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Articles 1 - 30 of 37
Full-Text Articles in Physics
Sdss-Iv Manga – The Spatially Resolved Transition From Star Formation To Quiescence, Francesco Belfiore, Roberto Maiolino, Claudia Maraston, Eric Emsellem, Matthew A. Bershady, Karen L. Masters, Dmitry Bizyaev, Médéric Boquien, Joel R. Brownstein, Kevin Bundy, Aleksandar M. Diamond-Stanic, Niv Drory, Timothy M. Heckman, David R. Law, Olena Malanushenko, Audrey Oravetz, Kaike Pan, Alexandre Roman-Lopes, Daniel Thomas, Anne-Marie Weijmans, Kyle B. Westfall, Renbin Yan
Sdss-Iv Manga – The Spatially Resolved Transition From Star Formation To Quiescence, Francesco Belfiore, Roberto Maiolino, Claudia Maraston, Eric Emsellem, Matthew A. Bershady, Karen L. Masters, Dmitry Bizyaev, Médéric Boquien, Joel R. Brownstein, Kevin Bundy, Aleksandar M. Diamond-Stanic, Niv Drory, Timothy M. Heckman, David R. Law, Olena Malanushenko, Audrey Oravetz, Kaike Pan, Alexandre Roman-Lopes, Daniel Thomas, Anne-Marie Weijmans, Kyle B. Westfall, Renbin Yan
Physics and Astronomy Faculty Publications
Using spatially resolved spectroscopy from SDSS-IV MaNGA we have demonstrated that low ionization emission-line regions (LIERs) in local galaxies result from photoionization by hot evolved stars, not active galactic nuclei, hence tracing galactic region hosting old stellar population where, despite the presence of ionized gas, star formation is no longer occurring. LIERs are ubiquitous in both quiescent galaxies and in the central regions of galaxies where star formation takes place at larger radii. We refer to these two classes of galaxies as extended LIER (eLIER) and central LIER (cLIER) galaxies, respectively. cLIERs are late-type galaxies primarily spread across the green …
Sdss-Iv Manga: A Serendipitous Observation Of A Potential Gas Accretion Event, Edmond Cheung, David V. Stark, Song Huang, Kate H. R. Rubin, Lihwai Lin, Christy Tremonti, Kai Zhang, Renbin Yan, Dmitry Bizyaev, Médéric Boquien
Sdss-Iv Manga: A Serendipitous Observation Of A Potential Gas Accretion Event, Edmond Cheung, David V. Stark, Song Huang, Kate H. R. Rubin, Lihwai Lin, Christy Tremonti, Kai Zhang, Renbin Yan, Dmitry Bizyaev, Médéric Boquien
Physics and Astronomy Faculty Publications
The nature of warm, ionized gas outside of galaxies may illuminate several key galaxy evolutionary processes. A serendipitous observation by the MaNGA survey has revealed a large, asymmetric Hα complex with no optical counterpart that extends ≈8'' (≈6.3 kpc) beyond the effective radius of a dusty, starbursting galaxy. This Hα extension is approximately three times the effective radius of the host galaxy and displays a tail-like morphology. We analyze its gas-phase metallicities, gaseous kinematics, and emission-line ratios and discuss whether this Hα extension could be diffuse ionized gas, a gas accretion event, or something else. We find …
Sdss-Iv Manga Ifs Galaxy Survey—Survey Design, Execution, And Initial Data Quality, Renbin Yan, Kevin Bundy, David R. Law, Matthew A. Bershady, Brett Andrews, Brian Cherinka, Aleksandar M. Diamond-Stanic, Niv Drory, Nicholas Macdonald, José R. Sánchez-Gallego, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle B. Westfall, Kai Zhang, Alfonso Aragón-Salamanca, Francesco Belfiore, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Joel Brownstein, Michele Cappellari, Richard D'Souza, Eric Emsellem, Hai Fu, Patrick Gaulme, Mark T. Graham, Daniel Goddard, James E. Gunn, Paul Harding
Sdss-Iv Manga Ifs Galaxy Survey—Survey Design, Execution, And Initial Data Quality, Renbin Yan, Kevin Bundy, David R. Law, Matthew A. Bershady, Brett Andrews, Brian Cherinka, Aleksandar M. Diamond-Stanic, Niv Drory, Nicholas Macdonald, José R. Sánchez-Gallego, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle B. Westfall, Kai Zhang, Alfonso Aragón-Salamanca, Francesco Belfiore, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Joel Brownstein, Michele Cappellari, Richard D'Souza, Eric Emsellem, Hai Fu, Patrick Gaulme, Mark T. Graham, Daniel Goddard, James E. Gunn, Paul Harding
Physics and Astronomy Faculty Publications
