605 research outputs found
High-precision analysis of binary stars with planets. I. Searching for condensation temperature trends in the HD 106515 system
We explore the probable chemical signature of planet formation in the
remarkable binary system HD 106515. The A star hosts a massive long-period
planet with 9 MJup detected by radial velocity. We also refine stellar and
planetary parameters by using non-solar-scaled opacities when modeling the
stars. Methods. We carried out a simultaneous determination of stellar
parameters and abundances, by applying for the first time non-solar-scaled
opacities in this binary system, in order to reach the highest possible
precision. Results. The stars A and B in the binary system HD 106515 do not
seem to be depleted in refractory elements, which is different when comparing
the Sun with solar-twins. Then, the terrestrial planet formation would have
been less efficient in the stars of this binary system. Together with HD
80606/7, this is the second binary system which does not seem to present a
(terrestrial) signature of planet formation, and hosting both systems an
eccentric giant planet. This is in agreement with numerical simulations, where
the early dynamical evolution of eccentric giant planets clear out most of the
possible terrestrial planets in the inner zone. We refined the stellar mass,
radius and age for both stars and found a notable difference of 78% in R
compared to previous works. We also refined the planet mass to mp sini = 9.08
+/- 0.20 MJup, which differs by 6% compared with literature. In addition, we
showed that the non-solar-scaled solution is not compatible with the classical
solar-scaled method, and some abundance differences are comparable to NLTE or
GCE effects specially when using the Sun as reference. Then, we encourage the
use of non-solar-scaled opacities in high-precision studies such as the
detection of Tc trends.[abridged]Comment: 9 pages, 10 figures, A&A accepted. arXiv admin note: text overlap
with arXiv:1507.0812
Hasta que naturalmente muera: ejecución pública en Chile colonial (1700-1810)
Son escasas las referencias sobre la práctica de la ejecución en el pasado colonial chileno,[1] sobre todo en lo que concierne a la participación y al comportamiento de la gente enfrentada al ceremonial del patíbulo
¿Veis aquí el Potro del tormento? ¡Decid la verdad! Tortura judicial en la Real Audiencia de Santiago de Chile
La tortura ha estado presente a largo de los siglos, tanto dentro como fuera de la ley. Durante el siglo XX esta realidad se nos ha presentado particularmente evidente y cruda en el acontecer mundial y nacional. La amplitud de este hecho nos ha llevado a preguntarnos por su ejercicio durante el período colonial en Chile, tema del cual daremos ciertas impresiones respecto de su práctica judicial. Ese tipo de tortura, llamada también cuestión de tormento, se define como «una prueba en el proceso penal, la cual era subsidiaria y reiterable, y estaba destinada a provocar por medios violentos la confesión de culpabilidad de aquel contra quien hubiera ciertos indicios; o dirigida a veces, a obtener la acusación del reo contra sus cómplices, o también a forzar las declaraciones de los testigos».[1] Para tratar lo anterior nos hemos basado en el material encontrado tras la revisión de juicios por homicidio contenidos en el archivo de la Real Audiencia de Santiago. El período estudiado va desde el siglo XVII hasta la primera década del XIX
Fundamentos y proyecciones de la teoría de la ley natural contemporánea
In this paper I will make a review of the core elements of the recent natural law ethical theories in analytic philosophy. I will expose the elements they share, and then its more essential differences, especially those related to epistemology and metaphysics. Finally, I shall explore the possibilities of development for natural law theories, and its metaethical implications, especially those related to a metaphysical and epistemological grounding for natural law.En este artículo se hará una revisión de los aspectos más destacados de las teorías éticas iusnaturalistas recientes en la tradición analítica. Se expondrán los aspectos unitarios de dichas teorías y, posteriormente, se analizarán sus divergencias más esenciales, específicamente, las epistemológicas y ontológicas. Finalmente, se explorarán las posibilidades de desarrollo para las teorías iusnaturalistas y sus implicancias metaéticas, especialmente las relativas a la fundamentación metafísica y epistemológica de la ley natural
Empirical instability strip for classical Cepheids: I. The LMC galaxy
The instability strip (IS) of classical Cepheids has been extensively studied
