434 research outputs found
Influence of irrigation and fertilization on the sterol and triterpene dialcohol compositions of virgin olive oil
The objective of this work was to evaluate the influence of irrigation and fertilization with nitrogen and potassium on the sterol and triterpene dialcohol contents in two trials of cv. Arbequina in super-intensive orchards in Madrid and Lleida (Spain), using a completely randomized block design. No significant differences in total sterols between deficit and full irrigation treatments were observed. Under very dry conditions, the sterol levels from fully irrigated trees were higher than from rain-fed treatments and the triterpene dialcohol erythrodiol+ uvaol content was lower in the irrigated treatments in Lleida. In the fertilizer trial with full irrigation, total sterols were higher in the two N treatments compared to the unfertilized one; while erythrodiol + uvaol decreased. The application of K fertilizer had no effect on total sterol or triterpene dialcohol contents. A proper fertilization and irrigation are vital to obtain high quality EVOOs that meet the regulatory range in sterol and erythrodiol + uvaol contents.Influencia del riego y la fertilización en los esteroles y dialcoholes triterpénicos del aceite de oliva. El
objetivo de este trabajo fue evaluar la influencia del riego y del abonado nitrogenado y potásico en los esteroles
y los dialcoholes tritepénicos, en sendos ensayos de arbequina en superintensivo, con un diseño en bloques al
azar, en Madrid y Lleida. No se observaron diferencias significativas de esteroles totales entre el riego deficitario y el riego completo. En condiciones de sequía extrema, los esteroles del riego completo fueron superiores al
secano y los dialcoholes tritepénicos eritrodiol y uvaol fueron inferiores en los tratamientos de riego en Lleida.
En el ensayo de abonado con riego completo, los esteroles totales fueron superiores en las dos aplicaciones de
nitrógeno respecto al testigo no tratado y también disminuyeron el eritrodiol + uvaol. El abonado potásico no
afectó a los esteroles totales ni a los dihalcoholes triterpénicos. Una fertilización y riego adecuados son de vital
importancia para obtener AOVEs de alta calidad que cumplan con los límites legales del contenido en esteroles
y eritrodiol + uvaol.info:eu-repo/semantics/publishedVersio
Influencia del riego y la fertilización en los esteroles y dialcoholes triterpénicos del aceite de oliva
The objective of this work was to evaluate the influence of irrigation and fertilization with nitrogen and potassium on the sterol and triterpene dialcohol contents in two trials of cv. Arbequina in super-intensive orchards in Madrid and Lleida (Spain), using a completely randomized block design. No significant differences in total sterols between deficit and full irrigation treatments were observed. Under very dry conditions, the sterol levels from fully irrigated trees were higher than from rain-fed treatments and the triterpene dialcohol erythrodiol+ uvaol content was lower in the irrigated treatments in Lleida. In the fertilizer trial with full irrigation, total sterols were higher in the two N treatments compared to the unfertilized one; while erythrodiol + uvaol decreased. The application of K fertilizer had no effect on total sterol or triterpene dialcohol contents. A proper fertilization and irrigation are vital to obtain high quality EVOOs that meet the regulatory range in sterol and erythrodiol + uvaol contents.El objetivo de este trabajo fue evaluar la influencia del riego y del abonado nitrogenado y potásico en los esteroles y los dialcoholes tritepénicos, en sendos ensayos de arbequina en superintensivo, con un diseño en bloques al azar, en Madrid y Lleida. No se observaron diferencias significativas de esteroles totales entre el riego deficitario y el riego completo. En condiciones de sequía extrema, los esteroles del riego completo fueron superiores al secano y los dialcoholes tritepénicos eritrodiol y uvaol fueron inferiores en los tratamientos de riego en Lleida. En el ensayo de abonado con riego completo, los esteroles totales fueron superiores en las dos aplicaciones de nitrógeno respecto al testigo no tratado y también disminuyeron el eritrodiol + uvaol. El abonado potásico no afectó a los esteroles totales ni a los dihalcoholes triterpénicos. Una fertilización y riego adecuados son de vital importancia para obtener AOVEs de alta calidad que cumplan con los límites legales del contenido en esteroles y eritrodiol + uvaol