The MaNGA Survey (Mapping Nearby Galaxies at Apache Point Observatory) is one of three core programs in the Sloan Digital Sky Survey IV. It is obtaining integral field spectroscopy for 10,000 nearby galaxies at a spectral resolution of R ~ 2000 from 3622 to 10354 Å. The design of the survey is driven by a set of science requirements on the precision of estimates of the following properties: star formation rate surface density, gas metallicity, stellar population age, metallicity, and abundance ratio, and their gradients; stellar and gas kinematics; and enclosed gravitational mass as a function of radius. We describe …
The Quenching Timescale And Quenching Rate Of Galaxies, Jianhui Lian, Renbin Yan, Kai Zhang, Xu Kong
The Quenching Timescale And Quenching Rate Of Galaxies, Jianhui Lian, Renbin Yan, Kai Zhang, Xu Kong
Physics and Astronomy Faculty Publications
The average star formation rate (SFR) in galaxies has been declining since the redshift of 2. A fraction of galaxies quench and become quiescent. We constrain two key properties of the quenching process: the quenching timescale and the quenching rate among galaxies. We achieve this by analyzing the galaxy number density profile in NUV−u color space and the distribution in NUV−u versus u − i color–color diagram with a simple toy-model framework. We focus on galaxies in three mass bins between 1010 and 1010.6 M ⊙. In the NUV−u versus u − i color–color …
Holographic Renormalization Of Einstein-Maxwell-Dilaton Theories, Bom Soo Kim
Holographic Renormalization Of Einstein-Maxwell-Dilaton Theories, Bom Soo Kim
Physics and Astronomy Faculty Publications
We generalize the boundary value problem with a mixed boundary condition that involves the gauge and scalar fields in the context of Einstein-Maxwell-Dilaton theories. In particular, the expectation value of the dual scalar operator can be a function of the expectation value of the current operator. The properties are prevalent in a fixed charge ensemble because the conserved charge is shared by both fields through the dilaton coupling, which is also responsible for non-Fermi liquid properties. We study the on-shell action and the stress energy tensor to note practical importances of the boundary value problem. In the presence of the …
The Intermediate-Line Region In Active Galactic Nuclei, T. P. Adhikari, A. Różańska, B. Czerny, K. Hryniewicz, Gary J. Ferland
The Intermediate-Line Region In Active Galactic Nuclei, T. P. Adhikari, A. Różańska, B. Czerny, K. Hryniewicz, Gary J. Ferland
Physics and Astronomy Faculty Publications
We show that the recently observed suppression of the gap between the broad-line region (BLR) and the narrow-line region (NLR) in some active galactic nuclei (AGNs) can be fully explained by an increase of the gas density in the emitting region. Our model predicts the formation of the intermediate-line region (ILR) that is observed in some Seyfert galaxies by the detection of emission lines with intermediate-velocity FWHM ~ 700–1200 km s−1. These lines are believed to be originating from an ILR located somewhere between the BLR and NLR. As was previously proved, the apparent gap is assumed to …
The Growth Of The Central Region By Acquisition Of Counterrotating Gas In Star-Forming Galaxies, Yan-Mei Chen, Yong Shi, Christy A. Tremonti, Matt Bershady, Michael Merrifield, Eric Emsellem, Yi-Fei Jin, Song Huang, Hai Fu, David A. Wake, Kevin Bundy, David Stark, Lihwai Lin, Maria Argudo-Fernandez, Thaisa Storchi Bergmann, Dmitry Bizyaev, Joel Brownstein, Martin Bureau, John Chisholm, Niv Drory, Qi Guo, Lei Hao, Jian Hu, Cheng Li, Ran Li, Alexandre Roman Lopes, Kai-Ke Pan, Rogemar A Riffel, Daniel Thomas, Lan Wang, Renbin Yan
The Growth Of The Central Region By Acquisition Of Counterrotating Gas In Star-Forming Galaxies, Yan-Mei Chen, Yong Shi, Christy A. Tremonti, Matt Bershady, Michael Merrifield, Eric Emsellem, Yi-Fei Jin, Song Huang, Hai Fu, David A. Wake, Kevin Bundy, David Stark, Lihwai Lin, Maria Argudo-Fernandez, Thaisa Storchi Bergmann, Dmitry Bizyaev, Joel Brownstein, Martin Bureau, John Chisholm, Niv Drory, Qi Guo, Lei Hao, Jian Hu, Cheng Li, Ran Li, Alexandre Roman Lopes, Kai-Ke Pan, Rogemar A Riffel, Daniel Thomas, Lan Wang, Renbin Yan
Physics and Astronomy Faculty Publications
