The inner dark matter distribution of the Cosmic Horseshoe (J1148+1930) with gravitational lensing and dynamics

We present a detailed analysis of the inner mass structure of the Cosmic Horseshoe (J1148+1930) strong gravitational lens system observed with the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3). In addition to the spectacular Einstein ring, this systems shows a radial arc. We obtained the redshift of the radial arc counter image $z_\text{s,r} = 1.961 \pm 0.001$ from Gemini observations. To disentangle the dark and luminous matter, we consider three different profiles for the dark matter distribution: a power-law profile, the NFW, and a generalized version of the NFW profile. For the luminous matter distribution, we base it on the observed light distribution that is fitted with three components: a point mass for the central light component resembling an active galactic nucleus, and the remaining two extended light components scaled by a constant M/L. To constrain the model further, we include published velocity dispersion measurements of the lens galaxy and perform a self-consistent lensing and axisymmetric Jeans dynamical modeling. Our model fits well to the observations including the radial arc, independent of the dark matter profile. Depending on the dark matter profile, we get a dark matter fraction between 60 % and 70 %. With our composite mass model we find that the radial arc helps to constrain the inner dark matter distribution of the Cosmic Hoseshoe independently of the dark matter profile.Comment: 19 pages, 14 figures, 8 tables, submitted to A&

Presence In Virtuality \u3e Reality | Review & Commentary

Presence In Virtuality \u3e Reality | Review & Commentary Meyers, M., & Sonnenfeld, A. Presentation It has been demonstrated in previous literature that participants may feel more present in virtuality than in reality. Why is this? Our team of researchers propose that this phenomenon neither suggest invalidity in both objective and subjective presence measurement - nor invalidity of the construct itself. Presence, as the experience of being in an environment, is refined in our review from insight gained from three psychological schools of thought which have conflicted for over twenty years. Just as our definitions of presence evolved over the last two decades, however - so have we as a society. If individuals are capable of experiencing a heightened sense of present in virtuality than reality, then we must understand what the root cause of this contradiction is - and discuss the implications of such a phenomena for our own experiences in the real world. What does it mean to experience an environment – to feel present – and how do we measure this phenomenon? What could cause individuals, both in the present and future, to feel more present in a virtual world than a real one? To what extent have our virtual interactions taken precedence over our daily interactions? Does our embodied presence impact our lives more so than our physical presence? How can we – living in reality – design our experiences to match the involvement and immersion afforded by computer interfaces and virtual environments? The researchers attempt to answer these questions using the support of previous research in this domain – combining the perspectives of human factors and applied psychological research, human-computer interaction, business (via experiential design), and philosophy. The researchers identify what elements of virtuality make it more appealing to the experience of the individual than reality, propose design solutions for our experience in reality, and outline a foundation for future research. Without continued investigation with support of the scientific community, modern society may remain unguided – perpetuating toward a future in which it will be impossible to feel present in reality, when virtual alternatives are both just as easily accessible and significant

A Conceptual Model of Transfer of Training via Virtual Environments

A Conceptual Model of Transfer of Training via Virtual Environments Sonnenfeld, N.A., & Meyers, M. Presentation A review of Transfer of Training (ToT) literature over the last several decades reveals both significant advancements and gaps in our conceptualization of the transfer process and its contributing factors - especially in the domain of training via the use of virtual environments. Updating our current model of the transfer of training process is necessary to ensure adequate preparation for personnel operating in extreme environments - particularly for those training for small unit operations in dynamic environments for extended periods of time - such as those in combat warfare, space exploration & operations, the medical operation room, and other domains in which lives are at stake. A general recognition of the impact of trainee characteristics, training design, and work environment upon transfer is not enough for the quantification and analysis of training and systems. Building from the Baldwin & Ford (1988) Transfer of Training model, the researchers expand upon existing literature regarding the inputs, outputs, and outcomes of training transfer to propose a synthesized model of transfer of training via the use of virtual environments, as a foundation for future inquiry into this dynamic process. Inclusion of previous reviews – among novel perspectives on the virtual experience, learning in virtual environments, presence, experiential design, and on the assessment and evaluation of the Transfer of Training construct - enable this fundamental work to inspire and provide framework for the next generation of applied training research

The effect of spiral arms on the Sérsic photometry of galaxies

Galaxie

Statistical strong lensing: II. Cosmology and galaxy structure with time-delay lenses

Large scale structure and cosmolog

Statistical strong lensing: III. Inferences with complete samples of lenses

Galaxie

Statistical strong lensing: IV. Inferences with no individual source redshifts

Galaxie

Experiment K-6-23. Effect of spaceflight on levels and function of immune cells

Two different immunology experiments were performed on samples received from rats flown on Cosmos 1887. In the first experiment, rat bone marrow cells were examined in Moscow for their response to colony stimulating factor-M. In the second experiment, rat spleen and bone marrow cells were stained in Moscow with a variety of antibodies directed against cell surface antigenic markers. These cells were preserved and shipped to the United States where they were subjected to analysis on a flow cytometer. The results of the studies indicate that bone marrow cells from flown rats showed a decreased response to colony stimulating factor than did bone marrow cells from control rats. There was a higher percentage of spleen cells from flown rats staining positively for pan-T-cell, suppressor-T-cell and innate interleukin-2 receptor antigens than from control animals. In addition, a higher percentage of cells that appeared to be part of the myelogenous population of bone marrow cells from flown rats stained positively for surface immunoglobulin than did equivalent cells from control rats

Next-Gen Virtual Reality: A Comparative Study of Immersive Tendency and Differential Presence

Advancement in Virtual Reality (VR) interface technology in recent years has grown exponentially, resulting in the design and modification of a great number of devices to bring the experience of virtual environments (VE) to the user in ways only barely conceivable just two decades ago, for a variety of applications ranging from gaming to education to simulation-based training (SBT). Our study examines how the experience of being in one environment when one is physically situated in another (known as presence) is measured in current virtual reality interfaces against standard interface systems, both available as a conglomerate of commercial off-the-shelf (COTS) devices. Statistical analyses will be conducted to determine the quality of the relationship between reported scores of immersive tendency – the affinity of an individual to become absorbed by a fictitious environment – and reported presence in the virtual environment. Individual immersive tendency will be measured with the Immersive Tendencies Questionnaire (ITQ) developed by Witmer & Singer (1998) and presence by the Temple Presence Inventory (TPI) developed by Lombard, Ditton, & Weinstein (2009). Results of this experiment will answer the following two research questions: “Is an individual’s presence in a virtual environment significantly increased via the use of the virtual reality interface as compared to a standard interface?” and, if a significant difference is found, “What is the quality of the relationship between one’s immersive tendency and the difference in presence scores between the interfaces?” The virtual environment to be used in this experiment is that of ARMA III, a commercial game created by the same developers of the Virtual Battlespace series commonly used in military-grade simulation-based training. This is to retain eternal validity of our experiment for the application of our research for military training and to enhance the significance of our experiment in virtual environments research. Furthermore, a Simulation Sickness Questionnaire (SSQ) will be used to assess a baseline score of cyber-simulation sickness for use of this generation of combined commercial-off-the-shelf virtual reality interface systems. This study among future investigations with these VR systems will have a profound impact across the domains of training psychology, human factors, education, and human-computer integration

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