Deep 1.1mm-Wavelength Imaging Of The Goods-S Field By Aztec/Aste - Ii. Redshift Distribution And Nature Of The Submillimetre Galaxy Population,
2012
University of Massachusetts Amherst
Deep 1.1mm-Wavelength Imaging Of The Goods-S Field By Aztec/Aste - Ii. Redshift Distribution And Nature Of The Submillimetre Galaxy Population, Min S. Yun, K. S. Scott, Yicheng Guo, I. Aretxaga, M. Giavalisco, J. E. Austermann, P. Capak, Yuxi Chen, H. Ezawa, B. Hatsukade, D. H. Hughes, D. Iono, S. Johnson, R. Kawabe, K. Kohno, James D. Lowenthal, N. Miller, G. Morrison, T. Oshima, T. A. Perera, M. Salvato, J. Silverman, Y. Tamura, C. C. Williams, G. W. Wilson
Astronomy: Faculty Publications
We report the results of the counterpart identification and a detailed analysis of the physical properties of the 48 sources discovered in our deep 1.1-mm wavelength imaging survey of the Great Observatories Origins Deep Survey-South (GOODS-S) field using the AzTEC instrument on the Atacama Submillimeter Telescope Experiment. One or more robust or tentative counterpart candidate is found for 27 and 14 AzTEC sources, respectively, by employing deep radio continuum, Spitzer/Multiband Imaging Photometer for Spitzer and Infrared Array Camera, and Large APEX Bolometer Camera 870μm data. Five of the sources (10 per cent) have two robust counterparts each, supporting the idea …
Star Formation In Self-Gravitating Disks In Active Galactic Nuclei. Ii. Episodic Formation Of Broad-Line Regions,
2012
Chinese Academy of Sciences, China
Star Formation In Self-Gravitating Disks In Active Galactic Nuclei. Ii. Episodic Formation Of Broad-Line Regions, Jian-Min Wang, Pu Du, Jack A. Baldwin, Jun-Qiang Ge, Chen Hu, Gary J. Ferland
Physics and Astronomy Faculty Publications
This is the second in a series of papers discussing the process and effects of star formation in the self-gravitating disk around the supermassive black holes in active galactic nuclei (AGNs). We have previously suggested that warm skins are formed above the star-forming (SF) disk through the diffusion of warm gas driven by supernova explosions. Here we study the evolution of the warm skins when they are exposed to the powerful radiation from the inner part of the accretion disk. The skins initially are heated to the Compton temperature, forming a Compton atmosphere (CAS) whose subsequent evolution is divided into …
3-D Mesoscale Mhd Simulations Of Magnetospheric Cusp-Like Configurations: Cusp Diamagnetic Cavities And Boundary Structure,
2012
University of Alaska, Fairbanks
3-D Mesoscale Mhd Simulations Of Magnetospheric Cusp-Like Configurations: Cusp Diamagnetic Cavities And Boundary Structure, E. Adamson, A. Otto, K. Nykyri
Publications
We present results from mesoscale simulations of the magnetospheric cusp region for both strongly northward and strongly southward interplanetary magnetic field (IMF). Simulation results indicate an extended region of depressed magnetic field and strongly enhanced plasma B which exhibits a strong dependence on IMF orientation. These structures correspond to the Cusp Diamagnetic Cavities (CDC’s). The typical features of these CDC’s are generally well reproduced by the simulation. The inner boundaries between the CDC and the magnetosphere are gradual transitions which form a clear funnel shape, regardless of IMF orientation. The outer CDC/magnetosheath boundary exhibits a clear indentation in both the …
Fragile Binary Candidates In The Sdss Dr8 Spectroscopic Archive,
2012
Florida Institute of Technology
Fragile Binary Candidates In The Sdss Dr8 Spectroscopic Archive, J K. Zhao, Terry D. Oswalt, G Zhao
Aerospace, Physics, and Space Science Faculty Publications
We present a catalog of 80 very wide fragile binary candidates (projected separations >10,000 AU) from the Sloan Digital Sky Survey Data Release Eight spectral archive. The pairs were selected based on proper motion, radial velocity, metallicity, and photometric parallax criteria. The angular separations of these pairs range from 3" to 250 ". The peak in the metallicity distribution of these pairs is about −0.5 dex of solar metallicity. Space motions and reduced proper motion diagrams indicate that all these pairs are members of the disk. The chromospheric activity index SHK of each component in 38 binary candidates having spectra …
The Initial–Final Mass Relation Among White Dwarfs In Wide Binaries,
2012
Florida Institute of Technology
The Initial–Final Mass Relation Among White Dwarfs In Wide Binaries, J. K. Zhao, T. D. Oswalt, L. A. Willson, Q. Wang, G. Zhao
Publications
