Astrophysics and Astronomy Commons^™

Measurement Of The Scattering Cross Section Of Slow Neutrons On Liquid Parahydrogen From Neutron Transmission, K. B. Grammer, R. Alarcon, L. Barrón-Palos, D. Blyth, J. D. Bowman, J. Calarco, Christopher Crawford, K. Craycroft, D. Evans, N. Fomin, J. Fry, M. Gericke, R. C. Gillis, G. L. Greene, J. Hamblen, C. Hayes, S. Kucuker, R. Mahurin, M. Maldonado-Velázquez, E. Martin, M. Mccrea, P. E. Mueller, M. Musgrave, H. Nann, S. I. Penttilä, W. M. Snow, Z. Tang, W. S. Wilburn

Physics and Astronomy Faculty Publications

Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many-body physics. . . .

The remainder of this abstract can be read at:

http://dx.doi.org/10.1103/PhysRevB.91.180301

Nuclear Parton Distributions And The Drell-Yan Reaction, S. A. Kulagin, Roberto Petti

Faculty Publications

We discuss the nuclear parton distribution functions on the basis of our recently developed semi-microscopic model, which takes into account a number of nuclear effects including Fermi motion and nuclear binding, nuclear meson-exchange currents and off-shell corrections to bound nucleon distributions as well as nuclear shadowing effect. We also discuss application to the nuclear Drell-Yan process and compare our predictions with data from the E772 and E866 experiments.

The Role Of Bulge Formation In The Homogenization Of Stellar Populations At Z ~ 2 As Revealed By Internal Color Dispersion In Candels, Steven Boada, V. Tilvi, R. F. Quadri, M. Hilton, S. Finkelstein, Yicheng Guo, N. Bond, C. Conselice, A. Dekel, H. Ferguson, M. Giavalisco, N. A. Grogin, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo

Physics and Astronomy Faculty Publications

We use data from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey to study how the spatial variation in the stellar populations of galaxies relates to the formation of galaxies at 1.5 < z < 3.5. We use the internal color dispersion (ICD), measured between the rest-frame UV and optical bands, which is sensitive to age (and dust attenuation) variations in stellar populations. The ICD shows a relation with the stellar masses and morphologies of the galaxies. Galaxies with the largest variation in their stellar populations as evidenced by high ICD have disk-dominated morphologies (with Sérsic indexes M/M_⊙) < 11. There is a marked decrease in the ICD as the stellar mass and/or the Sérsic index increases. By studying the relations between the ICD and other galaxy properties including size, total color, star formation rate, and dust attenuation, we conclude that the largest variations in stellar populations occur in galaxies where the light from newly, high star-forming clumps contrasts older stellar disk populations. This phase reaches a peak for galaxies only with a specific stellar mass range, 10 < log(M/M_⊙) < 11, and prior to the formation of a substantial bulge/spheroid. In contrast, galaxies at higher or lower stellar masses and/or higher Sérsic index (n > 2) show reduced ICD values, implying a greater homogeneity of their stellar populations. This indicates that if a galaxy is to have a quiescent bulge along with a star-forming disk, typical of Hubble sequence galaxies, this is most common for stellar masses 10 < log(M/M_⊙) < 11 and when the bulge component remains relatively small (n > 2).

The Differences In The Torus Geometry Between Hidden And Non-Hidden Broad Line Active Galactic Nuclei, Kohei Ichikawa, Christopher Packham, Cristina Ramos Almeida, Andrés Asensio Ramos, Almudena Alonso-Herrero, Omaira González-Martín, Enrique Lopez-Rodriguez, Yoshihiro Ueda, Tanio Díaz-Santos, Moshe Elitzur, Sebastian F. Hönig, Masatoshi Imanishi, Nancy A. Levenson, Rachel E. Mason, Eric S. Perlman, Crystal D. Alsip

Physics and Astronomy Faculty Publications

We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGNs) with clumpy torus models. We compiled high spatial resolution (~0.3–0.7 arcsec) mid-IR (MIR) N-band spectroscopy, Q-band imaging, and nuclear near- and MIR photometry from the literature. Combining these nuclear near- and MIR observations, far-IR photometry, and clumpy torus models enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties: type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without …

Gravitational Wave Background In The Quasi-Steady State Cosmology, Sree Ram Valluri, Sayantan Auddy, J V. Narlikar, S V. Dhurandhar, R G. Vishwakarma

Physics and Astronomy Publications

This paper calculates the expected gravitational wave background (GWB) in the quasi-steady state cosmology (QSSC). The principal sources of gravitational waves in the QSSC are the mini-creation events (MCE). With suitable assumptions the GWB can be computed both numerically and with analytical methods. It is argued that the GWB in QSSC differs from that predicted for the standard cosmology and a future technology of detectors will be able to decide between the two predictions. We also derive a formula for the flux density of a typical extragalactic source of gravitational waves.

