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2010

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Articles 241 - 270 of 276

Full-Text Articles in Astrophysics and Astronomy

Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward Chapin, Thomas Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher Conselice, Kristen Coppin, Mauro Giavalisco, David Hughes, Rob Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson Jan 2010

Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward Chapin, Thomas Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher Conselice, Kristen Coppin, Mauro Giavalisco, David Hughes, Rob Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson

Scholarship

We present a study of the cosmic infrared background, which is a measure of the dust obscured activity in all galaxies in the Universe. We venture to isolate the galaxies responsible for the background at 1mm; with spectroscopic and photometric redshifts we constrain the redshift distribution of these galaxies. We create a deep 1.16mm map (sigma ~ 0.5mJy) by combining the AzTEC 1.1mm and MAMBO 1.2mm datasets in GOODS-N. This combined map contains 41 secure detections, 13 of which are new. By averaging the 1.16mm flux densities of individually undetected galaxies with 24um flux densities > 25uJy, we resolve 31--45 per …

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Color-Magnitude Relation And Morphology Of Low-Redshift Ulirgs In Sloan Digital Sky Survey, Yuxi Chen, James D. Lowenthal, Min S. Yun Jan 2010

Color-Magnitude Relation And Morphology Of Low-Redshift Ulirgs In Sloan Digital Sky Survey, Yuxi Chen, James D. Lowenthal, Min S. Yun

Astronomy: Faculty Publications

We present color-magnitude and morphological analysis of 54 low-redshift ultraluminous infrared galaxies (ULIRGs; 0.018 < z < 0.265 with z = 0.151), a subset of the Infrared Astronomical Satellite 1Jy sample, in the Sloan Digital Sky Survey (SDSS). The ULIRGs are both bright and blue: they are on average 1mag brighter in than the SDSS galaxies within the same redshift range, and 0.2mag bluer in g - r. They form a group in the color-magnitude diagram distinct from both the red sequence and the blue cloud formed by the SDSS galaxies: 24 out of the 52 unsaturated objects (46%) lie outside the 90% level number density contour of the SDSS galaxies. The majority (47, or 87%) have the colors typical of the blue cloud, and only four (7%) sources are located in the red sequence. While ULIRGs are popularly thought to be precursors to a QSO phase, we find few (three, or 6%) in the "green valley" where the majority of the X-ray- and IR-selected active galactic nuclei (AGNs) are found. Moreover, none of the AGN-host ULIRGs are found in the green valley. For the 14 previously spectroscopic identified AGNs (28%), we perform point-spread function subtractions and find that on average the central point sources contribute less than one-third to the total luminosity, and that their high optical luminosities and overall blue colors are apparently the result of star formation activity of the host galaxies. Visual inspection of the SDSS images reveals a wide range of morphologies including many close pairs, tidal tails, and otherwise disturbed profiles, in strong support of previous studies and the general view of ULIRGs as major mergers of gas-rich disk galaxies. A detailed morphology analysis using Gini and M coefficients shows that slightly less than one-half (42% in g band) of the ULIRGs are located in the merger region defined by morphology studies of local galaxies, while the remaining sources are located in the region of late-type and irregular galaxies. The heterogeneous distribution of ULIRGs in the G-M space is qualitatively consistent with the results found by numerical simulations of disk-disk mergers, and our study also shows that the measured morphological parameters are systematically affected by the signal-to-noise ratio and thus the merging galaxies can appear in various regions of the G-M parameter space. We briefly discuss the origins of the uncertainties and note that the morphology measurements should be implemented with caution for low physical resolution images. In general, our results reinforce the view that ULIRGs contain young stellar populations and are mergers in progress, but we do not observe the concentration of ULIRGs/AGN in the green valley as found by other studies. Our study provides a uniform comparison sample for studying dusty starbursts at higher redshifts such as Spitzer MIPS 24 μm-selected ULIRGs at z = 1-2 or submillimeter galaxies.