Galaxies grow through both internal and external processes. In about 10% of nearby red galaxies with little star formation, gas and stars are counter-rotating, demonstrating the importance of external gas acquisition in these galaxies. However, systematic studies of such phenomena in blue, star-forming galaxies are rare, leaving uncertain the role of external gas acquisition in driving evolution of blue galaxies. Here, based on new measurements with integral field spectroscopy of a large representative galaxy sample, we find an appreciable fraction of counter-rotators among blue galaxies (9 out of 489 galaxies). The central regions of blue counter-rotators show younger stellar populations …
Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, Robert H. Brandenberger, Elisa G. M. Ferreira, Ian A. Morrison, Yi-Fu Cai, Sumit R. Das, Yi Wang
Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, Robert H. Brandenberger, Elisa G. M. Ferreira, Ian A. Morrison, Yi-Fu Cai, Sumit R. Das, Yi Wang
Physics and Astronomy Faculty Publications
We consider a time-dependent deformation of anti–de Sitter (AdS) space-time which contains a spacelike “singularity”—a spacelike region of high curvature. Making use of the AdS/CFT correspondence we can map the bulk dynamics onto the boundary. The boundary theory has a time dependent coupling constant which becomes small at times when the bulk space-time is highly curved. We investigate the propagation of small fluctuations of a test scalar field from early times before the bulk singularity to late times after the singularity. Under the assumption that the AdS/CFT correspondence extends to deformed AdS space-times, we can map the bulk evolution of …
Large Linear Magnetoresistance In Heavily-Doped Nb:Srtio3 Epitaxial Thin Films, Hyunwoo Jin, Keundong Lee, Seung-Hyub Baek, Jin-Sang Kim, Byung-Ki Cheong, Bae Ho Park, Sungwon Yoon, B. J. Suh, Changyoung Kim, Sung S. Ambrose Seo, Suyoun Lee
Large Linear Magnetoresistance In Heavily-Doped Nb:Srtio3 Epitaxial Thin Films, Hyunwoo Jin, Keundong Lee, Seung-Hyub Baek, Jin-Sang Kim, Byung-Ki Cheong, Bae Ho Park, Sungwon Yoon, B. J. Suh, Changyoung Kim, Sung S. Ambrose Seo, Suyoun Lee
Physics and Astronomy Faculty Publications
Interaction between electrons has long been a focused topic in condensed-matter physics since it has led to the discoveries of astonishing phenomena, for example, high-Tc superconductivity and colossal magnetoresistance (CMR) in strongly-correlated materials. In the study of strongly-correlated perovskite oxides, Nb-doped SrTiO3 (Nb:SrTiO3) has been a workhorse not only as a conducting substrate, but also as a host possessing high carrier mobility. In this work, we report the observations of large linear magnetoresistance (LMR) and the metal-to-insulator transition (MIT) induced by magnetic field in heavily-doped Nb:STO (SrNb0.2Ti0.8O3) epitaxial thin …
The Abundance Discrepancy Factor And T2 In Nebulae: Are Non-Thermal Electrons The Culprits?, Gary J. Ferland, W. J. Henney, C. R. O'Dell, M. Peimbert
The Abundance Discrepancy Factor And T2 In Nebulae: Are Non-Thermal Electrons The Culprits?, Gary J. Ferland, W. J. Henney, C. R. O'Dell, M. Peimbert
Physics and Astronomy Faculty Publications
We discuss recent claims that the free electrons in ionized nebulae may not have a significantly Maxwellian velocity distribution. Supra-thermal electrons, electrons with much more energy than is encountered at electron temperatures found in nebulae, may solve the t2/ADF puzzle, the observations that abundances obtained from recombination and collisionally excited lines do not agree, and that different temperature indicators give different results. These non-Maxwellian electrons can be designated by the kappa formalism. We show that the distance over which heating rates change are much longer than the distance supra-thermal electrons can travel, and that the timescale to thermalize …
The Baryon Cycle At High Redshifts: Effects Of Galactic Winds On Galaxy Evolution In Overdense And Average Regions, Raphael Sadoun, Isaac Shlosman, Jun-Hwan Choi, Emilio Romano-Díaz
The Baryon Cycle At High Redshifts: Effects Of Galactic Winds On Galaxy Evolution In Overdense And Average Regions, Raphael Sadoun, Isaac Shlosman, Jun-Hwan Choi, Emilio Romano-Díaz
Physics and Astronomy Faculty Publications
We employ high-resolution cosmological zoom-in simulations focusing on a high-sigma peak and an average cosmological field at z ~ 6–12 in order to investigate the influence of environment and baryonic feedback on galaxy evolution in the reionization epoch. Strong feedback, e.g., galactic winds, caused by elevated star formation rates (SFRs) is expected to play an important role in this evolution. We compare different outflow prescriptions: (i) constant wind velocity (CW), (ii) variable wind scaling with galaxy properties (VW), and (iii) no outflows (NW). The overdensity leads to accelerated evolution of dark matter and baryonic structures, absent from the "normal" region, …
