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Articles 4741 - 4770 of 8860

Full-Text Articles in Astrophysics and Astronomy

Neutral Pion Cross Section And Spin Asymmetries At Intermediate Pseudorapidity In Polarized Proton Collisions At √S=200  Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, Renee H. Fatemi, Robert G. Fersch, Wolfgang Korsch, Suvarna Ramachandran, G. Webb Jan 2014

Neutral Pion Cross Section And Spin Asymmetries At Intermediate Pseudorapidity In Polarized Proton Collisions At √S=200  Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, Renee H. Fatemi, Robert G. Fersch, Wolfgang Korsch, Suvarna Ramachandran, G. Webb

Physics and Astronomy Faculty Publications

The differential cross section and spin asymmetries for neutral pions produced within the intermediate pseudorapidity range 0.8<ηpT/c and is found to agree with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry ALL is measured in the same pseudorapidity range and spans a range of Bjorken-x down to x≈0.01. The measured ALL is consistent with model predictions for varying degrees of gluon polarization. The parity-violating asymmetry AL is also measured and found to be consistent with zero. The transverse single-spin asymmetry AN is measured over a previously unexplored kinematic range in …

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Long-Term Tev And X-Ray Observations Of The Gamma- Ray Binary Hess J0632+057, P. T. Reynolds, Veritas, Hess Jan 2014

Long-Term Tev And X-Ray Observations Of The Gamma- Ray Binary Hess J0632+057, P. T. Reynolds, Veritas, Hess

Physical Sciences Publications

HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories in both the northern and southern hemispheres. Here we report on long-term observations of HESS J0632+057 conducted with the Very Energetic Radiation Imaging Telescope Array System and High Energy Stereoscopic System Cherenkov telescopes and the X-ray satellite Swift, spanning a time range from 2004 to 2012 and covering most of the system's orbit. The very-high-energy (VHE) emission is found to be variable and is correlated with that at X-ray energies. An orbital period of days is derived from the …

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Energy Dependence Of The (E,2E) Recoil Peak To Binary Peak Ratio Across He (2P2)1D And (2S2P)1P Autoionizing Levels, B. A. Deharak, K. Bartschat, Nicholas L. S. Martin Jan 2014

Energy Dependence Of The (E,2E) Recoil Peak To Binary Peak Ratio Across He (2P2)1D And (2S2P)1P Autoionizing Levels, B. A. Deharak, K. Bartschat, Nicholas L. S. Martin

Physics and Astronomy Faculty Publications

The (e,2e) recoil peak to binary peak ratio as a function of the ejected-electron energy is reported for helium autoionizing levels (2p2)1D and (2s2p)1P. A special out-of-plane geometry is used where the ejected electrons are detected in a plane that includes the momentum transfer axis but is perpendicular to the scattering plane. The measured recoil peak to binary peak ratio is a dimensionless quantity that can be directly compared with calculations. A second-order model in the projectile-target interaction correctly reproduces the observed energy dependence …

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Annual Solar Motion And Spy Satellites, Margaret Jensen, Shane L. Larson Jan 2014

Annual Solar Motion And Spy Satellites, Margaret Jensen, Shane L. Larson

Browse All Undergraduate research

A topic often taught in introductory astronomy courses is the changing position of the Sun in the sky as a function of time of day, and season. The relevance and importance of this motion is explained in the context of seasons and the impact it has on human activities such as agriculture. The geometry of the ob- served motion in the sky is usually reduced to graphical representations and visualizations that can be difficult to render and grasp. Sometimes students are asked to observe the Suns changing motion and record their data, but this is a long-term project requiring several …

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Updating And Revising Star Camera For Future Flights Of Balloon Borne Experiment, Krystle N. Sy, Seth Hillbrand Jan 2014

Updating And Revising Star Camera For Future Flights Of Balloon Borne Experiment, Krystle N. Sy, Seth Hillbrand

