linear relationships
at the five selected sites. The highest correlation coefficients correspond to
Paranal and San Pedro Martir, while La Palma and La Silla show similar high to
low altitude wind connection. Mauna Kea shows the smallest degree of
correlation, which suggests a weaker linear relationship. Our results support
the idea of high altitude winds as a parameter for rank astronomical sites in
terms of their suitability for adaptive optics, although we have no evidence
for adopting the same linear coefficient at different sites. The final value of
this linear coefficient at a particular site could drastically change the
interpretation of high altitude wind speeds as a direct parameter for site
characterization.Comment: 18 pages, 5 figures. Accepted in MNRA
Atmospheric optical-turbulence at Roque de los Muchachos Observatory: database and recalibration of the generalized-SCIDAR data
We present the largest database so far of atmospheric optical-turbulence
profiles (197035 individual CN2(h)) for an astronomical site, the Roque de los
Muchachos Observatory (La Palma, Spain). This C2 (h) database was obtained
through generalized-SCIDAR observations at the 1 meter Jacobus Kapteyn
telescope from Febrary 2004 to August 2009, obtaining useful data for 211
nights. The overestimation of the turbulence strength induced during the
generalized SCIDAR data processing has been analyzed for the different
observational configurations. All the individual C2 (h) have been recalibrated
to compensate the introduced errors during data treatment following (Avila &
Cuevas 2009). Comparing results from profiles before and after the
recalibration, we analyze its impact on the calculation of relevant parameters
for adaptive optics.Comment: 8 pages, 3 figures, MNRAS accepte
The complex structure of HH 110 as revealed from Integral Field Spectroscopy
HH 110 is a rather peculiar Herbig-Haro object in Orion that originates due
to the deflection of another jet (HH 270) by a dense molecular clump, instead
of being directly ejected from a young stellar object. Here we present new
results on the kinematics and physical conditions of HH 110 based on Integral
Field Spectroscopy. The 3D spectral data cover the whole outflow extent (~4.5
arcmin, ~0.6 pc at a distance of 460 pc) in the spectral range 6500-7000 \AA.
We built emission-line intensity maps of H, [NII] and [SII] and of
their radial velocity channels. Furthermore, we analysed the spatial
distribution of the excitation and electron density from [NII]/H,
[SII]/H, and [SII] 6716/6731 integrated line-ratio maps, as well as
their behaviour as a function of velocity, from line-ratio channel maps. Our
results fully reproduce the morphology and kinematics obtained from previous
imaging and long-slit data. In addition, the IFS data revealed, for the first
time, the complex spatial distribution of the physical conditions (excitation
and density) in the whole jet, and their behaviour as a function of the
kinematics. The results here derived give further support to the more recent
model simulations that involve deflection of a pulsed jet propagating in an
inhomogeneous ambient medium. The IFS data give richer information than that
provided by current model simulations or laboratory jet experiments. Hence,
they could provide valuable clues to constrain the space parameters in future
theoretical works.Comment: 12 pages, 15 figures Accepted in MNRA
Bridging universities and industry through cleaner production activities. Experiences from the Cleaner Production Center at the University of Cienfuegos, Cuba
The involvement of universities is crucial to identify how Cleaner Production strategies are formed in practice so that companies integrate sustainability into their strategies. This paper discusses the experience of establishing and operating the Cleaner Production Center at the University of Cienfuegos. From 2008 to 2011, the University of Cienfuegos, the Free University of Brussels (Belgium) and the University of Leuven (Belgium) implemented a project, financially supported by the Flemish Interuniversity Council (Belgium) allowing establishing a Cleaner Production Center at the University of Cienfuegos. This first project was followed by a second University of Cienfuegos - University of Leuven one. So far, the collaboration allowed to establish a master program on Cleaner Production that constitutes a bridge between the university and the production and service sector, allowing to promote and implement cleaner production strategies. 34 master students graduated during two graduations and a third one is ongoing. Among the most important results of the master thesis were the yearly reduction of the emission of 60 000 t/a of carbon dioxide equivalent and of the electricity consumption by 400 MWh/a at a cement plant. Research activities on Cleaner Production were upgraded through the collaboration resulting in several publications in peer-reviewed journals with impact factor. This type of North-South cooperation aided establishing and developing the center, by transferring expertise and experience and by providing part of the necessary funding which is difficult to raise by developing economies. This case study offers an interesting practice example about developing academic (training, research) values on Cleaner Production
Integral Field Spectroscopy of HH 262: The Spectral Atlas
HH 262 is a group of emitting knots displaying an "hour-glass" morphology in
the Halpha and [SII] lines, located 3.5' to the northeast of the young stellar
object L1551-IRS5, in Taurus. We present new results of the kinematics and
physical conditions of HH 262 based on Integral Field Spectroscopy covering a
field of 1.5'x3', which includes all the bright knots in HH 262. These data
show complex kinematics and significant variations in physical conditions over
the mapped region of HH 262 on a spatial scale of <3". A new result derived
from the IFS data is the weakness of the [NII] emission (below detection limit
in most of the mapped region of HH 262), including the brightest central knots.