High-Velocity Bipolar Molecular Emission From An Agn Torus, Jack F. Gallimore, Moshe Elitzur, Robert Maiolino, Alessandro Marconi, Christopher P. O'Dea, Dieter Lutz, Stefi A. Baum, Robert Nikutta, C. M. V. Impellizzeri, Richard Davies, Amy E. Kimball, Eleonora Sani
High-Velocity Bipolar Molecular Emission From An Agn Torus, Jack F. Gallimore, Moshe Elitzur, Robert Maiolino, Alessandro Marconi, Christopher P. O'Dea, Dieter Lutz, Stefi A. Baum, Robert Nikutta, C. M. V. Impellizzeri, Richard Davies, Amy E. Kimball, Eleonora Sani
Physics and Astronomy Faculty Publications
We have detected in ALMA observations CO J = 6 → 5 emission from the nucleus of the Seyfert galaxy NGC 1068. The low-velocity (up to ±70 km s−1 relative to systemic) CO emission resolves into a 12 × 7 pc structure, roughly aligned with the nuclear radio source. Higher-velocity emission (up to ±400 km s−1) is consistent with a bipolar outflow in a direction nearly perpendicular (≃80°) to the nuclear disk. The position–velocity diagram shows that in addition to the outflow, the velocity field may also contain rotation about the disk axis. These observations provide compelling …
The Data Reduction Pipeline For The Sdss-Iv Manga Ifu Galaxy Survey, David R. Law, Brian Cherinka, Renbin Yan, Brett H. Andrews, Matthew A. Bershady, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Adam S. Bolton, Joel R. Brownstein, Kevin Bundy, Yanmei Chen, Niv Drory, Richard D'Souza, Hai Fu, Amy Jones, Guinevere Kauffmann, Nicholas Macdonald, Karen L. Masters, Jeffrey A. Newman, John K. Parejko, José R. Sánchez-Gallego, Sebastian F. Sánchez, David J. Schlegel, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle B. Westfall, Kai Zhang
The Data Reduction Pipeline For The Sdss-Iv Manga Ifu Galaxy Survey, David R. Law, Brian Cherinka, Renbin Yan, Brett H. Andrews, Matthew A. Bershady, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Adam S. Bolton, Joel R. Brownstein, Kevin Bundy, Yanmei Chen, Niv Drory, Richard D'Souza, Hai Fu, Amy Jones, Guinevere Kauffmann, Nicholas Macdonald, Karen L. Masters, Jeffrey A. Newman, John K. Parejko, José R. Sánchez-Gallego, Sebastian F. Sánchez, David J. Schlegel, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle B. Westfall, Kai Zhang
Physics and Astronomy Faculty Publications
Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) is an optical fiber-bundle integral-field unit (IFU) spectroscopic survey that is one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV). With a spectral coverage of 3622–10354 Å and an average footprint of ~500 arcsec2 per IFU the scientific data products derived from MaNGA will permit exploration of the internal structure of a statistically large sample of 10,000 low-redshift galaxies in unprecedented detail. Comprising 174 individually pluggable science and calibration IFUs with a near-constant data stream, MaNGA is expected to obtain ~100 million raw-frame spectra and ~10 million …
Jet-Like Correlations With Direct-Photon And Neutral-Pion Triggers At √SNn = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, Renee H. Fatemi, Suvarna Ramachandran
Jet-Like Correlations With Direct-Photon And Neutral-Pion Triggers At √SNn = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
Azimuthal correlations of charged hadrons with direct-photon (γdir) and neutral-pion (π0) trigger particles are analyzed in central Au+Au and minimum-bias p+p collisions at in the STAR experiment. The charged-hadron per-trigger yields at mid-rapidity from central Au+Au collisions are compared with p+p collisions to quantify the suppression in Au+Au collisions. The suppression of the away-side associated-particle yields per γdir trigger is independent of the transverse momentum of the trigger particle (ptrigT), whereas the suppression is smaller at low transverse momentum of the associated charged hadrons ( …