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Limit On Continuous Neutrino Emission From Neutron Stars, Itzhak Goldman, Shmuel Nussinov Jan 2010

Limit On Continuous Neutrino Emission From Neutron Stars, Itzhak Goldman, Shmuel Nussinov

Mathematics, Physics, and Computer Science Faculty Articles and Research

The timing data of the binary pulsar PSR1913+16, are used to establish an upper limit on the rate of continuous neutrino emission from neutron stars. Neutrino emission from each of the neutron stars of the binary system, increases the star binding energy and thus translates to a decrease in their masses. This in turn implies an increase with time of the binary period. Using the pulsar data we obtain an upper limit on the allowed rate of mass reduction: vertical bar M vertical bar < 1.1 x 10(-12) yr(-1) M, where M is the total mass of the binary. This constrains exotic nuclear equations of state that predict continuous neutrino emissions. The limit applies also to other channels of energy loss, e. g. axion emission. Continued timing measurements of additional binary pulsars, should yield a stronger limit in the future.

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Brightest Cluster Galaxies And Core Gas Density In Rexcess Clusters, Deborah B. Haarsma, Luke Leisman, Megan Donahue, Seth Bruch Jan 2010

Brightest Cluster Galaxies And Core Gas Density In Rexcess Clusters, Deborah B. Haarsma, Luke Leisman, Megan Donahue, Seth Bruch

University Faculty Publications and Creative Works

We investigate the relationship between brightest cluster galaxies (BCGs) and their host clusters using a sample of nearby galaxy clusters from the Representative XMM-Newton Cluster Structure Survey. The sample was imaged with the Southern Observatory for Astrophysical Research in R band to investigate the mass of the old stellar population. Using a metric radius of 12 h -1kpc, we found that the BCG luminosity depends weakly on overall cluster mass as L BCG M 0.180.07cl, consistent with previous work. We found that 90% of the BCGs are located within 0.035 r 500 of the peak of the X-ray emission, including …

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The Magnetic Field Induced By A Lightning Strikes Indirect Effect Double Exponential Current Waveform, S L. Meredith, S K. Earles, I N. Kostanic, Niescja E. Turner Jan 2010

The Magnetic Field Induced By A Lightning Strikes Indirect Effect Double Exponential Current Waveform, S L. Meredith, S K. Earles, I N. Kostanic, Niescja E. Turner

Physics and Astronomy Faculty Research

Problem statement: Develop a new formula which describes the magnetic field induced by a lightning strike's indirect effect double exponential current waveform. Approach: A novel approach for developing a closed-form solution for the magnetic field from the indirect effect double exponential current waveform will be presented. In the literature, models typically employ the pulse waveform to derive the corresponding electromagnetic fields. However, given the Department of Defense (DoD) has incorporated the double exponential current waveform as part of their "Electromagnetic Environmental Effects Requirements For Systems", we felt it important to develop a solution for the magnetic field which …

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A New Method For Describing The Horizontal Electric Field Induced By A Lightning Strike Return Stroke, S L. Meredith, S K. Earles, Niescja E. Turner Jan 2010

A New Method For Describing The Horizontal Electric Field Induced By A Lightning Strike Return Stroke, S L. Meredith, S K. Earles, Niescja E. Turner

Physics and Astronomy Faculty Research

No abstract provided.

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First Results On Terrestrial Gamma Ray Flashes From The Fermi Gamma-Ray Burst Monitor, Michael S. Briggs, Joseph R. Dwyer Jan 2010

First Results On Terrestrial Gamma Ray Flashes From The Fermi Gamma-Ray Burst Monitor, Michael S. Briggs, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

The Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope detected 12 intense terrestrial gamma ray flashes (TGFs) during its first year of observation. Typical maximum energies for most of the TGFs are ∼30 MeV, with one TGF having a 38 MeV photon; two of the TGFs are softer and longer than the others. After correcting for instrumental effects, a representative bright TGF is found to have a fluence of ∼0.7 photons cm-2. Pulses are either symmetrical or have faster risetimes than fall times; they are well fit with Gaussian or lognormal functions. The fastest risetime observed was 7 …

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Associations Between Fermi Gamma-Ray Burst Monitor Terrestrial Gamma Ray Flashes And Sferics From The World Wide Lightning Location Network, Valerie Connaughton, Eric S. Cramer, Joseph R. Dwyer Jan 2010

