We study the volume-limited and nearly mass-selected (stellar mass M
stars 6 × 109 M) ATLAS3D sample of 260 early-type galaxies (ETGs, ellipticals Es and lenticulars S0s). We construct detailed ...axisymmetric dynamical models (Jeans Anisotropic MGE), which allow for orbital anisotropy, include a dark matter halo and reproduce in detail both the galaxy images and the high-quality integral-field stellar kinematics out to about 1R
e, the projected half-light radius. We derive accurate total mass-to-light ratios (M/L)
e
and dark matter fractions f
DM, within a sphere of radius
centred on the galaxies. We also measure the stellar (M/L)stars and derive a median dark matter fraction f
DM = 13 per cent in our sample. We infer masses M
JAM ≡ L × (M/L)
e
2 × M
1/2, where M
1/2 is the total mass within a sphere enclosing half of the galaxy light. We find that the thin two-dimensional subset spanned by galaxies in the
coordinates system, which we call the Mass Plane (MP) has an observed rms scatter of 19 per cent, which implies an intrinsic one of 11 per cent. Here,
is the major axis of an isophote enclosing half of the observed galaxy light, while σ
e
is measured within that isophote. The MP satisfies the scalar virial relation
within our tight errors. This show that the larger scatter in the Fundamental Plane (FP) (L, σ
e
, R
e) is due to stellar population effects including trends in the stellar initial mass function (IMF). It confirms that the FP deviation from the virial exponents is due to a genuine (M/L)
e
variation. However, the details of how both R
e and σ
e
are determined are critical in defining the precise deviation from the virial exponents. The main uncertainty in masses or M/L estimates using the scalar virial relation is in the measurement of R
e. This problem is already relevant for nearby galaxies and may cause significant biases in virial mass and size determinations at high redshift. Dynamical models can eliminate these problems. We revisit the (M/L)
e
-σ
e
relation, which describes most of the deviations between the MP and the FP. The best-fitting relation is
(r band). It provides an upper limit to any systematic increase of the IMF mass normalization with σ
e
. The correlation is more shallow and has smaller scatter for slow rotating systems or for galaxies in Virgo. For the latter, when using the best distance estimates, we observe a scatter in (M/L)
e
of 11 per cent, and infer an intrinsic one of 8 per cent. We perform an accurate empirical study of the link between σ
e
and the galaxies circular velocity V
circ within 1R
e (where stars dominate) and find the relation max (V
circ) 1.76 × σ
e
, which has an observed scatter of 7 per cent. The accurate parameters described in this paper are used in the companion Paper XX (Cappellari et al.) of this series to explore the variation of global galaxy properties, including the IMF, on the projections of the MP.
To assess the US food industry's response to calls from public health authorities to reduce portion sizes by comparing current with past sizes of selected examples of single-serve ultra-processed ...packaged and fast foods.
We obtained manufacturers' information about current portion sizes and compared it with sizes when first introduced and in 2002.
Few companies in our sample reduced portion sizes since 2002; all still sold portions of ultra-processed foods in up to 5-times-larger sizes than when first introduced.
Policies and practices focused on reducing portion size could help discourage the consumption of excessive amounts of ultra-processed foods. (
. 2021;111(12):2223-2226. https://doi.org/10.2105/AJPH.2021.306513).
