A5059132500- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Gaussian Processes and Bayesian Inference
- Astrophysics and Cosmic Phenomena
- Statistical and numerical algorithms
- Planetary Science and Exploration
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Advanced Statistical Methods and Models
- Insurance, Mortality, Demography, Risk Management
- Calibration and Measurement Techniques
- Galaxies: Formation, Evolution, Phenomena
- Statistical Methods and Bayesian Inference
- Astrophysics and Star Formation Studies
- Spectroscopy and Chemometric Analyses
- Astrophysical Phenomena and Observations
- Time Series Analysis and Forecasting
- Meteorological Phenomena and Simulations
- Bayesian Methods and Mixture Models
- Scientific Research and Discoveries
- Target Tracking and Data Fusion in Sensor Networks
Cornell University
2012-2024
Planetary Science Institute
2021-2022
University of Chicago
1988-1992
Fermi National Accelerator Laboratory
1989
The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of art Doppler precision and identified critical path challenges for reaching 10 cm s−1 measurement precision. presentations discussion key issues instrumentation data analysis workshop recommendations achieving this bold are summarized here. Beginning with High Accuracy Velocity Planet Searcher spectrograph, technological advances radial velocity (RV) measurements have focused building extremely stable...
The size distribution in the Kuiper Belt records physical processes operating during formation and subsequent evolution of solar system. This paper reports a study apparent magnitude faint objects Belt, obtained via deep imaging on Canada-France-Hawaii Telescope ESO Very Large UT1. We find that entire range observed (magnitudes mR ∼ 20–27) is well represented by an unbroken power law, with number per square degree brighter than R being form Σ(mR < R) = 10, α 0.69 R0 23.5. luminosity...
view Abstract Citations (211) References (4) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A New Method for the Detection of a Periodic Signal Unknown Shape and Period Gregory, P. C. ; Loredo, Thomas J. method was developed detection measurement periodic signal with unknown characteristics in data set where existence such not known. The detects by using Bayesian probability theory to compare constant model members class models structure. applied simulated...
We present a Bayesian analysis of the energies and arrival times neutrinos from supernova SN 1987A detected by Kamiokande II, IMB, Baksan detectors, find strong evidence for two components in neutrino signal: long time scale component thermal Kelvin-Helmholtz cooling nascent neutron star, brief $(\ensuremath{\sim}1 \mathrm{s}),$ softer similar to that expected emission accreting material delayed scenario. In context this model, we show data constrain electron antineutrino rest mass be less...
The dayside of HD 149026b is near the edge detectability by Spitzer Space Telescope. We report on 11 secondary-eclipse events at 3.6, 4.5, 3 × 5.8, 4 8.0, and 2 16 μm plus three primary-transit 8.0 μm. eclipse depths from jointly fit models each wavelength are 0.040% ± 0.003% 3.6 μm, 0.034% 0.006% 4.5 0.044% 0.010% 5.8 0.052% 0.085% 0.032% Multiple observations longer wavelengths improved eclipse-depth signal-to-noise ratios up to a factor two estimates planet-to-star radius ratio (Rp/R⋆ =...
We observed two secondary eclipses of the exoplanet WASP-12b using Infrared Array Camera on Spitzer Space Telescope. The close proximity to its G-type star results in extreme tidal forces capable inducing apsidal precession with a period as short few decades. This would be measurable if orbit had significant eccentricity, leading an estimate Love number and assessment degree central concentration planetary interior. An initial ground-based eclipse phase reported by Lopez-Morales et al....
The transiting exoplanet WASP-18b was discovered in 2008 by the Wide Angle Search for Planets (WASP) project. Spitzer Exoplanet Target of Opportunity Program observed secondary eclipses using Spitzer's Infrared Array Camera (IRAC) 3.6 micron and 5.8 bands on December 20, 4.5 8.0 24. We report eclipse depths 0.30 +/- 0.02%, 0.39 0.37 0.03%, 0.41 brightness temperatures 3100 90, 3310 130, 3080 140 3120 110 K order increasing wavelength. is one hottest planets yet - as hot an M-class star....
The behavior of merging black holes (including the emitted gravitational waves and properties remnant) can currently be computed only by numerical simulations. This paper introduces ten relativity simulations binary with equal masses spins aligned or antialigned orbital angular momentum. initial spin magnitudes have $|{\ensuremath{\chi}}_{i}|\ensuremath{\lesssim}0.95$ are more concentrated in direction because greater astrophysical interest this case. We combine these data five previously...
