Hubble Space Telescope Hot Jupiter Transmission Spectral Survey: A Detection Of Na And Strong Optical Absorption In Hat-P-1b,
2013
University of Exeter
Hubble Space Telescope Hot Jupiter Transmission Spectral Survey: A Detection Of Na And Strong Optical Absorption In Hat-P-1b, Nikolay Nikolov, David K. Sing, Frederic Pont, Adam S. Burrows, Jonathan J. Fortney, Gilda E. Ballester, Thomas M. Evans, Catherine M. Huitson, Hannah R. Wakeford, Paul A. Wilson, Suzanne Aigrain, Drake Deming, Neale P. Gibson, Gregory W. Henry, Heather Knutson, Alain Lecavelier Des Etangs, Adam P. Showman, Alfred Vidal-Madjar, Kevin J. Zahnle
Information Systems and Engineering Management Research Publications
We present an optical to near-infrared transmission spectrum of the hot Jupiter HAT-P-1b, based on Hubble Space Telescope observations, covering the spectral regime from 0.29 to 1.027 μm with Space Telescope Imaging Spectrograph (STIS), which is coupled with a recent Wide Field Camera 3 (WFC3) transit (1.087 to 1.687 μm). We derive refined physical parameters of the HAT-P-1 system, including an improved orbital ephemeris. The transmission spectrum shows a strong absorption signature shortward of 0.55 μm, with a strong blueward slope into the near-ultraviolet. We detect atmospheric sodium absorption at a 3.3σ significance level, but find no evidence for the …
Discovery Of A New Tev Gamma-Ray Source: Ver J0521+211,
2013
Cork Institute of Technology
Discovery Of A New Tev Gamma-Ray Source: Ver J0521+211, P. T. Reynolds, Veritas
Physical Sciences Publications
We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov Telescope Array. These observations were motivated by the discovery of a cluster of >30 GeV photons in the first year of Fermi Large Area Telescope observations. VER J0521+211 is relatively bright at TeV energies, with a mean photon flux of (1.93 ± 0.13stat ± 0.78sys) × 10–11 cm–2 s–1 above 0.2 TeV during the period of the VERITAS observations. The source is strongly variable on a daily timescale across all wavebands, from optical to TeV, with a peak …
The Role Of Cross-Shock Potential On Pickup Ion Shock Acceleration In The Framework Of Focused Transport Theory,
2013
Florida Institute of Technology
The Role Of Cross-Shock Potential On Pickup Ion Shock Acceleration In The Framework Of Focused Transport Theory, Pingbing Zuo, Ming Zhang, Hamid K. Rassoul
Aerospace, Physics, and Space Science Faculty Publications
The focused transport theory is appropriate to describe the injection and acceleration of low-energy particles at shocks as an extension of diffusive shock acceleration (DSA). In this investigation, we aim to characterize the role of cross-shock potential (CSP) originated in the charge separation across the shock ramp on pickup ion (PUI) acceleration at various types of shocks with a focused transport model. The simulation results of energy spectrum and spatial density distribution for the cases with and without CSP added in the model are compared.With sufficient acceleration time, the focused transport acceleration finally falls into the DSA regime with the …
Gaussian Representation Of Active Galactic Nuclei,
2013
Purdue University
Gaussian Representation Of Active Galactic Nuclei, Jeffrey W. Klimes, Matthew Lister
The Summer Undergraduate Research Fellowship (SURF) Symposium