We present the initial–final mass relation derived from 10 white dwarfs in wide binaries that consist of a main-sequence star and a white dwarf. The temperature and gravity of each white dwarf were measured by fitting theoretical model atmospheres to the observed spectrum using a χ2 fitting algorithm. The cooling time and mass were obtained using theoretical cooling tracks. The total age of each binary was estimated from the chromospheric activity of its main-sequence component to an uncertainty of about 0.17 dex in log t. The difference between the total age and white dwarf cooling time is taken …
The Evaluation Of Erk1 Dimerization Models Using Fluorescence Correlation Spectroscopy And The Development Of Analysis Algorithms For Single-Molecule Super Resolution,
2012
University of New Mexico
The Evaluation Of Erk1 Dimerization Models Using Fluorescence Correlation Spectroscopy And The Development Of Analysis Algorithms For Single-Molecule Super Resolution, Fang Huang
Physics & Astronomy ETDs
In this dissertation, we describe three advancements in the area of fluorescence spectroscopy and microscopy. First, we have implemented Fluorescence Correlation Spectroscopy on a home-built confocal microscope. We proposed F/N analysis which stands for the ratio between average intensity and average number of moving objects in FCS as a method to detect dimerization of fluorescently tagged proteins diffusing in three dimensions. We used the technique to evaluate the dimerization hypothesis of ERK1 protein during nucleus translocation and it shows that ERK1 nucleus translocation is dimerization independent. Second, we have developed a multi-emitter analysis algorithm for single-molecule super resolution techniques that …
Stable Ordered Structures Of Binary Technetium Alloys From First Principles,
2012
Brigham Young University
Stable Ordered Structures Of Binary Technetium Alloys From First Principles, Gus L. W. Hart, Ohad Levy, Junkai Xue, Shidong Wang, Stefano Curtarolo
Faculty Publications
Technetium, element 43, is the only radioactive transition metal. It occurs naturally on earth in only trace amounts. Experimental investigation of its possible compounds is thus inherently difficult and limited. Half of the Tc-transition-metal systems (14 out of 28) are reported to be phase separating or lack experimental data. Using high-throughput first-principles calculations, we present a comprehensive investigation of the binary alloys of technetium with the transition metals. The calculations predict stable, ordered structures in nine of these 14 binary systems. They also predict additional compounds in all nine known compound-forming systems and in two of the five systems reported …
Rovibrationally Resolved Direct Photodissociation Through The Lyman And Werner Transitions Of H2 For Fuv/X-Ray-Irradiated Environments,
2012
University of Georgia
Rovibrationally Resolved Direct Photodissociation Through The Lyman And Werner Transitions Of H2 For Fuv/X-Ray-Irradiated Environments, C. D. Gay, N. P. Abel, R. L. Porter, P. C. Stancil, Gary J. Ferland, G. Shaw, P. A. M. Vanhoof, R. J. R. Williams
Physics and Astronomy Faculty Publications
Using ab initio potential curves and dipole transition moments, cross-section calculations were performed for the direct continuum photodissociation of H2 through the B1Σ+u ← X1Σ+g (Lyman) and C1Πu ← X1Σ+g (Werner) transitions. Partial cross-sections were obtained for wavelengths from 100 Å to the dissociation threshold between the upper electronic state and each of the 301 bound rovibrational levels v''J'' within the ground electronic state. The resulting cross-sections are incorporated into three representative classes of interstellar gas models: diffuse clouds, photon-dominated regions, and …
Stellar Populations And The Star Formation Histories Of Lsb Galaxies - Part I: Optical And Hα Imaging,
2012
Case Western Reserve University
Stellar Populations And The Star Formation Histories Of Lsb Galaxies - Part I: Optical And Hα Imaging, Stacy S. Mcgaugh
Faculty Scholarship
This paper presents optical and H imaging for a large sample of LSB galaxies selected from the PSS-II catalogs (Schombert et al., 1992). As noted in previous work, LSB galaxies span a range of luminosities (-10>MV>-20) and sizes (0.3kpc
The Baryonic Tully-Fisher Relation Of Gas-Rich Galaxies As A Test Of Λcdm And Mond,
2012
Case Western Reserve University
The Baryonic Tully-Fisher Relation Of Gas-Rich Galaxies As A Test Of Λcdm And Mond, Stacy S. Mcgaugh
Faculty Scholarship
The baryonic Tully-Fisher relation (BTFR) is an empirical relation between baryonic mass and rotation velocity in disk galaxies. It provides tests of galaxy formation models in ΛCDM and of alternative theories like modified Newtonian dynamics (MOND). Observations of gas-rich galaxies provide a measure of the slope and normalization of the BTFR that is more accurate (if less precise) than that provided by star-dominated spirals, as their masses are insensitive to the details of stellar population modeling. Recent independent data for such galaxies are consistent with M b = AV 4f with A = 47 6 M km -4 s 4. …