Associations Between Fermi Gamma-Ray Burst Monitor Terrestrial Gamma Ray Flashes And Sferics From The World Wide Lightning Location Network, Valerie Connaughton, Eric S. Cramer, Joseph R. Dwyer

Aerospace, Physics, and Space Science Faculty Publications

We report on a search for correlations between terrestrial gamma ray flashes (TGFs) detected by the Fermi Gamma-ray Burst Monitor (GBM) and lightning strokes measured using the World Wide Lightning Location Network (WWLLN). We associate 15 of a total 50 GBM-detected TGFs with individual discharges. We establish the relative timing between the TGF and the lightning stroke to an accuracy of <50 s, and find that in 13 of these 15 lightning-TGF associations, the lightning stroke and the peak of the TGF are simultaneous to ∼40 μs. This suggests that a large fraction of TGFs are coincident with lightning discharges. The two nonsimultaneous associations do not show a consistent TGF-lightning stroke temporal sequence. All 15 associations are with sferics within 300 km of the subspacecraft position. For those TGFs not correlated with a particular lightning stroke, we find storm activity within 300 km of the subspacecraft position in all but four of the TGFs. For three of these four TGFs, we find storm activity very close to one of the magnetic footprints of the spacecraft position. We associate the subspacecraft TGFs with gamma ray events and the footprint events with electrons traveling along magnetic field lines before hitting the Fermi spacecraft.

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Brightest Cluster Galaxies And Core Gas Density In Rexcess Clusters, Deborah B. Haarsma, Luke Leisman, Megan Donahue, Seth Bruch Jan 2010

Brightest Cluster Galaxies And Core Gas Density In Rexcess Clusters, Deborah B. Haarsma, Luke Leisman, Megan Donahue, Seth Bruch

University Faculty Publications and Creative Works

We investigate the relationship between brightest cluster galaxies (BCGs) and their host clusters using a sample of nearby galaxy clusters from the Representative XMM-Newton Cluster Structure Survey. The sample was imaged with the Southern Observatory for Astrophysical Research in R band to investigate the mass of the old stellar population. Using a metric radius of 12 h -1kpc, we found that the BCG luminosity depends weakly on overall cluster mass as L BCG M 0.180.07cl, consistent with previous work. We found that 90% of the BCGs are located within 0.035 r 500 of the peak of the X-ray emission, including …

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Off To A Good Start: Using Clustering To Select The Initial Training Set In Active Learning, Rong Hu, Brian Mac Namee, Sarah Jane Delany Jan 2010

Off To A Good Start: Using Clustering To Select The Initial Training Set In Active Learning, Rong Hu, Brian Mac Namee, Sarah Jane Delany

Conference papers

Active learning (AL) is used in textual classification to alleviate the cost of labelling documents for training. An important issue in AL is the selection of a representative sample of documents to label for the initial training set that seeds the process, and clustering techniques have been successfully used in this regard. However, the clustering techniques used are nondeterministic which causes inconsistent behaviour in the AL process. In this paper we first illustrate the problems associated with using non-deterministic clustering for initial training set selection in AL. We then examine the performance of three deterministic clustering techniques for this task …

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Star Formation And Uv Colors Of The Brightest Cluster Galaxies In The Representative Xmm-Newton Cluster Structure Survey, Megan Donahue, Seth Bruch, Emily Wang, G. Mark Voit Jan 2010

Star Formation And Uv Colors Of The Brightest Cluster Galaxies In The Representative Xmm-Newton Cluster Structure Survey, Megan Donahue, Seth Bruch, Emily Wang, G. Mark Voit

University Faculty Publications and Creative Works

We present UV broadband photometry and optical emission-line measurements for a sample of 32 brightest cluster galaxies (BCGs) in clusters of the Representative XMM-Newton Cluster Structure Survey (REXCESS) with z = 0.06-0.18. The REXCESS clusters, chosen to study scaling relations in clusters of galaxies, have X-ray measurements of high quality. The trends of star formation and BCG colors with BCG and host properties can be investigated with this sample. The UV photometry comes from the XMM-Newton Optical Monitor, supplemented by existing archival Galaxy Evolution Explorer photometry. We detected Hα and forbidden line emission in seven (22%) of these BCGs, in …