Active galactic nuclei (AGN) are the areas around the centers of galaxies with high luminosity in much of the electromagnetic spectrum. The existing model of AGN describes the high luminosity as the result of accretion of matter around a black hole at the galaxy’s center. Many AGN generate superluminal jets of density higher than the surrounding interstellar medium. The cause for and mechanics driving the relativistic jets are not well understood. In addition, the jets often change direction decaparsecs away from their associated cores, the cause of which has not been well explained. In order to better understand the mechanics …
Hst Hot-Jupiter Transmission Spectral Survey: Evidence For Aerosols And Lack Of Tio In The Atmosphere Of Wasp-12b,
2013
University of Exeter
Hst Hot-Jupiter Transmission Spectral Survey: Evidence For Aerosols And Lack Of Tio In The Atmosphere Of Wasp-12b, David K. Sing, Alain Lecavelier Des Etangs, Jonathan J. Fortney, Adam Burrows, Frederic Pont, Hannah R. Wakeford, Gilda E. Ballester, Nikolay Nikolov, Gregory W. Henry, Suzanne Aigrain, Drake Deming, Thomas M. Evans, Neale P. Gibson, Catherine M. Huitson, Heather Knutson, Adam P. Showman, Alfred Vidal-Madjar, Paul A. Wilson, Michael H. Williamson, Kevin J. Zahnle
Information Systems and Engineering Management Research Publications
We present Hubble Space Telescope (HST) optical transmission spectra of the transiting hot-Jupiter WASP-12b, taken with the Space Telescope Imaging Spectrograph instrument. The resulting spectra cover the range 2900–10 300 Å which we combined with archival Wide Field Camera 3 spectra and Spitzer photometry to cover the full optical to infrared wavelength regions. With high spatial resolution, we are able to resolve WASP-12A's stellar companion in both our images and spectra, revealing that the companion is in fact a close binary M0V pair, with the three stars forming a triple-star configuration. We derive refined physical parameters of the WASP-12 system, …
Broadband Monitoring Tracing The Evolution Of The Jet And Disk In The Black Hole Candidate X-Ray Binary Maxi J1659-152,
2013
Astronomical Institute, University of Amsterdam
Broadband Monitoring Tracing The Evolution Of The Jet And Disk In The Black Hole Candidate X-Ray Binary Maxi J1659-152, A. J. Horst, P. A. Curran, J. C. A. Miller-Jones, J. D. Linford, J. Gorosabel, D. M. Russell, A. De Ugarte Postigo, A. A. Lundgren, G. B. Taylor, D Maitra, S Guziy, T M. Belloni, C Kouveliotou, P G. Jonker, A Kamble, Z Paragi, J Homan, E Kuulkers, J Granot, D Altamirano, M M. Buxton, A Castro-Tirado, R P. Fender, M A. Garrett, N Gehrels, Dieter H. Hartmann, J A. Kennea, H A. Krimm, V Mangano, E Ramirez-Ruiz, P Romano, R.A.M.J. Wijers, R Wijnands, Y J. Yang
Publications
MAXI J1659−152 was discovered on 2010 September 25 as a new X-ray transient, initially identified as a gamma-ray burst, but was later shown to be a new X-ray binary with a blackhole as the most likely compact object. Dips in the X-ray light curves have revealed that MAXI J1659−152 is the shortest period black hole candidate identified to date. Here we present the results of a large observing campaign at radio, submillimetre, near-infrared (nIR), optical and ultraviolet (UV) wavelengths. We have combined this very rich data set with the available X-ray observations to compile a broad-band picture of the evolution …
Wesleyan's Mark Evans Observatory Designated Official Site,
2013
Illinois Wesleyan University
Wesleyan's Mark Evans Observatory Designated Official Site, Kim Hill
News and Events (Discontinued Series)
No abstract provided.
Bound Orbits And Virial Theorem In A Dark Energy Universe,
2013
University of Alabama in Huntsville
Bound Orbits And Virial Theorem In A Dark Energy Universe, Kristen Lackeos
Von Braun Symposium Student Posters
No abstract provided.