Observability Of Pulsar Beam Bending By The Sgr A* Black Hole,
2012
University of Texas Rio Grande Valley
Observability Of Pulsar Beam Bending By The Sgr A* Black Hole, K. Stovall, Teviet Creighton, Richard H. Price, Fredrick A. Jenet
Physics & Astronomy Faculty Publications
According to some models, there may be a significant population of radio pulsars in the Galactic center. In principle, a beam from one of these pulsars could pass close to the supermassive black hole (SMBH) at the center, be deflected, and be detected by Earth telescopes. Such a configuration would be an unprecedented probe of the properties of spacetime in the moderate- to strong-field regime of the SMBH. We present here background on the problem, and approximations for the probability of detection of such beams. We conclude that detection is marginally possible with current telescopes, but that telescopes that will …
A Search For Single Photon Events In Neutrino Interactions,
2012
University of South Carolina
A Search For Single Photon Events In Neutrino Interactions, C. T. Kullenberg, S. R. Mishra, D. Dimmery, X. C. Tian, D. Autiero, S. Gninenko, A. Rubbia, S. Alekhin, P. Astier, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, Roberto Petti, Et. Al.
Faculty Publications
We present a search for neutrino induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is 25 GeV. The search is motivated by an excess of electron-like events in the 200–475 MeV energy region as reported by the MiniBooNE experiment. In NOMAD, photons are identified via their conversion to e+e− in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino–nucleus …
All-Sky Search For Periodic Gravitational Waves In The Full S5 Ligo Data,
2012
The University of Texas Rio Grande Valley
All-Sky Search For Periodic Gravitational Waves In The Full S5 Ligo Data, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Malik Rakhmanov, Volker Quetschke, Joseph D. Romano
Physics & Astronomy Faculty Publications
We report on an all-sky search for periodic gravitational waves in the frequency band 50-800Hz and with the frequency time derivative in the range of 0 through -6×10-9Hz/s. Such a signal could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. After recent improvements in the search program that yielded a 10× increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational-wave strain to date. Near 150Hz our upper limit on worst-case linearly polarized strain …
All-Sky Search For Periodic Gravitational Waves In The Full S5 Ligo Data,
2012
California Institute of Technology
All-Sky Search For Periodic Gravitational Waves In The Full S5 Ligo Data, J. Abadie, B. P. Abbott, R. Abbott, T. D. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, C. Affeldt, P. Ajith, B. Allen, G. S. Allen, E. Amador Ceron, D. Amariutei, R. S. Amin, S. B. Anderson, W. G. Anderson, K. Arai, M. A. Arain, M. C. Araya, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, B. E. Aylott, S. Babak, P. Baker, G. Ballardin, S. Ballmer, Tiffany Z. Summerscales
Faculty Publications
We report on an all-sky search for periodic gravitational waves in the frequency band 50-800Hz and with the frequency time derivative in the range of 0 through -6×10-9Hz/s. Such a signal could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. After recent improvements in the search program that yielded a 10× increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational-wave strain to date. Near 150Hz our upper limit on worst-case linearly polarized strain …
Testing Yukawa-Like Potentials From F(R)-Gravity In Elliptical Galaxies,
2012
INAF-Osservatorio Astronomico di Capodimonte
Testing Yukawa-Like Potentials From F(R)-Gravity In Elliptical Galaxies, N. R. Napolitano, S. Capozziello, Aaron J. Romanowsky, M. Capaccioli, C. Tortora
Faculty Publications
We present the first analysis of extended stellar kinematics of elliptical galaxies where a Yukawa-like correction to the Newtonian gravitational potential derived from f(R)-gravity is considered as an alternative to dark matter. In this framework, we model long-slit data and planetary nebula data out to 7 R eff of three galaxies with either decreasing or flat dispersion profiles. We use the corrected Newtonian potential in a dispersion-kurtosis Jeans analysis to account for the mass-anisotropy degeneracy. We find that these modified potentials are able to fit nicely all three elliptical galaxies and the anisotropy distribution is consistent with that estimated if …
Evidence For Inhomogeneous Reionization In The Local Universe From Metal-Poor Globular Cluster Systems,
2012
Swinburne University
Evidence For Inhomogeneous Reionization In The Local Universe From Metal-Poor Globular Cluster Systems, L. R. Spitler, Aaron J. Romanowsky, J. Diemand, J. Strader, D. A. Forbes, B. Moore, J. P. Brodie