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Begin The Adventure : How To Break The Light Barrier By A.D. 2079 (3rd Ed.), Florentin Smarandache, Homer B. Tilton Jan 2010

Begin The Adventure : How To Break The Light Barrier By A.D. 2079 (3rd Ed.), Florentin Smarandache, Homer B. Tilton

Branch Mathematics and Statistics Faculty and Staff Publications

This edition, the third, has undergone a subtle name change, going from "A.D. 2070" in the title to A.D. 2079 as the timeline is fine-tuned. Because of the almost universal failure to recognize the distinction between physical (reality-based, dynamical) and visual (appearance-based, kinematical) variables, a tremendous volume of mythology arose over the past 100 years centered around Einstein's reality view of the distortions of special relativity. To get a sense of it, we point the reader to Paul J. Nahin's heroic book, Time Machines, 2nd ed.,- to these Tech Notes in particular: TN#6. "A High-Speed Rocket Is a One-Way Time …

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The Zeeman Effect In The Sobolev Approximation Ii. Radial Split Monopole Fields And The ‘Heartbeat’ Stokes V Profile., K. Gayley, Richard Ignace Jan 2010

The Zeeman Effect In The Sobolev Approximation Ii. Radial Split Monopole Fields And The ‘Heartbeat’ Stokes V Profile., K. Gayley, Richard Ignace

ETSU Faculty Works

We calculate the circularly polarized Stokes V(λ) profile for emission lines, formed in hot-star winds threaded with a weak radial magnetic field. For simplicity, the field is treated as a split monopole under the assumptions that it has been radially combed by the wind, and rotation is not playing a central role. Invoking the weak-field approximation, we find that the V(λ) profile has a characteristic “heartbeat” shape exhibiting multiple sign inversions, which might be mistaken for noise in the absence of theoretical guidance. We also conclude that there is a tendency for the V(λ) profile to integrate to zero on …

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Longitudinal Scaling Property Of The Charge Balance Function In Au + Au Collisions At √Snn= 200 Gev, B. I. Abelev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, B. D. Anderson, D. Arkhipkin, G. S. Averichev, J. Balewski, L. S. Barnby, S. Bültmann, I. Koralt, D. Plyku Jan 2010

Longitudinal Scaling Property Of The Charge Balance Function In Au + Au Collisions At √Snn= 200 Gev, B. I. Abelev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, B. D. Anderson, D. Arkhipkin, G. S. Averichev, J. Balewski, L. S. Barnby, S. Bültmann, I. Koralt, D. Plyku

Physics Faculty Publications

We present measurements of the charge balance function, from the charged particles, for diverse pseudorapidity and transverse momentum ranges in Au + Au collisions at √sNN = 200 GeV using the STAR detector at RHIC. We observe that the balance function is boost-invariant within the pseudorapidity coverage [ − 1.3 , 1.3 ] . The balance function properly scaled by the width of the observed pseudorapidity window does not depend on the position or size of the pseudorapidity window. This scaling property also holds for particles in different transverse momentum ranges. In addition, we find that the width …

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Deriving An X-Ray Luminosity Function Of Dwarf Novae Based On Parallax Measurements, K. Byckling, K. Mukai, J. R. Thorstensen, J. P. Osborne Jan 2010

Deriving An X-Ray Luminosity Function Of Dwarf Novae Based On Parallax Measurements, K. Byckling, K. Mukai, J. R. Thorstensen, J. P. Osborne

Dartmouth Scholarship

We have derived an X-ray luminosity function using parallax-based distance measurements of a set of 12 dwarf novae, consisting of Suzaku, XMM-Newton and ASCA observations. The shape of the X-ray luminosity function obtained is the most accurate to date, and the luminosities of our sample are concentrated between ~10^{30}-10^{31} erg s^{-1}, lower than previous measurements of X-ray luminosity functions of dwarf novae. Based on the integrated X-ray luminosity function, the sample becomes more incomplete below ~3 x 10^{30} erg s^{-1} than it is above this luminosity limit, and the sample is dominated by X-ray bright dwarf novae. The total integrated …

