Results for "J. Stansberry"

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(42355) Typhon-Echidna: Scheduling Observations for Binary Orbit DeterminationApr 15 2008We describe a strategy for scheduling astrometric observations to minimize the number required to determine the mutual orbits of binary transneptunian systems. The method is illustrated by application to Hubble Space Telescope observations of (42355) ... More
Epsilon Eridani's Planetary Debris Disk: Structure and Dynamics based on Spitzer and CSO ObservationsOct 24 2008Spitzer and Caltech Submillimeter Observatory (CSO) images and spectrophotometry of epsilon Eridani at wavelengths from 3.5 to 350 um reveal new details of its bright debris disk. The 350 um map confirms the presence of a ring at r = 11-28 arcsec (35-90 ... More
"TNOs are Cool": A survey of the trans-Neptunian region XIV. Size/albedo characterization of the Haumea family observed with Herschel and SpitzerApr 12 2019A group of trans-Neptunian objects (TNO) are dynamically related to the dwarf planet 136108 Haumea. Ten of them show strong indications of water ice on their surfaces, are assumed to have resulted from a collision, and are accepted as the only known TNO ... More
Debris Disk Evolution Around A StarsAug 25 2006We report 24 and/or 70 um measurements of ~160 A-type main-sequence stars using the Multiband Imaging Photometer for Spitzer (MIPS). Their ages range from 5 to 850 Myr based on estimates from the literature (cluster or moving group associations) or from ... More
Debris disks around Sun-like starsOct 29 2007We have observed nearly 200 FGK stars at 24 and 70 microns with the Spitzer Space Telescope. We identify excess infrared emission, including a number of cases where the observed flux is more than 10 times brighter than the predicted photospheric flux, ... More
The size, density, and formation of the Orcus-Vanth system in the Kuiper beltOct 26 2009The Kuiper belt object Orcus and its satellite Vanth form an unusual system in the Kuiper belt. Orcus is amongst the largest objects known in the Kuiper belt, but the relative size of Vanth is much larger than that of the tiny satellites of the other ... More
Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. I. The Stellar Calibrator Sample and the 24 micron CalibrationApr 17 2007We present the stellar calibrator sample and the conversion from instrumental to physical units for the 24 micron channel of the Multiband Imaging Photometer for Spitzer (MIPS). The primary calibrators are A stars, and the calibration factor based on ... More
Searching for Saturn's Dust Swarm: Limits on the size distribution of Irregular Satellites from km to micron sizesJul 11 2011We describe a search for dust created in collisions between the Saturnian irregular satellites using archival \emph{Spitzer} MIPS observations. Although we detected a degree scale Saturn-centric excess that might be attributed to an irregular satellite ... More
Albedos and diameters of three Mars Trojan asteroidsSep 12 2007Sep 21 2007We observed the Mars Trojan asteroids (5261) Eureka and (101429) 1998 VF31 and the candidate Mars Trojan 2001 FR127 at 11.2 and 18.1 microns using Michelle on the Gemini North telescope. We derive diameters of 1.28, 0.78, and <0.52 km, respectively, with ... More
Near-Infrared Spectral Monitoring of Triton with IRTF/SpeX II: Spatial Distribution and Evolution of IcesAug 18 2009Aug 18 2009This report arises from an ongoing program to monitor Neptune's largest moon Triton spectroscopically in the 0.8 to 2.4 micron range using IRTF/SpeX. Our objective is to search for changes on Triton's surface as witnessed by changes in the infrared absorption ... More
Spatially Resolved Ultraviolet, H-alpha, Infrared, and Radio Star Formation in M81Jun 02 2004We present Multiband Imaging Photometer for Spitzer (MIPS) observations of M81 at 24, 70, and 160 micron. The grand design nature of M81 is clearly seen, showing two well resolved spiral arms containing numerous bright star forming regions. The MIPS images ... More
Reduction Algorithms for the Multiband Imaging Photometer for SpitzerFeb 03 2005We describe the data reduction algorithms for the Multiband Imaging Photometer for Spitzer (MIPS) instrument. These algorithms were based on extensive preflight testing and modeling of the Si:As (24 micron) and Ge:Ga (70 and 160 micron) arrays in MIPS ... More
