Children as social actors, agency, and social competence: sociological reflections for early childhood

The study of children in early childhood has, for most of the last 100 years, been dominated by developmental perspectives. This has resulted not only in a huge body of work documenting, accounting for and theorising how children grow up (controversies notwithstanding), but has also led to early childhood being in effect ›colonised‹ by this type of science and by questions of development and change. Qvortrup (1994: 4) summed this up as a dominant focus on what children will become to the neglect of what they are as persons in their early life. This hegemonic emphasis on development has been to the detriment of understanding childhood and children’s lives from a fully social scientific perspective. Until the 1990s the grip of developmental framings of the study of children and childhood left little room for sociological accounts of childhood, other than those stemming from theories of socialisation. This situation was challenged by sociological work which foregrounded an empirical sensibility towards children as social actors. This opened up a space of enquiry for understanding the social significance of the subjectivities of children and the implications of these for analyses and theorisations of both those social phenomena which are directly relevant for children and/or childhood and those which intersect with children’s lives and social worlds

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

Methodological insights from researching temporality in families with teenage children

The often unremarked processes through which gender and generation play out in families with teenage children in, through, and over time, was the topic of a mixed qualitative methods study, drawing on the accounts of multiple family members – 14 and 15 year olds and their resident parent(s). Using this as a case study the paper critically considers a number of methodological, ethical, and political issues faced in undertaking the research, particularly with respect to research with children. These pertain to challenges of a social constructionist approach and to research from multiple perspectives. We argue that there are paradoxes and contradictions that arise between a social constructionist approach and the practicalities of carrying out research into dynamic phenomena, such as “generationing”, particularly when trying to understand this from multiple perspectives. But rather than consider these as flaws we show how they are in fact opportunities for insight into the interplay between the structural and the dynamic nature of intergenerational relations

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 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

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

Evolution of the Stellar Mass-Metallicity Relation. II. Constraints on Galactic Outflows from the Mg Abundances of Quiescent Galaxies

We present the stellar mass–[Fe/H] and mass–[Mg/H] relation of quiescent galaxies in two galaxy clusters at z ~ 0.39 and z ~ 0.54. We derive the age, [Fe/H], and [Mg/Fe] for each individual galaxy using a full-spectrum fitting technique. By comparing with the relations for z ~ 0 Sloan Digital Sky Survey galaxies, we confirm our previous finding that the mass–[Fe/H] relation evolves with redshift. The mass–[Fe/H] relation at higher redshift has lower normalization and possibly steeper slope. However, based on our sample, the mass–[Mg/H] relation does not evolve over the observed redshift range. We use a simple analytic chemical evolution model to constrain the average outflow that these galaxies experience over their lifetime, via the calculation of mass-loading factor. We find that the average mass-loading factor η is a power-law function of galaxy stellar mass, $\eta \propto {M}_{* }^{-0.21\pm 0.09}$. The measured mass-loading factors are consistent with the results of other observational methods for outflow measurements and with the predictions where outflow is caused by star formation feedback in turbulent disks

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