Astrophysics and Astronomy Commons^™

An Inventory Of The Stellar Initial Mass Function In Early-Type Galaxies, C. Tortora, Aaron J. Romanowsky, N. R. Napolitano

Faculty Publications

Given a flurry of recent claims for systematic variations in the stellar initial mass function (IMF), we carry out the first inventory of the observational evidence using different approaches. This includes literature results, as well as our own new findings from combined stellar population synthesis (SPS) and Jeans dynamical analyses of data on ~4500 early-type galaxies (ETGs) from the SPIDER project. We focus on the mass-to-light ratio mismatch relative to the Milky Way IMF, δIMF, correlated against the central stellar velocity dispersion, σsstarf. We find a strong correlation between δIMF and σsstarf, for a wide set of dark matter (DM) …

The Sluggs Survey: Wide-Field Stellar Kinematics Of Early-Type Galaxies, J. A. Arnold, Aaron J. Romanowsky, J. P. Brodie, D. A. Forbes, J. Strader, C. Foster, S. S. Kartha, N. Pastorello, V. Pota, C. Usher, K. A. Woodley

Faculty Publications

No abstract provided.

Mather Explains The Known And Unknown Universe, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

The Sluggs Survey: Kinematics For Over 2500 Globular Clusters In Twelve Early-Type Galaxies, V. Pota, D. A. Forbes, Aaron J. Romanowsky, J. P. Brodie, L. R. Spitler, J. Strader, C. Foster, J. A. Arnold, A. Benson, C. Blom, J. R. Hargis, K. L. Rhode, C. Usher

Faculty Publications

We present a spectrophotometric survey of 2522 extragalactic globular clusters (GCs) around 12 early-type galaxies, nine of which have not been published previously. Combining space-based and multicolour wide-field ground-based imaging, with spectra from the Keck/DEep Imaging Multi-Object Spectrograph (DEIMOS) instrument, we obtain an average of 160 GC radial velocities per galaxy, with a high-velocity precision of ∼15 km s−1 per GC. After studying the photometric properties of the GC systems, such as their spatial and colour distributions, we focus on the kinematics of metal-poor (blue) and metal-rich (red) GC subpopulations to an average distance of ∼8 effective radii from the …

Celestial Paleontology: The Legacy Of Dying Stars, Alexa Hodgson Hart

Electronic Theses and Dissertations

In their death throes, stars dole out their atmospheric material to the interstellar medium in dramatic stellar winds and spectacular explosions. The details of this profound metamorphosis, from star to remnant, play a key role in the next generation of star formation as well as the energetic and chemical evolution of galaxies and the universe as a whole. Dying stars are thought to be the source of all of the nuclei heavier than iron in the universe, as well as more complex molecules, such as carbon chains, which form the backbone of life as we know it.

High mass Wolf-Rayet …

Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson

Student Showcase

The distribution of spiral and bar galaxy inclination angles is expected to be uniform. However, analysis of several major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and interstellar medium (ISM) density distributions. The luminous mass component is integrated along a particular line …

Optimization Of Gold Nanoring Arrays For Biosensing In The Fiber-Optic Communication Window, Hao Jiang, Tingjie Li, Jun Yang, Silvia Mittler, Jayshri Sabarinathan

Physics and Astronomy Publications

To improve the limit of detection in a nanoplasmonic sensor system, the optical performance of the metal nanostructures should be optimized according to the best spectral window of the measurement instrument. We propose that the spectral window from 1460 to 1610 nm can potentially provide ultrahigh instrumental resolution for biosensing. We optimized gold nanoring arrays such that the extinction peak position is inside the proposed window, the extinction peak is sharp enough to track the peak shift with high resolution and the figure of merit (sensitivity/linewidth) of the array is optimized at the same time. The peak-sharpening effect of the …

A Biosensor Based On Periodic Arrays Of Gold Nanodisks Under Normal Transmission, Hao Jiang, Tingjie Li, Erden Ertorer, Jun Yang, Jayshri Sabarinathan, Silvia Mittler

Physics and Astronomy Publications

We present a biosensor based on periodic arrays of gold nanodisks patterned on top of a glass substrate. The sensor’s resonance wavelength, peak linewidth and figure of merit were studied both in experiments and in simulations. We analyzed the dependence of the sensor’s resolution on the inherent figure of merit of the sensor structure and the signal to noise ratio of the detection system. The best achieved refractive index resolution is 1.5×10-4 RIU and the detection limit on and antigen-antibody binding is better than 1 ng/mL.

