Astrophysics and Astronomy Commons^™

The Meaning Of Wise Colours – I. The Galaxy And Its Satellites, Robert Nikutta, Nicholas Hunt-Walker, Maia M. Nenkova, Željko Ivezić, Moshe Elitzur

Physics and Astronomy Faculty Publications

Through matches with the Sloan Digital Sky Survey (SDSS) catalogue we identify the location of various families of astronomical objects in WISE colour space. We identify reliable indicators that separate Galactic/local from extragalactic sources and concentrate here on the objects in our Galaxy and its closest satellites. We develop colour and magnitude criteria that are based only on WISE data to select asymptotic giant branch (AGB) stars with circumstellar dust shells, and separate them into O-rich and C-rich classes. With these criteria we produce an all-sky map for the count ratio of the two populations. The map reveals differences between …

Measurement Of Longitudinal Spin Asymmetries For Weak Boson Production In Polarized Proton-Proton Collisions At Rhic, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer

Physics and Astronomy Faculty Publications

We report measurements of single- and double-spin asymmetries for W^± and Z/γ^∗ boson production in longitudinally polarized p+p collisions at √^S=510  GeV by the STAR experiment at RHIC. The asymmetries for W^± were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton’s polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05<x<0.2.

J/Ψ Production At Low PT In Au + Au And Cu + Cu Collisions At √SNn = 200 Gev With The Star Detector, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin

Physics and Astronomy Faculty Publications

The J/ψ p_T spectrum and nuclear modification factor (R_AA) are reported for p_T < 5 GeV/c and |y| < 1 from 0% to 60% central Au + Au and Cu + Cu collisions at √^SNN = 200 GeV at STAR. A significant suppression of p_T-integrated J/ψ production is observed in central Au + Au events. The Cu + Cu data are consistent with no suppression, although the precision is limited by the available statistics. R_AA in Au + Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with p_T. The data are compared to high-p_{T …}

Star Formation Quenching In High-Redshift Large-Scale Structure: Post-Starburst Galaxies In The Ci 1604 Supercluster At Z ~ 0.9, Po-Feng Wu, Roy R. Gal, Brian C. Lemaux, Dale D. Kocevski, Lori M. Lubin, Nicholas Rumbaugh, Gordon K. Squires

Physics and Astronomy Faculty Publications

The Cl 1604 supercluster at z ~ 0.9 is one of the most extensively studied high-redshift large-scale structures, with more than 500 spectroscopically confirmed members. It consists of eight clusters and groups, with members numbering from a dozen to nearly a hundred, providing a broad range of environments for investigating the large-scale environmental effects on galaxy evolution. Here we examine the properties of 48 post-starburst galaxies in Cl 1604, comparing them to other galaxy populations in the same supercluster. Incorporating photometry from ground-based optical and near-infrared imaging, along with Spitzer mid-infrared observations, we derive stellar masses for all Cl 1604 …

Ibex: The First Five Years (2009-2013), D. J. Mccomas, F. Allegrini, M. Bzowski, M. A. Dayeh, R. Demajistre, H. O. Funsten, S. A. Fuselier, M. Gruntman, Paul H. Janzen, M. A. Kubiak, H. Kucharek, E. Möbius, Daniel B. Reisenfeld, N. A. Schwadron, J. M. Sokol, M. Tokumaru

Physics and Astronomy Faculty Publications

The Interstellar Boundary Explorer (IBEX) returned its first five years of scientific observations from 2009 to 2013. In this study, we examine, validate, initially analyze, and provide to the broad scientific community this complete set of energetic neutral atom (ENA) observations for the first time. IBEX measures the fluxes of ENAs reaching 1 AU from sources in the outer heliosphere and most likely the very nearby interstellar space beyond the heliopause. The data, maps, and documentation provided in this study represent the fourth major release of the IBEX data, incorporate important improvements, and should be used for future studies and …

Nonperturbative Renormalization Of Overlap Quark Bilinears On 2+1-Flavor Domain Wall Fermion Configurations, Zhaofeng Liu, Ying Chen, Shao-Jing Dong, Michael Glatzmaier, Ming Gong, Anyi Li, Keh-Fei Liu, Yi-Bo Yang, Jian-Bo Zhang

Physics and Astronomy Faculty Publications

We present renormalization constants of overlap quark bilinear operators on 2+1-flavor domain wall fermion configurations. . . .