Calculation of the interventilatory threshold area: a method for examining the aerobic-anaerobic transition
El objetivo fue determinar la relación entre el área interumbrales (ITA) [la zona comprendida entre el primer y el segundo umbral ventilatorio (VT1 y VT2) en la función VO2/VE, Carga/VO2 y Carga/VE] y las variables ergoespirométricas. Treinta y tres hombres realizaron un test incremental. El ITA se calculó: 1) como la integral definida por el área entre VT1 y VT2 bajo las curvas de VO2/VE, Carga/VO2 y Carga/VE y 2) como la suma de las áreas descritas por el triángulo y rectángulo entre los mismos puntos. El ITA para la función Carga/VE se correlacionó positivamente (p<0,01) con la carga en VT2 (r = 0,831) y la ventilación en VT2 (r = 0,799). El ITA para la función VO2/VE fue significativamente mayor en los ciclistas que en los estudiantes. La determinación del ITA es un método simple para evaluar la transición aeróbica-anaeróbica durante las pruebas de esfuerzo incremental.The aim was to determine the relationship between the interthreshold area (ITA) [the area between the first and second ventilatory threshold (VT1 and VT2) for the function VO2/VE, load/VO2 and load/VE] and the traditional variables measured. Thirty-three men underwent an incremental test. The ITA was calculated: 1) as the integral defined by the area between VT1 and VT2 under the curves for the functions VO2/VE, load/VO2 and load/VE and 2) as the simple sum of the areas described by the triangle and rectangle between the same points. The mean ITA for the function load/VE was positively correlated (p<0.01) with load at VT2 (r=0.831) and ventilation at VT2 (r=0.799). The mean ITA for the function VO2/VE was significantly greater in the cyclists than in the students. The ITA for the function load/VE differed between March and July as training progressed. The determination of the ITA is a simple method of assessing the aerobic-anaerobic transition process during incremental exercise tests
The space density distribution of galaxies in the absolute magnitude - rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA stellar kinematics
The space density distribution of galaxies in the absolute magnitude -
rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA
stellar kinematicsComment: Accepted to A&
Central star formation and metallicity in CALIFA interacting galaxies
We use optical integral-field spectroscopic (IFS) data from 103 nearby
galaxies at different stages of the merging event, from close pairs to merger
remnants provided by the CALIFA survey, to study the impact of the interaction
in the specific star formation and oxygen abundance on different galactic
scales. To disentangle the effect of the interaction and merger from internal
processes, we compared our results with a control sample of 80 non-interacting
galaxies. We confirm the moderate enhancement (2-3 times) of specific star
formation for interacting galaxies in central regions as reported by previous
studies; however, the specific star formation is comparable when observed in
extended regions. We find that control and interacting star-forming galaxies
have similar oxygen abundances in their central regions, when normalized to
their stellar masses. Oxygen abundances of these interacting galaxies seem to
decrease compared to the control objects at the large aperture sizes measured
in effective radius. Although the enhancement in central star formation and
lower metallicities for interacting galaxies have been attributed to tidally
induced inflows, our results suggest that other processes such as stellar
feedback can contribute to the metal enrichment in interacting galaxies.Comment: 9 pages, 9 figures. Accepted for publication in Astronomy &
Astrophysic
Observational hints of radial migration in disc galaxies from CALIFA
Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important, galaxies with different surface brightness (SB) profiles must display differences in their stellar population properties.
Aims: We investigate the role of radial migration in the light distribution and radial stellar content by comparing the inner colour, age, and metallicity gradients for galaxies with different SB profiles. We define these inner parts, avoiding the bulge and bar regions and up to around three disc scale lengths (type I, pure exponential) or the break radius (type II, downbending; type III, upbending).
