135 research outputs found
Spatially resolved kinematics of the central regions of M83: hidden mass signatures and the role of supernovae
The barred grand-design spiral M83 (NGC 5236) is one of the most studied
galaxies given its proximity, orientation, and particular complexity.
Nonetheless, many aspects of the central regions remain controversial conveying
our limited understanding of the inner gas and stellar kinematics, and
ultimately of the nucleus evolution.
In this work, we present AO VLT-SINFONI data of its central ~235x140 pc with
an unprecedented spatial resolution of ~0.2 arcsec, corresponding to ~4 pc. We
have focused our study on the distribution and kinematics of the stars and the
ionised and molecular gas by studying in detail the Pa_alpha and Br_gamma
emission, the H_2 1-0S(1) line at 2.122 micron and the [FeII] line at 1.644
micron, together with the CO absorption bands at 2.293 micron and 2.323 micron.
Our results reveal a complex situation where the gas and stellar kinematics are
totally unrelated. Supernova explosions play an important role in shaping the
gas kinematics, dominated by shocks and inflows at scales of tens of parsecs
that make them unsuitable to derive general dynamical properties.
We propose that the location of the nucleus of M83 is unlikely to be related
to the off-centre 'optical nucleus'. The study of the stellar kinematics
reveals that the optical nucleus is a gravitationally bound massive star
cluster with M_dyn = (1.1 \pm 0.4)x10^7 M_sun, formed by a past starburst. The
kinematic and photometric analysis of the cluster yield that the stellar
content of the cluster is well described by an intermediate age population of
log T(yr) = 8.0\pm0.4, with a mass of M \simeq (7.8\pm2.4)x10^6 M_sun.Comment: 14 pages, 10 figures, accepted for publication in Ap
Effects of Including a Penetration Test in Motorcyclist Helmet Standards: Influence on Helmet Stiffness and Impact Performance
Regulation ECE-22.05/06 does not require a helmet penetration test. Penetration testing is controversial since it has been shown that it may cause the helmet to behave in a non-desirable stiff way in real-world crashes. This study aimed to assess the effect of the penetration test in the impact performance of helmets. Twenty full-face motorcycle helmets were penetration tested at multiple locations of the helmet shell. Then, 10 helmets were selected and split into two groups (hard shell and soft shell) depending on the results of the penetration tests. These 10 helmets were then drop tested at front, lateral, and top areas at two different impact speeds (5 m/s and 8.2 m/s) to assess their impact performance against head injuries. The statistical analyses did not show any significant difference between the two groups (hard/soft shell) at 5 m/s. Similar results were observed at 8.2 m/s, except for the top area of the helmet in which the peak linear acceleration was significantly higher for the soft shell group than for the hard shell group (230 ± 12 g vs. 211 ± 11 g; p-value = 0.038). The results of this study suggest that a stiffer shell does not necessarily cause helmets to behave in a stiffer way when striking rigid flat surfaces. These experiments also showed that hard shell helmets can provide better protection at higher impact speeds without damaging helmet performance at lower impact speeds. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Kinematic assessment of subject personification of human body models (THUMS)
The goal of this study was to quantify the effect of improving the geometry of a human body model on the accuracy of the predicted kinematics for 4 post-mortem human subject sled tests. Three modifications to the computational human body model THUMS were carried out to evaluate if subject personification can increase the agreement between predicted and measured kinematics of post-mortem human subjects in full frontal and nearside oblique impacts. The modifications consisted of: adjusting the human body model mass to the actual subject mass, morphing it to the actual anthropometry of each subject and finally adjustment of the model initial position to the measured position in selected post-mortem human subject tests. A quantitative assessment of the agreement between predicted and measured response was carried out by means of CORA analysis by comparing the displacement of selected anatomical landmarks (head CoG, T1 and T8 vertebre and H-Point). For all three scenarios, the more similar the human body model was to the anthropometry and posture of the sled tested post-mortem human subject, the more similar the predictions were to the measured responses of the post-mortem human subject, resulting in higher CORA score
ESTIMACIÓN DE LA EVAPORACIÓN/TRANSPIRACIÓN EN UN CULTIVO DE TRIGO MEDIANTE RADIOMETRÍA TÉRMICA
[EN] This work shows the application of a two-source energy balance model, together with
surface temperature measurements, to derive hourly and daily values of land surface energy
fluxes of wheat, crop evapotranspiration (ETc) included. An experiment was carried out
during the spring of 2014 in a wheat field located in the experimental farm of “Las Tiesas” in
Barrax, Albacete. Soil and canopy radiometric temperatures were measured, as well as
meteorological variables and biophysical parameters, from plantation to senescence. Results
were compared to measurements in a weighing lysimeter installed within the wheat field.