Sdss-Iv Manga: Properties Of Galaxies With Kinematically Decoupled Stellar And Gaseous Components, Yifei Jin, Yanmei Chen, Yong Shi, C. A. Tremonti, M. A. Bershady, M. Merrifield, E. Emsellem, Hai Fu, D. Wake, K. Bundy, Lihwai Lin, M. Argudo-Fernandez, Song Huang, D. V. Stark, T. Storchi-Bergmann, D. Bizyaev, J. Brownstein, J. Chisholm, Qi Guo, Lei Hao, Jian Hu, Cheng Li, Ran Li, K. L. Masters, E. Malanushenko, Kaike Pan, R. A. Riffel, A. Roman-Lopes, A. Simmons, D. Thomas, Renbin Yan
Sdss-Iv Manga: Properties Of Galaxies With Kinematically Decoupled Stellar And Gaseous Components, Yifei Jin, Yanmei Chen, Yong Shi, C. A. Tremonti, M. A. Bershady, M. Merrifield, E. Emsellem, Hai Fu, D. Wake, K. Bundy, Lihwai Lin, M. Argudo-Fernandez, Song Huang, D. V. Stark, T. Storchi-Bergmann, D. Bizyaev, J. Brownstein, J. Chisholm, Qi Guo, Lei Hao, Jian Hu, Cheng Li, Ran Li, K. L. Masters, E. Malanushenko, Kaike Pan, R. A. Riffel, A. Roman-Lopes, A. Simmons, D. Thomas, Renbin Yan
Physics and Astronomy Faculty Publications
We study the properties of 66 galaxies with kinematically misaligned gas and stars from MaNGA survey. The fraction of kinematically misaligned galaxies varies with galaxy physical parameters, i.e. M*, SFR and sSFR. According to their sSFR, we further classify these 66 galaxies into three categories, 10 star-forming, 26 ‘Green Valley’ and 30 quiescent ones. The properties of different types of kinematically misaligned galaxies are different in that the star-forming ones have positive gradient in Dn4000 and higher gas-phase metallicity, while the green valley/quiescent ones have negative Dn4000 gradients and lower gas-phase metallicity on average. …
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, Douglas R. Strachan, David P. Hunley
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, Douglas R. Strachan, David P. Hunley
Physics and Astronomy Faculty Patents
A thermal and electrical conducting apparatus includes a few-layer graphene film having a thickness D where D≦1.5 nm and a plurality of carbon nanotubes crystallographically aligned with the few-layer graphene film.
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, David P. Hunley, Douglas R. Strachan
Crystallographically-Oriented Carbon Nanotubes Grown On Few-Layer Graphene Films, David P. Hunley, Douglas R. Strachan
Physics and Astronomy Faculty Patents
A thermal and electrical conducting apparatus includes a few-layer graphene film having a thickness D where D≦1.5 nm and a plurality of carbon nanotubes crystallographically aligned with the few-layer graphene film.
Holographic Chern-Simons Defects, Mitsutoshi Fujita, Charles M. Melby-Thompson, René Meyer, Shigeki Sugimoto
Holographic Chern-Simons Defects, Mitsutoshi Fujita, Charles M. Melby-Thompson, René Meyer, Shigeki Sugimoto
Physics and Astronomy Faculty Publications
We study SU(N ) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of the …
Ultraviolet Emission Lines Of Si Ii In Quasars—Investigating The "Si Ii Disaster", Sibasish Laha, Francis P. Keenan, Gary J. Ferland, Catherine A. Ramsbottom, Kanti M. Aggarwal
Ultraviolet Emission Lines Of Si Ii In Quasars—Investigating The "Si Ii Disaster", Sibasish Laha, Francis P. Keenan, Gary J. Ferland, Catherine A. Ramsbottom, Kanti M. Aggarwal
Physics and Astronomy Faculty Publications
The observed line intensity ratios of the Si II λ1263 and λ1307 multiplets to that of Si II λ1814 in the broad-line region (BLR) of quasars are both an order of magnitude larger than the theoretical values. This was first pointed out by Baldwin et al., who termed it the "Si II disaster," and it has remained unresolved. We investigate the problem in the light of newly published atomic data for Si II. Specifically, we perform BLR calculations using several different atomic data sets within the CLOUDY modeling code under optically thick quasar cloud conditions. In addition, …
Orion's Veil: Magnetic Field Strengths And Other Properties Of A Pdr In Front Of The Trapezium Cluster, Thomas H. Troland, W. M. Goss, C. L. Brogan, R. M. Crutcher, D. A. Roberts
Orion's Veil: Magnetic Field Strengths And Other Properties Of A Pdr In Front Of The Trapezium Cluster, Thomas H. Troland, W. M. Goss, C. L. Brogan, R. M. Crutcher, D. A. Roberts
Physics and Astronomy Faculty Publications
We present an analysis of physical conditions in the Orion Veil, an atomic photon-dominated region (PDR) that lies just in front (≈2 pc) of the Trapezium stars of Orion. This region offers an unusual opportunity to study the properties of PDRs, including the magnetic field. We have obtained 21 cm H i and 18 cm (1665 and 1667 MHz) OH Zeeman effect data that yield images of the line-of-sight magnetic field strength B los in atomic and molecular regions of the Veil. We find B los ≈ −50 to −75 μG in the atomic gas across much of the …