High Albedos of Low Inclination Classical Kuiper Belt ObjectsDec 22 2008Jan 01 2009We present observations of thermal emission from fifteen transneptunian objects (TNOs) made using the Spitzer Space Telescope. Thirteen of the targets are members of the Classical population: six dynamically hot Classicals, five dynamically cold Classicals, ... More
The Albedo, Size, and Density of Binary Kuiper Belt Object (47171) 1999 TC36Feb 14 2006We measured the system-integrated thermal emission of the binary Kuiper Belt Object 1999 TC36 at wavelengths near 24 and 70 microns using the Spitzer space telescope. We fit these data and the visual magnitude using both the Standard Thermal Model and ... More
The orbit, mass, size, albedo, and density of (65489) Ceto/Phorcys: A tidally-evolved binary CentaurApr 12 2007Hubble Space Telescope observations of Uranus- and Neptune-crossing object (65489) Ceto/Phorcys (provisionally designated 2003 FX128) reveal it to be a close binary system. The mutual orbit has a period of 9.554 +/- 0.011 days and a semimajor axis of ... More
Diameters and albedos of three sub-kilometer Near Earth Objects derived from Spitzer observationsJul 10 2008Near Earth Objects (NEOs) are fragments of remnant primitive bodies that date from the era of Solar System formation. At present, the physical properties and origins of NEOs are poorly understood. We have measured thermal emission from three NEOs -- (6037) ... More
New Infrared Emission Features and Spectral Variations in NGC 7023Jul 11 2004We have observed the reflection nebula NGC 7023, with the Short-High module and long-slit Short-Low and Long-Low modules of the Infrared Spectrograph on the Spitzer Space Telescope. We also present Infrared Array Camera and Multiband Imaging Photometer ... More
Spitzer/MIPS Limits on Asteroidal Dust in the Pulsar Planetary System PSR B1257+1Apr 05 2006With the MIPS camera on Spitzer, we have searched for far-infrared emission from dust in the planetary system orbiting pulsar PSR 1257+12. With accuracies of 0.05 mJy at 24 um and 1.5 mJy at 70 um, photometric measurements find no evidence for emission ... More
The Spectral Energy Distribution and Mass-loss Rate of the A-Type Supergiant DenebJan 14 2002A stellar wind module has been developed for the PHOENIX stellar atmosphere code for the purpose of computing non-LTE, line-blanketed, expanding atmospheric structures and detailed synthetic spectra of hot luminous stars with winds. We apply the code ... More
The thermal emission of Centaurs and Trans-Neptunian objects at millimeter wavelengths from ALMA observationsSep 20 2017The sensitivity of ALMA makes it possible to detect thermal mm/submm emission from small/distant Solar System bodies at the sub-mJy level. Measured fluxes are primarily sensitive to the objects' diameters, but deriving precise sizes is somewhat hampered ... More
The Mutual Orbit, Mass, and Density of the Large Transneptunian Binary System Varda and IlmarëMay 04 2015From observations by the Hubble Space Telescope, Keck II Telescope, and Gemini North Telescope, we have determined the mutual orbit of the large transneptunian object (174567) Varda and its satellite Ilmar\"e. These two objects orbit one another in a ... More
Nereid from space: Rotation, size and shape analysis from Kepler/K2, Herschel and Spitzer observationsJan 11 2016In this paper we present an analysis of Kepler K2 mission Campaign 3 observations of the irregular Neptune satellite, Nereid. We determined a rotation period of P=11.594(+/-)0.017 h and amplitude of dm=0.0328(+/-)00018, confirming previous short rotation ... More
The long-wavelength thermal emission of the Pluto-Charon system from Herschel observations. Evidence for emissivity effectsJan 21 2016Thermal observations of the Pluto-Charon system acquired by the Herschel Space Observatory in February 2012 are presented. They consist of photometric measurements with the PACS and SPIRE instruments (nine visits to the Pluto system each), covering six ... More
Optimized Herschel/PACS photometer observing and data reduction strategies for moving solar system targetsSep 17 2013Sep 19 2013The "TNOs are Cool!: A survey of the trans-Neptunian region" is a Herschel Open Time Key Program that aims to characterize planetary bodies at the outskirts of the Solar System using PACS and SPIRE data, mostly taken as scan-maps. In this paper we summarize ... More
