Galaxy Kinematics With Virus-P: The Dark Matter Halo Of M87

We present two-dimensional stellar kinematics of M87 out to R = 238 '' taken with the integral field spectrograph VIRUS-P. We run a large set of axisymmetric, orbit-based dynamical models and find clear evidence for a massive dark matter halo. While a logarithmic parameterization for the dark matter halo is preferred, we do not constrain the dark matter scale radius for a Navarro-Frenk-White (NFW) profile and therefore cannot rule it out. Our best-fit logarithmic models return an enclosed dark matter fraction of 17.2(-5.0)(+5.0)% within one effective radius (R-e congruent to 100 ''), rising to 49.4(-8.8)(+7.2)% within 2 R-e. Existing SAURON data (R <= 13 ''), and globular cluster (GC) kinematic data covering 145 '' <= R <= 554 '' complete the kinematic coverage to R = 47 kpc (similar to 5R(e)). At this radial distance, the logarithmic dark halo comprises 85.3(-2.4)(+2.5)% of the total enclosed mass of 5.7(-0.9)(+1.3) x 10(12) M-circle dot making M87 one of the most massive galaxies in the local universe. Our best-fit logarithmic dynamical models return a stellar mass-to-light ratio (M/L) of 9.1(-0.2)(+0.2) (V band), a dark halo circular velocity of 800(-25)(+75) km s(-1), and a dark halo scale radius of 36(-3)(+7) kpc. The stellar M/L, assuming an NFW dark halo, is well constrained to 8.20(-0.10)(+0.05) (V band). The stars in M87 are found to be radially anisotropic out to R congruent to 0.5 R-e, then isotropic or slightly tangentially anisotropic to our last stellar data point at R = 2.4 R-e where the anisotropy of the stars and GCs are in excellent agreement. The GCs then become radially anisotropic in the last two modeling bins at R = 3.4 R-e and R = 4.8 R-e. As one of the most massive galaxies in the local universe, constraints on both the mass distribution of M87 and anisotropy of its kinematic components strongly inform our theories of early-type galaxy formation and evolution in dense environments.Astronom

Development of Novel Iridium(III) Complexes for Light-Emitting Devices

Photochemistry and photophysics are omnipresent in the natural world, making them of great scientific interest. The reproduction and application of their processes in chemical, physical, biological, and medical technologies have emerged as areas of great interest. The forefront of current research lies in the development of highly efficient light-emitting devices, where increased efficiency translates to reduced energy consumption. This pursuit holds paramount importance in mitigating the climate crisis by curbing carbon emissions. Recent advancements in OLEDs and LEECs have demonstrated significantly more efficiency compared to traditional lighting methods.Amongst transition metal complexes, Ir(III) complexes emerge as the most promising candidates for photo- and electroluminescence. Tunability across the colour spectrum can be achieved by modifying their ligands. These complexes exhibit a remarkable array of photophysical properties, including the ability to modify emission characteristics via ligand manipulation, good kinetic and thermodynamic stability, and exceedingly high quantum yields.The primary objective of this thesis revolves around the advancement and exploration of light-emitting complexes through the synthesis of novel Ir(III) complexes, aiming to modulate the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). This research work seeks to contribute to the development and progress of light-emitting devices, enriching our understanding of their properties, and open up new possibilities for a multitude of applications.This thesis presents the findings of my research in the development of Ir(III) complexes for light-emitting devices:Chapter 2 consists of the synthesis of heterodinuclear Ir(III)-Ru(II) complexes where the bridging ligand between the two metal centres is based on aryl-1,2,3-triazole ligands. The mononuclear counterparts were also synthesised. The photophysical properties of these complexes were investigated. It was revealed that two of the fluorinated multinuclear complexes were white light emitting. The reported complexes were tested for their photostability and were found to be photolabile. The photochemical properties were investigated for the heterodinuclear Ir(III)-Ru(II) complexes. The metal centres separated through photolysis resulting in a turning of the Ir(III) emission.Chapter 3 consists of the synthesis of a series of cyclometalated Ir(III) complexes designed to explore the high energy T1 states for Ir(III) complexes. The cyclometalating C^N ligand was selected to be 3, 5-Dimethylpyrazole phenyl whilst the N^N ancillary ligand was a series from 2,2’-bipyridyl (bpy)→ 2-(1-benzyl-1H-1,2,3-triazol-4-yl)pyridine (pytz) → 4,4-bi-1,2,3-triazol-4-y (btz) and 2-(1-benzyl-1H-1,2,3-triazol-4-yl)-6-methylpyridine (m-pytz). The photophysical properties were investigated for these complexes. It was found that the btz and m-pytz complexes were readily accessing the 3MC states upon excitation. Computational studies confirm that the btz complex accesses the 3MC states, this was achieved through manipulation of the electronic properties of the complex. Whilst the m-pytz complex also accesses the 3MC states, this was performed through the ligand architecture, designed to increase bond lengths through steric hindrance.Chapter 4 consists of the synthesis of novel Ir 3+2+1 triazoles complexes based on the [Ir(N^N^N)(C^N)Cl]+ structure. The synthesis entails aryl-1,2,3-traizole ligands and archetypal pyridine-based ligands. The complexes were designed to explore new chemical space thus their photophysical properties were assessed. The C^N triazole based complex showed respectable photophysical properties, with a relative photoluminescent quantum yield (ϕ) of 9.1 % and lifetime (τ) of 1.7 μs. The N^N^N triazole based complexes had less impressive relative quantum yields (ϕ