Faculty Publications
Exploiting a fundamental characteristic of galaxy assembly in the Λ cold dark matter paradigm, the observed spatial biasing and kinematics of metal-poor globular star clusters are used to constrain the local reionization epoch around individual galaxies. Selecting three galaxies located in different environments, the first attempt at constraining the environmental propagation of reionization in the local Universe is carried out. The joint constraint from the three galaxies (Graphic) agrees remarkably well with the latest Wilkinson Microwave Anisotropy Probe constraint on zreion for a simple instantaneous reionization model. More importantly, the range of zreion values found here is consistent with the …
The Sluggs Survey: Ngc 3115, A Critical Test Case For Metallicity Bimodality In Globular Cluster Systems,
2012
University of California, Santa Cruz
The Sluggs Survey: Ngc 3115, A Critical Test Case For Metallicity Bimodality In Globular Cluster Systems, J. P. Brodie, C. Usher, C. Conroy, J. Strader, J. A. Arnold, D. A. Forbes, Aaron J. Romanowsky
Faculty Publications
Due to its proximity (9 Mpc) and the strongly bimodal color distribution of its spectroscopically well-sampled globular cluster (GC) system, the early-type galaxy NGC 3115 provides one of the best available tests of whether the color bimodality widely observed in GC systems generally reflects a true metallicity bimodality. Color bimodality has alternatively been attributed to a strongly nonlinear color-metallicity relation reflecting the influence of hot horizontal-branch stars. Here, we couple Subaru Suprime-Cam gi photometry with Keck/DEIMOS spectroscopy to accurately measure GC colors and a CaT index that measures the Ca II triplet. We find the NGC 3115 GC system to …
The Sluggs Survey: Globular Cluster System Kinematics And Substructure In Ngc 4365,
2012
Swinburne University
The Sluggs Survey: Globular Cluster System Kinematics And Substructure In Ngc 4365, C. Blom, D. A. Forbes, J. P. Brodie, C. Foster, Aaron J. Romanowsky, L. R. Spitler, J. Strader
Faculty Publications
We present a kinematic analysis of the globular cluster (GC) system of the giant elliptical galaxy NGC 4365 and find several distinct kinematic substructures. This analysis is carried out using radial velocities for 269 GCs, obtained with the DEIMOS (DEep Imaging Multi-Object Spectrograph) instrument on the Keck II telescope as part of the SAGES Legacy Unifying Globulars and Galaxies Survey (SLUGGS). We find that each of the three (formerly identified) GC colour subpopulations reveal distinct rotation properties. The rotation of the green GC subpopulation is consistent with the bulk of NGC 4365's stellar light, which ‘rolls’ about the photometric major …
The Sluggs Survey: Calcium Triplet-Based Spectroscopic Metallicites For Over 900 Globular Clusters,
2012
Swinburne University of Technology
The Sluggs Survey: Calcium Triplet-Based Spectroscopic Metallicites For Over 900 Globular Clusters, C. Usher, D. A. Forbes, J. P. Brodie, C. Foster, L. R. Spitler, J. A. Arnold, Aaron J. Romanowsky, J. Strader, V. Pota
Faculty Publications
Although the colour distribution of globular clusters in massive galaxies is well known to be bimodal, the spectroscopic metallicity distribution has been measured in only a few galaxies. After redefining the calcium triplet index–metallicity relation, we use our relation to derive the metallicity of 903 globular clusters in 11 early-type galaxies. This is the largest sample of spectroscopic globular cluster metallicities yet assembled. We compare these metallicities with those derived from Lick indices finding good agreement. In six of the eight galaxies with sufficient numbers of high-quality spectra we find bimodality in the spectroscopic metallicity distribution. Our results imply that …
The Globular Cluster System Of Ngc 1316 - Ii. The Extraordinary Object Sh2,
2012
Departamento de Astronomía, Casilla 160-CUniversidad de Concepción
The Globular Cluster System Of Ngc 1316 - Ii. The Extraordinary Object Sh2, T. Richtler, B. Kumar, L. Bassino, B. Dirsch, Aaron J. Romanowsky
Faculty Publications
Context. SH2 has been described as an isolated HII-region, located about 6.5′ south of the nucleus of NGC 1316 (Fornax A), a merger remnant in the the outskirts of the Fornax cluster of galaxies. Aims. We give a first, preliminary description of the stellar content and environment of this remarkable object. Methods. We used photometric data in the Washington system and HST photometry from the Hubble Legacy Archive for a morphological description and preliminary aperture photometry. Low-resolution spectroscopy provides radial velocities of the brightest star cluster in SH2 and a nearby intermediate-age cluster. Results. SH2 is not a normal HII-region, …