An Excess Due to Small Grains Around The Nearby K0V Star HD69830: Asteroid or Cometary Debris?Apr 22 2005May 11 2005Spitzer photometry and spectroscopy of the star HD69830 reveal an excess of emission relative to the stellar photosphere between 8 and 35 $\mu$m dominated by strong features attributable to crystalline silicates with an emitting surface area more than ... More
Formation of Charon's Red Poles From Seasonally Cold-Trapped VolatilesMar 09 2019A unique feature of Pluto's large satellite Charon is its dark red northern polar cap. Similar colours on Pluto's surface have been attributed to organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location of ... More
Reorientation of Sputnik Planitia implies a Subsurface Ocean on PlutoMar 13 2019The deep nitrogen-covered Sputnik Planitia (SP; informal name) basin on Pluto is located very close to the longitude of Pluto's tidal axis[1] and may be an impact feature [2], by analogy with other large basins in the solar system[3,4]. Reorientation[5-7] ... More
Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigorMar 13 2019The vast, deep, volatile-ice-filled basin informally named Sputnik Planum is central to Pluto's geological activity[1,2]. Composed of molecular nitrogen, methane, and carbon monoxide ices[3], but dominated by N2-ice, this ice layer is organized into cells ... More
Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer: IV. The Spectral Energy Distribution ModeFeb 26 2008The Spectral Energy Distribution (SED) mode of the Multiband Imaging Photometer for Spitzer (MIPS) Space Telescope provides low-spectral resolution (R ~ 15-25) spectroscopy in the far infrared using the MIPS 70 um detector. A reflective grating provides ... More
TNOs are Cool: A Survey of the Transneptunian Region XI: A Herschel-PACS view of 16 CentaursSep 04 2013Mar 05 2014Centaurs are the transitional population between trans-Neptunian objects (TNOs) and Jupiter-family comets. For this reason it is possible to access the smaller ones, which is more difficult to do with the TNO population. The goal of this work is to characterize ... More
Detection of CO and HCN in Pluto's atmosphere with ALMAJun 10 2016Oct 13 2016Observations of the Pluto-Charon system, acquired with the ALMA interferometer on June 12-13, 2015, have yielded a detection of the CO(3-2) and HCN(4-3) rotational transitions from Pluto, providing a strong confirmation of the presence of CO, and the ... More
Debris disks in main sequence binary systemsDec 01 2006We observed 69 A3-F8 main sequence binary star systems using the Multiband Imaging Photometer for Spitzer onboard the Spitzer Space Telescope. We find emission significantly in excess of predicted photospheric flux levels for 9(+4/-3)% and 40(+7/-6)% ... More
TNOs are Cool: a survey of the Transneptunian Region XII. Thermal light curves of Haumea, 2003 VS2 and 2003 AZ84 with Herschel Space Observatory-PACSMay 25 2017Time series observations of the dwarf planet Haumea and the Plutinos 2003VS2 and 2003AZ84 with Herschel/PACS are presented in this work. Thermal emission of these trans-Neptunian objects were acquired as part of the TNOs are Cool Herschel Space Observatory ... More
"TNOs are Cool": A survey of the trans-Neptunian region X. Analysis of classical Kuiper belt objects from Herschel and Spitzer observationsMar 25 2014The classical Kuiper belt contains objects both from a low-inclination, presumably primordial, distribution and from a high-inclination dynamically excited population. Based on a sample of classical TNOs with observations at thermal wavelengths we determine ... More
Planets and IR Excesses: Preliminary Results from a Spitzer/MIPS Survey of Solar-Type StarsDec 10 2004As part of a large Spitzer/MIPS GTO program, we have searched for infrared excesses due to debris disks toward 26 FGK field stars known from radial velocity (RV) studies to have one or more planets. While none of these stars show excesses at 24um, we ... More
Five New and Three Improved Mutual Orbits of Transneptunian BinariesMar 14 2011We present three improved and five new mutual orbits of transneptunian binary systems (58534) Logos-Zoe, (66652) Borasisi-Pabu, (88611) Teharonhiawako-Sawiskera, (123509) 2000 WK183, (149780) Altjira, 2001 QY297, 2003 QW111, and 2003 QY90 based on Hubble ... More
