Environmental Effects in the Evolution of Galactic Bulges

We investigate possible environmental trends in the evolution of galactic bulges over the redshift range 0<z<0.6. For this purpose, we construct the Fundamental Plane (FP) for cluster and field samples at redshifts =0.4 and =0.54 using surface photometry based on HST imaging and velocity dispersions based on Keck spectroscopy. As a reference point for our study we include data for pure ellipticals, which we model as single-component Sersic profiles; whereas for multi-component galaxies we undertake decompositions using Sersic and exponential models for the bulge and disk respectively. Although the FP for both distant cluster and field samples are offset from the local relation, consistent with evolutionary trends found in earlier studies, we detect significant differences in the zero point of ~=0.2 dex between the field and cluster samples at a given redshift. For both clusters, the environmentally-dependent offset is in the sense expected for an accelerated evolution of bulges in dense environments. By matching the mass range of our samples, we confirm that this difference does not arise as a result of the mass-dependent downsizing effects seen in larger field samples. Our result is also consistent with the hypothesis that - at fixed mass and environment - the star formation histories of galactic bulges and pure spheroids are indistinguishable, and difficult to reconcile with the picture whereby the majority of large bulges form primarily via secular processes within spiral galaxies.Comment: 5 pages, 3 figures, accepted for publication in ApJ Letter

Nuevos estudios de infancia, política de infancia y derechos de los niños y niñas

In a time where the future of democracy is at stake, it is necessary to recognize the significance of the contribution that the “new” childhood studies can make to securing that future, particularly with respect to establishing the importance of the agency and social competence (in different arenas of everyday life) of children as political social actors. The combination of these recognitions with the task of conceptualizing childhood politics (as politics with children) and an emancipatory development in the field of children’s rights is vital for fuller socio-theoretical and socio-political debates on solutions to the problem of positive human future for all generations. In this paper, we show how the conceptualizations and empirical work from childhood studies enhance the role that children’s rights can play in the improvement of democratic processes at a societal level, i.e. real participation. This is something that goes way beyond the tendency to treat children’s rights as an individual concern, arguing instead for a consideration of children’s rights and agency as a social requirement for democracy

Evolution of the Stellar Mass--Metallicity Relation - I: Galaxies in the z~0.4 Cluster Cl0024

We present the stellar mass-stellar metallicity relationship (MZR) in the Cl0024+1654 galaxy cluster at z~0.4 using full spectrum stellar population synthesis modeling of individual quiescent galaxies. The lower limit of our stellar mass range is $M_*=10^{9.7}M_\odot$, the lowest galaxy mass at which individual stellar metallicity has been measured beyond the local universe. We report a detection of an evolution of the stellar MZR with observed redshift at $0.037\pm0.007$ dex per Gyr, consistent with the predictions from hydrodynamical simulations. Additionally, we find that the evolution of the stellar MZR with observed redshift can be explained by an evolution of the stellar MZR with their formation time, i.e., when the single stellar population (SSP)-equivalent ages of galaxies are taken into account. This behavior is consistent with stars forming out of gas that also has an MZR with a normalization that decreases with redshift. Lastly, we find that over the observed mass range, the MZR can be described by a linear function with a shallow slope, ($[Fe/H] \propto (0.16 \pm 0.03) \log M_*$). The slope suggests that galaxy feedback, in terms of mass-loading factor, might be mass-independent over the observed mass and redshift range.Comment: 22 pages, 10 figures. Accepted for publication in Ap

The Dynamical Distinction between Elliptical and Lenticular Galaxies in Distant Clusters: Further Evidence for the Recent Origin of S0 Galaxies