Corrigendum To “Suppression Of Υ Production In D + Au And Au + Au Collisions At √SNn = 200 Gev” [Phys. Lett. B 735 (2014) 127–137], James K. Adkins, Renee Fatemi, Wolfgang Korsch, Suvarna Ramachandran, 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

No abstract provided.

Zfourge/Candels: On The Evolution Of M* Galaxy Progenitors From Z=3 To 0.5*, C. Papovich, I. Labbé, R. Quadri, V. Tilvi, P. Behroozi, E. F. Bell, K. Glazebrook, L. Spitler, C. M.S. Straatman, K.-V. Tran, M. Cowley, R. Davé, A. Dekel, M. Dickinson, H. C. Ferguson, S. L. Finkelstein, E. Gawiser, H. Inami, S. M. Faber, G. G. Kacprzak, L. Kawinwanichakij, Dale D. Kocevski, A. Koekemoer, D. C. Koo, P. Kurczynski, J. M. Lotz, Y. Lu, R. A. Lucas, D. Mcintosh, N. Mehrtens, B. Mobasher, A. Monson, G. Morrison, T. Nanayakkara, S. E. Persson, B. Salmon, R. Simons, A. Tomczak, P. Van Dokkum, B. Weiner, S. P. Willner

Physics and Astronomy Faculty Publications

Galaxies with stellar masses near M* contain the majority of stellar mass in the universe, and are therefore of special interest in the study of galaxy evolution. The Milky Way (MW) and Andromeda (M31) have present-day stellar masses near M*, at 5 × 10¹⁰ M _☉ (defined here to be MW-mass) and 10¹¹ M _☉ (defined to be M31-mass). We study the typical progenitors of these galaxies using the FOURSTAR Galaxy Evolution Survey (ZFOURGE). ZFOURGE is a deep medium-band near-IR imaging survey, which is sensitive to the progenitors of these galaxies out to z ~ 3. …

Effect Of Event Selection On Jetlike Correlation Measurement In D+Au Collisions At √SNn=200 Gev, James K. Adkins, Renee H. Fatemi, Suvarna Ramachandran, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev

Physics and Astronomy Faculty Publications

Dihadron correlations are analyzed in √^sNN = 200 GeV d + Au collisions classified by forward charged particle multiplicity and zero-degree neutral energy in the Au-beam direction. It is found that the jetlike correlated yield increases with the event multiplicity. After taking into account this dependence, the non-jet contribution on the away side is minimal, leaving little room for a back-to-back ridge in these collisions.

Gravitational-Wave Mediated Preheating, Stephon Alexander, Sam Cormack, Antonino Marcianò, Nicolás Yunes

Dartmouth Scholarship

We propose a new preheating mechanism through the coupling of the gravitational field to both the inflaton and matter fields, without direct inflaton–matter couplings. The inflaton transfers power to the matter fields through interactions with gravitational waves, which are exponentially enhanced due to an inflation–graviton coupling. One such coupling is the product of the inflaton to the Pontryagin density, as in dynamical Chern–Simons gravity. The energy scales involved are constrained by requiring that preheating happens fast during matter domination.

Holographic Calculations Of Euclidean Wilson Loop Correlator In Euclidean Anti-De Sitter Space, Sannah Ziama

Physics and Astronomy Faculty Publications

The correlation functions of two or more Euclidean Wilson loops of various shapes in Euclidean anti-de Sitter space are computed by considering the minimal area surfaces connecting the loops. The surfaces are parametrized by Riemann theta functions associated with genus three hyperelliptic Riemann surfaces. In the case of two loops, the distance L by which they are separated can be adjusted by continuously varying a specific branch point of the auxiliary Riemann surface. When L is much larger than the characteristic size of the loops, then the loops are approximately regarded as local operators and their correlator as the correlator …