Observing Planetary Rings with JWST: Science Justification and Observation RequirementsMar 26 2014Oct 22 2015The James Webb Space Telescope (JWST) will provide unprecedented opportunities to observe the rings and small satellites in our solar system, accomplishing three primary objectives: 1) discovering new rings and moons, 2) unprecedented spectroscopy, and ... More
Cameras a Million Miles Apart: Stereoscopic Imaging Potential with the Hubble and James Webb Space TelescopesOct 13 2016The two most powerful optical/IR telescopes in history -- NASA's Hubble and James Webb Space Telescopes -- will be in space at the same time. We have a unique opportunity to leverage the 1.5 million kilometer separation between the two telescopic nodal ... More
The size and shape of the oblong dwarf planet HaumeaFeb 18 2014We use thermal radiometry and visible photometry to constrain the size, shape, and albedo of the large Kuiper belt object Haumea. The correlation between the visible and thermal photometry demonstrates that Haumea's high amplitude and quickly varying ... More
The James Webb Space Telescopes plan for operations and instrument capabilities for observations in the Solar SystemOct 15 2015The James Webb Space Telescope (JWST) is optimized for observations in the near and mid infrared and will provide essential observations for targets that cannot be conducted from the ground or other missions during its lifetime. The state of the art science ... More
The mass and density of the dwarf planet (225088) 2007 OR10Mar 13 2019The satellite of (225088) 2007 OR10 was discovered on archival Hubble Space Telescope images and along with new observations with the WFC3 camera in late 2017 we have been able to determine the orbit. The orbit's notable eccentricity, e$\approx$0.3, may ... More
ExploreNEOs I: Description and first results from the Warm Spitzer NEO SurveyJul 06 2010We have begun the ExploreNEOs project in which we observe some 700 Near Earth Objects (NEOs) at 3.6 and 4.5 microns with the Spitzer Space Telescope in its Warm Spitzer mode. From these measurements and catalog optical photometry we derive albedos and ... More
ExploreNEOs III: Physical characterization of 65 low-deltaV NEOsJan 25 2011Space missions to NEOs are being planned at all major space agencies, and recently a manned mission to an NEO was announced as a NASA goal. Efforts to find and select suitable targets (plus backup targets) are severely hampered by our lack of knowledge ... More
The Vega Debris Disk -- A Surprise from SpitzerApr 04 2005We present high spatial resolution mid- and far-infrared images of the Vega debris disk obtained with the Multiband Imaging Photometer for Spitzer (MIPS). The disk is well resolved and its angular size is much larger than found previously. The radius ... More
Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. III. An Asteroid-based Calibration of MIPS at 160 micronsJul 16 2007Jul 24 2007We describe the absolute calibration of the Multiband Imaging Photometer for Spitzer (MIPS) 160 micron channel. After the on-orbit discovery of a near-IR ghost image that dominates the signal for sources hotter than about 2000 K, we adopted a strategy ... More
"TNOs are Cool": A survey of the trans-Neptunian region VI. Herschel/PACS observations and thermal modeling of 19 classical Kuiper belt objectsApr 03 2012Trans-Neptunian objects (TNO) represent the leftovers of the formation of the Solar System. Their physical properties provide constraints to the models of formation and evolution of the various dynamical classes of objects in the outer Solar System. Based ... More
TNOs are Cool: A survey of the trans-Neptunian region V. Physical characterization of 18 Plutinos using Herschel PACS observationsFeb 16 2012We present Herschel PACS photometry of 18 Plutinos and determine sizes and albedos for these objects using thermal modeling. We analyze our results for correlations, draw conclusions on the Plutino size distribution, and compare to earlier results. Flux ... More
JWST observations of stellar occultations by solar system bodies and ringsOct 22 2015Nov 24 2015In this paper we investigate the opportunities provided by the James Webb Space Telescope (JWST) for significant scientific advances in the study of solar system bodies and rings using stellar occultations. The strengths and weaknesses of the stellar ... More
TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of 9 bright targets at 70--500 micronMay 02 2013May 03 2013Transneptunian objects (TNOs) are bodies populating the Kuiper Belt and they are believed to retain the most pristine and least altered material of the solar system. The Herschel Open Time Key Program entitled "TNOs are Cool: A survey of the trans-Neptunian ... More