Evidence For Fluorescent Fe Ii Emission From Extended Low Ionization Outflows In Obscured Quasars, Tinggui Wang, Gary J. Ferland, Chenwei Yang, Huiyuan Wang, Shaohua Zhang
Evidence For Fluorescent Fe Ii Emission From Extended Low Ionization Outflows In Obscured Quasars, Tinggui Wang, Gary J. Ferland, Chenwei Yang, Huiyuan Wang, Shaohua Zhang
Physics and Astronomy Faculty Publications
Recent studies have shown that outflows in at least some broad absorption line (BAL) quasars are extended well beyond the putative dusty torus. Such outflows should be detectable in obscured quasars. We present four WISE selected infrared red quasars with very strong and peculiar ultraviolet Fe II emission lines: strong UV Fe II UV arising from transitions to ground/low excitation levels, and very weak Fe II at wavelengths longer than 2800 Å. The spectra of these quasars display strong resonant emission lines, such as C IV, Al III and Mg II but sometimes, a lack of non-resonant lines such as …
Hst Imaging Of The Dusty Filaments And Nucleus Swirl In Ngc4696 At The Centre Of The Centaurus Cluster, A. C. Fabian, S. A. Walker, H. R. Russell, C. Pinto, R. E. A. Canning, P. Salome, J. S. Sanders, G. B. Taylor, E. G. Zweibel, C. J. Conselice, F. Combes, C. S. Crawford, Gary J. Ferland, J. S. Gallagher Iii, N. A. Hatch, R. M. Johnstone, C. S. Reynolds
Hst Imaging Of The Dusty Filaments And Nucleus Swirl In Ngc4696 At The Centre Of The Centaurus Cluster, A. C. Fabian, S. A. Walker, H. R. Russell, C. Pinto, R. E. A. Canning, P. Salome, J. S. Sanders, G. B. Taylor, E. G. Zweibel, C. J. Conselice, F. Combes, C. S. Crawford, Gary J. Ferland, J. S. Gallagher Iii, N. A. Hatch, R. M. Johnstone, C. S. Reynolds
Physics and Astronomy Faculty Publications
Narrow-band HST imaging has resolved the detailed internal structure of the 10 kpc diameter H α+[N II] emission line nebulosity in NGC4696, the central galaxy in the nearby Centaurus cluster, showing that the dusty, molecular, filaments have a width of about 60 pc. Optical morphology and velocity measurements indicate that the filaments are dragged out by the bubbling action of the radio source as part of the active galactic nucleus feedback cycle. Using the drag force we find that the magnetic field in the filaments is in approximate pressure equipartition with the hot gas. The filamentary nature of the …
Space Telescope And Optical Reverberation Mapping Project. Iv. Anomalous Behavior Of The Broad Ultraviolet Emission Lines In Ngc 5548, M. R. Goad, K. T. Korista, G. De Grosa, G. A. Kriss, R. Edelson, A. J. Barth, Gary J. Ferland, C. S. Kochanek, H. Netzer, B. M. Peterson, M. C. Bentz, S. Bisogni, D. M. Crenshaw, K. D. Denney, J. Ely, M. M. Fausnaugh, C. J. Grier, A. Gupta, K. D. Horne, J. Kaastra, A. Pancoast, L. Pei, R. W. Pogge, A. Skielboe, D. Starkey, M. Vestergaard, Y. Zu, M. D. Anderson, P. Arévalo, C. Bazhaw
Space Telescope And Optical Reverberation Mapping Project. Iv. Anomalous Behavior Of The Broad Ultraviolet Emission Lines In Ngc 5548, M. R. Goad, K. T. Korista, G. De Grosa, G. A. Kriss, R. Edelson, A. J. Barth, Gary J. Ferland, C. S. Kochanek, H. Netzer, B. M. Peterson, M. C. Bentz, S. Bisogni, D. M. Crenshaw, K. D. Denney, J. Ely, M. M. Fausnaugh, C. J. Grier, A. Gupta, K. D. Horne, J. Kaastra, A. Pancoast, L. Pei, R. W. Pogge, A. Skielboe, D. Starkey, M. Vestergaard, Y. Zu, M. D. Anderson, P. Arévalo, C. Bazhaw
Physics and Astronomy Faculty Publications
During an intensive Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) UV monitoring campaign of the Seyfert 1 galaxy NGC 5548 performed from 2014 February to July, the normally highly correlated far UV continuum and broad emission line variations decorrelated for ~60–70 days, starting ~75 days after the first HST/COS observation. Following this anomalous state, the flux and variability of the broad emission lines returned to a more normal state. This transient behavior, characterized by significant deficits in flux and equivalent width of the strong broad UV emission lines, is the first of its kind to be unambiguously identified …
