A spectroscopically confirmed z=1.327 galaxy-scale deflector magnifying a z~8 Lyman-Break galaxy in the Brightest of Reionizing Galaxies survey

We present a detailed analysis of an individual case of gravitational lensing of a $z\sim8$ Lyman-Break galaxy (LBG) in a blank field, identified in Hubble Space Telescope imaging obtained as part of the Brightest of Reionizing Galaxies survey. To investigate the close proximity of the bright ($m_{AB}=25.8$) $Y_{098}$-dropout to a small group of foreground galaxies, we obtained deep spectroscopy of the dropout and two foreground galaxies using VLT/X-Shooter. We detect H-$\alpha$, H-$\beta$, [OIII] and [OII] emission in the brightest two foreground galaxies (unresolved at the natural seeing of $0.8$ arcsec), placing the pair at $z=1.327$. We can rule out emission lines contributing all of the observed broadband flux in $H_{160}$ band at $70\sigma$, allowing us to exclude the $z\sim8$ candidate as a low redshift interloper with broadband photometry dominated by strong emission lines. The foreground galaxy pair lies at the peak of the luminosity, redshift and separation distributions for deflectors of strongly lensed $z\sim8$ objects, and we make a marginal detection of a demagnified secondary image in the deepest ($J_{125}$) filter. We show that the configuration can be accurately modelled by a singular isothermal ellipsoidal deflector and a S\'{e}rsic source magnified by a factor of $\mu=4.3\pm0.2$. The reconstructed source in the best-fitting model is consistent with luminosities and morphologies of $z\sim8$ LBGs in the literature. The lens model yields a group mass of $9.62\pm0.31\times10^{11} M_{\odot}$ and a stellar mass-to-light ratio for the brightest deflector galaxy of $M_{\star}/L_{B}=2.3^{+0.8}_{-0.6} M_{\odot}/L_{\odot}$ within its effective radius. The foreground galaxies' redshifts would make this one of the few strong lensing deflectors discovered at $z>1$.Comment: Accepted for publication in MNRAS. 16 pages, 11 figures, 3 table

Direct measurement of the magnification produced by galaxy clusters as gravitational lenses

Context. Weak lensing is one of the most readily available diagnostic tools to measure the total density profiles of distant clusters of galaxies. Unfortunately, it suffers from the well-known mass-sheet degeneracy, so that weak lensing analyses cannot lead to fully reliable determinations of the total mass of the clusters. One possible way to set the relevant scale of the density profile would be to make a direct measurement of the magnification produced by the clusters as gravitational lenses; in the past, this objective has been addressed in a number of ways, but with no significant success. Aims. We revisit a suggestion made a few years ago for this general purpose, based on the use of the fundamental plane as a standard rod for early-type galaxies. Here we move one step further, beyond the simple outline of the idea given earlier, and quantify some statistical properties of this innovative diagnostic tool, with the final goal of identifying clear guidelines for a future observational test of concrete cases, which turns out to be well within the current instrument capabilities. Methods. The study is carried out by discussing the statistical properties of fundamental plane measurements for a sample of early-type source galaxies behind a massive cluster, for which a weak lensing analysis is assumed to be available. Some general results are first obtained analytically and then tested and extended by means of dedicated simulations. Results. We proceed with determining the optimal way of using fundamental plane measurements to determine the mass scale of a given cluster, which we find to be the study of a sample of early-type galaxies behind the cluster distributed approximately uniformly on the sky. We discuss the role of the redshift distribution of the source galaxies, in relation to the redshift of the lensing cluster and to the limitations of fundamental plane measurements. Simple simulations are carried out for clusters with intrinsic properties similar to those of the Coma cluster. We also show that, within a realistic cosmological scenario, substructures do not contribute much to the magnification signal that we are looking for, but add only a modest amount of scatter. Conclusions. We find that for a massive cluster (M-200 > 10(15) M-circle dot) located at redshift 0.3 +/- 0.1, a set of about 20 fundamental plane measurements, combined with a robust weak lensing analysis, should be able to lead to a mass determination with a precision of 20% or better

Galaxy And Mass Assembly (GAMA): Stellar-to-Dynamical Mass Relation I. Constraining the Precision of Stellar Mass Estimates

