Search Publications
The Velocity Dispersion Function for Quiescent Galaxies in Nine Strong-lensing Clusters
Diaferio, Antonaldo; Hwang, Ho Seong; Geller, Margaret J. +2 more
We measure the central stellar velocity dispersion function for quiescent galaxies in a set of nine northern clusters in the redshift range 0.18 < z < 0.29 and with strong lensing arcs in Hubble Space Telescope images. The velocity dispersion function links galaxies directly to their dark matter halos. From dense SDSS and MMT/Hectospec spect…
Xenon Isotopes Identify Large-scale Nucleosynthetic Heterogeneities across the Solar System
Avice, G.; Moreira, M.; Gilmour, J. D.
Nucleosynthetic isotopic anomalies in meteorites and planetary objects contribute to our understanding of the formation of the solar system. Isotope systematics of chondrites demonstrate the existence of a physical separation between isotopic reservoirs in the solar system. The isotopic composition of atmospheric xenon (Xe) indicates that its prog…
Statistical Properties of Habitable Zones in Stellar Binary Systems
Sozzetti, Alessandro; Vladilo, Giovanni; Silva, Laura +1 more
Observations of exoplanets and protoplanetary disks show that binary stellar systems can host planets in stable orbits. Given the high binary fraction among stars, the contribution of binary systems to Galactic habitability should be quantified. Therefore, we have designed a suite of Monte Carlo experiments aimed at generating large (up to 10…
Simulation of the Interplanetary Bz Using a Data-driven Heliospheric Solar Wind Model
Feng, Xueshang; Zuo, Pingbing; Wei, Fengsi +1 more
Aimed to be ready for the transition from research to operation, we have developed a solar wind model by coupling a data-driven empirical coronal model with a magnetohydrodynamics heliospheric model. We performed a data-driven simulation of the solar wind for a two-year period during the declining and minimum phases of solar cycle 23. Comparisons …
X-Ray Emission and Disk Irradiation of HL Tau and HD 100546
Skinner, Stephen L.; Güdel, Manuel
We present new X-ray observations of the optically obscured protostar HL Tau and the intermediate-mass Herbig Be star HD 100546. Both objects are surrounded by spectacular disks showing complex morphology, including rings and gaps that may have been sculpted by protoplanets. HL Tau was detected as a variable hard X-ray source by Chandra, typical o…
The Solar Origin of Particle Events Measured by Parker Solar Probe
Vourlidas, Angelos; Poirier, Nicolas; Kouloumvakos, Athanasios +4 more
During the second solar encounter phase of Parker Solar Probe (PSP), two small solar energetic particle (SEP) events were observed by the Integrated Science Investigation of the Sun, on 2019 April 2 and 4. At the time, PSP was approaching its second perihelion at a distance of ∼24.8 million kilometers from the solar center, it was in near-radial a…
CS Depletion in Prestellar Cores
Soam, Archana; Kim, Shinyoung; Kim, Gwanjeong +6 more
The CS molecule is known to be adsorbed onto dust in cold and dense conditions, causing it to be significantly depleted in the central region of cores. This study is aimed to investigate the depletion of the CS molecule using the optically thin {C}34{S} molecular line observations. We mapped five prestellar cores, L1544, L1552, L1689B, …
Extrapolation of Three-dimensional Magnetic Field Structure in Flare-productive Active Regions with Different Initial Conditions
Shimizu, T.; Inoue, S.; Kawabata, Y.
Nonlinear force-free field (NLFFF) modeling has been extensively used as a tool to infer three-dimensional (3D) magnetic field structure. In this study, the dependency of the NLFFF calculation with respect to the initial guess of the 3D magnetic field is investigated. While major parts of the previous studies used the potential field as the initia…
Magnetohydrodynamic Modeling of the Solar Wind Key Parameters and Current Sheets in the Heliosphere: Radial and Solar Cycle Evolution
Malova, H. V.; Popov, V. Yu.; Petrukovich, A. A. +4 more
We develop an axisymmetric numerical MHD model that allows us to investigate the spatial characteristics of the interplanetary magnetic field (IMF) and key solar wind plasma parameters from 20 to 400 solar radii over all heliolatitudes. The study is aimed at an analysis of the evolution of the spatial structure of the heliosphere through the solar…
A Retrograde Spin of the Black Hole in MAXI J1659-152
Méndez, Mariano; Vadawale, Santosh; Rout, Sandeep K.
We present the results of spectral analysis of the galactic black hole binary MAXI J1659-152 in the rising phase of the outburst that lasted for about 65 days starting on 2010 September 25. The presence of a broad Fe line, verified by Monte Carlo simulations, and coverage of a wide energy band by utilizing the combined spectral capabilities of XMM…