theoretically. Comparison of the theoretical IS edges with those obtained
empirically, using the most recent Cepheids catalogs available, can provide us
with insights into the physical processes that determine the position of the IS
boundaries. In this study, we investigate the empirical positions of the IS of
the classical Cepheids in the Large Magellanic Cloud (LMC), considering any
effect that increases its width, to obtain intrinsic edges that can be compared
with theoretical models. We use data of classical fundamental-mode (F) and
first-overtone (1O) LMC Cepheids from the OGLE-IV variable star catalog,
together with a recent high-resolution reddening map from the literature. Our
final sample includes 2058 F and 1387 1O Cepheids. We studied their position on
the Hertzsprung-Russell diagram and determined the IS borders by tracing the
edges of the color distribution along the strip. We obtain the blue and red
edges of the IS in V- and I-photometric bands, in addition to and . The results obtained show a break located at the Cepheids'
period of about 3 days, which was not reported before. We compare our empirical
borders with theoretical ones published in the literature obtaining a good
agreement for specific parameter sets. The break in the IS borders is most
likely explained by the depopulation of second and third crossing classical
Cepheids in the faint part of the IS, since blue loops of evolutionary tracks
in this mass range do not extend blueward enough to cross the IS at the LMC
metallicity. Results from the comparison of our empirical borders with
theoretical ones prove that our empirical IS is a useful tool for constraining
theoretical models.Comment: 10 pages, 13 figures, accepted for publication in Astronomy &
Astrophysic
The ALMA Frontier Fields Survey - IV. Lensing-corrected 1.1 mm number counts in Abell 2744, MACSJ0416.1-2403 and MACSJ1149.5+2223
[abridged] Characterizing the number counts of faint, dusty star-forming
galaxies is currently a challenge even for deep, high-resolution observations
in the FIR-to-mm regime. They are predicted to account for approximately half
of the total extragalactic background light at those wavelengths. Searching for
dusty star-forming galaxies behind massive galaxy clusters benefits from strong
lensing, enhancing their measured emission while increasing spatial resolution.
Derived number counts depend, however, on mass reconstruction models that
properly constrain these clusters. We estimate the 1.1 mm number counts along
the line of sight of three galaxy clusters, i.e. Abell 2744, MACSJ0416.1-2403
and MACSJ1149.5+2223, which are part of the ALMA Frontier Fields Survey. We
perform detailed simulations to correct these counts for lensing effects. We
use several publicly available lensing models for the galaxy clusters to derive
the intrinsic flux densities of our sources. We perform Monte Carlo simulations
of the number counts for a detailed treatment of the uncertainties in the
magnifications and adopted source redshifts. We find an overall agreement among
the number counts derived for the different lens models, despite their
systematic variations regarding source magnifications and effective areas. Our
number counts span ~2.5 dex in demagnified flux density, from several mJy down
to tens of uJy. Our number counts are consistent with recent estimates from
deep ALMA observations at a 3 level. Below 0.1 mJy, however,
our cumulative counts are lower by 1 dex, suggesting a flattening in
the number counts. In our deepest ALMA mosaic, we estimate number counts for
intrinsic flux densities 4 times fainter than the rms level. This
highlights the potential of probing the sub-10 uJy population in larger samples
of galaxy cluster fields with deeper ALMA observations.Comment: 19 pages, 14 figures, 3 tables. Accepted for publication in A&
Musical preferences and technologies: Contemporary material and symbolic distinctions criticised
Today how individuals interact with various cultural items is not perfectly consistent with theoretical frameworks of influential scholars on cultural consumption, such as Bourdieu (1984), Gans (1999), and Peterson and Simkus (1992). One such variation is in the ever increasing variety of technological modes to acquire and listen to music (Pinch and Bijsterveld, 2004). However, as a consequence of digital divides (van Dijk, 2006), technological items may not be distributed equally among social groups. At present, the value of status-making through a preference for different genres of music extends itself to different forms of consumption and ways of experiencing music. We are yet to fully understand the power these practices have on generating status. This article is therefore motivated by the need to integrate within quantitative frameworks of taste and cultural consumption, an analysis of individuals’ technological engagement. These two dimensions, integrated as components of musical practices, enhance our understanding of cultural boundaries across different social groups.The objective is to bridge a gap detected in the literature, addressing the following questions: Are technological modes to listen to music related to musical tastes