For the remainder of the abstract, please visit: http://dx.doi.org/10.1103/PhysRevD.90.034505

Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au+Au Collisions At Rhic, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer

Physics and Astronomy Faculty Publications

Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with …

Suppression Of Υ Production In D + Au And Au + Au Collisions At √SNn = 200 Gev, James K. Adkins, Renee Fatemi, Wolfgang Korsch, Suvarna Ramachandran, L. Adamczyk, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee

Physics and Astronomy Faculty Publications

We report measurements of Υ meson production in p + p, d + Au, and Au + Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au + Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Υ (1S + …

Candels+3d-Hst: Compact Sfgs At Z ~ 2-3, The Progenitors Of The First Quiescent Galaxies, G. Barro, S. M. Faber, P. G. Pérez-González, C. Pacifici, J. R. Trump, D. C. Koo, S. Wuyts, Y. Guo, E. Bell, A. Dekel, L. Porter, J. Primack, H. Ferguson, M. L. N. Ashby, K. Caputi, D. Ceverino, D. Croton, G. G. Fazio, M. Giavalisco, L. Hsu, Dalibor D. Kocevski, A. Koekemoer, P. Kurcynski, P. Kollipara, J. Lee, D. H. Mcintosh, E. Mcgrath, C. Moody, R. Somerville, C. Papovich, M. Salvato, P. Santini, T. Tal, A. Van Der Wel, C. C. Williams, S. P. Willner, A. Zolotov

Physics and Astronomy Faculty Publications

We analyze the star-forming and structural properties of 45 massive (log(M/M _☉) >10) compact star-forming galaxies (SFGs) at 2 < z < 3 to explore whether they are progenitors of compact quiescent galaxies at z ~ 2. The optical/NIR and far-IR Spitzer/Herschel colors indicate that most compact SFGs are heavily obscured. Nearly half (47%) host an X-ray-bright active galactic nucleus (AGN). In contrast, only about 10% of other massive galaxies at that time host AGNs. Compact SFGs have centrally concentrated light profiles and spheroidal morphologies similar to quiescent galaxies and are thus strikingly different from other SFGs, which typically are disk-like and sometimes clumpy or irregular. Most compact …

The Violent Youth Of Bright And Massive Cluster Galaxies And Their Maturation Over 7 Billion Years, B. Ascaso, B. C. Lemaux, L. M. Lubin, R. R. Gal, Dale D. Kocevski, N. Rumbaugh, G. Squires

Physics and Astronomy Faculty Publications

In this study, we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift (z ∼ 0.9), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift (z ∼ 0.1) counterparts drawn from the MCXC meta-catalogue, supplemented by Sloan Digital Sky Survey imaging and spectroscopy. We observed striking differences in the morphological, colour, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broad-band colours, properties largely absent amongst …

The Gentle Growth Of Galaxies At High Redshifts In Overdense Environments, Emilio Romano-Díaz, Isaac Shlosman, Jun-Hwan Choi, Raphael Sadoun

Physics and Astronomy Faculty Publications

We have explored prevailing modes of galaxy growth for redshifts z ~ 6-14, comparing substantially overdense and normal regions of the universe, using high-resolution zoom-in cosmological simulations. Such rare overdense regions have been projected to host high-z quasars. We demonstrate that galaxies in such environments grow predominantly by a smooth accretion from cosmological filaments which dominates the mass input from major, intermediate, and minor mergers. We find that by z ~ 6, the accumulated galaxy mass fraction from mergers falls short by a factor of 10 of the cumulative accretion mass for galaxies in the overdense regions, and by …