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The Study Of Radio Frequency Interference (Rfi) For Radio Astronomy In Some Remote Locations In Peninsular Malaysia., Syed Bahari Ramadzan Syed Adnan Jan 2010

The Study Of Radio Frequency Interference (Rfi) For Radio Astronomy In Some Remote Locations In Peninsular Malaysia., Syed Bahari Ramadzan Syed Adnan

Student Works (2010-2019)

Radio Frequency Interference (RFI) is the main parameter to find the best site for radio astronomy research development. The increasing levels of RFI will pose a big problem for researchers in the radio astronomy field. The radio astronomers are encouraged to choose sites as free as possible from interference. In this research we aimed to survey the RFI at frequency 1 MHz-2000MHz to look the overview of the RFI profile and at frequency 1419 MHz-1421 MHz to monitor the RFI profile at Hydrogen line frequency (1420.4 MHz). We chose Peninsular Malaysia as the research area for RFI observation. We have …

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The Afterglows Of Swift-Era Gamma-Ray Bursts. I. Comparing Pre-Swift And Swift-Era Long/Soft (Type Ii) Grb Optical Afterglows, D. A. Kann, S. Klose, B. Zhang, D. Malesani, E. Nakar, A. Pozanenko, A. C. Wilson, N. R. Butler, P. Jakobsson, S. Schulze, M. Andreev, L. A. Antonelli, I. F. Bikmaev, V. Biryukov, M. B¨Ottcher, R. A. Burenin, J. M. Castro Cer´On, A. J. Castro-Tirado, G. Chincarini, B. E. Cobb, S. Covino, P. D’Avanzo, V. D’Elia, M. Della Valle, A. De Ugarte Postigo, Yu Efimov, P. Ferrero, D. Fugazza, D. Fugazza, J. P.U. Fynbo, M. Gålfalk, F. Grundahl, J. Gorosabel, S. Gupta, S. Guziy, B. Hafizov, J. Hjorth, K. Holhjem, M. Ibrahimov, M. Im, G. L. Israel, M. Je´Linek, B. L. Jensen, R. Karimov, I. M. Khamitov, U. KizilogˇLu, E. Klunko, P. Kuba´Nek, A. S. Kutyrev, P. Laursen, A. J. Levan, F. Mannucci, C. M. Martin, A. Mescheryakov, N. Mirabal, J. P. Norris, J. -E. Ovaldsen, D. Paraficz, E. Pavlenko, S. Piranomonte, A. Rossi, V. Rumyantsev, R. Salinas, A. Sergeev, D. Sharapov, J. Sollerman, B. Stecklum, L. Stella, G. Tagliaferri, N. R. Tanvir, J. Telting, V. Testa, Adria Updike, A. Volnova, D. Watson, K. Wiersema, D. Xu Jan 2010

The Afterglows Of Swift-Era Gamma-Ray Bursts. I. Comparing Pre-Swift And Swift-Era Long/Soft (Type Ii) Grb Optical Afterglows, D. A. Kann, S. Klose, B. Zhang, D. Malesani, E. Nakar, A. Pozanenko, A. C. Wilson, N. R. Butler, P. Jakobsson, S. Schulze, M. Andreev, L. A. Antonelli, I. F. Bikmaev, V. Biryukov, M. B¨Ottcher, R. A. Burenin, J. M. Castro Cer´On, A. J. Castro-Tirado, G. Chincarini, B. E. Cobb, S. Covino, P. D’Avanzo, V. D’Elia, M. Della Valle, A. De Ugarte Postigo, Yu Efimov, P. Ferrero, D. Fugazza, D. Fugazza, J. P.U. Fynbo, M. Gålfalk, F. Grundahl, J. Gorosabel, S. Gupta, S. Guziy, B. Hafizov, J. Hjorth, K. Holhjem, M. Ibrahimov, M. Im, G. L. Israel, M. Je´Linek, B. L. Jensen, R. Karimov, I. M. Khamitov, U. KizilogˇLu, E. Klunko, P. Kuba´Nek, A. S. Kutyrev, P. Laursen, A. J. Levan, F. Mannucci, C. M. Martin, A. Mescheryakov, N. Mirabal, J. P. Norris, J. -E. Ovaldsen, D. Paraficz, E. Pavlenko, S. Piranomonte, A. Rossi, V. Rumyantsev, R. Salinas, A. Sergeev, D. Sharapov, J. Sollerman, B. Stecklum, L. Stella, G. Tagliaferri, N. R. Tanvir, J. Telting, V. Testa, Adria Updike, A. Volnova, D. Watson, K. Wiersema, D. Xu