Core-Collapse Supernovae Overview With Swift Collaboration, Kiranjyot Gill, Michele Zanolin, Marek Szczepańczyk

Publications

The Core-Collapse supernovae (CCSNe) mark the dynamic and explosive end of the lives of massive stars. The mysterious mechanism, primarily focused with the shock revival phase, behind CCSNe explosions could be explained by detecting the corresponding gravitational wave (GW) emissions by the laser interferometer gravitational wave observatory, LIGO. GWs are extremely hard to detect because they are weak signals in a floor of instrument noise. Optical observations of CCSNe are already used in coincidence with LIGO data, as a hint of the times where to search for the emission of GWs. More of these hints would be very helpful. For …

Elastic Waves Along A Fracture Intersection, Bradley C. Abell

Open Access Dissertations

Fractures and fracture networks play a significant role in the subsurface hydraulic connectivity within the Earth. While a significant amount of research has been performed on the seismic response of single fractures and sets of fractures, few studies have examined the effect of fracture intersections on elastic wave propagation. Intersections play a key role in the connectivity of a fracture network that ultimately affects the hydraulic integrity of a rock mass. In this dissertation two new types of coupled waves are examined that propagate along intersections. 1) A coupled wedge wave that propagates along a surface fracture with particle motion …

Meson Mass Decomposition From Lattice Qcd, Yi-Bo Yang, Ying Chen, Terrence Draper, Ming Gong, Keh-Fei Liu, Zhaofeng Liu, Jian-Ping Ma

Physics and Astronomy Faculty Publications

Hadron masses can be decomposed as a sum of quark and glue components that are defined through hadronic matrix elements of QCD operators. The components consist of the quark mass term, the quark energy term, the glue energy term, and the trace anomaly term. We calculate these components for mesons with lattice QCD for the first time. The calculation is carried out with overlap fermion on 2+1 flavor domain-wall fermion gauge configurations. We confirm that ~50% of the light pion mass comes from the quark mass term and ~10% comes from the quark energy; whereas, for the ρ meson, the …

Spitzer Space Telescope Measurements Of Dust Reverberation Lags In The Seyfert 1 Galaxy Ngc 6418, Billy Vazquez, Pasquale Galianni, Michael Richmond, Andrew Robinson, David J. Axon, Keith Horne, Triana Almeyda, Michael Fausnaugh, Bradley M. Peterson, Mark Bottorff, Jack Gallimore, Moshe Elitzur, Hagai Netzer, Thaisa Storchi-Bergmann, Alessandro Marconi, Alessandro Capetti, Dan Batcheldor, Catherine Buchanan, Giovanna Stirpe, Makoto Kishimoto, Christopher Packham, Enrique Perez, Clive Tadhunter, John Upton, Vincente Estrada-Carpenter

Physics and Astronomy Faculty Publications

We present results from a 15 month campaign of high-cadence (~3 days) mid-infrared Spitzer and optical (B and V) monitoring of the Seyfert 1 galaxy NGC 6418, with the objective of determining the characteristic size of the dusty torus in this active galactic nucleus (AGN). . . .

For the remainder of the abstract, please visit:

http://dx.doi.org/10.1088/0004-637X/801/2/127

Stellar Masses From The Candels Survey: The Goods-South And Uds Fields, P. Santini, H. C. Ferguson, A. Fontana, B. Mobasher, G. Barro, M. Castellano, S. L. Finkelstein, A. Grazian, L. T. Hsu, B. Lee, S.-K. Lee, J. Pforr, M. Salvato, T. Wiklind, S. Wuyts, O. Almaini, M. C. Cooper, A. Galametz, B. Weiner, R. Amorin, K. Boutsia, C. J. Conselice, T. Dahlen, M. E. Dickinson, M. Giavalisco, N. A. Grogin, Y. Guo, N. P. Hathi, Dale D. Kocevski, A. M. Koekemoer, P. Kurczynski, E. Merlin, A. Mortlock, J. A. Newman, D. Paris, L. Pentericci, R. Simons, S. P. Willner

Physics and Astronomy Faculty Publications

We present the public release of the stellar mass catalogs for the GOODS-S and UDS fields obtained using some of the deepest near-IR images available, achieved as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey project. We combine the effort from 10 different teams, who computed the stellar masses using the same photometry and the same redshifts. Each team adopted their preferred fitting code, assumptions, priors, and parameter grid. The combination of results using the same underlying stellar isochrones reduces the systematics associated with the fitting code and other choices. Thanks to the availability of different estimates, we …