We examine resolved spectroscopic data obtained with the Keck II telescope for 44 spheroidal galaxies in the fields of two rich clusters, Cl0024+16 (z=0.40) and MS0451-03 (z=0.54), and contrast this with similar data for 23 galaxies within the redshift interval 0.3<z<0.65 in the GOODS northern field. For each galaxy we examine the case for systemic rotation, derive central stellar velocity dispersions sigma and photometric ellipticities, epsilon. Using morphological classifications obtained via Hubble Space Telescope imaging as the basis, we explore the utility of our kinematic quantities in distinguishing between pressure-supported ellipticals and rotationally-supported lenticulars (S0s). We demonstrate the reliability of using the v/(1-epsilon) vs sigma and v/sigma vs epsilon distributions as discriminators, finding that the two criteria correctly identify 63%+-3% and 80%+-2% of S0s at z~0.5, respectively, along with 76%+8-3% and 79%+-2% of ellipticals. We test these diagnostics using equivalent local data in the Coma cluster, and find that the diagnostics are similarly accurate at z=0. Our measured accuracies are comparable to the accuracy of visual classification of morphologies, but avoid the band-shifting and surface brightness effects that hinder visual classification at high redshifts. As an example application of our kinematic discriminators, we then examine the morphology-density relation for elliptical and S0 galaxies separately at z~0.5. We confirm, from kinematic data alone, the recent growth of rotationally-supported spheroidals. We discuss the feasibility of extending the method to a more comprehensive study of cluster and field galaxies to z~1, in order to verify in detail the recent density-dependent growth of S0 galaxies.Comment: 7 pages, 4 figures, updated with version accepted to Ap

The relevance of ‘competence’ for enhancing or limiting children’s participation: unpicking conceptual confusion

Recent debates about children’s participation rights, formulated in the UN Convention on the Rights of the Child, primarily focus on ‘effectiveness’ of implementation. However, children’s participation remains problematic, its limited impact on adult power in decision-making or on the nature of decisions made persists, and reservations about children’s competence as participants are implicated in both. In respect of this, we analysed conceptualisations of competence in 67 articles, published between 2007 and 2017 in six childhood studies’ journals, where ‘competence’ and its variations appear in the abstract. Although competence is rarely defined, conceptualisations were wide-ranging, covering competence as skills, as compliance with adult views, and as a trope signalling the field of childhood studies. As a result of our findings, we argue that epistemological clarity is vital for this concept to be useful regarding children’s participation and that attention must be paid to the different kinds of competence relevant for ‘effective’ participation

Reflections of Cluster Assembly in the Stellar Populations and Dynamics of Member Galaxies

We combine optical (HST) and UV (GALEX) imaging of two intermediate redshift galaxy clusters with spectroscopy of member galaxies, to study the relation between the formation history of cluster galaxies and the assembly history of the cluster structure itself. We identify key differences in the large-scale structure and intracluster medium properties of each cluster. In order to assess the importance of cluster substructure and the ICM in the evolution of cluster galaxies, we examine several key indicators of the recent star-formation and assembly history of cluster galaxies. We find that galaxies in cluster MS 0451 (z = 0.54) exhibit a markedly lower incidence of recent star formation activity than galaxies in cluster Cl 0024 (z = 0.39), likely the result of starvation by the ICM. In addition, Cl 0024 members show evidence for kinematic disturbances that can be linked to the assembly of substructure

Introducción : cultivando los aspectos culturales al hacer investigación

El objetivo de esta introducción es enmarcar dentro de la complejidad cultural de nuestro mundo contemporáneo, las 14 contribuciones incluidas en este volumen especial. No debe descuidarse la particularidad de hacer investigación cualitativa en específicos contextos locales, nacionales o de lenguaje. Se brinda una breve descripción de cada artículo para presentar este nuevo volumen sobre las prácticas cualitativas de investigación en algunas de las periferias de nuestro globalizado mundo académicoFraming the 14 contributions included in this special issue on "Advances in Qualitative Research in Ibero America" within the cultural complexity of our current world is the objective of this introduction. The particularity of doing qualitative research in specific local, national, and even language contexts should not be overlooked. A brief description of each article is provided to introduce this new issue on qualitative research practices in some of the peripheries of our globalized academic worl

All-sky Galactic radiation at 45 MHz and spectral index between 45 and 408 MHz

Aims: We study the Galactic large-scale synchrotron emission by generating a reliable all-sky spectral index map and temperature map at 45 MHz. Methods: We use our observations, the published all-sky map at 408 MHz, and a bibliographical compilation to produce a map corrected for zero-level offset and extragalactic contribution. Results: We present full sky maps of the Galactic emission at 45 MHz and the Galactic spectral index between 45 and 408 MHz with an angular resolution of 5\degs. The spectral index varies between 2.1 and 2.7, reaching values below 2.5 at low latitude because of thermal free-free absorption and its maximum in the zone next to the Northern Spur.Comment: A&A accepte