Sdss Iv Manga – Spatially Resolved Diagnostic Diagrams: A Proof That Many Galaxies Are Liers, Francesco Belfiore, Roberto Maiolino, Claudia Maraston, Eric Emsellem, Matthew A. Bershady, Karen L. Masters, Renbin Yan, Dmitry Bizyaev, Médéric Boquien, Joel R. Brownstein, Kevin Bundy, Niv Drory, Timothy M. Heckman, David R. Law, Alexandre Roman-Lopes, Kaike Pan, Letizia Stanghellini, Daniel Thomas, Anne-Marie Weijmans, Kyle B. Westfall
Sdss Iv Manga – Spatially Resolved Diagnostic Diagrams: A Proof That Many Galaxies Are Liers, Francesco Belfiore, Roberto Maiolino, Claudia Maraston, Eric Emsellem, Matthew A. Bershady, Karen L. Masters, Renbin Yan, Dmitry Bizyaev, Médéric Boquien, Joel R. Brownstein, Kevin Bundy, Niv Drory, Timothy M. Heckman, David R. Law, Alexandre Roman-Lopes, Kaike Pan, Letizia Stanghellini, Daniel Thomas, Anne-Marie Weijmans, Kyle B. Westfall
Physics and Astronomy Faculty Publications
We study the spatially resolved excitation properties of the ionized gas in a sample of 646 galaxies using integral field spectroscopy data from the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) programme. Making use of Baldwin–Philips–Terlevich diagnostic diagrams we demonstrate the ubiquitous presence of extended (kpc scale) low-ionization emission-line regions (LIERs) in both star-forming and quiescent galaxies. In star-forming galaxies LIER emission can be associated with diffuse ionized gas, most evident as extraplanar emission in edge-on systems. In addition, we identify two main classes of galaxies displaying LIER emission: ‘central LIER’ (cLIER) galaxies, where …
Investigations Of Metastable Ca2Iro4 Epitaxial Thin-Films: Systematic Comparison With Sr2Iro4 And Ba2Iro4, Maryam Souri, John H. Gruenewald, Jsaminka Terzic, Joseph W. Brill, Gang Cao, Sung S. Ambrose Seo
Investigations Of Metastable Ca2Iro4 Epitaxial Thin-Films: Systematic Comparison With Sr2Iro4 And Ba2Iro4, Maryam Souri, John H. Gruenewald, Jsaminka Terzic, Joseph W. Brill, Gang Cao, Sung S. Ambrose Seo
Physics and Astronomy Faculty Publications
We have synthesized thermodynamically metastable Ca2IrO4 thin-films on YAlO3 (110) substrates by pulsed laser deposition. The epitaxial Ca2IrO4 thin-films are of K2NiF4-type tetragonal structure. Transport and optical spectroscopy measurements indicate that the electronic structure of the Ca2IrO4 thin-films is similar to that of Jeff = 1/2 spin-orbit-coupled Mott insulator Sr2IrO4 and Ba2IrO4, with the exception of an increased gap energy. The gap increase is to be expected in Ca2IrO4 due to its increased octahedral rotation …
Stellar Mass–Gas-Phase Metallicity Relation At 0.5 ≤ Z ≤ 0.7: A Power Law With Increasing Scatter Toward The Low-Mass Regime, Yicheng Guo, David C. Koo, Yu Lu, John C. Forbes, Marc Rafelski, Jonathan R. Trump, Ricardo Amorín, Guillermo Barro, Romeel Davé, S. M. Faber, Nimish P. Hathi, Hassen Yesuf, Michael C. Cooper, Avishai Dekel, Puragra Guhathakurta, Evan N. Kirby, Anton M. Koekemoer, Pablo G. Pérez-González, Lihwai Lin, Jeffery A. Newman, Joel R. Primack, David J. Rosario, Christopher N. A. Willmer, Renbin Yan
Stellar Mass–Gas-Phase Metallicity Relation At 0.5 ≤ Z ≤ 0.7: A Power Law With Increasing Scatter Toward The Low-Mass Regime, Yicheng Guo, David C. Koo, Yu Lu, John C. Forbes, Marc Rafelski, Jonathan R. Trump, Ricardo Amorín, Guillermo Barro, Romeel Davé, S. M. Faber, Nimish P. Hathi, Hassen Yesuf, Michael C. Cooper, Avishai Dekel, Puragra Guhathakurta, Evan N. Kirby, Anton M. Koekemoer, Pablo G. Pérez-González, Lihwai Lin, Jeffery A. Newman, Joel R. Primack, David J. Rosario, Christopher N. A. Willmer, Renbin Yan
Physics and Astronomy Faculty Publications
We present the stellar mass (M*)–gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts (0.5 ≤ z ≤ 0.7) for for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a given M* of this magnitude-limited (R ≲ 24 AB) sample are representative of normal star-forming galaxies. For masses below 109 M☉ our sample of 237 galaxies is ~10 times larger than those in previous studies beyond the local universe. This huge gain in sample size enables superior constraints on the MZR and its scatter …
An Apparatus For Studying Electrical Breakdown In Liquid Helium At 0.4 K And Testing Electrode Materials For The Neutron Electric Dipole Moment Experiment At The Spallation Neutron Source, T. M. Ito, J. C. Ramsey, W. Yao, D. H. Beck, V. Cianciolo, S. M. Clayton, Christopher B. Crawford, S. A. Currie, B. W. Filippone, W. C. Griffith, M. Makela, R. Schmid, G. M. Seidel, Z. Tang, D. Wagner, W. Wei, S. E. Williamson