Methods: We analysed 214 spiral galaxies from the CALIFA survey covering different SB profiles. We made use of GASP2D and SDSS data to characterise the light distribution and obtain colour profiles of these spiral galaxies. The stellar age and metallicity profiles were computed using a methodology based on full-spectrum fitting techniques (pPXF, GANDALF, and STECKMAP) to the Integral Field Spectroscopic CALIFA data.
Results: The distributions of the colour, stellar age, and stellar metallicity gradients in the inner parts for galaxies displaying different SB profiles are unalike as suggested by Kolmogorov-Smirnov and Anderson-Darling tests. We find a trend in which type II galaxies show the steepest profiles of all, type III show the shallowest, and type I display an intermediate behaviour.
Conclusions: These results are consistent with a scenario in which radial migration is more efficient for type III galaxies than for type I systems, where type II galaxies present the lowest radial migration efficiency. In such a scenario, radial migration mixes the stellar content, thereby flattening the radial stellar properties and shaping different SB profiles. However, in light of these results we cannot further quantify the importance of radial migration in shaping spiral galaxies, and other processes, such as recent star formation or satellite accretion, might play a role
Bar pattern speeds in CALIFA galaxies: I. Fast bars across the Hubble sequence
The bar pattern speed () is defined as the rotational
frequency of the bar, and it determines the bar dynamics. Several methods have
been proposed for measuring . The non-parametric method
proposed by Tremaine \& Weinberg (1984; TW) and based on stellar kinematics is
the most accurate. This method has been applied so far to 17 galaxies, most of
them SB0 and SBa types. We have applied the TW method to a new sample of 15
strong and bright barred galaxies, spanning a wide range of morphological types
from SB0 to SBbc. Combining our analysis with previous studies, we investigate
32 barred galaxies with their pattern speed measured by the TW method. The
resulting total sample of barred galaxies allows us to study the dependence of
on galaxy properties, such as the Hubble type. We measured
using the TW method on the stellar velocity maps provided by
the integral-field spectroscopy data from the CALIFA survey. Integral-field
data solve the problems that long-slit data present when applying the TW
method, resulting in the determination of more accurate . In
addition, we have also derived the ratio of the corotation radius to
the bar length of the galaxies. According to this parameter, bars can be
classified as fast ( \cal{R}\%\cal{R}$ and the galaxy morphological
type. Our results indicate that independent of the Hubble type, bars have been
formed and then evolve as fast rotators. This observational result will
constrain the scenarios of formation and evolution of bars proposed by
numerical simulations.Comment: 17 pages, 10 figures, accepted for publication in A&
Ionized gas kinematics of galaxies in the CALIFA survey : I. Velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems
J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). Date of Acceptance: 01/08/2014Context. Ionized gas kinematics provide important clues to the dynamical structure of galaxies and hold constraints to the processes driving their evolution. Aims. The motivation of this work is to provide an overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the Calar Alto Legacy Integral field Area (CALIFA), offering kinematic clues to potential users of the CALIFA survey for including kinematical criteria in their selection of targets for specific studies. From the first 200 galaxies observed by CALIFA survey in its two configurations, we present the two-dimensional kinematic view of the 177 galaxies satisfaying a gas content/detection threshold. Methods. After removing the stellar contribution, we used the cross-correlation technique to obtain the radial velocity of the dominant gaseous component for each spectrum in the CALIFA data cubes for different emission lines (namely, [O ii] λλ3726,3729, [O iii] λλ4959,5007, Hα+[N ii] λλ6548,6584, and [SII]λλ6716,6730). The main kinematic parameters measured on the plane of the sky were directly derived from the radial velocities with no assumptions on the internal prevailing motions. Evidence of the presence of several gaseous components with different kinematics were detected by using [O iii] λλ4959,5007 emission line profiles. Results. At the velocity resolution of CALIFA, most objects in the sample show regular velocity fields, although the ionized-gas kinematics are rarely consistent with simple coplanar circular motions. Thirty-five percent of the objects present evidence of a displacement between the photometric and kinematic centers larger than the original