STAR Program Research Presentations

The BLAST (Balloon-borne Large Aperture Submillimeter Telescope) experiment surveys the galaxy from altitudes of 100,000 ft in order to answer important cosmological questions, such as how stars are formed. This experiment is conducted above Antarctica to minimize unwanted noise. Two star cameras are used in the navigation systems to identify known stars. The cameras take pictures and match stars in the image to known star positions from a catalog stored in the star camera's computer. This is done using code written in C++, a computer programming language. In order to modernize the system, the code needs to be updated. A …

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Probing The Alfvén Speed Profile Using Type Ii Radio Bursts, Peter Sullivan, Hazel M. Bain Jan 2014

Probing The Alfvén Speed Profile Using Type Ii Radio Bursts, Peter Sullivan, Hazel M. Bain

STAR Program Research Presentations

Type II radio bursts can be produced when a coronal mass ejection (CME) traveling faster than the local plasma speed of the ambient medium produces a shock. From the drift rate of type II bursts it is possible to calculate the velocity of the CME. We present a statistical survey of type II radio burst events during 2012-2013. Using radio observations we determine speeds of CME shocks as a means of setting limits on the Alfvén speed profile of the interplanetary medium as a function of distance from the sun. In particular we use observations from the WAVES instruments onboard …

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Landsat-8: Science And Product Vision For Terrestrial Global Change Research, David P. Roy, M. A. Wulder, T. R. Loveland, C. E. Woodcock, R. G. Allen, M. C. Anderson, D. Helder, J. R. Irons, D. M. Johnson, R. Kennedy, T. A. Scambos, C. B. Schaaf, J. R. Schott, Y. Sheng, E. F. Vermote, A. S. Belward, R. Bindschadler, W. B. Cohen, F. Gao, J. D. Hipple, P. Hostert, Desert Research Institute, Reno, Nv, C. O. Justice, Ayse Kilic, V. Kovalskyy, Z. P. Lee, L. Lymburner, J. G. Masek, J. Mccorkel, Y. Shuai, R. Trezza, J. Vogelmann, R. H. Wynne, Z. Zhu Jan 2014

Landsat-8: Science And Product Vision For Terrestrial Global Change Research, David P. Roy, M. A. Wulder, T. R. Loveland, C. E. Woodcock, R. G. Allen, M. C. Anderson, D. Helder, J. R. Irons, D. M. Johnson, R. Kennedy, T. A. Scambos, C. B. Schaaf, J. R. Schott, Y. Sheng, E. F. Vermote, A. S. Belward, R. Bindschadler, W. B. Cohen, F. Gao, J. D. Hipple, P. Hostert, Desert Research Institute, Reno, Nv, C. O. Justice, Ayse Kilic, V. Kovalskyy, Z. P. Lee, L. Lymburner, J. G. Masek, J. Mccorkel, Y. Shuai, R. Trezza, J. Vogelmann, R. H. Wynne, Z. Zhu

School of Natural Resources: Faculty Publications

Landsat 8, a NASA and USGS collaboration, acquires global moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave, and thermal infrared. Landsat 8 extends the remarkable 40 year Landsat record and has enhanced capabilities including new spectral bands in the blue and cirrus cloud-detection portion of the spectrum, two thermal bands, improved sensor signal-to-noise performance and associated improvements in radiometric resolution, and an improved duty cycle that allows collection of a significantly greater number of images per day. This paper introduces the current (2012–2017) Landsat Science Team's efforts to establish an initial understanding of …

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Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton Jan 2014

Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton

School of Natural Resources: Faculty Publications

Photosynthesis (PSN) is a pigment level process in which antenna pigments (predominately chlorophylls) in chloroplasts absorb photosynthetically active radiation (PAR) for the photochemical process. PAR absorbed by foliar non-photosynthetic components is not used for PSN. The fraction of PAR absorbed (fAPAR) by a canopy/vegetation (i.e., fAPARcanopy) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) images, referred to as MOD15A2 FPAR, has been used to compute absorbed PAR (APAR) for PSN (APARPSN) which is utilized to produce the standard MODIS gross primary production (GPP) product, referred to as MOD17A2 GPP. In this study, the fraction of PAR …