We use interferometric 12CO(1-0) observations to compare and contrast the extent, surface brightness profiles and kinematics of the molecular gas in CO-rich ATLAS3D early-type galaxies (ETGs) and ...spiral galaxies. We find that the molecular gas extent is smaller in absolute terms in ETGs than in late-type galaxies, but that the size distributions are similar once scaled by the galaxies optical/stellar characteristic scalelengths. Amongst ETGs, we find that the extent of the gas is independent of its kinematic misalignment (with respect to the stars), but does depend on the environment, with Virgo cluster ETGs having less extended molecular gas reservoirs, further emphasizing that cluster ETGs follow different evolutionary pathways from those in the field. Approximately half of ETGs have molecular gas surface brightness profiles that follow the stellar light profile. These systems often have relaxed gas out to large radii, suggesting they are unlikely to have had recent merger/accretion events. A third of the sample galaxies show molecular gas surface brightness profiles that fall off slower than the light, and sometimes show a truncation. These galaxies often have a low mass, and either have disturbed molecular gas or are in the Virgo cluster, suggesting that recent mergers, ram pressure stripping and/or the presence of hot gas can compress/truncate the gas. The remaining galaxies have rings, or composite profiles, that we argue can be caused by the effects of bars. We investigated the kinematics of the molecular gas using position-velocity diagrams, and compared the observed kinematics with dynamical model predictions, and the observed stellar and ionized gas velocities. We confirm that the molecular gas reaches beyond the turnover of the circular velocity curve in 70 per cent of our CO-rich ATLAS3D ETGs, validating previous work on the CO Tully-Fisher relation. In general we find that in most galaxies the molecular gas is dynamically cold, and the observed CO rotation matches well model predictions of the circular velocity. In the galaxies with the largest molecular masses, dust obscuration and/or population gradients can cause model predictions of the circular velocity to disagree with observations of the molecular gas rotation; however, these effects are confined to the most star forming systems. Bars and non-equilibrium conditions can also make the gas deviate from circular orbits. In both these cases, one expects the model circular velocity to be higher than the observed CO velocity, in agreement with our observations. Molecular gas is a better direct tracer of the circular velocity than the ionized gas, justifying its use as a kinematic tracer for Tully-Fisher and similar analyses.
We present Spectral and Photometric Imaging Receiver (SPIRE) spectroscopy for nine early-type galaxies (ETGs) representing the most CO-rich and far-infrared (FIR) bright galaxies of the ...volume-limited Atlas3D sample. Our data include detections of mid- to high-J CO transitions (J = 4-3 to J = 13-12) and the C i (1-0) and (2-1) emission lines. CO spectral line energy distributions (SLEDs) for our ETGs indicate low gas excitation, barring NGC 1266. We use the C i emission lines to determine the excitation temperature of the neutral gas, as well as estimate the mass of molecular hydrogen. The masses agree well with masses derived from CO, making this technique very promising for high-redshift galaxies. We do not find a trend between the N ii 205 flux and the infrared luminosity, but we do find that the N ii 205/CO(6-5) line ratio is correlated with the 60/100 m Infrared Astronomical Satellite colors. Thus the N ii 205/CO(6-5) ratio can be used to infer a dust temperature and hence the intensity of the interstellar radiation field. Photodissociation region models show that use of C i and CO lines in addition to the typical C ii, O i, and FIR fluxes drive the model solutions to higher densities and lower values of G0. In short, the SPIRE lines indicate that the atomic and molecular gas in the CO-rich ETGs have similar properties to other galaxies. As might be expected from their low levels of star formation activity, the ETGs have rather low excitation CO SLEDs, low temperatures inferred from the C i lines, and modestly lower C i/CO ratios.
ABSTRACT In this letter we construct a large sample of early-type galaxies (ETGs) with measured gas-phase metallicities from the Sloan Digital Sky Survey and Galaxy Zoo in order to investigate the ...origin of the gas that fuels their residual star formation. We use this sample to show that star-forming elliptical galaxies have a substantially different gas-phase metallicity distribution from spiral galaxies, with ≈7.4 per cent having a very low gas-phase metallicity for their mass. These systems typically have fewer metals in the gas phase than they do in their stellar photospheres, which strongly suggests that the material fuelling their recent star formation was accreted from an external source. We use a chemical evolution model to show that the enrichment time-scale for low-metallicity gas is very short, and thus that cosmological accretion and minor mergers are likely to supply the gas in ≳ 37 per cent of star-forming ETGs, in good agreement with estimates derived from other independent techniques.