Bright Radio Emission From An Ultraluminous Stellar-Mass Microquasar In M31, Matthew J. Middleton, James C. A. Miller-Jones, Sera Markoff, Rob Fender, Martin Henze, Natasha Hurley-Walker, Anna M. M. Scaife, Timorthy P. Roberts, Dominic Walton, John Carpenter, Jean-Pierre Macquart, Geoffrey C. Bower, Mark Gurwell, Wolfgang Pietsch, Frank Haberl, Jonathan Harris, Michael Daniel, Junayd Miah, Chris Done, John Morgan, Hugh Dickinson, Phil Charles, Vadim Burwitz, Massimo Della Valle, Michael Freyberg, Jochen Greiner, Margarita Hernanz, Dieter H. Hartmann, Despina Hatzidimitriou, Arno Riffeser, Gloria Sala, Stella Seitz, Pablo Reig, Arne Rau, Marina Orio, David Titterington, Keith Grainge

Publications

A subset of ultraluminous X-ray sources (those with luminosities < 10^40 erg s^-1)^1 are thought to be powered by the accretion of gas onto black holes with masses of ~5-20 M⊙, probably via an accretion disc. The X-ray and radio emission are coupled in such Galactic sources, with the radio emission originating in a relativistic jet thought to be launched from the innermost regions near the black hole4,5, with the most powerful emission occurring when the rate of infalling matter approaches a theoretical maximum (the Eddington limit). Only four such maximal sources are known in the Milky Way, and the absorption of soft X-rays in the interstellar medium precludes determining the causal sequence of events that leads to the ejection of the jet. Here we report radio and X-ray observations of a bright new X-ray source whose peak luminosity can exceed 1039 erg s^-1 in the nearby galaxy, M31. The radio luminosity is extremely high and shows variability on a timescale of tens of minutes, arguing that the source is highly compact and powered by accretion close to the Eddington limit onto a stellar mass black hole. Continued radio and X-ray monitoring of such sources should reveal the causal relationship between the accretion flow and the powerful jet emission.

Supersoft X-Rays Reveal A Classical Nova In The M31 Globular Cluster Bol 126, M. Henze, W. Pietsch, F. Haberl, M. Della Valle, A. Riffeser, G. Sala, D. Hatzidimitriou, F. Hofmann, Dieter H. Hartmann, J. Koppenhoefer

Publications

Context. Classical novae (CNe) represent the main class of supersoft X-ray sources (SSSs) in the central region of our neighbouring galaxy M 31. Only three confirmed novae and three SSSs have been discovered in globular clusters (GCs) of any galaxy so far, of which one nova and two SSSs (including the nova) were found in M 31 GCs. Aims. To study the SSS state of CNe we carried out a high-cadence X-ray monitoring of the M 31 central area with XMM-Newton and Chandra. This project is supplemented by regular optical monitoring programmes at various observatories. Methods. We analysed X-ray and …

Photometric Observations Of 782 Montefiore, 3842 Harlansmith, 5542 Moffatt, 6720 Gifu, And (19979) 1989 Vj, Xianming Han, Bin Li, Haibin Zhao, Wenjuan Liu, Luming Sun, Jingjing Shi, Shan Gao, Shufen Wang, Xiang Pan, Peng Jiang, Hongyan Zhou

Scholarship and Professional Work - LAS

Five solar system minor planets were measured photometrically between 2012 October and December using the SARA (Southeastern Association for Research in Astronomy) telescopes located in Kitt Peak National Observatory in USA and Cerro Tololo Inter-American Observatory in Chile. The following synodic periods were found: 782 Montefiore P = 4.0728 ± 0.0006 h; 3842 Harlansmith, P = 2.7938 ± 0.0005 h; 5542 Moffatt P = 5.187 ± 0.001 h; 6720 Gifu, P = 4.231 ± 0.001 h; and (19979) 1989 VJ, P = 7.568 ± 0.005 h.