spaxel radii. Only 17% of the objects in the sample exhibit kinematic lopsidedness when comparing receding and approaching sides of the velocity fields, but most of them are interacting galaxies exhibiting nuclear activity (AGN or LINER). Early-type (E+S0) galaxies in the sample present clear photometric-kinematic misaligments. There is evidence of asymmetries in the emission line profiles in 117 out of the 177 analyzed galaxies, suggesting the presence of kinematically distinct gaseous components located at different distances from the optical nucleus. The kinematic decoupling between the dominant and secondary component/s suggested by the observed asymmetries in the profiles can be characterized by a limited set of parameters. Conclusions. This work constitutes the first determination of the ionized gas kinematics of the galaxies observed in the CALIFA survey. The derived velocity fields, the reported kinematic distortions/peculiarities and the identification of the presence of several gaseous components in different regions of the objects might be used as additional criteria for selecting galaxies for specific studies.Publisher PDFPeer reviewe
Tracing kinematic (mis)alignments in CALIFA merging galaxies: Stellar and ionized gas kinematic orientations at every merger stage
We present spatially resolved stellar and/or ionized gas kinematic properties
for a sample of 103 interacting galaxies, tracing all merger stages: close
companions, pairs with morphological signatures of interaction, and coalesced
merger remnants. We compare our sample with 80 non-interacting galaxies. We
measure for the stellar and the ionized gas components the major (projected)
kinematic position angles (PA, approaching and receding)
directly from the velocity fields with no assumptions on the internal motions.
This method allow us to derive the deviations of the kinematic PAs from a
straight line (PA). Around half of the interacting
objects show morpho-kinematic PA misalignments that cannot be found in the
control sample. Those misalignments are present mostly in galaxies with
morphological signatures of interaction. Alignment between the kinematic sides
for both samples is similar, with most of the galaxies displaying small
misalignments. Radial deviations of the kinematic PA from a straight line in
the stellar component measured by PA are large for
both samples. However, for a large fraction of interacting galaxies the ionized
gas PA is larger than typical values derived from
isolated galaxies (48%), making this parameter a good indicator to trace the
impact of interaction and mergers in the internal motions of galaxies. By
comparing the stellar and ionized gas kinematic PA, we find that 42% (28/66) of
the interacting galaxies have misalignments larger than 16 degrees, compared to
10% from the control sample. Our results show the impact of interactions in the
internal structure of galaxies as well as the wide variety of their velocity
distributions. This study also provides a local Universe benchmark for
kinematic studies in merging galaxies at high redshift.Comment: 24 pages,11 Figures, Accepted for publication in Astronomy &
Astrophysics. The entire set of stellar and ionized gas velocity fields of
the interacting/merging sample will be available in the electronic version of
the journa
Insights on the stellar mass-metallicity relation from the CALIFA survey
We use spatially and temporally resolved maps of stellar population
properties of 300 galaxies from the CALIFA integral field survey to investigate
how the stellar metallicity (Z*) relates to the total stellar mass (M*) and the
local mass surface density (*) in both spheroidal and disk dominated
galaxies. The galaxies are shown to follow a clear stellar mass-metallicity
relation (MZR) over the whole 10 to 10 M range. This
relation is steeper than the one derived from nebular abundances, which is
similar to the flatter stellar MZR derived when we consider only young stars.
We also find a strong relation between the local values of * and Z* (the
ZR), betraying the influence of local factors in determining Z*. This
shows that both local (*-driven) and global (M*-driven) processes are
important in determining the metallicity in galaxies. We find that the overall
balance between local and global effects varies with the location within a
galaxy. In disks, * regulates Z*, producing a strong ZR whose
amplitude is modulated by M*. In spheroids it is M* who dominates the physics
of star formation and chemical enrichment, with * playing a minor,
secondary role. These findings agree with our previous analysis of the star
formation histories of CALIFA galaxies, which showed that mean stellar ages are
mainly governed by surface density in galaxy disks and by total mass in
spheroids.Comment: 6 pages, 3 figures, accepted for publication in ApJ
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