In this empirical work, we aim to quantify the systematic uncertainties in stellar mass $(M_\star)$ estimates made from spectral energy distribution (SED) fitting through stellar population synthesis (SPS), for galaxies in the local Universe, by using the dynamical mass $(M_\text{dyn})$ estimator as an SED-independent check on stellar mass. We first construct a statistical model of the high dimensional space of galaxy properties; size $(R_e)$, velocity dispersion $(\sigma_e)$, surface brightness $(I_e)$, mass-to-light ratio $(M_\star/L)$, rest-frame colour, S\'ersic index $(n)$ and dynamical mass $(M_\text{dyn})$; accounting for selection effects and covariant errors. We disentangle the correlations among galaxy properties and find that the variation in $M_\star/M_\text{dyn}$ is driven by $\sigma_e$, S\'ersic index and colour. We use these parameters to calibrate an SED-independent $M_\star$ estimator, $\hat{M}_\star$. We find the random scatter of the relation $M_\star-\hat{M}_\star$ to be $0.108\text{dex}$ and $0.147\text{dex}$ for quiescent and star-forming galaxies respectively. Finally, we inspect the residuals as a function of SPS parameters (dust, age, metallicity, star formation rate) and spectral indices (H$\alpha$, H$\delta$, $D_n4000)$. For quiescent galaxies, $\sim65\%$ of the scatter can be explained by the uncertainty in SPS parameters, with dust and age being the largest sources of uncertainty. For star-forming galaxies, while age and metallicity are the leading factors, SPS parameters account for only $\sim13\%$ of the scatter. These results leave us with remaining unmodelled scatters of $0.055\text{dex}$ and $0.122\text{dex}$ for quiescent and star-forming galaxies respectively. This can be interpreted as a conservative limit on the precision in $M_\star$ that can be achieved via simple SPS-modelling.Comment: Accepted for publication in the Astrophysical Journal on 14 June 202

Spaceflight and immune responses of rhesus monkeys

The effects of restraint on immunological parameters was determined in an 18 day ARRT (adult rhesus restraint test). The monkeys were restrained for 18 days in the experimental station for the orbiting primate (ESOP), the chair of choice for Space Shuttle experiments. Several immunological parameters were determined using peripheral blood, bone marrow, and lymph node specimens from the monkeys. The parameters included: response of bone marrow cells to GM-CSF (granulocyte-macrophage colony stimulating factor), leukocyte subset distribution, and production of IFN-a (interferon-alpha) and IFN-gamma (interferon-gamma). The only parameter changed after 18 days of restraint was the percentage of CD8+ T cells. No other immunological parameters showed changes due to restraint. Handling and changes in housing prior to the restraint period did apparently result in some restraint-independent immunological changes. Handling must be kept to a minimum and the animals allowed time to recover prior to flight. All experiments must be carefully controlled. Restraint does not appear to be a major issue regarding the effects of space flight on immune responses

Movement Limitation and Immune Responses of Rhesus Monkeys

The effects of restraint on immunological parameters was determined in an 18 day ARRT (adult rhesus restraint test). The monkeys were restrained for 18 days in the experimental station for the orbiting primate (ESOP), the chair of choice for Space Shuttle experiments. Several immunological parameters were determined using peripheral blood, bone marrow, and lymph node specimens from the monkeys. The parameters included: response of bone marrow cells to GM-CSF (granulocyte-macrophage colony stimulating factor), leukocyte subset distribution, and production of IFN-alpha (interferon-alpha) and IFN-gamma (interferon-gamma). The only parameter changed after 18 days of restraint was the percentage of CDB+ T cells. No other immunological parameters showed changes due to restraint. Handling and changes in housing prior to the restraint period did apparently result in some restraint-independent immunological changes. Handling must be kept to a minimum and the animals allowed time to recover prior to flight. All experiments must be carefully controlled. Restraint does not appear to be a major issue regarding the effects of space flight on immune responses

Exploring the Future of Human Factors Education; Online Learning, MOOCs, Next Generation Standards, and the Technological Skills We Need to Impart