We present interferometric observations of H I in nine slow rotator early-type galaxies of the Atlas3D sample. With these data, we now have sensitive H I searches in 34 of the 36 slow rotators. The ...aggregate detection rate is 32 per cent ± 8 per cent, consistent with the previous work; however, we find two detections with extremely high H I masses, whose gas kinematics are substantially different from what was previously known about H I in slow rotators. These two cases (NGC 1222 and NGC 4191) broaden the known diversity of H I properties in slow rotators. NGC 1222 is a merger remnant with prolate-like rotation and, if it is indeed prolate in shape, an equatorial gas disc; NGC 4191 has two counter-rotating stellar discs and an unusually large H I disc. We comment on the implications of this disc for the formation of 2σ galaxies. In general, the H I detection rate, the incidence of relaxed H I discs, and the H I/stellar mass ratios of slow rotators are indistinguishable from those of fast rotators. These broad similarities suggest that the H I we are detecting now is unrelated to the galaxies' formation processes and was often acquired after their stars were mostly in place. We also discuss the H I non-detections; some of these galaxies that are undetected in H I or CO are detected in other tracers (e.g. FIR fine structure lines and dust). The question of whether there is cold gas in massive galaxies' scoured nuclear cores still needs work. Finally, we discuss an unusual isolated H I cloud with a surprisingly faint (undetected) optical counterpart.
Australia lags behind other jurisdictions in considering the relevance of a mature minor's decision-making capacity to parenting disputes. Gillick competency, as it is known, is routinely discussed ...in the case of medical decision-making, however is ignored when it comes to parenting decisions concerning very mature minors. This article explores this failure and in particular considers: (a) the jurisdiction of the court to determine a matter when a child is competent; (b) the extent to which the courts are entitled to ignore a child's competency, based on their best interests; (c) to the extent a court should, but does not, consider a child's competency, why they do not; and (d) the arguments for overriding, or not, competency where there is a discretion. The article concludes that the court needs to reconsider this area of law, highlighting that this would play a part in the larger project of giving due recognition to children's rights in parenting proceedings.
Recent changes in food portions are analyzed. Discussion focuses on education and public health campaigns aimed at individuals, uniform and reality-based serving-size standards, price incentives for ...smaller portions, and limits on portion sizes in food service establishments.
Galactic archaeology based on star counts is instrumental to reconstruct the past mass assembly of Local Group galaxies. The development of new observing techniques and data reduction, coupled with ...the use of sensitive large field of view cameras, now allows us to pursue this technique in more distant galaxies exploiting their diffuse low surface brightness (LSB) light. As part of the ATLAS3D project, we have obtained with the MegaCam camera at the Canada–France–Hawaii Telescope extremely deep, multiband images of nearby early-type galaxies (ETGs). We present here a catalogue of 92 galaxies from the ATLAS3D sample, which are located in low- to medium-density environments. The observing strategy and data reduction pipeline, which achieve a gain of several magnitudes in the limiting surface brightness with respect to classical imaging surveys, are presented. The size and depth of the survey are compared to other recent deep imaging projects. The paper highlights the capability of LSB-optimized surveys at detecting new prominent structures that change the apparent morphology of galaxies. The intrinsic limitations of deep imaging observations are also discussed, among those, the contamination of the stellar haloes of galaxies by extended ghost reflections, and the cirrus emission from Galactic dust. The detection and systematic census of fine structures that trace the present and past mass assembly of ETGs are one of the prime goals of the project. We provide specific examples of each type of observed structures – tidal tails, stellar streams and shells – and explain how they were identified and classified. We give an overview of the initial results. The detailed statistical analysis will be presented in future papers.
Background
This paper describes findings from research conducted on students who participated in a service-learning course in South Africa.
Objective
The study aimed to understand how participants ...constructed their experiences of service-learning and to interrogate their emotional investments in these constructions.
Method
Data were collected and analyzed using a psychosocial methodology, consisting of discursive and psychoanalytic readings of interview transcripts, reflective journal entries, and researcher field notes.
Results
The discursive findings focus on how participants employed liberal traditional learning discourses to construct service-learning as linear resulting in subject positions that reinforced prejudices and the power structures supporting these. A psychoanalytic reading of the data suggests that participants invested in these constructions to defend against their own anxiety related to uncertainty and guilt about privilege in an unfamiliar context.
Conclusion
Students invest in liberal traditional discourses of service-learning for defensive reasons, which can be understood as arising from the intersubjective and social context in which the service-learning takes place.
Teaching Implications
Recognizing prejudice as emanating from anxiety generated by the affective work required for service-learning means thinking creatively about how to both contain and allow this affective work to take place in service-learning activities.
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