Estimation errors of ±0.10 mm h-1 and ±0.9 mm d-1 were obtained at hourly and daily scales,
respectively. Cumulated value of ETc for the whole campaign was only 4% over that
registered in the lysimeter. Furthermore, a percentage 30% - 70% between evaporation (E)
and transpiration (T) components was obtained for the full campaign. Modeled values of the
wheat crop coefficients were also retrieved and compared to those proposed by FAO56.[ES] En este trabajo se propone la aplicación de un modelo de balance de energía de dos
fuentes que, junto con medidas de la temperatura de la superficie, proporcione valores
horarios y diarios de los flujos energéticos en superficie, incluyendo la evapotranspiración
real del cultivo de trigo (ETc). Para mostrar la aplicación y utilidad del método se realizó un
experimento en la primavera de 2014 sobre una plantación de trigo situada dentro de la finca
experimental “Las Tiesas” en el término de Barrax, Albacete. Se midieron temperaturas del
suelo y de la vegetación, además de variables meteorológicas y parámetros biofísicos,
desde el momento de la siembra hasta la recolección. Los resultados se compararon con las
medidas de un lisímetro de pesada instalado en la parcela, obteniendo unos errores de
estimación de ±0,10 mm h-1 y ±0,9 mm d-1 a escalas horaria y diaria, respectivamente. Por
su parte el valor de ETc acumulado para toda la campaña fue solo el 4% mayor que el valor
medido en el lisímetro. Además, el porcentaje entre la componente evaporativa (E) y
transpirativa (T) fue de 30%-70% para el total de la campaña. El modelo también permite
estimar los coeficientes de cultivo del trigo, y compararlos con los propuestos por FAO56.Sánchez, J.; López-Urrea, R.; Doña, C.; Caselles, V.; González-Piqueras, J. (2015). ESTIMACIÓN DE LA EVAPORACIÓN/TRANSPIRACIÓN EN UN CULTIVO DE TRIGO MEDIANTE RADIOMETRÍA TÉRMICA. En XXXIII CONGRESO NACIONAL DE RIEGOS. Valencia 16-18 junio de 2015. Editorial Universitat Politècnica de València. https://doi.org/10.4995/CNRiegos.2015.1504OCS
Unidad Técnica de Biblioteca y Documentación de la Estación Experimental de Aula Dei (CSIC) (Z-EEAD)
2 Pag. A-3, 1 Fot., 1 Map.Información actualizada de la Unidad Técnica de Biblioteca y Documentación (UTBD) de la Estación Experimental de Aula Dei (EEAD-CSIC), una de las 78 Bibliotecas que conforman la Red de Bibliotecas CSIC, en consonancia con la proporcionada en reciente Plan Estratégico CSIC 2010-2013. Incluye relación de Prestaciones de servicio ofrecidas para el período 2010-2013.Peer reviewe
The host galaxies of luminous type 2 AGNs at z ~ 0.3-0.4
We study the morphological and structural properties of the host galaxies associated with 57 optically selected luminous type 2 active galactic nuclei (AGNs) at z ∼ 0.3–0.4: 16 high-luminosity Seyfert 2 [HLSy2, 8.0 ≤ log(L[OIII]/L⊙)< 8.3] and 41 obscured [QSO2, log(L[OIII]/L⊙)≥ 8.3] quasars. With this work, the total number of QSO2s at z < 1 with parametrized galaxies increases from ∼35 to 76. Our analysis is based on Hubble Space Telescope WFPC2 and ACS images that we fit with GALFIT. HLSy2s and QSO2s show a wide diversity of galaxy hosts. The main difference lies in the higher incidence of highly disturbed systems among QSO2s. This is consistent with a scenario in which galaxy interactions are the dominant mechanism triggering nuclear activity at the highest AGN power. There is a strong dependence of galaxy properties with AGN power (assuming L[OIII] is an adequate proxy). The relative contribution of the spheroidal component to the total galaxy light (B/T) increases with L[OIII]. While systems dominated by the spheroidal component spread across the total range of L[OIII], most disc-dominated galaxies concentrate at log(L[OIII]/L⊙)<8.6. This is expected if more powerful AGNs are powered by more massive black holes which are hosted by more massive bulges or spheroids. The average galaxy sizes (〈re〉) are 5.0 ± 1.5 kpc for HLSy2s and 3.9 ± 0.6 kpc for HLSy2s and QSO2s, respectively. These are significantly smaller than those found for QSO1s and narrow-line radio galaxies at similar z. We put the results of our work in the context of related studies of AGNs with quasar-like luminosities.JUM and MVM acknowledge support from the Spanish former Ministerio de Economía y Competitividad through the grants AYA2012-32295 and AYA2015-64346-C2-2-P. FB acknowledges the support by FCT via the postdoctoral fellowship SFRH/BPD/103958/2014. This work is supported by Fundacao para a Ciencia e a Tecnologia (FCT) through national funds (UID/FIS/04434/2013) and by FEDER through COMPETE2020 (POCI-01-0145-FEDER-007672). FB also acknowledges support from grant AYA2016-77237-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO). JPL acknowledges support from the Spanish Ministerio de Economía y Competitividad through the grant AYA2017-85170-R. BRP acknowledges financial support from the Spanish Ministry of Economy and Competitiveness through grant ESP2015-68964. F.J.C. acknowledges financial support through grant AYA2015-64346-C2-1-P (MINECO/FEDER)