The objective of this panel was to examine how the future of human factors education is changing given the influx of technology, a push for online learning, and adapting to the changing market. The panel will begin by Heather Lum briefly giving an overview and the precipice for this discussion panel. The panelists then provided their views and experiences regarding this topic. Kelly Steelman will discuss the potential for MOOCs and other online formats to create faster and more flexible postgraduate programs. Christina Frederick will discuss her perspectives on the technological skills we should be equipping our human factors graduates with to be successful. Nathan Sonnenfeld will give his unique take on this as an undergraduate student currently obtaining a human factors education. Susan Amato-Henderson will discuss the Next Generation Science Standards and the ramifications for educators. Lastly, Thomas Smith will focus on the advantages and disadvantages of online learning at the K-12 level. Dr. Lum will foster discussion among the panelists and questions from the general audience. Discussion time: 90 minutes

Moir\'e patterns on STM images of graphite from surface and subsurface rotated layer

We have observed with STM moir\'e patterns corresponding to the rotation of one graphene layer on HOPG surface. The moir\'e patterns were characterized by rotation angle and extension in the plane. Additionally, by identifying border domains and defects we can discriminate between moir\'e patterns due to rotation on the surface or subsurface layer. For a better understanding of moir\'e patterns formation we have studied by first principles an array of three graphene layers where the top or the middle layer appears rotated around the stacking axis. We compare the experimental and theoretical results and we show the strong influence of rotations both in surface and subsurface layers for moir\'e patterns formation in corresponding STM images.Comment: 5 pages, 6 figure

The Drosophila tango gene encodes a bHLH-PAS protein that is orthologous to mammalian Arnt and controls CNS midline and tracheal development

The Drosophila single-minded and trachealess bHLH-PAS genes control transcription and development of the CNS midline cell lineage and tracheal tubules, respectively. We show that Single-minded and Trachealess activate transcription by forming dimers with the Drosophila Tango protein that is an orthologue of the mammalian Arnt protein. Both cell culture and in vivo studies show that a DNA enhancer element acts as a binding site for both Single-minded::Tango and Trachealess::Tango heterodimers and functions in controlling CNS midline and tracheal transcription. Isolation and analysis of tango mutants reveal CNS midline and tracheal defects, and gene dosage studies demonstrate in vivo interactions between single-minded::tango and trachealess::tango. These experiments support the existence of an evolutionarily conserved, functionally diverse bHLH-PAS protein regulatory system

The Galaxy Zoo survey for giant AGN-ionized clouds: past and present black hole accretion events

Some active galactic nuclei (AGN) are surrounded by extended emission-line regions (EELRs), which trace both the illumination pattern of escaping radiation and its history over the light travel time from the AGN to the gas. From a new set of such EELRs, we present evidence that the AGN in many Seyfert galaxies undergo luminous episodes 0.2–2 ×105 years in duration. Motivated by the discovery of the spectacular nebula known as Hanny’s Voorwerp, ionized by a powerful AGN which has apparently faded dramatically within ≈ 105 years, Galaxy Zoo volunteers have carried out both targeted and serendipitous searches for similar emission-line clouds around low-redshift galaxies. We present the resulting list of candidates and describe spectroscopy identifying 19 galaxies with AGN-ionized regions at projected radii rproj \u3e 10 kpc. This search recovered known EELRs (such as Mrk 78, Mrk 266 and NGC 5252) and identified additional previously unknown cases, one with detected emission to r = 37 kpc. One new Sy 2 was identified. At least 14/19 are in interacting or merging systems, suggesting that tidal tails are a prime source of distant gas out of the galaxy plane to be ionized by an AGN. We see a mix of one-and two-sided structures, with observed cone angles from 23◦ to 112◦. We consider the energy balance in the ionized clouds, with lower and upper bounds on ionizing luminosity from recombination and ionization-parameter arguments, and estimate the luminosity of the core from the far-infrared data. The implied ratio of ionizing radiation seen by the clouds to that emitted by the nucleus, on the assumption of a non-variable nuclear source, ranges from 0.02 to \u3e12; 7/19 exceed unity. Small values fit well with a heavily obscured AGN in which only a small fraction of the ionizing output escapes to be traced by surrounding gas. However, large values may require that the AGN has faded over tens of thousands of years, giving us several examples of systems in which such dramatic long-period variation has occurred; this is the only current technique for addressing these time-scales in AGN history. The relative numbers of faded and non-faded objects we infer, and the projected extents of the ionized regions, give our estimate (0.2–2×105 years) for the length of individual bright phases