New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. Viii. Hr 1528, Hr 6993, 2 Sagittae, And 18 Vulpeculae,
2013
Tennessee State University
New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. Viii. Hr 1528, Hr 6993, 2 Sagittae, And 18 Vulpeculae, Francis C. Fekel, Jocelyn Tomkin, Michael H. Williamson
Information Systems and Engineering Management Research Publications
Improved orbital elements for four A-star double-lined spectroscopic binaries have been determined with numerous new radial velocities. Three of the four systems, HR 1528, 2 Sge, and 18 Vul, have moderately short orbital periods of 7.05, 7.39, and 9.31 days, respectively, and also have circular or nearly circular orbits. Only HR 6993 with a period of 14.68 days has a significantly eccentric orbit. The close visual companion of 2 Sge has been detected spectroscopically, and its velocity measured. The orbital dimensions (a1 sin i and a2 sin i) and minimum masses (m1 sin3 i and m2 sin3 i) of the …
Current-Sheet-Like Structures In Solar Winds And Their Effects On The Solar Wind Mhd Turbulence,
2013
University of Alabama in Huntsville
Current-Sheet-Like Structures In Solar Winds And Their Effects On The Solar Wind Mhd Turbulence, Junxiang Hu, Allison Bratcher
Von Braun Symposium Student Posters
No abstract provided.
Design Reference Space Radiation Environments For Spacecraft Design And Mission Planning,
2013
University of Alabama in Huntsville
Design Reference Space Radiation Environments For Spacecraft Design And Mission Planning, Z Robinson
Von Braun Symposium Student Posters
No abstract provided.
Turbulence Transport Modelling Of The Temporal Outer Heliosphere,
2013
University of Alabama in Huntsville
Turbulence Transport Modelling Of The Temporal Outer Heliosphere, Laxman Adhikari
Von Braun Symposium Student Posters
No abstract provided.
The Alignment Of The Marshall Grazing Incidence X-Ray Spectrometer (Magixs),
2013
University of Alabama in Huntsville
The Alignment Of The Marshall Grazing Incidence X-Ray Spectrometer (Magixs), Mark Sterrett
Von Braun Symposium Student Posters
No abstract provided.
Particle Acceleration At Shock Pair,
2013
University of Alabama in Huntsville
Particle Acceleration At Shock Pair, Lulu Zhao
Von Braun Symposium Student Posters
No abstract provided.
X-Ray Nuclear Activity In S4g Barred Galaxies: No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling,
2013
Instituto de Astrofísica de Canarias
X-Ray Nuclear Activity In S4g Barred Galaxies: No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling, Mauricio Cristernas, Trisha Mizusawa
Aerospace, Physics, and Space Science Faculty Publications
Stellar bars can lead to gas inflow toward the center of a galaxy and stimulate nuclear star formation. However, there is no compelling evidence on whether they also feed a central supermassive black hole: by measuring the fractions of barred active and inactive galaxies, previous studies have yielded conflicting results. In this paper, we aim to understand the lack of observational evidence for bar-driven active galactic nucleus (AGN) activity by studying a sample of 41 nearby (d < 35 Mpc) barred galaxies from the Spitzer Survey for Stellar Structure in Galaxies. We use Chandra observations to measure nuclear 2–10 keV X-ray luminosities and estimate Eddington ratios, together with Spitzer 3.6 μm imaging to quantify the strength of the stellar bar in two independent ways: (1) from its structure, as traced by its ellipticity and boxiness, and (2) from its gravitational torque Qb, taken as the maximum ratio of the tangential force to the mean background radial force. In this way, rather than discretizing the presence of both stellar bars and nuclear activity, we are able to account for the continuum of bar strengths and degrees of AGN activity. We find nuclear X-ray sources in 31 out of 41 galaxies with median X-ray luminosity and Eddington ratio of LX = 4.3×1038 erg s−1 and Lbol/LEdd = 6.9×10−6, respectively, consistent with low-luminosity AGN activity. Including upper limits for those galaxies without nuclear detections, we find no significant correlation between any of the bar strength indicators and the degree of nuclear activity, irrespective of galaxy luminosity, stellar mass, Hubble type, or bulge size. Strong bars do not favor brighter or more efficient nuclear activity, implying that at least for the low-luminosity regime, supermassive black hole fueling is not closely connected to large-scale features.