Different Response Of Transport And Magnetic Properties Of Bairo3 To Chemical And Physical Pressure, M. A. Laguna-Marco, G. Fabbris, N. M. Souza-Neto, S. Chikara, J. S. Schilling, Gang Cao, D. Haskel

Physics and Astronomy Faculty Publications

A combination of x-ray absorption, x-ray-diffraction, and transport measurements at high pressure is used to investigate the interplay between the electronic properties of Ir 5d states and lattice degrees of freedom in the weakly ferromagnetic insulator BaIrO₃. Although the Ir 5d local magnetic moment is highly stable against lattice compression, remaining nearly unperturbed to at least 30 GPa, the weak ferromagnetism (net ordered moment) is quickly quenched by 4.5 GPa (3% volume reduction). Under chemical pressure, where Sr is substituted for the larger Ba in BaIrO₃, the local magnetic moment on Ir remains stable, …

Casimir Energy Of Smooth Compact Surfaces, Joseph P. Straley, Eugene B. Kolomeisky

Physics and Astronomy Faculty Publications

We discuss the formalism of Balian and Duplantier [Balian and Duplantier, Ann. Phys. (NY) 104, 300 (1977); Balian and Duplantier, Ann. Phys. (NY) 112, 165 (1978)] for the calculation of the Casimir energy for an arbitrary smooth compact surface and use it to give some examples: a finite cylinder with hemispherical caps, a torus, an ellipsoid of revolution, a cube with rounded corners and edges, and a drum made of disks and part of a torus. We propose a model function that approximately captures the shape dependence of the Casimir energy.

Orbital-Dependent Polaron Formation In The Relativistic Mott Insulator Sr2Iro4, C. H. Sohn, Min-Cheol Lee, H. J. Park, Kyung Joo Noh, H. K. Yoo, S. J. Moon, K. W. Kim, T. F. Qi, Gang Cao, Deok-Yong Cho, T. W. Noh

Physics and Astronomy Faculty Publications

We use optical spectroscopy to investigate the electron-phonon interaction in Sr₂IrO₄, a well-known 5d transition metal oxide with spin-orbit entangled states. The temperature evolution in the optical spectra is well described by the Fröhlich polaron model, indicating a large electron-phonon interaction. We further find that electrons in different orbitals selectively couple with different phonon modes. While J_eff = 3/2 holes do not seem to couple with any phonons, J_eff = 1/2 and 3z²−r² electrons mainly couple with in-plane and out-of-plane Ir-O bending modes, respectively. The symmetries of the …

Measurement Of The Target-Normal Single-Spin Asymmetry In Deep-Inelastic Scattering From The Reaction 3He↑(E,E′)X, K. Allada, C. Dutta, A. Kolarkar, Wolfgang Korsch, J. Katich, X. Qian, Y. X. Zhao, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted

Physics and Astronomy Faculty Publications

We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction ³He^↑(e,e′)X on a polarized ³He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7<W<2.9 GeV, 1.0<Q²<4.0 GeV² and 0.16<x<6.5. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-³He cross-section ratios. The measured neutron asymmetries are negative with an average value of (−1.09±0.38)×10⁻² for invariant mass W>2 …

Local Density Of States Study Of A Spin-Orbit-Coupling Induced Mott Insulator Sr2Iro4, Jixia Dai, Eduardo Calleja, Gang Cao, Kyle Mcelroy

Physics and Astronomy Faculty Publications

We present scanning tunneling microscopy and spectroscopy experiments on the novel J_eff=1/2 Mott insulator Sr₂IrO₄. Local density of states (LDOS) measurements show an intrinsic insulating gap of 620 meV that is asymmetric about the Fermi level and is larger than previously reported values. The size of this gap suggests that Sr₂IrO₄ is likely a Mott rather than Slater insulator. In addition, we found a small number of native defects which create in-gap spectral weight. Atomically resolved LDOS measurements on and off the defects show that this energy gap is quite fragile. …

Dielectron Mass Spectra From Au+Au Collisions At √SNn<=200  Gev, J. Kevin Adkins, Renee Fatemi, Wolfgang Korsch, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer

Physics and Astronomy Faculty Publications

We report the STAR measurements of dielectron (e⁺e⁻) production at midrapidity (|y_ee|^S_NN=200  GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30–0.76 (ρ-like), 0.76–0.80 (ω-like), and 0.98–1.05 (ϕ-like)   GeV/c². The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined …

The Inside-Out Growth Of The Most Massive Galaxies At 0.3 < Z < 0.9, Lei Bai, H. K. C. Yee, Renbin Yan, Eve Lee, David G. Gilbank, E. Ellingson, L. F. Barrientos, M. D. Gladders, B. C. Hsieh, I. H. Li

Physics and Astronomy Faculty Publications

We study the surface brightness profiles of a sample of brightest cluster galaxies (BCGs) with 0.3 < z < 0.9.

For the remainder of the abstract, please download this article or visit https://doi.org/10.1088/0004-637X/789/2/134

Optical-Faint, Far-Infrared-Bright Herschel Sources In The Candels Fields: Ultra-Luminous Infrared Galaxies At Z > 1 And The Effect Of Source Blending, Haojing Yan, Mauro Stefanon, Zhiyuan Ma, S. P. Willner, Rachel Somerville, Matthew L.N. Ashby, Romeel Davé, Pablo G. Pérez-González, Antonio Cava, Tommy Wiklind, Dale D. Kocevski, Marc Rafelski, Jeyhan Kartaltepe, Asantha Cooray, Anton M. Koekemoer, Norman A. Grogin

Physics and Astronomy Faculty Publications

The Herschel very wide field surveys have charted hundreds of square degrees in multiple far-IR (FIR) bands. While the Sloan Digital Sky Survey (SDSS) is currently the best resource for optical counterpart identifications over such wide areas, it does not detect a large number of Herschel FIR sources and leaves their nature undetermined. As a test case, we studied seven "SDSS-invisible," very bright 250 μm sources (S ₂₅₀ > 55 mJy) in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey fields where we have a rich multi-wavelength data set. We took a new approach to decompose the FIR sources, using …

Type Ia Supernova Rate Measurements To Redshift 2.5 From Candels: Searching For Prompt Explosions In The Early Universe, Steven A. Rodney, Adam G. Riess, Louis-Gregory Strolger, Tomas Dahlen, Or Graur, Stefano Casertano, Mark E. Dickinson, Henry C. Ferguson, Peter Garnavich, Brian Hayden, Saurabh W. Jha, David O. Jones, Robert P. Kirshner, Anton M. Koekemoer, Curtis Mccully, Bahram Mobasher, Brandon Patel, Benjamin J. Weiner, S. Bradley Cenko, Kelsey I. Clubb, Michael Cooper, Alexei V. Filippenko, Teddy F. Frederiksen, Jens Hjorth, Bruno Leibundgut, Thomas Matheson, Hooshang Nayyeri, Kyle Penner, Jonathan Trump, Jeffrey M. Silverman, Vivian U, K. Azalee Bostroem, Peter Challis, Abhijith Rajan, Schuyler Wolff, S. M. Faber, Norman A. Grogin, Dale D. Kocevski

Physics and Astronomy Faculty Publications

The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope (HST) that surveyed a total area of ~0.25 deg² with ~900 HST orbits spread across five fields over three years. . . .

For the remainder of the abstract, please visit:

http://dx.doi.org/10.1088/0004-6256/148/1/13

Radiative Cooling Ii: Effects Of Density And Metallicity, Ye Wang, Gary J. Ferland, Matt Lykins, R. L. Porter, Peter A. M. Van Hoof, R. J. R. Williams

Physics and Astronomy Faculty Publications

This work follows Lykins et al. discussion of classic plasma cooling function at low density and solar metallicity. Here, we focus on how the cooling function changes over a wide range of density (n_H <10¹² cm⁻³) and metallicity (Z < 30 Z_⊙). We find that high densities enhance the ionization of elements such as hydrogen and helium until they reach local thermodynamic equilibrium. By charge transfer, the metallicity changes the ionization of hydrogen when it is partially ionized. We describe the total cooling function as a sum of four parts: those due to H&He, the heavy …