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Orbital Solutions And Absolute Elements Of The Short-Period Eclipsing Binary Es Librae, Nicole E. Cabrera, James R. Sowell, Richard M. Williamon, Thomas F. Collins, Francis C. Fekel, Michael H. Williamson, Matthew W. Muterspaugh Jan 2014

Orbital Solutions And Absolute Elements Of The Short-Period Eclipsing Binary Es Librae, Nicole E. Cabrera, James R. Sowell, Richard M. Williamon, Thomas F. Collins, Francis C. Fekel, Michael H. Williamson, Matthew W. Muterspaugh

Information Systems and Engineering Management Research Publications

We have obtained new differential UBV photoelectric photometry and radial velocities of both components of the short-period eclipsing binary ES Lib. The system has a circular orbit with a period of 0.883040928 days and is seen at an inclination of 70.1°. With the Wilson-Devinney analysis program, we obtained a simultaneous solution of our photometric and spectroscopic observations that resulted in masses of M1 = 2.30 ± 0.03 M⊙ and M2 = 0.97 ± 0.01 M⊙ and the equal-volume radii of R1 = 2.69 ± 0.02 R⊙ and R2 = 1.83 ± 0.01 R⊙ for the primary and secondary, respectively. The …

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Dynamical Models Of Elliptical Galaxies – I. Simple Methods, A. Angello, N. Evans, Aaron Romanowsky Jan 2014

Dynamical Models Of Elliptical Galaxies – I. Simple Methods, A. Angello, N. Evans, Aaron Romanowsky

Faculty Publications

We study dynamical models for elliptical galaxies, deriving the projected kinematic profiles in a form that is valid for general surface-brightness profiles and (spherical) total mass profiles, without the need for any explicit deprojection. We then show that an almost flat rotation curve, combined with modest velocity anisotropy, is already sufficient to recover the kinematic profiles of nearby ellipticals. As an application, we provide two different sets of mass estimators for elliptical galaxies, based on either the velocity dispersion at a specific location near the effective radius, or the aperture-averaged velocity dispersion. In the large aperture (virial) limit, mass estimators …

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[Sabbatical Report], Louis-Gregory Strolger Jan 2014

[Sabbatical Report], Louis-Gregory Strolger

Sabbatical Reports

I spent my AY2014 sabbatical year at the Space Telescope Science Institute (STScI), with plans of completing the analyses of supernova rates for both thermonuclear and corecolliape events in high redshift galaxies from the Multi-cycle Treasury Projects with the Hubble Space Telescope.

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Comparative Analysis Of A Transition Region Bright Point With A Blinker And Coronal Bright Point Using Multiple Eis Emission Lines, N B. Orange, H M. Oluseyi, D L. Chesny, M Patel, K Hesterly, L Preuss, C Neira, Niescja E. Turner Jan 2014

Comparative Analysis Of A Transition Region Bright Point With A Blinker And Coronal Bright Point Using Multiple Eis Emission Lines, N B. Orange, H M. Oluseyi, D L. Chesny, M Patel, K Hesterly, L Preuss, C Neira, Niescja E. Turner

Physics and Astronomy Faculty Research

Since their discovery 20 year ago, transition region bright points have never been observed spectroscopically. Bright point properties have not been compared with similar transition region and coronal structures. In this work we have investigated three transient quiet Sun brightenings including a transition region bright point (TR BP), a coronal bright point (CBP) and a blinker. We use time-series observations of the extreme-ultraviolet emission lines of a wide range of temperature T(logT=5.3 – 6.4) from the EUV Imaging Spectrometer (EIS) onboard the Hinode satellite. We present the EIS temperature maps and Doppler maps, which are compared with …

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Studying Short-Period Comets And Long-Period Comets Detected By Wise/Neowise, Emily Kramer Jan 2014

Studying Short-Period Comets And Long-Period Comets Detected By Wise/Neowise, Emily Kramer