Lightcurve Analysis Of Four Asteroids, Bin Li, Haibin Zhao, Xianming Han, Lina R. Annable, Eli M. Finkel, Orry R. Heffner, Adam W. Kidd, Bradley J. Magnetta, Tiffany M. Ramires, Frederick W. Rastede, Sean G. Sproston

Scholarship and Professional Work - LAS

From June 2011 through May 2012 May, photometric data for four asteroids were obtained using the Southeastern Association for Research in Astronomy (SARA) telescope located at the Kitt Peak National Observatory. The following synodic periods were found: 4808 Ballaero, P = 8.8976 ± 0.0007 h; 7750 McEwen, P = 27.82 ± 0.01 h; 11941 Archinal, P = 2.717 ±0.006 h; and (47035) 1998WS, P = 7.996 ± 0.001 h.

Rotation Periods Of 1660 Wood, 7173 Sepkoski, 12738 Satoshimiki, And (23233) 2000 Wm72, Xianming Han, Bin Li, Haibin Zhao

Scholarship and Professional Work - LAS

We present rotation periods of four asteroids: 1660 Wood, 7173 Sepkoski, 12738 Satoshimiki, and (23233) 2000 WM72. The observations were undertaken using the SARA (Southeastern Association for Research in Astronomy) South telescope, located in Cerro Tololo Inter-American Observatory in Chile, from 2011 December to 2012 April. The following synodic periods were found: 1660 Wood, P = 6.8088 ± 0.0002 h; 7173 Sepkoski, P = 2.44 ± 0.02 h; 12738 Satoshimiki, P = 8.708 ± 0.001 h; and (23233) 2000 WM72, P = 3.732 ± 0.003 h.

Photometric Observation Of 3024 Hainan, 3920 Aubignan, And 5951 Alicemonet, Bin Li, Haibin Zhao, Xianming Han, Wenjuan Liu, Luming Sun, Jingjing Shi, Shan Gao, Hongyan Zhou

Scholarship and Professional Work - LAS

Three minor planets were measured photometrically between 2012 September 4 and 21 using the SARA (Southeastern Association for Research in Astronomy) South telescope, located in Cerro Tololo Inter-American Observatory. The following synodic periods were found: 3024 Hainan, P = 11.785 ± 0.005 h; 3920 Aubignan, P = 4.4762 ± 0.0005 h; and 5951 Alicemonet, P = 3.8871 ± 0.0005 h.

Grb 091024a And The Nature Of Ultra-Long Gamma-Ray Bursts, F.J. Virgili, C.G. Mundell, V. Pal’Shin, C. Guidorzi, R. Margutti, A. Melandri, R. Harrison, S. Kobayashi, R. Chornock, A. Henden, Adria Updike, S.B. Cenko, N.R. Tanvir, I.A. Steele, A. Cucchiara, A. Gomboc, A. Levan, Z. Cano, C.J. Mottram, N.R. Clay, D. Bersier, D. KopaˇC, J. Japelj, A.V. Filippenko, W. Li, D. Svinkin, S. Golenetskii, D.H. Hartmann, P.A. Milne, G. Williams, P.T. O’Brien, D.B. Fox, E. Berger

Arts & Sciences Faculty Publications

We present a broadband study of gamma-ray burst (GRB) 091024A within the context of other ultra-long-duration GRBs. An unusually long burst detected by Konus–Wind (KW), Swift, and Fermi, GRB 091024A has prompt emission episodes covering ∼1300 s, accompanied by bright and highly structured optical emission captured by various rapid-response facilities, including the 2 m autonomous robotic Faulkes North and Liverpool Telescopes, KAIT, S-LOTIS, and the Sonoita Research Observatory.We also observed the burst with 8 and 10mclass telescopes and determine the redshift to be z = 1.0924 ± 0.0004. We find no correlation between the …

The Unusual Afterglow Of The Gamma-Ray Burst 100621a, J. Greiner, T. Krühler, M. Nardini, R. Filgas, A. Moin, C. De Breuck, F. Montenegro-Montes, A. Lundgren, S. Klose, P.M.J. Fonso, F. Bertoldi, J. Elliott, D.A. Kann, F. Knust, K. Menten, A. Nicuesa Guelbenzu, F. Olivares E., A. Rau, A. Rossi, P. Schady, S. Schmidl, G. Siringo, L. Spezzi, V. Sudilovsky, S.J. Tingay, Adria Updike, Z. Wang, A. Weiss, M. Wieringa, F. Wyrowski