Time-correlated noise is a significant source of uncertainty when modeling exoplanet light-curve data. A correct assessment correlated fundamental to determine the true statistical significance our findings. Here we review three most widely used correlated-noise estimators in field, time-averaging, residual-permutation, and wavelet-likelihood methods. We argue that residual-permutation method unsound estimating parameter estimates. thus recommend refrain from this altogether. characterize...
The radial velocity method is one of the most successful techniques for detecting exoplanets. It works by a host star, induced gravitational effect an orbiting planet, specifically, along our line sight which called star. Low-mass planets typically cause their star to move with velocities 1 m/s or less. By analyzing time series stellar spectra from modern astronomical instruments can, in theory, detect such planets. However, practice, intrinsic variability (e.g., spots, convective motion,...
We have conducted pencil-beam searches for outer solar system objects to a limiting magnitude of R ~ 26. Five new trans-neptunian were detected in these searches. Our combined data set provides an estimate ~90 per square degree brighter than 25.9. This is factor 3 above the expected number based on extrapolation previous surveys with limits, and appears consistent hypothesis single power-law luminosity function entire region. Maximum likelihood fits all self-consistent published efficiency...
We explore the possible role of evolution in analysis data on Type Ia supernovae (SNe Ia) at cosmological distances. First, using a variety simple sleuthing techniques, we find evidence that properties high- and low-redshift SNe observed so far differ from one another. Next, examine effects allowing for an uncertain amount analysis, two phenomenological models prior probabilities express preference no but allow it to be present. One model shifts magnitudes high-redshift relative by fixed...
Exoplanet WASP-14b is a highly irradiated, transiting hot Jupiter. Joshi et al. calculate an equilibrium temperature (Teq) of 1866 K for zero albedo and reemission from the entire planet, mass 7.3 ± 0.5 Jupiter masses (MJ), radius 1.28 0.08 radii (RJ). Its mean density 4.6 g cm-3 one highest known planets with periods less than three days. We obtained secondary eclipse light curves Spitzer Space Telescope. The depths best jointly fit model are 0.224% 0.018% at 4.5 μm 0.181% 0.022% 8.0 μm....
Abstract We present the open-source Bayesian Atmospheric Radiative Transfer (BART) retrieval package, which produces estimates and uncertainties for an atmosphere’s thermal profile chemical abundances from observations. Several BART components are also stand-alone packages, including parallel Multi-Core Markov-chain Monte Carlo (MC3), implements several samplers; a line-by-line radiative-transfer model, transit ; code that calculates Thermochemical Equilibrium Abundances (TEA), test suite...
We present {\em Spitzer} secondary-eclipse observations of the hot Jupiter HAT-P-13 b in 3.6 {\micron} and 4.5 bands. inhabits a two-planet system with configuration that enables constraints on planet's second Love number, \math{k\sb{2}}, from precise eccentricity measurements, which turn constrains models interior structure. exploit direct measurements \math{e \cos \omega} our data combine them previously published radial velocity to generate refined model orbit thus an improved estimate...
Abstract We present the Infrared Database of Extragalactic Observables from Spitzer (IDEOS), a homogeneous, publicly available, database 77 fitted mid-infrared observables in 5.4–36 μ m range, comprising measurements for 3335 galaxies observed low-resolution staring mode Spectrometer on board Space Telescope. Among included are polycyclic aromatic hydrocarbon fluxes and their equivalent widths, strength 9.8 silicate feature, emission-line fluxes, solid-state features, rest-frame continuum...
We briefly summarize the main features of our Bayesian method for detecting and measuring periodic signals in event arrival time data, compare it to more common fast Fourier transform (FFT) epoch folding (EF) methods a case study using ROSAT observations X-ray pulsar PSR 0540-693. Although originally detected an FFT analysis Einstein Observatory data (Seward, Harnden, & Helfand), same approach failed detect signal data. show that both EF can reliably we demonstrate several important...
In summer 1999, we performed a survey optimized for the discovery of irregular satellites Uranus and Neptune. We imaged 11.85 deg2 sky discovered 66 new outer Solar system objects (not counting three Uranian satellites). Given very short orbital arcs our observations, only heliocentric distance can be reliably determined. were able to model radial distribution trans-Neptunian (TNOs). Our data support idea strong depletion in surface density beyond 45 au.
I discuss an issue arising in analyzing data from astronomical surveys: accounting for measurement uncertainties the properties of individual sources detected a survey when making inferences about entire population sources. Source require analyst to introduce unknown "incidental" parameters each source. The number thus grows with size sample, and standard theorems guaranteeing asymptotic convergence maximum likelihood estimates fail such settings. From Bayesian point view, missing ingredient...