Electronic Theses and Dissertations

The Wide-field Infrared Survey Explorer (WISE) mission surveyed the sky in four infrared wavelength bands (3.4, 4.6, 12 and 22 μm) between January 2010 and February 2011. During the mission, WISE serendipitously observed 160 comets, including 21 newly discovered objects. About 89 of the comets observed by WISE displayed a significant dust tail in the 12 and 22 μm (thermal emission) bands, showing a wide range of activity levels and dust morphology. Since the observed objects are a mix of both long-period comets (LPCs) and short-period comets (SPCs), differences in their activity can be used to better understand the thermal …

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Surface Plasmon Resonance Sensing Properties Of A 3d Nanostructure Consisting Of Aligned Nanohole And Nanocone Arrays, Mohamadreza Najiminaini, Erden Ertorer, Bozena Kaminska, Silvia Mittler, Jeffrey J.L. Carson Jan 2014

Surface Plasmon Resonance Sensing Properties Of A 3d Nanostructure Consisting Of Aligned Nanohole And Nanocone Arrays, Mohamadreza Najiminaini, Erden Ertorer, Bozena Kaminska, Silvia Mittler, Jeffrey J.L. Carson

Physics and Astronomy Publications

Molecular surface plasmon resonance (SPR) sensing is one of the most common applications of an array of periodic nanoholes in a metal film. However, metallic nanohole arrays (NHAs) with low-hole count have lower resolution and SPR sensing performance compared to NHAs with high-hole count. In this paper, we present a compact three-dimensional (3D) plasmonic nanostructure with extraordinary optical transmission properties benefiting from surface plasmon matching and enhanced localized surface plasmon coupling. The 3D nanostructure consisted of a gold film containing a NHA with an underlying cavity and a gold nanocone array (NCA) at the bottom of the cavity. Each nanocone …

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Embedded Star Formation In S4g Galaxy Dust Lanes., Debra M. Elmegreen, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Johan H. Knapen, Yaron Teich, Mark Popinchalk, E. Athanassoula, Albert Bosma, Sebastien Comeron, Yuri N. Efremov, Dimitri A. Gadotti, Armando Gil De Paz, Joannah L. Hinz, Luis C. Ho, Benne W. Holwerda, Taehyun Kim, Jarkko Laine, Eija Laurikainen, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Michael W. Regan, Heikki Salo, Mark Seibert, Kartik Sheth Jan 2014

Embedded Star Formation In S4g Galaxy Dust Lanes., Debra M. Elmegreen, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Johan H. Knapen, Yaron Teich, Mark Popinchalk, E. Athanassoula, Albert Bosma, Sebastien Comeron, Yuri N. Efremov, Dimitri A. Gadotti, Armando Gil De Paz, Joannah L. Hinz, Luis C. Ho, Benne W. Holwerda, Taehyun Kim, Jarkko Laine, Eija Laurikainen, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Michael W. Regan, Heikki Salo, Mark Seibert, Kartik Sheth

Faculty and Staff Scholarship

Star-forming regions that are visible at 3.6 μm and Hα but not in the u, g, r, i, z bands of the Sloan Digital Sky Survey are measured in five nearby spiral galaxies to find extinctions averaging ∼3.8 mag and stellar masses averaging ∼5 × 104 M. These regions are apparently young star complexes embedded in dark filamentary shock fronts connected with spiral arms. The associated cloud masses are ∼107 M. The conditions required to make such complexes are explored, including gravitational instabilities in spiral-shocked gas and compression of incident clouds. We find that instabilities are too slow for a …

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Exomol Molecular Line Lists V: The Ro-Vibrational Spectra Of Nacl And Kcl, Emma J. Barton, Christopher Chiu, Shirin Golpayegani, Sergei N. Yurchenko, Jonathan Tennyson, Daniel J. Frohman, Peter F. Bernath Jan 2014

Exomol Molecular Line Lists V: The Ro-Vibrational Spectra Of Nacl And Kcl, Emma J. Barton, Christopher Chiu, Shirin Golpayegani, Sergei N. Yurchenko, Jonathan Tennyson, Daniel J. Frohman, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Accurate rotation-vibration line lists for two molecules, NaCl and KCl, in their ground electronic states are presented. These line lists are suitable for temperatures relevant to exoplanetary atmospheres and cool stars (up to 3000 K). Isotopologues 23Na35Cl, 23Na37Cl, 39K35Cl, 39K37Cl, 41K35Cl and 41K37Cl are considered. Laboratory data were used to refine ab initio potential energy curves in order to compute accurate ro-vibrational energy levels. Einstein A coefficients are generated using newly determined ab initio dipole moment curves calculated using the CCSD(T) method. …