The host galaxies of luminous type 2 AGNs at z ∼ 0.3–0.4
ABSTRACT: We study the morphological and structural properties of the host galaxies associated with 57 optically selected luminous type 2 active galactic nuclei (AGNs) at z ∼ 0.3–0.4: 16 high-luminosity Seyfert 2 [HLSy2, 8.0 ≤ log(L[oIII]/Lʘ) < 8.3] and 41 obscured [QSO2, log(L[O III]/Lʘ) ≥ 8.3] quasars. With this work, the total number of QSO2s at z < 1 with parametrized galaxies increases from ∼35 to 76. Our analysis is based on Hubble Space Telescope WFPC2 and ACS images that we fit with GALFIT. HLSy2s and QSO2s show a wide diversity of galaxy hosts. The main difference lies in the higher incidence of highly disturbed systems among QSO2s. This is consistent with a scenario in which galaxy interactions are the dominant mechanism triggering nuclear activity at the highest AGN power. There is a strong dependence of galaxy properties with AGN power (assuming L[O III] is an adequate proxy). The relative contribution of the spheroidal component to the total galaxy light (B/T) increases with L[O III]. While systems dominated by the spheroidal component spread across the total range of L[O III], most disc-dominated galaxies concentrate at log(L[O III]/Lʘ)JUM and MVM acknowledge support from the Spanish former Ministerio de Economía y Competitividad through the grants AYA2012-32295 and AYA2015-64346-C2-2-P. FB also acknowledges support from grant AYA2016-77237-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO). JPL
acknowledges support from the Spanish Ministerio de Economía y Competitividad through the grant AYA2017-85170-R. BRP acknowledges financial support from the Spanish Ministry of Economy and Competitiveness through grant ESP2015-68964. F.J.C. acknowledges financial support through grant AYA2015-64346-C2-1-P (MINECO/FEDER)
High contrast optical imaging of companions: the case of the brown dwarf binary HD-130948BC
High contrast imaging at optical wavelengths is limited by the modest
correction of conventional near-IR optimized AO systems.We take advantage of
new fast and low-readout-noise detectors to explore the potential of fast
imaging coupled to post-processing techniques to detect faint companions to
stars at small separations. We have focused on I-band direct imaging of the
previously detected brown dwarf binary HD130948BC,attempting to spatially
resolve the L2+L2 benchmark system. We used the Lucky-Imaging instrument
FastCam at the 2.5-m Nordic Telescope to obtain quasi diffraction-limited
images of HD130948 with ~0.1" resolution.In order to improve the detectability
of the faint binary in the vicinity of a bright (I=5.19 \pm 0.03) solar-type
star,we implemented a post-processing technique based on wavelet transform
filtering of the image which allows us to strongly enhance the presence of
point-like sources in regions where the primary halo dominates. We detect for
the first time the BD binary HD130948BC in the optical band I with a SNR~9 at
2.561"\pm 0.007" (46.5 AU) from HD130948A and confirm in two independent
dataset that the object is real,as opposed to time-varying residual speckles.We
do not resolve the binary, which can be explained by astrometric results
posterior to our observations that predict a separation below the NOT
resolution.We reach at this distance a contrast of dI = 11.30 \pm 0.11, and
estimate a combined magnitude for this binary to I = 16.49 \pm 0.11 and a I-J
colour 3.29 \pm 0.13. At 1", we reach a detectability 10.5 mag fainter than the
primary after image post-processing. We obtain on-sky validation of a technique
based on speckle imaging and wavelet-transform processing,which improves the
high contrast capabilities of speckle imaging.The I-J colour measured for the
BD companion is slightly bluer, but still consistent with what typically found
for L2 dwarfs(~3.4-3.6).Comment: accepted in A\&
- …