Arts & Sciences Faculty Publications

We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to 2009 September, for a total of 76 GRBs, and present an additional three pre-Swift GRBs not included in an earlier sample. Furthermore, we publish 840 additional new photometry data points on a total of 42 GRB afterglows, including large data sets for GRBs 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A, and 080810. We analyzed the light curves of all GRBs in the sample and derived spectral energy distributions for the sample with the best data quality, allowing …

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High-Order Finite Difference Methods With Subcell Resolution For Hyperbolic Conservation Laws With Stiff Reaction Terms: Preliminary Results, W. Wang, C.-W. Shu, Helen Yee, Bjorn Sjögreen Jan 2010

High-Order Finite Difference Methods With Subcell Resolution For Hyperbolic Conservation Laws With Stiff Reaction Terms: Preliminary Results, W. Wang, C.-W. Shu, Helen Yee, Bjorn Sjögreen

United States National Aeronautics and Space Administration: Publications

The motivation for this research stems from the high-speed chemical reacting flows which have stiff reaction terms, where the chemical time scales are often much smaller than the fluid dynamics time scales. It is usually too expensive to resolve all the spatial/ temporal scales if we are only interested in the main flow. On the other hand, insufficient spatial/temporal resolution will cause the speed of propagation of discontinuities to be incorrectly predicted for many numerical methods. This numerical phenomenon was first observed by Colella et al. (1986). Then LeVeque & Yee (1990) showed that a similar spurious propagation phenomenon can …

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High-Order Simulation Of Hypersonic Nonequilibrium Flows On Overset Grids, A. Lani, Bjorn Sjögreen, Helen Yee Jan 2010

High-Order Simulation Of Hypersonic Nonequilibrium Flows On Overset Grids, A. Lani, Bjorn Sjögreen, Helen Yee

United States National Aeronautics and Space Administration: Publications

The time-accurate unsteady 3D compressible flow solver ADPDIS3D is supported by a grant from the Department of Energy (DOE) SciDAC program through the Science Application Partnership (SAP) initiative. The objective of this grant is to develop, implement and validate this variable high-order 3-D multiblock overlapping (overset) grid solver for turbulence with strong shocks and density variations. ADPDIS3D includes capabilities for both direct numerical simulation (DNS), resolving all scales of the flow fields, and large eddy simulation (LES) modeling the small turbulent scales. One of the unique features of the code is the ability to perform DNS and LES computations in …

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Effects Of Α-Element Enhancement And The Thermally Pulsing-Asymptotic Giant Branch On Surface Brightness Fluctuation Magnitudes And Broadband Colors, Hyun Chul Lee, Guy Worthey, John P. Blakeslee Jan 2010

Effects Of Α-Element Enhancement And The Thermally Pulsing-Asymptotic Giant Branch On Surface Brightness Fluctuation Magnitudes And Broadband Colors, Hyun Chul Lee, Guy Worthey, John P. Blakeslee

Physics & Astronomy Faculty Publications

We investigate the effects of α-element enhancement and the thermally pulsing-asymptotic giant branch (TP-AGB) stars on the surface brightness fluctuation (SBF) magnitudes and broadband colors of simple stellar populations and compare to the empirical calibrations. We consider a broad range of ages and metallicities using the recently updated Teramo BaSTI isochrones. We find that the α-element-enhanced I-band SBF magnitudes are about 0.35mag brighter and their integrated V - I colors are about 0.02mag redder, mostly because of oxygen-enhancement effects on the upper red giant branch and AGB. We also demonstrate, using both the Teramo BaSTI and Padova isochrones, the acute …

