552 research outputs found
Nuclear Activity in UZC Compact Groups
AbstractWe have analyzed the level and type of nuclear activity in 720 galaxies belonging to a large complete sample of Compact Groups (UZC-CGs). We have found that most (67%) galaxies show emission lines and that the most frequent (43%) nuclear activity is AGN. AGNs are mainly hosted in bright early type galaxies and early spirals, at variance with HII which reside in late spirals of lower luminosity. CGs which have a dominant content of AGNs and TOs have larger σv and lower Rp than CGs dominated by HII
Family History in the Iberian Peninsula during Chalcolithic and Bronze Age: An Interpretation through the Genetic Analysis of Plural Burials
Throughout history, it has been observed that human populations have buried the deceased members of their communities following different patterns. During the Copper Age and the Bronze Age-periods on which this study focuses-in the northern sub-plateau of the Iberian Peninsula, we identified different patterns of multiple or collective burial. This work analyzes a total of 58 individuals buried in different multiple or collective graves, to investigate whether the practice of these burials implies a family or biological link between individuals buried together. With this aim, STR markers of nuclear DNA were analyzed, as well as the hypervariable regions I and II of mitochondrial DNA, establishing both close kinship relationships and relationships through maternal lineage. We observed different burial patterns, detecting certain maternal lines preserved in some common burials maintained over time. Close family relationships were observed to a lesser extent, with some occasional exceptions. The results of the analysis formed the basis for a discussion on the concepts of family and community
The quasar main sequence and its potential for cosmology
The main sequence offers a method for the systematization of quasar spectral
properties. Extreme FeII emitters (or extreme Population A, xA) are believed to
be sources accreting matter at very high rates. They are easily identifiable
along the quasar main sequence, in large spectroscopic surveys over a broad
redshift range. The very high accretion rate makes it possible that massive
black holes hosted in xA quasars radiate at a stable, extreme
luminosity-to-mass ratio. After reviewing the basic interpretation of the main
sequence, we report on the possibility of identifying virial broadening
estimators from low-ionization line widths, and provide evidence of the
conceptual validity of redshift-independent luminosities based on virial
broadening for a known luminosity-to-mass ratio.Comment: 5 pages, 2 figures, contribution presented at the IAU Symposium 356,
Nuclear Activity in Galaxies Across Cosmic Time, held in Addis Ababa,
Ethiopia, on Oct. 7-11, 2019. M. Povic et al. (Eds.
Stellar populations of galaxies in the ALHAMBRA survey up to . I. MUFFIT: A Multi-Filter Fitting code for stellar population diagnostics
We present MUFFIT, a new generic code optimized to retrieve the main stellar
population parameters of galaxies in photometric multi-filter surveys, and we
check its reliability and feasibility with real galaxy data from the ALHAMBRA
survey. Making use of an error-weighted -test, we compare the
multi-filter fluxes of galaxies with the synthetic photometry of mixtures of
two single stellar populations at different redshifts and extinctions, to
provide through a Monte Carlo method the most likely range of stellar
population parameters (mainly ages and metallicities), extinctions, redshifts,
and stellar masses. To improve the diagnostic reliability, MUFFIT identifies
and removes from the analysis those bands that are significantly affected by
emission lines. We highlight that the retrieved age-metallicity locus for a
sample of early-type galaxies in ALHAMBRA at different stellar
mass bins are in very good agreement with the ones from SDSS spectroscopic
diagnostics. Moreover, a one-to-one comparison between the redshifts, ages,
metallicities, and stellar masses derived spectroscopically for SDSS and by
MUFFIT for ALHAMBRA reveals good qualitative agreements in all the parameters.
In addition, and using as input the results from photometric-redshift codes,
MUFFIT improves the photometric-redshift accuracy by -, and it
also detects nebular emissions in galaxies, providing physical information
about their strengths. Our results show the potential of multi-filter galaxy
data to conduct reliable stellar population studies with the appropiate
analysis techniques, as MUFFIT.Comment: 31 pages, 18 figures, accepted for publication in A&
The ALHAMBRA Survey: Bayesian Photometric Redshifts with 23 bands for 3 squared degrees
The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift
Astronomical) survey has observed 8 different regions of the sky, including
sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a
new photometric system with 20 contiguous ~ filters covering the
optical range, combining them with deep imaging. The observations,
carried out with the Calar Alto 3.5m telescope using the wide field (0.25 sq.
deg FOV) optical camera LAICA and the NIR instrument Omega-2000, correspond to
~700hrs on-target science images. The photometric system was designed to
maximize the effective depth of the survey in terms of accurate spectral-type
and photo-zs estimation along with the capability of identification of
relatively faint emission lines. Here we present multicolor photometry and
photo-zs for ~438k galaxies, detected in synthetic F814W images, complete down
to I~24.5 AB, taking into account realistic noise estimates, and correcting by
PSF and aperture effects with the ColorPro software. The photometric ZP have
been calibrated using stellar transformation equations and refined internally,
using a new technique based on the highly robust photometric redshifts measured
for emission line galaxies. We calculate photometric redshifts with the BPZ2
code, which includes new empirically calibrated templates and priors. Our
photo-zs have a precision of for I<22.5 and 1.4% for
22.5<I<24.5. Precisions of less than 0.5% are reached for the brighter
spectroscopic sample, showing the potential of medium-band photometric surveys.