An Apparatus For Studying Electrical Breakdown In Liquid Helium At 0.4 K And Testing Electrode Materials For The Neutron Electric Dipole Moment Experiment At The Spallation Neutron Source, T. M. Ito, J. C. Ramsey, W. Yao, D. H. Beck, V. Cianciolo, S. M. Clayton, Christopher B. Crawford, S. A. Currie, B. W. Filippone, W. C. Griffith, M. Makela, R. Schmid, G. M. Seidel, Z. Tang, D. Wagner, W. Wei, S. E. Williamson
Physics and Astronomy Faculty Publications
We have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and ∼600 Torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of 1–2 cm between them, and a potential up to ±50 kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a wide range of pressures …
Hallmarks Of The Mott-Metal Crossover In The Hole-Doped Pseudospin-1/2 Mott Insulator Sr2Iro4, Yue Cao, Qiang Wang, Justin A. Waugh, Theodore J. Reber, Haoxiang Li, Xiaoqing Zhou, Stephen Parham, S. -R. Park, Nicholas C. Plumb, Eli Rotenberg, Aaron Bostwick, Jonathan D. Denlinger, Tongfei Qi, Michael A. Hermele, Gang Cao, Daniel S. Dessau
Hallmarks Of The Mott-Metal Crossover In The Hole-Doped Pseudospin-1/2 Mott Insulator Sr2Iro4, Yue Cao, Qiang Wang, Justin A. Waugh, Theodore J. Reber, Haoxiang Li, Xiaoqing Zhou, Stephen Parham, S. -R. Park, Nicholas C. Plumb, Eli Rotenberg, Aaron Bostwick, Jonathan D. Denlinger, Tongfei Qi, Michael A. Hermele, Gang Cao, Daniel S. Dessau
Physics and Astronomy Faculty Publications
The physics of doped Mott insulators remains controversial after decades of active research, hindered by the interplay among competing orders and fluctuations. It is thus highly desired to distinguish the intrinsic characters of the Mott-metal crossover from those of other origins. Here we investigate the evolution of electronic structure and dynamics of the hole-doped pseudospin-1/2 Mott insulator Sr2IrO4. The effective hole doping is achieved by replacing Ir with Rh atoms, with the chemical potential immediately jumping to or near the top of the lower Hubbard band. The doped iridates exhibit multiple iconic low-energy features previously observed …
H, He-Like Recombination Spectra – I. L-Changing Collisions For Hydrogen, Francisco Guzmán, N. R. Badnell, R. J. R. Williams, P. A. M. Van Hoof, Marios Chatzikos, Gary J. Ferland
H, He-Like Recombination Spectra – I. L-Changing Collisions For Hydrogen, Francisco Guzmán, N. R. Badnell, R. J. R. Williams, P. A. M. Van Hoof, Marios Chatzikos, Gary J. Ferland
Physics and Astronomy Faculty Publications
Hydrogen and helium emission lines in nebulae form by radiative recombination. This is a simple process which, in principle, can be described to very high precision. Ratios of He I and H I emission lines can be used to measure the He+/H+ abundance ratio to the same precision as the recombination rate coefficients. This paper investigates the controversy over the correct theory to describe dipole l-changing collisions (nl → nl′ = l ± 1) between energy-degenerate states within an n-shell. The work of Pengelly & Seaton has, for half-a-century, been considered the definitive …
Conducting Laalo3/Srtio3 Heterointerfaces On Atomically-Flat Substrates Prepared By Deionized-Water, John G. Connell, J. Nichols, John H. Gruenewald, D. -W. Kim, Sung S. Ambrose Seo
Conducting Laalo3/Srtio3 Heterointerfaces On Atomically-Flat Substrates Prepared By Deionized-Water, John G. Connell, J. Nichols, John H. Gruenewald, D. -W. Kim, Sung S. Ambrose Seo
Physics and Astronomy Faculty Publications
We have investigated how the recently-developed water-leaching method for atomically-flat SrTiO3 (STO) substrates affects the transport properties of LaAlO3 (LAO) and STO heterointerfaces. Using pulsed laser deposition at identical growth conditions, we have synthesized epitaxial LAO thin-films on two different STO substrates, which are prepared by water-leaching and buffered hydrofluoric acid (BHF) etching methods. The structural, transport, and optical properties of LAO/STO heterostructures grown on water-leached substrates show the same high-quality as the samples grown on BHF-etched substrates. These results indicate that the water-leaching method can be used to grow complex oxide heterostructures with atomically well-defined heterointerfaces without …