Structural Distortion-Induced Magnetoelastic Locking In Sr2Iro4 Revealed Through Nonlinear Optical Harmonic Generation, D. H. Torchinsky, H. Chu, L. Zhao, N. B. Perkins, Y. Sizyuk, T. Qi, Gang Cao, D. Hsieh

Physics and Astronomy Faculty Publications

We report a global structural distortion in Sr₂IrO₄ using spatially resolved optical second and third harmonic generation rotational anisotropy measurements. A symmetry lowering from an I4₁/acd to I4₁/a space group is observed both above and below the Néel temperature that arises from a staggered tetragonal distortion of the oxygen octahedra. By studying an effective superexchange Hamiltonian that accounts for this lowered symmetry, we find that perfect locking between the octahedral rotation and magnetic moment canting angles can persist even in the presence of large noncubic local distortions. Our results …

Magnetic Response Of Aperiodic Wire Networks Based On Fibonacci Distortions Of Square Antidot Lattices, Barry Farmer, Vinayak Bhat, J. Sklenar, Eric Teipel, Justin Woods, J. B. Ketterson, J. Todd Hastings, Lance Delong

Physics and Astronomy Faculty Publications

The static and dynamic magnetic responses of patterned ferromagnetic thin films are uniquely altered in the case of aperiodic patterns that retain long-range order (e.g., quasicrystals). We have fabricated permalloy wire networks based on periodic square antidot lattices (ADLs) distorted according to an aperiodic Fibonacci sequence applied to two lattice translations, d₁  = 1618 nm and d₂  = 1000 nm. The wire segment thickness is fixed at t = 25 nm, and the width W varies from 80 to 510 nm. We measured the DC magnetization between room temperature and 5 K. Room-temperature, narrow-band (9.7 GHz) ferromagnetic resonance …

Room Temperature Optical Anisotropy Of A Lamno3 Thin-Film Induced By Ultra-Short Pulse Laser, Purevdorj Munkhbaatar, Zsolt Marton, Baatarchuluun Tsermaa, Woo Seok Choi, Sung S. Ambrose Seo, Jin Seung Kim, Naoyuki Nakagawa, Harold Y. Hwang, Ho Nyung Lee, Kim Myung-Whun

Physics and Astronomy Faculty Publications

We observed ultra-short laser pulse-induced transient optical anisotropy in a LaMnO₃ thin film. The anisotropy was induced by laser pulse irradiation with a fluence of less than 0.1 mJ/cm² at room temperature. The transmittance and reflectance showed strong dependence on the polarization states of the pulses. For parallel and perpendicular polarization states, there exists a difference of approximately 0.2% for transmittance and 0.05% for reflectance at 0.3 ps after the irradiation with a pump pulse, respectively. The theoretical values for optical transmittance and reflectance with an assumption of an orbital ordering of 3d e_g electrons in …

Advanced Ligo, J. Aasi, B. P. Abbott, T. D. Abbott, M. R. Abernathy, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

The Advanced LIGO gravitational wave detectors are second-generation instruments designed and built for the two LIGO observatories in Hanford, WA and Livingston, LA, USA. The two instruments are identical in design, and are specialized versions of a Michelson interferometer with 4 km long arms. As in Initial LIGO, Fabry–Perot cavities are used in the arms to increase the interaction time with a gravitational wave, and power recycling is used to increase the effective laser power. Signal recycling has been added in Advanced LIGO to improve the frequency response. In the most sensitive frequency region around 100 Hz, the design strain …

Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos

Presentations and Publications

Rainich-type conditions giving a spacetime “geometrization” of matter fields in general relativity are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and elec- tromagnetic fields. Necessary and sufficient conditions on a spacetime metric for it to be part of a perfect fluid solution of the Einstein equa- tions are given. Formulas for constructing the fluid from the metric are obtained. All fluid results hold for any spacetime dimension. Ge- ometric conditions on a metric which are necessary and sufficient for it to define a solution of the Einstein-scalar field equations and for- mulas for constructing …

Transitions To Valence-Bond Solid Order In A Honeycomb Lattice Antiferromagnet, Sumiran Pujari, Fabien Alet, Kedar Damle