The global shows a mean redshift =0.56 for I=0.86 for
I<24.5 AB. The data presented here covers an effective area of 2.79 sq. deg,
split into 14 strips of 58.5'x15.5' and represents ~32 hrs of on-target.Comment: The catalog data and a full resolution version of this paper is
available at https://cloud.iaa.csic.es/alhambra
Reliability of a standing isokinetic shoulder rotators strength test using a functional electromechanical dynamometer: Effects of velocity
Indexación: Scopus.Background. The evaluation of the force in internal rotation (IR) and external rotation (ER) of the shoulder is commonly used to diagnose possible pathologies or disorders in the glenohumeral joint and to assess patient's status and progression over time. Currently, there is new technology of multiple joint isokinetic dynamometry that allows to evaluate the strength in the human being. The main purpose of this study was to determine the absolute and relative reliability of concentric and eccentric internal and external shoulder rotators with a functional electromechanical dynamometer (FEMD). Methods. Thirty-two male individuals (21.46±2.1 years) were examined of concentric and eccentric strength of shoulder internal and external rotation with a FEMD at velocities of 0.3 m s-1and 0.6 m s-1. Relative reliability was determined by intraclass correlation coefficients (ICC). Absolute reliability was quantified by standard error of measurement (SEM) and coefficient of variation (CV). Systematic differences across velocities testing circumstances, were analyzed with dependent t tests or repeatedmeasures analysis of variance in case of two or more than two conditions, respectively. Results. Reliability was high to excellent for IR and ER on concentric and eccentric strength measurements, regardless of velocity used (ICC: 0.81-0.98, CV: 5.12-8.27% SEM: 4.06-15.04N). Concentric outcomes were more reliable than eccentric due to the possible familiarization of the population with the different stimuli. Conclusion. All procedures examined showed high to excellent reliability for clinical use. However, a velocity of 0.60 m s-1should be recommended for asymptomatic male patients because it demands less time for evaluation and patients find it more comfortable. © 2020 PeerJ Inc.. All rights reserved.https://peerj.com/articles/9951
VizieR Online Data Catalog: Spectra of 28 intermediate redshift quasars (Sulentic+, 2017)
Spectroscopic data for 28 intermediate redshift quasars are identified in Table 1. Actual data files are in FITS format in the spectra sub-directory. Units are in wavelength in Angstroms, and specific flux in erg/s/cm2/Angstrom (pW/m3)x1E15 in the rest frame (i.e., after redshift correction). The last column of Table 1 reports the FITS file names. (2 data files)
Assessment of the load-velocity profile in the free-weight prone bench pull exercise through different velocity variables and regression models
This aims of this study were (I) to determine the velocity variable and regression model which best fit the load-velocity relationship during the free-weight prone bench pull exercise, (II) to compare the reliability of the velocity attained at each percentage of the one-repetition maximum (1RM) between different velocity variables and regression models, and (III) to compare the within- and between-subject variability of the velocity attained at each %1RM. Eighteen men (14 rowers and four weightlifters) performed an incremental test during the free-weight prone bench pull exercise in two different sessions. General and individual load-velocity relationships were modelled through three velocity variables (mean velocity [MV], mean propulsive velocity [MPV] and peak velocity [PV]) and two regression models (linear and second-order polynomial). The main findings revealed that (I) the general (Pearson's correlation coefficient [r] range = 0.964-0.973) and individual (median r = 0.986 for MV, 0.989 for MPV, and 0.984 for PV) load-velocity relationships were highly linear, (II) the reliability of the velocity attained at each %1RM did not meaningfully differ between the velocity variables (coefficient of variation [CV] range = 2.55-7.61% for MV, 2.84-7.72% for MPV and 3.50-6.03% for PV) neither between the regression models (CV range = 2.55-7.72% and 2.73-5.25% for the linear and polynomial regressions, respectively), and (III) the within-subject variability of the velocity attained at each %1RM was lower than the between-subject variability for the light-moderate loads. No meaningful differences between the within- and between-subject CVs were observed for the MV of the 1RM trial (6.02% vs. 6.60%; CVratio = 1.10), while the within-subject CV was lower for PV (6.36% vs. 7.56%; CVratio = 1.19). These results suggest that the individual load-MV relationship should be determined with a linear regression model to obtain the most accurate prescription of the relative load during the free-weight prone bench pull exercise
Strike-slip faults mediate the rise of crustal-derived fluids and mud volcanism in the deep sea
We report on newly discovered mud volcanoes located at ∼4500 m water depth ∼90 km west of the deformation front of the accretionary wedge of the Gulf of Cadiz, and thus outside of their typical geotectonic environment. Seismic data suggest that fluid flow is mediated by a >400-km-long strike-slip fault marking the transcurrent plate boundary between Africa and Eurasia. Geochemical data (Cl, B, Sr, 87Sr/86Sr, δ18O, δD) reveal that fluids originate in oceanic crust older than 140 Ma. On their rise to the surface, these fluids receive strong geochemical signals from recrystallization of Upper Jurassic carbonates and clay-mineral dehydration in younger terrigeneous units. At present, reports of mud volcanoes in similar deep-sea settings are rare, but given that the large area of transform-type plate boundaries has been barely investigated, such pathways of fluid discharge may provide an important, yet unappreciated link between the deeply buried oceanic crust and the deep ocean
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