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A Transition Mass For Black Holes To Show Broad Emission Lines, Susmita Chakravorty, Martin Elvis, Gary J. Ferland Jan 2014

A Transition Mass For Black Holes To Show Broad Emission Lines, Susmita Chakravorty, Martin Elvis, Gary J. Ferland

Physics and Astronomy Faculty Publications

Although the supermassive (AGN) and stellar mass (BHBs) black holes have many properties in common, the broad emission lines (BELs) are exclusively signatures of the active galactic nuclei (AGN). Based on the detection of these lines from Sloan Digital Sky Survey (SDSS) data bases, there seems to be no AGN with mass MBH ≲ 105 M⊙. In this paper, we investigate if such low-mass black holes are really non-existent or they are undetected because the BELs in them are not produced efficiently. Using the ionizing spectral energy distribution for a wide range of black hole mass, …

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Suppression Of Dielectronic Recombination At Finite Densities, T. W. Gorczyca, D. Nikolić, N. R. Badnell, Gary J. Ferland Jan 2014

Suppression Of Dielectronic Recombination At Finite Densities, T. W. Gorczyca, D. Nikolić, N. R. Badnell, Gary J. Ferland

Physics and Astronomy Faculty Publications

Density-dependent effective dielectronic recombination rate coefficients are determined in order to explore finite-density effects on the ionization balance of plasmas.

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Binary Star Light Curve And Model Of Tyc 3670-588-1 From Professional-Amateur Collaboration, A, J. W. Robertson, B. Mcmath, D. Waters, R. T. Campbell, G. Roberts Jan 2014

Binary Star Light Curve And Model Of Tyc 3670-588-1 From Professional-Amateur Collaboration, A, J. W. Robertson, B. Mcmath, D. Waters, R. T. Campbell, G. Roberts

Journal of the Arkansas Academy of Science

We present the orbital light curve and model system parameters of a newly discovered eclipsing binary star in the constellation of Perseus. Our professional-amateur astronomy collaboration between Arkansas Tech University (ATU), the Central Arkansas Astronomy Society (CAAS) and Whispering Pine Observatory, produced photometry in two wavelengths (Johnson V and R) in order to model the system for fundamental parameters with a binary modeling code. We determined that this binary system contains two F-type stars orbiting each other with a short orbital period and having the following characteristics for the two components: mass ratio (q ~ 0.92), temperatures (T1~ 7170 K, …

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Unidirectional Lasing Emerging From Frozen Light In Nonreciprocal Cavities, Hamidreza Ramezani, S. Kalish, I. Vitebskiy, T. Kottos Jan 2014

Unidirectional Lasing Emerging From Frozen Light In Nonreciprocal Cavities, Hamidreza Ramezani, S. Kalish, I. Vitebskiy, T. Kottos

Physics & Astronomy Faculty Publications

We introduce a class of unidirectional lasing modes associated with the frozen mode regime of nonreciprocal slow-wave structures. Such asymmetric modes can only exist in cavities with broken timereversal and space inversion symmetries. Their lasing frequency coincides with a spectral stationary inflection point of the underlying passive structure and is virtually independent of its size. These unidirectional lasers can be indispensable components of photonic integrated circuitry.