"TNOs are Cool": A Survey of the Transneptunian Region IV. Size/albedo characterization of 15 scattered disk and detached objects observed with Herschel Space Observatory-PACSFeb 07 2012Physical characterization of Trans-Neptunian objects, a primitive population of the outer solar system, may provide constraints on their formation and evolution. The goal of this work is to characterize a set of 15 scattered disk (SDOs) and detached objects, ... More
Confusion in the infrared: Spitzer and beyondJun 01 2004We use the source counts measured with the Multiband Imaging Photometer for Spitzer (MIPS) at 24, 70, and 160 microns to determine the 5-sigma confusion limits due to extragalactic sources: 56 micro-Jy, 3.2 and 40 mJy at 24, 70 and 160 microns, respectively. ... More
Far Infrared Imaging of NGC 55Jun 07 2004We present images of the galaxy NGC 55 at 24, 70, and 160 micron obtained with the Multiband Imaging Photometer for Spitzer (MIPS) instrument aboard the Spitzer Space Telescope. The new images display the far infrared emission in unprecedented detail ... More
"TNOs are Cool": A survey of the trans-Neptunian region I. Results from the Herschel Science Demonstration Phase (SDP)May 17 2010The goal of the Herschel Open Time Key programme "TNOs are Cool!" is to derive the physical and thermal properties for a large sample of Centaurs and trans-Neptunian objects (TNOs), including resonant, classical, detached and scattered disk objects. We ... More
"TNOs are cool": A survey of the trans-neptunian region. II. The thermal lightcurve of (136108) HaumeaJun 01 2010Thermal emission from Kuiper Belt object (136108) Haumea was measured with Herschel-PACS at 100 and 160 micrometers for almost a full rotation period. Observations clearly indicate a 100-micrometer thermal lightcurve with an amplitude of a factor of ~ ... More
Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space TelescopeFeb 20 2007Nov 05 2007Detecting heat from minor planets in the outer solar system is challenging, yet it is the most efficient means for constraining the albedos and sizes of Kuiper Belt Objects (KBOs) and their progeny, the Centaur objects. These physical parameters are critical, ... More
New debris disk candidates: 24 micron stellar excesses at 100 MyrJun 01 2004Sixty three members of the 100 Myr old open cluster M47 (NGC 2422) have been detected at 24 micron with Spitzer. The Be star V 378 Pup shows an excess both in the near-infrared and at 24 micron (K-[24] = 2.4 mag), probably due to free-free emission from ... More
Reduction Algorithms for the Multiband Imaging Photometer for Spitzer: 6 Months of Flight DataFeb 03 2005The first six months of flight data from the Multiband Imaging Photometer for Spitzer (MIPS) were used to test MIPS reduction algorithms based on extensive preflight laboratory data and modeling. The underlying approach for the preflight algorithms has ... More
Inflight Radiometric Calibration of New Horizons' Multispectral Visible Imaging Camera (MVIC)Mar 29 2016We discuss two semi-independent calibration techniques used to determine the in-flight radiometric calibration for the New Horizons' Multi-spectral Visible Imaging Camera (MVIC). The first calibration technique compares the observed stellar flux to modeled ... More
Surface Compositions Across Pluto and CharonApr 18 2016The New Horizons spacecraft mapped colors and infrared spectra across the encounter hemispheres of Pluto and Charon. The volatile ices CH$_4$, CO, and N$_2$, that dominate Pluto's surface, have complicated spatial distributions resulting from sublimation, ... More
Spitzer 24 micron Survey of Debris Disks in the PleiadesJun 02 2006We performed a 24 micron 2 Deg X 1 Deg survey of the Pleiades cluster, using the MIPS instrument on Spitzer. Fifty four members ranging in spectral type from B8 to K6 show 24 micron fluxes consistent with bare photospheres. All Be stars show excesses ... More
Planetary Science Goals for the Spitzer Warm EraNov 15 2007The overarching goal of planetary astronomy is to deduce how the present collection of objects found in our Solar System were formed from the original material present in the proto-solar nebula. As over two hundred exo-planetary systems are now known, ... More