Category bias in facial memory

Existing knowledge has been shown to interact with episodic information in a variety of memory tasks. The present study examined a known bias due to existing knowledge in the context of memory for facial features. Specifically, we examined if the category bias, a systematic error in remembering a target toward the prototypical location of its region, increased as a function of distance away from its prototypical location and if time and degree of distortion moderated the bias. We manipulated eye width along a horizontal axis to create a set of face stimuli. In Experiment 1, participants saw one face at a time, and after a short delay, they were asked to reproduce the location of one of the eyes and complete a recognition task. In Experiment 2, we increased the delay from 2000ms to 5000ms. We hypothesized and found that bias towards the prototype increased for the moderately distorted face conditions; however, the decrease in bias in the highly distorted conditions was not statistically significant. Additionally, bias did not increase over time. We discuss our results in the context of Huttenlocher et al.\u27s (1991) category adjustment model, as well as the practical implications of our study in the field of eyewitness memory

N=1 Sigma Models in AdS_4

We study sigma models in AdS_4 with global N=1 supersymmetry and find that they differ significantly from their flat-space cousins -- the target space is constrained to be a Kahler manifold with an exact Kahler form, the superpotential transforms under Kahler transformations, the space of supersymmetric vacua is generically a set of isolated points even when the superpotential vanishes, and the R-symmetry is classically broken by the cosmological constant. Remarkably, the exactness of the Kahler class is also required for the sigma model to arise as a decoupling limit of N=1 supergravity, and ensures the vanishing of gravitational anomalies. As simple applications of these results, we argue that fields with AdS_4 scale masses are ubiquitous in, for example, type IIB N=1 AdS_4 vacua stabilized near large volume; we also show that the Affleck-Dine-Seiberg runaway of N_f < N_c SQCD is regulated by considering the theory in AdS_4.Comment: 32 pages; v2: minor changes and references added; v3: discussion in sect. 5 extended, version published in JHE

“I Almost Quit”: Exploring the Prevalence of the Ferguson Effect in Two Small Sized Law Enforcement Agencies in Rural Southcentral Virginia

Recent negatively publicized police-citizen interactions in the media, followed by a subsequent de-policing of police in the United States, has been named the Ferguson Effect. The Ferguson Effect has been explored by prominent scholars in the criminal justice community; however, little is known about how police officers in small rural police agencies perceive the Ferguson Effect. The purpose of this qualitative phenomenological study was to explore the perceptions and lived experiences of police officers regarding the Ferguson Effect in small rural police agencies, as well as police officers’ perceptions of their own organizational justice. Organizational justice theory was utilized as the theoretical lens for this study. Research questions focused on exploring police officers’ perceptions, attitudes, and experiences of the Ferguson Effect phenomenon and willingness to partner with the community. Purposeful sampling was utilized and semi structured interviews were conducted of nine active sworn law enforcement personnel in southcentral Virginia. Data were analyzed through in vivo coding, pattern coding, and structural analysis utilizing NVivo 11 Pro. Themes included: (a) racial division, (b) rush to judgment, and (c) steadfast leadership. Findings indicated participants demanded clear and fair policies and procedures from leadership, increased effort of transparency in policing, feelings of racial tension, and the need to regain community trust post-Ferguson

A Lighthouse in the Sea of Qualitative Textbooks: A Book Review of Kakali Bhattacharya’s Fundamentals of Qualitative Research—A Practical Guide

Kakali Bhattacharya (2017) effortlessly advances the pedagogical literature on qualitative research. As a scholar-practitioner of the field of criminal justice, a recent doctoral graduate, and a qualitative methodologist, reading this book allowed me to reflect on my strengths and weaknesses in conducting qualitative inquiry. This review presents the primary intent of the book, which is to be a supplemental text for an introductory qualitative research methods course. Bhattacharya (2017) offers a succinct and straightforward recipe to improve one’s understanding of qualitative research methods, as well as provides best practices while doing so. This book is the perfect roadmap for the instructor who is asked to facilitate his or her first qualitative research methods course to follow or for a student to supplement their course text

Is the ridge formed by aligned jet propagation and medium flow?

Motivated by the recent observation that the ridge decreases with trigger particle angle ($\phi_s$) relative to the event plane, it is theorized that the ridge is formed by interplay between jet propagation and medium flow. Such interplay may produce asymmetry in the ridge azimuthal correlation at a fixed $\phi_s$. We present an analysis of this asymmetry from STAR data. We found an asymmetric ridge with maximum asymmetry at $\phi_s\approx45^{\circ}$ concurrent with a symmetric jet at all $\phi_s$.Comment: 2 pages, 2 figures, Quark Matter 200