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Numerical Simulations Of Compact Intracloud Discharges As The Relativistic Runaway Electron Avalanche-Extensive Air Shower Process, Shahab Arabshahi, Joseph R. Dwyer, A. Nag, V. A. Rakov, Hamid K. Rassoul Jan 2014

Numerical Simulations Of Compact Intracloud Discharges As The Relativistic Runaway Electron Avalanche-Extensive Air Shower Process, Shahab Arabshahi, Joseph R. Dwyer, A. Nag, V. A. Rakov, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

Compact intracloud discharges (CIDs) are sources of the powerful, often isolated radio pulses emitted by thunderstorms. The VLF-LF radio pulses are called narrow bipolar pulses (NBPs). It is still not clear how CIDs are produced, but two categories of theoretical models that have previously been considered are the Transmission Line (TL) model and the Relativistic Runaway Electron Avalanche-Extensive Air Showers (RREA-EAS) model. In this paper, we perform numerical calculations of RREA-EASs for various electric field configurations inside thunderstorms. The results of these calculations are compared to results from the other models and to the experimental data. Our analysis shows that …

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Emission Lines Properties Of The Radio-Loud Quasar Lamost J1131+3114, Zhixin Shi, Georges Comte, Ali L. Luo, Tuehong H. Zhao, Jingkun K. Zhao, T D. Oswalt, Fuchao C. Wu Jan 2014

Emission Lines Properties Of The Radio-Loud Quasar Lamost J1131+3114, Zhixin Shi, Georges Comte, Ali L. Luo, Tuehong H. Zhao, Jingkun K. Zhao, T D. Oswalt, Fuchao C. Wu

Aerospace, Physics, and Space Science Faculty Publications

The radio-loud quasar LAMOST J1131+3114 (Ton 580, B2 1128+315), showing asymmetrical profile in Hβ and [O III] lines, has been selected from the LAMOST Pilot Survey for further study. We present an analysis of its emission lines by means of multiple Gaussian fitting, performed on LAMOST, Apache Point Observatory, and archival spectra. The broad line region, with an Hβ line of FWHM ~ 4000 km sˉ¹ has been fit with a double Gaussian, one of which is very broad and redshifted from the reference frame. The object is a likely Population B quasar. The [O III] λλ4959,5007 lines profiles of …

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Modulated X-Ray Emission Of The Magnetic O8.5v-Star Tr16-22, Yaël Nazé, Gregg A. Wade, Véronique Petit Jan 2014

Modulated X-Ray Emission Of The Magnetic O8.5v-Star Tr16-22, Yaël Nazé, Gregg A. Wade, Véronique Petit

Aerospace, Physics, and Space Science Faculty Publications

Using an extensive X-ray dataset, we analyzed the X-ray emission of the massive O-star Tr16-22, which was recently found to be magnetic. Its bright X-ray emission is found to be modulated with a 54d period. This timescale should represent the rotational timescale of the star, as it does for other magnetic massive stars. In parallel, new spectropolarimetric data confirm the published magnetic detection.

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Arrakis: Atlas Of Resonance Rings As Known In The S⁴G, Sébastien Comerón, Trisha Mizusawa Jan 2014

Arrakis: Atlas Of Resonance Rings As Known In The S⁴G, Sébastien Comerón, Trisha Mizusawa

Aerospace, Physics, and Space Science Faculty Publications

Context. Resonance rings and pseudorings (here collectively called rings) are thought to be related to the gathering of material near dynamical resonances caused by non-axisymmetries in galaxy discs. This means that they are the result of secular evolution processes that redistribute material and angular momentum in discs. Studying them may give clues on the formation and growth of bars and other disc non-axisymmetries. Aims. Our aims are to produce a catalogue and an atlas of the rings detected in the Spitzer Survey of Stellar Structure in Galaxies (S⁴G) and to conduct a statistical study of the data in the catalogue. …

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Extended Warm Gas In The Ulirg Mrk273: Galactic Outflows And Tidal Debris, Javier Rodríguez Zaurín, Clive N. Tadhunter, David S.N. Rupke, Sylvain Veilleux, Henrik W.W. Spoon, Marco Chiaberge, Cristina Ramos Almeida, Dan Batcheldor, William B. Sparks Jan 2014

Extended Warm Gas In The Ulirg Mrk273: Galactic Outflows And Tidal Debris, Javier Rodríguez Zaurín, Clive N. Tadhunter, David S.N. Rupke, Sylvain Veilleux, Henrik W.W. Spoon, Marco Chiaberge, Cristina Ramos Almeida, Dan Batcheldor, William B. Sparks