Asteroids and the James Webb Space TelescopeOct 28 2015The James Webb Space Telescope (JWST) provides the opportunity for ground-breaking observations of asteroids. It covers wavelength regions that are unavailable from the ground, and does so with unprecedented sensitivity. The main-belt and Trojan asteroids ... More
Discovery of a satellite of the large trans-Neptunian object (225088) 2007OR10Mar 04 20172007OR10 is currently the third largest known dwarf planet in the transneptunian region, with an effective radiometric diameter of ~1535 km. It has a slow rotation period of ~45 h that was suspected to be caused by tidal interactions with a satellite ... More
Observing Outer Planet Satellites (except Titan) with JWST: Science Justification and Observational RequirementsNov 12 2015The James Webb Space Telescope (JWST) will allow observations with a unique combination of spectral, spatial, and temporal resolution for the study of outer planet satellites within our Solar System. We highlight the infrared spectroscopy of icy moons ... More
Observing Near-Earth Objects with the James Webb Space TelescopeOct 19 2015The James Webb Space Telescope (JWST) has the potential to enhance our understanding of near-Earth objects (NEOs). We present results of investigations into the observability of NEOs given the nominal observing requirements of JWST on elongation (85-135 ... More
Solar System Observations with the James Webb Space TelescopeMar 26 2014Oct 22 2015The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science ... More
Slitless spectroscopy with the James Webb Space Telescope Near-Infrared Camera (JWST NIRCam)Jun 13 2016Jul 20 2016The James Webb Space Telescope near-infrared camera (JWST NIRCam) has two 2.'2 $\times$ 2.'2 fields of view that are capable of either imaging or spectroscopic observations. Either of two $R \sim 1500$ grisms with orthogonal dispersion directions can ... More
The albedo-color diversity of transneptunian objectsJun 05 2014Sep 07 2014We analyze albedo data obtained using the Herschel Space Observatory that reveal the existence of two distinct types of surface among midsized transneptunian objects. A color-albedo diagram shows two large clusters of objects, one redder and higher albedo ... More
Two NIRCam channels are Better than One: How JWST Can Do More Science with NIRCam's Short-Wavelength Dispersed Hartmann SensorOct 06 2016The James Webb Space Telescope (JWST) offers unprecedented sensitivity, stability, and wavelength coverage for transiting exoplanet studies, opening up new avenues for measuring atmospheric abundances, structure, and temperature profiles. Taking full ... More
Observations of Transiting Exoplanets with the James Webb Space Telescope (JWST), Publications of the Astronomical Society of the Pacific (PASP), December 2014Nov 06 2014This article summarizes a workshop held on March, 2014, on the potential of the James Webb Space Telescope (JWST) to revolutionize our knowledge of the physical properties of exoplanets through transit observations. JWST's unique combination of high sensitivity ... More
Far Infrared Prperties of M DwarfsJul 03 2007We report the mid- and far-infrared properties of nearby M dwarfs. Spitzer/MIPS measurements were obtained for a sample of 62 stars at 24 um, with subsamples of 41 and 20 stars observed at 70 um and 160 um respectively. We compare the results with current ... More
"TNOs are Cool": A survey of the trans-Neptunian region -- VII. Size and surface characteristics of (90377) Sedna and 2010 EK139Apr 04 2012We present estimates of the basic physical properties (size and albedo) of (90377) Sedna, a prominent member of the detached trans-Neptunian object population and the recently discovered scattered disk object 2010 EK139, based on the recent observations ... More
Physical Characterization of TNOs with JWSTNov 03 2015Studies of the physical properties of Trans-Neptunian Objects (TNOs) are a powerful probe into the processes of planetesimal formation and solar system evolution. JWST will provide unique new capabilities for such studies. Here we outline where the capabilities ... More
Stability of spherical stellar systems I : Analytical resultsNov 22 1995The so-called ``symplectic method'' is used for studying the linear stability of a self-gravitating collisionless stellar system, in which the particles are also submitted to an external potential. The system is steady and spherically symmetric, and its ... More
Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. II. 70 micron ImagingApr 17 2007The absolute calibration and characterization of the Multiband Imaging Photometer for Spitzer (MIPS) 70 micron coarse- and fine-scale imaging modes are presented based on over 2.5 years of observations. Accurate photometry (especially for faint sources) ... More
Origin of the quasi-universality of the graphene minimal conductivityApr 15 2010Sep 16 2010It is a fact that the minimal conductivity $\sigma_0$ of most graphene samples is larger than the well-established universal value for ideal graphene $4e^2/\pi h$; in particular, larger by a factor $\gtrsim\pi$. Despite intense theoretical activity, this ... More
Vortex matter in superconducting mesoscopic disks: Structure, magnetization, and phase transitionsJun 04 1998The dense vortex matter structure and associated magnetization are calculated for type-II superconducting mesoscopic disks. The magnetization exhibits generically first-order phase transitions as the number of vortices changes by one and presents two ... More
The Cosmological Signatures and Flux Distribution of Gamma-Ray Bursts with a Broad Luminosity DistributionJul 10 1997Aug 16 1997The cosmological expansion cannot produce the reported correlations of the gamma-ray burst timescale and spectral energy with peak flux if the burst model reproduces the BATSE 3B peak-flux distribution for a non-evolving burst source density. Power law ... More
A Quantum Monte Carlo Study of Static Properties of One 3He Atom in Superfluid 4HeJul 20 1998The local environment and the energetic properties of one $^3$He atom solved in bulk superfluid $^4$He are studied by means of the diffusion Monte Carlo method. The chemical potential of the $^3$He impurity is calculated with a generalized reweighting ... More
Nuclear Suppression of Dileptons at Large xFSep 23 2009Oct 09 2009We study a significant nuclear suppression of the relative production rates (p(d)+A)/(p+d(p)) for the Drell-Yan process at large Feynman xF. Since this is the region of minimal values for the light-front momentum fraction variable x2 in the target nucleus, ... More
A New Method for Finding Clusters of Galaxies at z>1Aug 16 1994At large redshifts, a cluster or group may be too distant for the galaxies within the cluster to be detected individually. However, the light from these ``undetected'' galaxies still modulates the surface brightness of the background sky. Clusters can ... More
Hadronization of Expanding QGPNov 04 2005We discuss how the dynamics of an exploding hot fireball of quark--gluon matter impacts the actual phase transition conditions between the deconfined and confined state of matter. We survey the chemical conditions prevailing at hadronization.
QCD Equations of State and the QGP Liquid ModelJan 15 2003Recent advances in the study of equations of state of thermal lattice Quantum Chromodynamics obtained at non-zero baryon density allow validation of the quark-gluon plasma (QGP) liquid model equations of state (EoS). We study here the properties of the ... More
Lensless Slide Projection: A Demonstrative ExperienceJun 27 2006A 2D transparency may be projected on a diffractive screen by just illuminating it with a filament lamp of the same height. Sharpness of the filament width is naturally related to sharpness on the image, but some peculiar properties makes this experience ... More
Holoprojection of Images by a Double Diffraction ProcessAug 17 2005Three dimensional images having continuous horizontal parallax were developed by wavelength enconding of view followed by a natural decoding process of projection onto a diffractive screen. It allows for the direct criation of "holoimages" by using projected ... More
Effective bounds for Faltings's delta functionDec 09 2013We obtain bounds for the Faltings's delta function for any Riemann surface of genus greater than one. The bounds are in terms of the genus of the surface and two basic quantities coming from hyperbolic geometry: The length of the shortest closed geodesic, ... More
Parametric resonance in quantum field theoryAug 07 2002Jul 09 2003We present the first study of parametric resonance in quantum field theory from a complete next-to-leading order calculation in a 1/N-expansion of the 2PI effective action, which includes scattering and memory effects. We present a complete numerical ... More