Physics and Astronomy Faculty Publications

We use quantum Monte Carlo methods to study the ground-state phase diagram of a S=1/2 honeycomb lattice magnet in which a nearest-neighbor antiferromagnetic exchange J (favoring Néel order) competes with two different multispin interaction terms: a six-spin interaction Q₃ that favors columnar valence-bond solid (VBS) order, and a four-spin interaction Q₂ that favors staggered VBS order. For Q₃∼Q₂≫J, we establish that the competition between the two different VBS orders stabilizes Néel order in a large swath of the phase diagram even when J is the smallest energy scale in the …

Ward Identities For Transport In 2+1 Dimensions, Carlos Hoyos, Bom Soo Kim, Yaron Oz

Physics and Astronomy Faculty Publications

We use the Ward identities corresponding to general linear transformations, and derive relations between transport coefficients of (2 + 1)-dimensional systems. Our analysis includes relativistic and Galilean invariant systems, as well as systems without boost invariance such as Lifshitz theories. We consider translation invariant, as well as broken translation invariant cases, and include an external magnetic field. Our results agree with effective theory relations of incompressible Hall fluid, and with holographic calculations in a magnetically charged black hole background.

The Dust Geometric Distribution In Seyfert 1 And Seyfert 2 Galaxies, Isolated And In Interaction, S. Mendoza-Castrejón, D. Dultzin, Y. Krongold, J. J. González, Moshe Elitzur

Physics and Astronomy Faculty Publications

We analyse the mid-infrared (MIR) spectra of 39 Seyfert galaxies observed with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope. Our sample consists of 19 Seyfert type 1 (Sy1) galaxies, three intermediate Seyfert galaxies and 17 type 2 Seyfert (Sy2) galaxies in the nearby Universe. This sample was extracted from a larger sample, the circumgalactic environment of which was studied in a previous work by Dultzin-Hacyan et al., who found that Sy2 objects are in interaction more frequently than normal galaxies, while Sy1s are not. In this article, we study the silicate dust distribution that dominates the …

Charged-To-Neutral Correlation At Forward Rapidity In Au + Au Collisions At √SNn=200 Gev, 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

Event-by-event fluctuations of the multiplicities of inclusive charged particles and photons at forward rapidity in Au+Au collisions at √^S_NN=200 GeV have been studied. The dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidence of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as base lines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A nonzero statistically significant signal of dynamical fluctuations is …

The Galaxy Stellar Mass Function At 3.5 ≤ Z ≤ 7.5 In The Candels/Uds, Goods-South, And Hudf Fields, A. Grazian, A. Fontana, P. Santini, J. S. Dunlop, H. C. Ferguson, M. Castellano, R. Amorin, M. L. N. Ashby, G. Barro, P. Behroozi, K. Boutsia, K. I. Caputi, R. R. Chary, A. Dekel, M. E. Dickenson, S. M. Faber, G. G. Fazio, S. L. Finkelstein, A. Galametz, E. Giallongo, M. Giavalisco, N. A. Grogin, Y. Guo, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo, K.-S. Lee, Y. Lu, E. Merlin, B. Mobasher, M. Nonino, C. Paovich, D. Paris, L. Pentericci, N. Reddy, A. Renzini, B. Salmon, M. Salvato, V. Sommariva, M. Song, E. Vanzella

Physics and Astronomy Faculty Publications

Context. The form and evolution of the galaxy stellar mass function (GSMF) at high redshifts provide crucial information on star formation history and mass assembly in the young Universe, close or even prior to the epoch of reionization.

Aims. We used the unique combination of deep optical/near-infrared/mid-infrared imaging provided by HST, Spitzer, and the VLT in the CANDELS-UDS, GOODS-South, and HUDF fields to determine the GSMF over the redshift range 3.5 ≤ z ≤ 7.5.