Subaru Spectroscopy And Spectral Modeling Of Cygnus A, Matthew J. Merlo, Erik S. Perlman, Robert Nikutta, Christopher Packham, Moshe Elitzur, Masatoshi Imanishi, N. A. Levenson, James T. Radomski, Itziar Aretxaga

Physics and Astronomy Faculty Publications

We present high angular resolution (~0.''5) MIR spectra of the powerful radio galaxy, Cygnus A (Cyg A), obtained with the Subaru telescope. The overall shape of the spectra agree with previous high angular resolution MIR observations, as well as previous Spitzer spectra. Our spectra, both on and off nucleus, show a deep silicate absorption feature. The absorption feature can be modeled with a blackbody obscured by cold dust or a clumpy torus. The deep silicate feature is best fit by a simple model of a screened blackbody, suggesting that foreground absorption plays a significant, if not dominant, role in shaping …

On The Observability Of Optically Thin Coronal Hyperfine Structure Lines, Marios Chatzikos, Gary J. Ferland, R. J. R. Williams, A. C. Fabian

Physics and Astronomy Faculty Publications

We present CLOUDY calculations for the intensity of coronal hyperfine lines in various environments. We model indirect collisional and radiative transitions, and quantify the collisionally excited line emissivity in the density-temperature phase space. As an observational aid, we also express the emissivity in units of that in the 0.4-0.7 keV band. For most hyperfine lines, knowledge of the X-ray surface brightness and the plasma temperature is sufficient for rough estimates. We find that the radiation fields of both Perseus A and Virgo A can enhance the populations of highly ionized species within 1 kpc. They can also enhance line emissivity …

Investigating Evidence For Different Black Hole Accretion Modes Since Redshift Z ∼ 1, A. Georgakakis, P. G. Pérez-González, N. Fanidakis, M. Salvato, J. Aird, H. Messias, J. M. Lotz, G. Barro, Li-Ting Hsu, K. Nandra, D. Rosario, M. C. Cooper, Dalibor D. Kocevski, J. A. Newman

Physics and Astronomy Faculty Publications

Chandra data in the COSMOS, AEGIS-XD and 4 Ms Chandra Deep Field South are combined with multiwavelength photometry available in those fields to determine the rest-frame U − V versus V − J colours of X-ray AGN hosts in the redshift intervals 0.1 < z < 0.6 (mean z¯=0.40) and 0.6 < z < 1.2 (mean z¯=0.85). This combination of colours provides an effective and least model-dependent means of separating quiescent from star-forming, including dust reddened, galaxies. Morphological information emphasizes differences between AGN populations split by theirU − V versus V − J colours. AGN in quiescent galaxies consist almost exclusively of bulges, while star-forming hosts are equally split between early- and late-type hosts. The position of AGN hosts on the U − V versusV − J diagram is then used to set limits on the accretion density of the …

Event-Plane-Dependent Dihadron Correlations With Harmonic VN Subtraction In Au + Au Collisions At √SNn=200 Gev, H Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, C. D. Anson, D. Arkhipkin, G. S. Averichev, Renee H. Fatemi, Robert G. Fersch, Wolfgang Korsch, G. Webb, Wayne Otto Witzke

Physics and Astronomy Faculty Publications

STAR measurements of dihadron azimuthal correlations (Δϕ) are reported in midcentral (20–60%) Au + Au collisions at √^sNN = 200 GeV as a function of the trigger particle's azimuthal angle relative to the event plane, ϕ_s = |ϕ_t − ^ψEP |. The elliptic (^v2), triangular (^v3), and quadratic (^v4) flow harmonic backgrounds are subtracted using the zero yield at minimum (ZYAM) method. The results are compared to minimum-bias d + Au collisions. It is found that a finite near-side (|Δϕ| < π/2) long-range pseudorapidity correlation (ridge) is present in the in-plane direction (ϕ_s∼0). The …