Transport Simulations with Pi and Delta In-Medium PropertiesJul 23 1998Transport simulations including in-medium properties derived in a microscopic pi + nucleon-hole + delta-hole model in infinite nuclear matter are presented. In-medium pion dispersion relations, partial delta decay widths, pion absorption cross sections ... More
Treatment of Pionic Modes at the Nuclear Surface for Transport DescriptionsAug 22 1995Dispersion relations and amplitudes of collective pionic modes are derived in a pi + nucleon-hole + delta-hole model for use in transport descriptions by means of a local density approximation. It is discussed how pionic modes can be converted to real ... More
The Spectrum of the MSSM with Non-Standard Supersymmetry BreakingAug 24 2001Aug 29 2001The Minimal Supersymmetric Standard Model (MSSM) can include two soft breaking terms which are often neglected: a non-analytic scalar trilinear coupling and a Higgsino bilinear term. A set of high-scale boundary conditions consistent with the reparameterisation ... More
Tables of the partition functions for iron, Fe I -- Fe XApr 23 2002We present extensive tables of the Atomic Partition Function for iron ions, Fe I -- Fe X, and discuss details of the computational method. Partition functions are given in wide range of temperatures, 10^3 K < T < 10^6 K, and lowering of ionization energy ... More
Antibaryon-nucleus bound statesNov 27 2014We calculated antibaryon ($\bar{B}$ = $\bar{p}$, $\bar{\Lambda}$, $\bar{\Sigma}$, $\bar{\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\bar{B}$-meson coupling constants were scaled to yield ... More
On Electro-weak mixing derived from radiative corrections and the necessity of the Higgs mechanismJun 12 1996Jun 20 1996Starting from the unmixed Lagrangian, the electro-weak radiative corrections are recomputed using symmetrical generalised functions. All gauge bosons acquire an indeterminate mass. Electro-weak mixing is obtained by diagonalization of the mass matrix. ... More
Quantum-Electrodynamics without renormalization V. Bosonic contributions to the photon massMay 11 1994The bosonic contributions to the photon mass are shown to be of the same form as the fermionic contributions, but of opposite sign. A mass sum rule for bosons and fermions follows from gauge invariance. Assuming completeness of the standard model the ... More
Horizons in de-Sitter SupergravityJan 14 2010Nov 26 2010We classify all pseudo-supersymmetric extremal near-horizon geometries in minimal five-dimensional de-Sitter supergravity. It is shown that the only such near-horizon geometry is the near-horizon geometry of the de-Sitter BMPV solution, and hence there ... More
XMM-Newton Data Processing for Faint Diffuse Emission: Proton Flares, Exposure Maps and Report on EPIC MOS1 Bright CCDs ContaminationAug 04 2005We present a study of the in-flight performance of the XMM-Newton EPIC MOS and pn detectors, with focus on the influence of proton flares and vignetting on the data. The very wide range in the conditions of our sample of observations, in terms of exposure ... More
Multiplicative noise and charge density wave dynamics in Rb0.30MoO3Jul 17 2012We have investigated the combined effects of a multiplicative noise and nonlinear conductivity on the charge density wave (CDW) dynamics of the quasi-one dimensional conductor Rb0.30MoO3. When the amplitude of a bipolar rectangular voltage pulse excitation ... More
Broad band noise and stochastic resonance in the CDW conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002)May 09 2012We have investigated nonlinear characteristics and broad band noise in the quasi-one dimensional charge-density-wave conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002) When the amplitude of a bipolar rectangular voltage pulse excitation is ... More
Primordial fluctuations without scalar fieldsJul 10 2009Jan 29 2010We revisit the question of whether fluctuations in hydrodynamical, adiabatical matter could explain the observed structures in our Universe. We consider matter with variable equation of state $w=p_0/\ep_0$ and a concomitant (under the adiabatic assumption) ... More
Efficiency of the SQUID Ratchet Driven by External CurrentFeb 19 2015We study theoretically the efficiency of an asymmetric superconducting quantum interference device (SQUID) which is constructed as a loop with three capacitively and resistively shunted Josephson junctions. Two junctions are placed in series in one arm ... More