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Search For Gravitational-Wave Bursts Associated With Gamma-Ray Bursts Using Data From Ligo Science Run 5 And Virgo Science Run 1, B. P. Abbott, R. Abbott, F. Acernese, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Malik Rakhmanov, Joseph D. Romano Jan 2010

Search For Gravitational-Wave Bursts Associated With Gamma-Ray Bursts Using Data From Ligo Science Run 5 And Virgo Science Run 1, B. P. Abbott, R. Abbott, F. Acernese, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present the results of a search for gravitational-wave bursts (GWBs) associated with 137 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray experiments during the fifth LIGO science run and first Virgo science run. The data used in this analysis were collected from 2005 November 4 to 2007 October 1, and most of the GRB triggers were from the Swift satellite. The search uses a coherent network analysis method that takes into account the different locations and orientations of the interferometers at the three LIGO-Virgo sites. We find no evidence for GWB signals associated with this sample of GRBs. …

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Search For Gravitational Waves From Compact Binary Coalescence In Ligo And Virgo Data From S5 And Vsr1, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano Jan 2010

Search For Gravitational Waves From Compact Binary Coalescence In Ligo And Virgo Data From S5 And Vsr1, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We report the results of the first search for gravitational waves from compact binary coalescence using data from the Laser Interferometer Gravitational-Wave Observatory and Virgo detectors. Five months of data were collected during the Laser Interferometer Gravitational-Wave Observatory’s S5 and Virgo’s VSR1 science runs. The search focused on signals from binary mergers with a total mass between 2 and 35M⊙. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for nonspinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7×10−3  yr−1 L−110, 2.2×10−3  yr−1 L−110, …

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All-Sky Search For Gravitational-Wave Bursts In The First Joint Ligo-Geo-Virgo Run, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Malik Rakhmanov, Joseph D. Romano, Robert Stone Jan 2010

All-Sky Search For Gravitational-Wave Bursts In The First Joint Ligo-Geo-Virgo Run, J. Abadie, B. P. Abbott, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soumya Mohanty, Soma Mukherjee, Malik Rakhmanov, Joseph D. Romano, Robert Stone

Physics & Astronomy Faculty Publications

We present results from an all-sky search for unmodeled gravitational-wave bursts in the data collected by the LIGO, GEO 600 and Virgo detectors between November 2006 and October 2007. The search is performed by three different analysis algorithms over the frequency band 50–6000 Hz. Data are analyzed for times with at least two of the four LIGO-Virgo detectors in coincident operation, with a total live time of 266 days. No events produced by the search algorithms survive the selection cuts. We set a frequentist upper limit on the rate of gravitational-wave bursts impinging on our network of detectors. When combined …

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The Lisa Gravitational Wave Foreground: A Study Of Double White Dwarfs, Ashley J. Ruiter, Krzysztof Belczynski, Matthew Benacquista, Shane L. Larson, Gabriel Williams Jan 2010

The Lisa Gravitational Wave Foreground: A Study Of Double White Dwarfs, Ashley J. Ruiter, Krzysztof Belczynski, Matthew Benacquista, Shane L. Larson, Gabriel Williams

Physics & Astronomy Faculty Publications

Double white dwarfs (WDs) are expected to be a source of confusion-limited noise for the future gravitational wave observatory LISA. In a specific frequency range, this \"foreground noise\" is predicted to rise above the instrumental noise and hinder the detection of other types of signals, e.g., gravitational waves arising from stellar-mass objects inspiraling into massive black holes. In many previous studies, only detached populations of compact object binaries have been considered in estimating the LISA gravitational wave foreground signal. Here, we investigate the influence of compact object detached and Roche-Lobe overflow (RLOF) Galactic binaries on the shape and strength of …

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Buddhist Thought: Murakami Senshō And Critical Buddhism, A. Aguilar-Arevalo, Sally Koutsoliotas Jan 2010

Buddhist Thought: Murakami Senshō And Critical Buddhism, A. Aguilar-Arevalo, Sally Koutsoliotas

Faculty Journal Articles

No abstract provided.