Ds/Cft At Uniform Energy Density And A De Sitter “Bluewall”, Diptarka Das, Sumit R. Das, K. Narayan

Physics and Astronomy Faculty Publications

We describe a class of spacetimes that are asymptotically de Sitter in the Poincare slicing. Assuming that a dS/CFT correspondence exists, we argue that these are gravity duals to a CFT on a circle leading to uniform energy-momentum density, and are equivalent to an analytic continuation of the Euclidean AdS black brane. These are solutions with a complex parameter which then gives a real energy-momentum density. We also discuss a related solution with the parameter continued to a real number, which we refer to as a de Sitter “bluewall”. This spacetime has two asymptotic de Sitter universes and Cauchy horizons …

Single Spin Asymmetries Of Inclusive Hadrons Produced In Electron Scattering From A Transversely Polarized 3He Target, K. Allada, Y. X. Zhao, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted, A. Camsonne, C. Dutta, Ameya Suresh Kolarkar, Wolfgang Korsch

Physics and Astronomy Faculty Publications

We report the first measurement of target single spin asymmetries (A_N) in the inclusive hadron production reaction, e+³He^↑→h+X, using a transversely polarized ³He target. The experiment was conducted at Jefferson Lab in Hall A using a 5.9-GeV electron beam. Three types of hadrons (π^±, K^±, and proton) were detected in the transverse hadron momentum range 0.54 <p_T< 0.74 GeV/c. The range of x_F for pions was −0.29 <x_F< −0.23 and for kaons was −0.25 <x_F< −0.18. The observed asymmetry strongly depends on the type of hadron. A positive asymmetry is observed for π⁺ and K⁺. A negative asymmetry is observed for π⁻. The …

Transit Timing Analysis In The Hat-P-32 System, M. Seeliger, D. P. Dimitrov, D. Kjurkchieva, M. Mallonn, M. Fernandez, M. Kitze, V. Casanova, G. Maciejewski, J. M. Ohlert, J. G. Schmidt, A. Pannicke, D. Puchalski, E. Gogus, T. Guver, S. Bilir, T. Ak, M. M. Hohle, T. O.B. Schmidt, R. Errmann, E.L.N. Jensen, D. H. Cohen, Laurence A. Marschall, G. Saral, I. Bernt, E. Derman, C. Galan, R. Neuhauser

Physics and Astronomy Faculty Publications

We present the results of 45 transit observations obtained for the transiting exoplanet HATP- 32b. The transits have been observed using several telescopes mainly throughout the YETI (Young Exoplanet Transit Initiative) network. In 25 cases, complete transit light curves with a timing precision better than 1.4 min have been obtained. These light curves have been used to refine the system properties, namely inclination i, planet-to-star radius ratio Rp/Rs, and the ratio between the semimajor axis and the stellar radius a/Rs. First analyses by Hartman et al. suggests the existence of a second planet in the system, thus we tried to …

Jet-Hadron Correlations In √SNn=200 Gev P+P And Central Au+Au Collisions, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, Renee H. Fatemi, Suvarna Ramachandran, G. Webb

Physics and Astronomy Faculty Publications

Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √^sNN=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (p^assoc_T) and enhanced at low p^assoc_T in 0%–20% central …

Evolution Of Broad-Line Emission From Active Galactic Nuclei, Moshe Elitzur, Luis C. Ho, Jonathan R. Trump

Physics and Astronomy Faculty Publications

Apart from viewing-dependent obscuration, intrinsic broad-line emission from active galactic nuclei (AGN) follows an evolutionary sequence: type 1 → 1.2/1.5 → 1.8/1.9 → 2 as the accretion rate on to the central black hole is decreasing. This spectral evolution is controlled, at least in part, by the parameter L_bol/M^2/3, where L_bol is the AGN bolometric luminosity and M is the black hole mass. Both this dependence and the double-peaked profiles that emerge along the sequence arise naturally in the disc-wind scenario for the AGN broad-line region.