Detection Of Ch4 In The Gv Tau N Protoplanetary Disk,
2013
University of Missouri-St. Louis
Detection Of Ch4 In The Gv Tau N Protoplanetary Disk, David Horne, Erika Gibb
Physics Faculty Works
T Tauri stars are low mass young stars that may serve as analogs to the early solar system. Observations of organic molecules in the protoplanetary disks surrounding T Tauri stars are important for characterizing the chemical and physical processes that lead to planet formation. Searches for undetected molecules, particularly in the inner, planet forming regions of these disks are important for testing protoplanetary disk chemical models and for understanding the evolution of volatiles through the star and planet formation process. We used NIRSPEC on Keck 2 to perform a high resolution (λ/Δλ ~ 25,000) L-band survey of T Tauri star …
Rainich-Type Conditions For Null Electrovacuum Spacetimes Ii,
2013
Department of Physics, Utah State University
Rainich-Type Conditions For Null Electrovacuum Spacetimes Ii, Charles G. Torre
Research Vignettes
In this second of two worksheets I continue describing local Rainich-type conditions which are necessary and sufficient for the metric to define a null electrovacuum. In other words, these conditions, which I will call the null electrovacuum conditions, guarantee the existence of a null electromagnetic field such that the metric and electromagnetic field satisfy the Einstein-Maxwell equations. When it exists, the electromagnetic field is easily constructed from the metric. In this worksheet I consider the null electrovacuum conditions which apply when a certain null geodesic congruence determined by the metric is twisting. I shall illustrate the these conditions using a …
Astr 407,
2013
University of Nebraska - Lincoln
Astr 407: Physics Of The Interstellar Medium,
2013
University of Nebraska-Lincoln
Astr 407: Physics Of The Interstellar Medium, Edward Schmidt
Department of Physics and Astronomy: Syllabi
Syllabus for ASTR 407: Physics of the Interstellar Medium syllabus for Fall 2013 semester.
X-Ray Nuclear Activity In S4g Barred Galaxies : No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling.,
2013
Instituto de Astrofísica de Canarias, Spain
X-Ray Nuclear Activity In S4g Barred Galaxies : No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling., Mauricio Cisternas, Dimitri A. Gadotti, Johan H. Knapen, Taehyun Kim, Simon Diaz-Garcia, Eija Laurikainen, Heikki Salo, Omaira Gonzalez-Martin, Luis C. Ho, Bruce G. Elmegreen, Dennis Zaritsky, Kartik Sheth, E. Athanassoula, Albert Bosma, Sebastien Comeron, Santiago Erroz-Ferrer, Armando Gil De Paz, Joannah L. Hinz, Benne W. Holwerda, Jarkko Laine, Sharon Meidt, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Michael W. Regan, Mark Seibert
Faculty and Staff Scholarship
Stellar bars can lead to gas inflow toward the center of a galaxy and stimulate nuclear star formation. However, there is no compelling evidence on whether they also feed a central supermassive black hole: by measuring the fractions of barred active and inactive galaxies, previous studies have yielded conflicting results. In this paper, we aim to understand the lack of observational evidence for bar-driven active galactic nucleus (AGN) activity by studying a sample of 41 nearby (d < 35 Mpc) barred galaxies from the Spitzer Survey for Stellar Structure in Galaxies. We use Chandra observations to measure nuclear 2–10 keV X-ray luminosities and estimate Eddington ratios, together with Spitzer 3.6 μm imaging to quantify the strength of the stellar bar in two independent ways: (1) from its structure, as traced by its ellipticity and boxiness, and (2) from its gravitational torque Qb, taken as the maximum ratio of the tangential force to the mean background radial force. In this way, rather than discretizing the presence of both stellar bars and nuclear activity, we are able to account for the continuum of bar strengths and degrees of AGN activity. We find nuclear X-ray sources in 31 out of 41 galaxies with median X-ray luminosity and Eddington ratio of LX = 4.3×1038 erg s−1 and Lbol/LEdd = 6.9×10−6, respectively, consistent with low-luminosity AGN activity. Including upper limits for those galaxies without nuclear detections, we find no significant correlation between any of the bar strength indicators and the degree of nuclear activity, irrespective of galaxy luminosity, stellar mass, Hubble type, or bulge size. Strong bars do not favor brighter or more efficient nuclear activity, implying that at least for the low-luminosity regime, supermassive black hole fueling is not closely connected to large-scale features.
