Search Publications
High-contrast Imaging of Intermediate-mass Giants with Long-term Radial Velocity Trends
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +62 more
A radial velocity (RV) survey for intermediate-mass giants has been in operation for over a decade at Okayama Astrophysical Observatory (OAO). The OAO survey has revealed that some giants show long-term linear RV accelerations (RV trends), indicating the presence of outer companions. Direct-imaging observations can help clarify what objects genera…
Quantifying the Interstellar Medium and Cosmic Rays in the MBM 53, 54, and 55 Molecular Clouds and the Pegasus Loop Using Fermi-LAT Gamma-ray Observations
Mizuno, T.; Okumura, A.; Fukui, Y. +4 more
A study of the interstellar medium (ISM) and cosmic rays (CRs) using Fermi Large Area Telescope (LAT) data, in a region encompassing the nearby molecular clouds MBM 53, 54, and 55 and a far-infrared loop-like structure in Pegasus, is reported. By comparing the Planck dust thermal emission model with Fermi-LAT γ-ray data, it was found that neither …
Comparison of CME/Shock Propagation Models with Heliospheric Imaging and In Situ Observations
Lu, Lei; Feng, Xueshang; Liu, Ying D. +3 more
The prediction of the arrival time for fast coronal mass ejections (CMEs) and their associated shocks is highly desirable in space weather studies. In this paper, we use two shock propagation models, I.e., Data Guided Shock Time Of Arrival (DGSTOA) and Data Guided Shock Propagation Model (DGSPM), to predict the kinematical evolution of interplanet…
Tracing back the evolution of the candidate LBV HD 168625
Mahy, L.; Waelkens, C.; Royer, P. +1 more
Context. The luminous blue variable phase is a crucial transitory phase that is not clearly understood in the massive star evolution.
Aims: We have obtained far-infrared Herschel/PACS imaging and spectroscopic observations of the nebula surrounding the candidate LBV HD 168625. By combining these data with optical spectra of the central star, …
The Comparison of Total Electron Content Between Radio and Thompson Scattering
Llebaria, A.; Lamy, P.; Jensen, E. A. +5 more
The total electron content (TEC) of the solar corona in June 2002 is calculated by three observational techniques and the results are compared. The first technique is solar rotational tomography (SRT) applied to a 14-day time series of LASCO-C2 polarized brightness images, and the other two techniques use the Cassini spacecraft radio beacon for Do…
Properties of Interstellar Medium In Infrared-bright QSOs Probed by [O I] 63 um and [C II] 158 um Emission Lines
Tsai, Chao-Wei; Zhao, Yinghe; Yan, Lin
We present a study of the interstellar medium (ISM) in the host galaxies of nine QSOs at 0.1 < z < 0.2 with black hole masses of 3× {10}7 {M}⊙ to 3× {10}9 {M}⊙ based on the far-IR spectroscopy taken with Herschel Space Observatory. We detect the [O I] 63 µm ([C II] 158 µm) emission in…
Search for Gamma-Ray Emission from AE Aquarii with Seven Years of Fermi-LAT Observations
Rea, Nanda; Torres, Diego F.; Li, Jian +4 more
AE Aquarii (AE Aqr) is a cataclysmic binary hosting one of the fastest rotating ({P}{spin} = 33.08 s) white dwarfs (WDs) known. Based on seven years of Fermi Large Area Telescope (LAT) Pass 8 data, we report on a deep search for gamma-ray emission from AE Aqr. Using X-ray observations from ASCA, XMM-Newton, Chandra, Swift, Suzaku, and N…
The ACS LCID Project. XI. On the Early Time Resolution of SFHs of Local Group Dwarf Galaxies: Comparing the Effects of Reionization in Models with Observations
Dolphin, Andrew; Skillman, Evan; Monelli, Matteo +10 more
The analysis of the early star formation history (SFH) of nearby galaxies, obtained from their resolved stellar populations, is relevant as a test for cosmological models. However, the early time resolution of observationally derived SFHs is limited by several factors. Thus, direct comparison of observationally derived SFHs with those derived from…
Stratigraphy and formation of clays, sulfates, and hydrated silica within a depression in Coprates Catena, Mars
Weitz, Catherine M.; Bishop, Janice L.
We investigate the morphology, mineralogy, and stratigraphy of light-toned layered deposits within a trough of Coprates Catena, centered at -15°N, 300°E. One of the deposits in the eastern portion of the trough contains numerous hydrated minerals, including Al-phyllosilicates, Fe/Mg-phyllosilicates, hydrated silica, hydrated sulfates, jarosite and…
Cosmological Parameters from CMB Maps without Likelihood Approximation
Eriksen, H. K.; Wehus, I. K.; Racine, B. +1 more
We propose an efficient Bayesian Markov chain Monte Carlo (MCMC) algorithm for estimating cosmological parameters from cosmic microwave background (CMB) data without the use of likelihood approximations. It builds on a previously developed Gibbs sampling framework that allows for exploration of the joint CMB sky signal and power spectrum posterior…