Our data reinforce the association of HH 262 with the redshifted lobe of the
evolved molecular outflow L1551-IRS5. The interaction of this outflow with a
younger one, powered by L1551 NE, around the position of HH 262 could give rise
to the complex morphology and kinematics of HH 262.Comment: Accepted for publication in MNRA
3D kinematics of the near-IR HH 223 outflow in L723
In this work, we derive the full 3D kinematics of the near-infrared outflow HH 223, located in the dark cloud Lynds 723 (L723), where a well-defined quadrupolar CO outflow is found. HH 223 appears projected on to the two lobes of the eastwest CO outflow. The radio continuum source VLA 2, towards the centre of the CO outflow, harbours a multiple system of low-mass young stellar objects. One of the components has been proposed to be the exciting source of the eastwest CO outflow. From the analysis of the kinematics, we get further evidence on the relationship between the near-infrared and CO outflows and on the location of their exciting source. The proper motions were derived using multi-epoch, narrow-band H2 (2.122 μm line) images. Radial velocities were derived from the 2.122 μm line of the spectra. Because of the extended (∼5 arcmin), S-shaped morphology of the target, the spectra were obtained with the multi-object-spectroscopy (MOS) observing mode using the instrument Long-Slit Intermediate Resolution Infrared Spectrograph (LIRIS) at the 4.2 m William Herschel Telescope. To our knowledge, this work is the first time that MOS observing mode has been successfully used in the near-infrared range for an extended target
Integral field spectroscopy of the central regions of 3C 120: Evidence of a past merging event
Optical integral field spectroscopy (IFS), combined with Hubble Space Telescope (HST ) WFPC imaging, was used to characterize the central regions of the Seyfert 1 radio galaxy 3C 120. We carried out the analysis of the data, deriving intensity maps of different emission lines and the continua at different wavelengths from the observed spectra. Applying a two-dimensional modeling to the HST images, we decoupled the nucleus and the host galaxy and analyzed the host morphology. The host is a highly distorted bulge-dominated galaxy, rich in substructures. We developed a new technique to model the IFS data extending the two-dimensional modeling (hereafter threedimensional modeling). Using this technique, we separated the Seyfert nucleus and the host galaxy spectra and derived a residual data cube with spectral and spatial information of the different structures in 3C 120. Three continuum-dominated structures (named A, B, and C) and three other extended emission-line regions (EELRs, named E1, E2, and E3) are found in 3C 120, which does not follow the general behavior of a bulge-dominated galaxy. We also found shells in the central kiloparsec that may be remnants of a past merging event in this galaxy. The origin of E1 is most probably due to the interaction of the radio jet of 3C 120 with the intergalactic medium (Axon et al. 1989; Sa´nchez et al. 2004a). Structures A, B, and the shell at the southeast of the nucleus seem to correspond to a larger morphological clumpy structure that may be a tidal tail, a consequence of the past merging event. We found a bright EELR (E2) in the innermost part of this tidal tail, nearby the nucleus, which shows a high ionization level. The kinematics of the E2 region and its connection to the tidal tail suggest that the tail has channeled gas from the outer regions to the cente
3D Spectroscopic Observations of Star-Forming Dwarf Galaxies
We give an introduction into the observational technique of integral field or
3D spectroscopy. We discuss advantages and drawbacks of this type of
observations and highlight a few science projects enabled by this method. In
the second part we describe our 3D spectroscopic survey of Blue Compact Dwarf
Galaxies. We show preliminary results from data taken with the VIMOS integral
field unit and give an outlook on how automated spectral analysis and
forthcoming instruments can provide a new view on star formation and associated
processes in dwarf galaxies.Comment: To appear in the proceedings of the JENAM 2010 Symposium "Dwarf
Galaxies: Keys to Galaxy Formation and Evolution" (Lisbon, 9-10 September
2010), P. Papaderos, S. Recchi, G. Hensler (eds.), Springer Verlag (2011), in
pres
Métodos de sincronización de celo en conejas primíparas lactantes a 25 días post-parto
La sincronización del celo es una técnica necesaria en las explotaciones cunícolas. En este trabajo se han utilizado un total de 60 conejas primíparas lactantes en día 25 post-parto (pp) distribuidas en 5 grupos de 12 animales: el grupo PG recibió un 2.5% de propilen glicol en el agua de bebida desde el día 22 pp, el grupo eCG se trató con 25 UI de eCG (i.m.) el día 23 pp, el grupo BIO fue separado transitoriamente de sus camadas durante 24 horas, el grupo PGBIO se suplementó con 2,5% de PG y además se le separó transitoriamente de su camada, y por último, el grupo C que no fue sincronizado. Estudiamos el efecto de estos tratamientos sobre el peso vivo, la composición corporal, el consumo de alimento, la concentración de los ácidos grasos no esterificados (AGNE), la glucosa y las proteínas plasmáticas, el crecimiento de los gazapos y la fisiología ovárica. Aunque todos los grupos tuvieron el mismo consumo de pienso, las conejas del grupo PG presentaron menos cantidad de proteína (P<0,003) y de grasa corporal (P<0,06) el día 25 pp que al principio del tratamiento. En los grupos PG y PGBIO, las concentraciones de AGNE no se modificaron y las concentraciones de proteínas plasmáticas eran más altas el día 22 que el 25 pp. En todos los grupos las concentraciones de glucosa aumentaron (P<0,001) y las camadas crecieron significativamente (P<0,001). Las poblaciones foliculares ováricas en el día 25 pp, así como la maduración nuclear in vitro de los oocitos no se vieron afectadas por ningún tratamiento. El grupo PG presentó una baja proporción de oocitos no madurados citoplásmicamente (P<0,05). En conclusión, ninguno de los tratamientos aplicados, incluido el hormonal, ha presentado resultados definitivamente mejores que el grupo control, por lo que es necesario estudiar otras combinaciones o métodos para poder conseguir mejorar sustancialmente los parámetros reproductivos en conejas primíparas lactantes en el día 25 pp
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