Arts & Sciences Faculty Publications

Aims. With the afterglow of GRB 100621A being the brightest detected so far in X-rays, and superb GROND coverage in the optical/near-infrared during the first few hours, an observational verification of basic fireball predictions seemed possible. Methods. In order to constrain the broad-band spectral energy distribution of the afterglow of GRB 100621A, dedicated observations were performed in the optical/near-infrared with the 7-channel Gamma-Ray Burst Optical and Near-infrared Detector (GROND) at the 2.2mMPG/ESO telescope, in the sub-millimeter band with the large bolometer array LABOCA at APEX, and at radio frequencies with ATCA. Utilizing also Swift X-ray observations, we attempt an interpretation …

Semiclassical Partition Functions For Gravity With Cosmic Strings, Christopher L. Duston

Physics Faculty Publications

In this paper we describe an approach to construct semiclassical partition functions in gravity which are complete in the sense that they contain a complete description of the differentiable structures of the underlying 4-manifold. In addition, we find our construction naturally includes cosmic strings. We prove that the mass density of these strings uniquely specifies the topology of the leaves of a dimension 2 foliation, and conjecture that spacetime topology emerges as a result of the symmetry breaking of the fundamental fields. We discuss some possible applications of the partition functions in the fields of both quantum gravity and topological …

The Lismullin Enclosure:A Designed Ritual Space, Frank Prendergast

Book/Book Chapter

The discovery in 2007 of a prehistoric post-built enclosure at Lismullin, Co. Meath, during archaeological investigations in advance of the construction of the M3 motorway is, arguably, the most significant Irish archaeological discovery of recent times. This appendix summarises a commissioned specialist report on the spatial and archaeoastronomical features of the enclosure.

Contellation: Taurus, Gabriel Chaille

Natural Sciences Student Research Presentations

Using the constellation Taurus, the purpose of this project was to gain insight on how information is gathered about stars and what purpose that information serves.

Constellation: Perseus, Marci Holman

Natural Sciences Student Research Presentations

Using the constellation Perseus, the purpose of this project was to gain insight on how information is gathered about stars and what purpose that information serves. This is a project for the Natural Sciences Poster Session at Parkland College.

Dark Energy Interaction Models, H. Shojaei, D. Waters

Journal of the Arkansas Academy of Science

A specific interaction between dark energy and matter has been introduced in order to present possible solutions to the cosmic coincidence problem. We also compared the result of our differential equations with the experimental supernova data obtained by WMAP.

Carbon Monoxide Adsorption On Platinum-Osmium And Platinum-Ruthenium-Osmium Mixed Nanoparticles, Nicholas Dimakis, Nestor E. Navarro, Eugene S. Smotkin

Physics & Astronomy Faculty Publications

Density functional calculations (DFT) on carbon monoxide (CO) adsorbed on platinum, platinum-osmium, and platinum-ruthenium-osmium nanoclusters are used to elucidate changes on the adsorbate internal bond and the carbon-metal bond, as platinum is alloyed with osmium and ruthenium atoms. The relative strengths of the adsorbate internal bond and the carbon-metal bond upon alloying, which are related to the DFT calculated C–O and C–Pt stretching frequencies, respectively, cannot be explained by the traditional 5σ-donation/2π*-back-donation theoretical model. Using a modified π-attraction σ-repulsion mechanism, we ascribe the strength of the CO adsorbate internal bond to changes in the polarization of the adsorbate-substrate hybrid orbitals …

Massive Quiescent Disk Galaxies In The Candels Survey, Aurora Y. Kesseli

Honors Theses

We used data from the GOODS-S field of the CANDELS survey in order to confirm previous studies that found that large fractions of high-redshift galaxies (z ∼ 2) are disk-dominated (McGrath et al. 2008; van der Wel et al. 2011). In the GOODS-S field we selected out all the massive quiescent disk galaxies by imposing a mass limit of M > 10¹⁰M_⊙ and a redshift range of 0.5 ≤ z ≤ 2.5, and then choosing the quiescent red galaxies from a color-color plot. Once we had our sample, we did a qualitative visual classification of each galaxy and …

The X-Ray And Spectropolarimetric View Of Mass Loss And Transfer In Massive Binary Stars, Jamie Renae Lomax

Electronic Theses and Dissertations

The majority of massive stars are members of binary systems. In order to have a better understanding of their evolutionary pathways, the mass and angular momentum loss from massive binaries needs to be well understood. Self consistent explanations for their behavior need to be valid across many wavelength regimes in order to illuminate key phases of mass loss to completely determine how it affects their evolution. In this dissertation I present the results of X-ray and specropolarimetric studies on one Roche-lobe overflow binary (β Lyr) and two colliding wind binaries (V444 Cyg and WR 140).