ζ1 + ζ2 Reticuli binary system: a puzzling chromospheric activity pattern
We perform, for the first time, a detailed long-term activity study of the binary system ζ Ret. We use all available HARPS spectra obtained between the years 2003 and 2016. We build a time series of the Mount Wilson S index for both stars, then we analyse these series by using Lomb-Scargle periodograms. The components ζ1 Ret and ζ2 Ret that belong to this binary system are physically very similar to each other and also similar to our Sun, which makes it a remarkable system. We detect in the solar-analogue star ζ2 Ret a long-term activity cycle with a period of ?10 yr, similar to the solar one (?11 yr). It is worthwhile to mention that this object satisfies previous criteria for a flat star and for a cycling star simultaneously. Another interesting feature of this binary system is a high ?0.220 dex difference between the average log (R^´ }_HK) activity levels of both stars. Our study clearly shows that ζ1 Ret is significantly more active than ζ2 Ret. In addition, ζ1 Ret shows an erratic variability in its stellar activity. In this work, we explore different scenarios trying to explain this rare behaviour in a pair of coeval stars, which could help to explain the difference in this and other binary systems. From these results, we also warn that for the development of activity-age calibrations (which commonly use binary systems and/or stellar clusters as calibrators) the whole history of activity available for the stars involved should be taken into account.Fil: Flores, M. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Saffe, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Buccino, Andrea Paola. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Jaque Arancibia, Marcelo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: González, J F. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Nuñez, N E. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Jofré, E. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentin
KELT-17: a chemically peculiar Am star and a hot-Jupiter planet
Context. The detection of planets orbiting chemically peculiar stars is very
scarcely known in the literature. Aims. To determine the detailed chemical
composition of the remarkable planet host star KELT-17. This object hosts a
hot-Jupiter planet with 1.31 MJup detected by transits, being one of the more
massive and rapidly rotating planet hosts to date. We aimed to derive a
complete chemical pattern for this star, in order to compare it with those of
chemically peculiar stars. Methods. We carried out a detailed abundance
determination in the planet host star KELT-17 via spectral synthesis. Stellar
parameters were estimated iteratively by fitting Balmer line profiles and
imposing the Fe ionization balance, using the program SYNTHE together with
plane-parallel ATLAS12 model atmospheres. Specific opacities for an arbitrary
composition and microturbulence velocity vmicro were calculated through the
Opacity Sampling (OS) method. The abundances were determined iteratively by
fitting synthetic spectra to metallic lines of 16 different chemical species
using the program SYNTHE. The complete chemical pattern of KELT-17 was compared
to the recently published average pattern of Am stars. We estimated the stellar
radius by two methods: a) comparing the synthetic spectral energy distribution
with the available photometric data and the Gaia parallax, and b) using a
Bayesian estimation of stellar parameters using stellar isochrones. Results. We
found overabundances of Ti, Cr, Mn, Fe, Ni, Zn, Sr, Y, Zr, and Ba, together
with subsolar values of Ca and Sc. Notably, the chemical pattern agrees with
those recently published of Am stars, being then KELT-17 the first exoplanet
host whose complete chemical pattern is unambiguously identified with this
class. The stellar radius derived by two different methods agrees to each other
and with those previously obtained in the literature.Comment: 5 pages, 8 figures, 2 tables, A&A accepte
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