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A Spitzer Search For Planetary-Mass Brown Dwarfs With Circumstellar Disks: Candidate Selection, Paul M. Harvey, Daniel T. Jaffe, Katelyn N. Allers, Michael Liu Jan 2010

A Spitzer Search For Planetary-Mass Brown Dwarfs With Circumstellar Disks: Candidate Selection, Paul M. Harvey, Daniel T. Jaffe, Katelyn N. Allers, Michael Liu

Faculty Journal Articles

No abstract provided.

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The Physical And Dynamical Structure Of Serpens - Two Very Different Sub-(Proto)Clusters, A. Duarte-Cabral, G. A. Fuller, N. Peretto, J. Hatchell, Edwin F. Ladd, J. Buckle, J. Richer, S. F. Graves Jan 2010

The Physical And Dynamical Structure Of Serpens - Two Very Different Sub-(Proto)Clusters, A. Duarte-Cabral, G. A. Fuller, N. Peretto, J. Hatchell, Edwin F. Ladd, J. Buckle, J. Richer, S. F. Graves

Faculty Journal Articles

No abstract provided.

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Physical Conditions Including Magnetic Fields In Several Star Forming Regions Of The Galaxy, Matt Lykins Jan 2010

Physical Conditions Including Magnetic Fields In Several Star Forming Regions Of The Galaxy, Matt Lykins

University of Kentucky Doctoral Dissertations

This document describes studies of two independent regions of the interstellar medium (ISM). These studies have the common element that both pertain to regions in our Galaxy that are known to be associated with present-day star formation. These studies aim to help us understand the ISM, star formation, and ultimately where we came from, since, after all, our star, the Sun, is itself the product of star formation 4.5 billion years ago. The first project measured the Zeeman Effect on the 21 cm H I absorption line in order to create a map of the line of sight magnetic fields …

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Triplets Of Supermassive Black Holes: Astrophysics Gravitational Waves And Detection, Pau Amaro-Seoane, Alberto Sesana, Loren Hoffman, Matthew Benacquista, Christoph Eichhorn, Junichiro Makino, Rainer Spurzem Jan 2010

Triplets Of Supermassive Black Holes: Astrophysics Gravitational Waves And Detection, Pau Amaro-Seoane, Alberto Sesana, Loren Hoffman, Matthew Benacquista, Christoph Eichhorn, Junichiro Makino, Rainer Spurzem

Physics & Astronomy Faculty Publications

Supermassive black holes (SMBHs) found in the centres of many galaxies are understood to play a fundamental, active role in the cosmological structure formation process. In hierarchical formation scenarios, SMBHs are expected to form binaries following the merger of their host galaxies. If these binaries do not coalesce before the merger with a third galaxy, the formation of a black hole triple system is possible. Numerical simulations of the dynamics of triples within galaxy cores exhibit phases of very high eccentricity (as high as e∼ 0.99). During these phases, intense bursts of gravitational radiation can be emitted at orbital periapsis, …

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Searches For Gravitational Waves From Known Pulsars With Science Run 5 Ligo Data, B. P. Abbott, R. Abbott, F. Acernese, Teviet Creighton, Matthew Benacquista, Mario C. Diaz, Soumya D. Mohanty, Soma Mukherjee, Malik Rakhmanov, Joseph D. Romano Jan 2010

Searches For Gravitational Waves From Known Pulsars With Science Run 5 Ligo Data, B. P. Abbott, R. Abbott, F. Acernese, Teviet Creighton, Matthew Benacquista, Mario C. Diaz, Soumya D. Mohanty, Soma Mukherjee, Malik Rakhmanov, Joseph D. Romano

Physics & Astronomy Faculty Publications

We present a search for gravitational waves from 116 known millisecond and young pulsars using data from the fifth science run of the LIGO detectors. For this search, ephemerides overlapping the run period were obtained for all pulsars using radio and X-ray observations. We demonstrate an updated search method that allows for small uncertainties in the pulsar phase parameters to be included in the search. We report no signal detection from any of the targets and therefore interpret our results as upper limits on the gravitational wave signal strength. The most interesting limits are those for young pulsars. We present …

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