In β Lyr a …

Modeling The X-Ray Light Curves Of Cygnus X-3 Possible Role Of The Jet, Osmi Vilhu, Diana Carina Hannikainen

Aerospace, Physics, and Space Science Faculty Publications

Context. We address the physics behind the soft X-ray light curve asymmetries in Cygnus X-3, a well-known microquasar. Aims. Observable eff ects of the jet close to the line-of-sight were investigated and interpreted within the frame of light curve physics. Methods. The path of a hypothetical imprint of the jet, advected by theWolf-Rayet-wind, was computed and its crossing with the line-of-sight during the binary orbit determined. We explored the possibility that physically this “imprint” is a formation of dense clumps triggered by jet bow shocks in the wind (“clumpy trail”). Models for X-ray continuum and emission line light curves were …

Azimuthal Anisotropy Of Π⁰ And Η Mesons In Au + Au Collisions At √Snn=200, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Marcus Hohlmann

Aerospace, Physics, and Space Science Faculty Publications

The azimuthal anisotropy coefficients v₂ and v₄ of π⁰ and η mesons are measured in Au + Au collisions at √sNN=200 GeV as a function of transverse momentum pT (1-14 GeV/c) and centrality. The extracted v₂ coefficients are found to be consistent between the two meson species over the measured pT range. The ratio of v₄/v₂² for π⁰ mesons is found to be independent of pT for 1-9 GeV/c, implying a lack of sensitivity of the ratio to the change of underlying physics with pT. Furthermore, the ratio of v₄/v₂² is systematically larger in central collisions, which may reflect the …

Accompanying Figures For "Rotation Periods Of Small Trojan Asteroids", Linda French

Scholarship

No abstract provided.

Search For Long-Lived Gravitational-Wave Transients Coincident With Long Gamma-Ray Bursts, J. Aasi, Daniel Bessis, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Malik Rakhmanov, Volker Quetschke, Joseph D. Romano, Robert Stone, Lappoon R. Tang, Cristina V. Torres

Physics & Astronomy Faculty Publications

Long gamma-ray bursts (GRBs) have been linked to extreme core-collapse supernovae from massive stars. Gravitational waves (GW) offer a probe of the physics behind long GRBs. We investigate models of long-lived (~10–1000 s) GW emission associated with the accretion disk of a collapsed star or with its protoneutron star remnant. Using data from LIGO’s fifth science run, and GRB triggers from the Swift experiment, we perform a search for unmodeled long-lived GW transients. Finding no evidence of GW emission, we place 90% confidence-level upper limits on the GW fluence at Earth from long GRBs for three waveforms inspired by a …

Scalar Polarization Operator In A Superfluid Medium, Sajib Kumar Barman

Open Access Theses & Dissertations

A QCD-inspired effective theory of fermions is considered to study superfluidity. We calculate the quark propagator in a theory with fermion-fermion condensate at finite density. In this theory color degrees of freedom are absent and the quark-quark interaction is modeled through a Yukawa interaction term. Since the diquark condensate is neutral, the system is a superfluid. To study the response of this superfluid to the scalar field propagation, we find the scalar polarization operator of the system.

Fuzzy Analysis Of School Dropouts And Their Life After, Florentin Smarandache, W.B. Vasantha Kandasamy, K. Amal, K. Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

In this book authors study and analyze the problem of school dropouts and their life after. The problems can by no means be analyzed by collecting the numerical data. For such data can only serve as information beyond that the data can be of no use, for the school dropouts suffer an environment change after becoming a school dropout. Thus the emotions of the school dropout; is technically involved. A school dropout can be a child labourer, a rag picker or a social miscreant or be in police custody or be in a rehabilitation home if he/she is a runaway. …