Methods. We used the HST WFC3/IR near-infrared imaging from CANDELS and HUDF09, reaching H ≃ 27 − 28.5 over a total area of 369 …

Simulations Of Electron Trajectories In An Intense Laser Focus For Photon Scattering Experiments, Grayson J. Tarbox

Theses and Dissertations

An experiment currently underway at BYU is designed to test whether the size of a free electron wave packet affects the character of scattered radiation. Using a semi-classical argument wherein the wave packet is treated as a diffuse charge distribution, one would expect strong suppression of radiation in the direction perpendicular to the propagating field as the wave packet grows in size to be comparable to the wavelength of the driving field. If one disallows the interaction of the wave packet with itself, as is the case when calculating the rate of emission using QED, then regardless of size, the …

Radio Emission Toward Regions Of Massive Star Formation In The Large Magellanic Cloud, Adam Johanson

Theses and Dissertations

Four regions of massive star formation in the Large Magellanic Cloud (LMC) were observed for water and methanol maser emission and radio continuum emission. A total of 42 radio detections were made including 27 new radio sources, four water masers, and eight compact HII regions. The lobes of a radio galaxy were resolved for the first time, and the host galaxy identified. Seven sources were associated with known massive young stellar objects (YSOs). A multi-wavelength analysis using both the infrared and radio spectrum was used to characterize the sources. Mid-infrared color-magnitude selection criteria for ultracompact HII (UCHII) regions in the …

An Optical Spectroscopic Survey Of The Serpens Main Cluster: Evidence For Two Populations?, Kristen Erickson, Bruce Wilking, Michael Meyer, Jinyoung Kim, William Sherry, Matthew Freeman

Physics Faculty Works

We have completed an optical spectroscopic survey of a sample of candidate young stars in the Serpens Main star-forming region selected from deep B, V, and R band images. While infrared, X-ray, and optical surveys of the cloud have identified many young stellar objects (YSOs), these surveys have been biased toward particular stages of pre-main sequence evolution. We have obtained over 700 moderate resolution optical spectra that, when combined with published data, have led to the identification of 63 association members based on the presence of Hα in emission, lithium absorption, X-ray emission, a mid-infrared excess, and/or reflection nebulosity. Twelve …

Galaxy Zoo: Are Bars Responsible For The Feeding Of Active Galactic Nuclei At 0.2 < Z < 1.0?, Edmond Cheung, Jonathan R. Trump, E. Athanassoula, Steven P. Bamford, Eric F. Bell, A. Bosma, Carolin N. Cardamone, Kevin R. V. Casteels, S. M. Faber, Jerome J. Fang, Lucy F. Fortson, Dale D. Kocevski, David C. Koo, Seppo Laine, Chris Lintott, Karen L. Masters, Thomas Melvin, Robert C. Nichol, Kevin Schawinski, Brooke Simmons, Rebecca Smethurst, Kyle W. Willett

Physics and Astronomy Faculty Publications

We present a new study investigating whether active galactic nuclei (AGN) beyond the local universe are preferentially fed via large-scale bars. Our investigation combines data from Chandra and Galaxy Zoo: Hubble (GZH) in the AEGIS (All-wavelength Extended Groth strip International Survey), COSMOS (Cosmological Evolution Survey), and (Great Observatories Origins Deep Survey-South) GOODS-S surveys to create samples of face-on, disc galaxies at 0.2 < z < 1.0. We use a novel method to robustly compare a sample of 120 AGN host galaxies, defined to have 10⁴² erg s⁻¹ < L_X < 10⁴⁴ erg s⁻¹, with inactive control galaxies matched in stellar mass, rest-frame colour, size, Sérsic index, and redshift. Using the GZH bar classifications of each sample, we demonstrate that …

Deconstructing The Galaxy Stellar Mass Function With Ukidss And Candels: The Impact Of Colour, Structure And Environment, Alice Mortlock, Christopher J. Conselice, William G. Hartley, Ken Duncan, Caterina Lani, Jamie R. Owensworth, Omar Almaini, Arjen Van Der Wel, Kuang-Han Huang, Matthew L.N. Ashby, S. P. Willner, Adriano Fontana, Avishai Dekel, Anton M. Koekemoer, Harry C. Ferguson, Sandra M. Faber, Norman A. Grogin, Dale D. Kocevski

Physics and Astronomy Faculty Publications

We combine photometry from the Ultra Deep Survey (UDS), Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) UDS and CANDELS the Great Observatories Origins Deep Survey-South (GOODS-S) surveys to construct the galaxy stellar mass function probing both the low- and high-mass end accurately in the redshift range 0.3 < z < 3. The advantages of using a homogeneous concatenation of these data sets include meaningful measures of environment in the UDS, due to its large area (0.88 deg²), and the high-resolution deep imaging in CANDELS (H₁₆₀ > 26.0), affording us robust measures of structural parameters. We construct stellar mass functions for the entire sample as parametrized by the Schechter function, and find that there is a decline in the values of ϕ and of α with …