Aerospace, Physics, and Space Science Faculty Publications

We present new HST/ACS medium-and narrow-band images and optical Isaac Newton Telescope long-slit spectra of the merging system Mrk273. The HST observations sample the [OIII]λλ4959,5007 emission from the galaxy and the nearby continuum. These data were taken as a part of a larger study of ultraluminous infrared galaxies (ULIRGs) with the aim of investigating the importance of the warm, AGN induced outflows in such objects. The HST images show that the morphologies of the extended continuum and the ionised gas emission from the galaxy are decoupled, extending almost perpendicular to each other. In particular, we detect for the first time …

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Embedded Star Formation In S4g Galaxy Dust Lanes, Debra M. Elmegreen, Trisha Mizusawa Jan 2014

Embedded Star Formation In S4g Galaxy Dust Lanes, Debra M. Elmegreen, Trisha Mizusawa

Aerospace, Physics, and Space Science Faculty Publications

Star-forming regions that are visible at 3.6 μm and Hα but not in the u, g, r, i, z bands of the Sloan Digital Sky Survey are measured in five nearby spiral galaxies to find extinctions averaging ∼3.8 mag and stellar masses averaging ∼5 × 104 M ⊙. These regions are apparently young star complexes embedded in dark filamentary shock fronts connected with spiral arms. The associated cloud masses are ∼10 7 M ⊙. The conditions required to make such complexes are explored, including gravitational instabilities in spiral-shocked gas and compression of incident clouds. We find that instabilities are too …

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An Analytical Approach For Calculating Energy Spectra Of Relativistic Runaway Electron Avalanches In Air, Eric S. Crame, Joseph R. Dwyer, Shahab Arabshahi, Igor B. Vodopiyanov, Ningyu Liu, Hamid K. Rassoul Jan 2014

An Analytical Approach For Calculating Energy Spectra Of Relativistic Runaway Electron Avalanches In Air, Eric S. Crame, Joseph R. Dwyer, Shahab Arabshahi, Igor B. Vodopiyanov, Ningyu Liu, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

Simplified equations describing the transport and energy spectrum of runaway electrons are derived from the basic kinematics of the continuity equations. These equations are useful in modeling the energy distribution of energetic electrons in strong electric fields, such as those found inside thunderstorms. Dwyer and Babich (2011) investigated the generation of low-energy electrons in relativistic runaway electron avalanches. The paper also developed simple analytical expressions to describe the detailed physics of Monte Carlo simulations of relativistic runaway electrons in air. In the current work, the energy spectra of the runaway electron population are studied in detail. Dependence of electron avalanche …

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Bayesian Detection And Characterization Of Extra-Solar Planets Via Photometric Variations, Ben H. Placek Jan 2014

Bayesian Detection And Characterization Of Extra-Solar Planets Via Photometric Variations, Ben H. Placek

Legacy Theses & Dissertations (2009 - 2024)

Exoplanets are known to be responsible for a variety of photometric effects, which collectively can be used for both exoplanet detection and characterization. A portion of the observed flux variation originates directly from the exoplanet itself as both a reflected light component and thermal emission. Additional effects originate from the influence of the exoplanet on its host star. These include Doppler boosting, or beaming, caused by the radial velocity variations due to the stellar wobble, as well as variations in flux caused by the ellipsoidal shape of the star, which is induced by the planetary tidal forces. The newly developed …

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Orion, Katelyn G. Gyorkos Jan 2014

Orion, Katelyn G. Gyorkos

Natural Sciences Student Research Presentations

The purpose of this project was to gather information about the stars and objects in the constellation Orion. This is a project for the Natural Sciences Poster Session at Parkland College.

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Welcome To Maxwell Montes, Nichole S. Buck Jan 2014

Welcome To Maxwell Montes, Nichole S. Buck

Natural Sciences Student Research Presentations

This poster poses Venus as a travel destination through a fictional travel agency, Venusian Journeys, and provides facts about the planet, the continent Ishtar Terra and its highest point, Maxwell Montes. This is a project for the Natural Sciences Poster Session at Parkland College.

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