Search Publications
A High Angular Resolution Survey of Massive Stars in Cygnus OB2: JHK Adaptive Optics Results from the Gemini Near-Infrared Imager
Goodwin, S. P.; Gies, D. R.; ten Brummelaar, T. A. +8 more
We present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the Near-Infrared Imager camera and ALTAIR adaptive optics system of the Gemini North telescope. We observed 74 O- and early-B-type stars in Cyg OB2 in the JHK infrared bands in order to detect binary and multiple compani…
New Expansion Rate Estimate of the Scorpius-Centaurus Association Based on T Tauri Stars from the Gaia DR2 Catalog
Bobylev, V. V.; Baykova, A. T.
The kinematic properties of the Scorpius-Centaurus association were studied using spatial velocities of approximately 700 young T Tauri stars. Their proper motions and trigonometric parallaxes were selected by Zari et al. from the Gaia DR2 catalog, and radial velocities were taken from various sources. The linear expansion coefficient's new estima…
Spinning Bar and a Star-formation Inefficient Repertoire: Turbulence in Hickson Compact Group NGC 7674
Kewley, Lisa J.; Federrath, Christoph; Groves, Brent +2 more
The physics regulating star formation (SF) in Hickson Compact Groups (HCG) has thus far been difficult to describe, due to their unique kinematic properties. In this study, we expand upon previous works to devise a more physically meaningful SF relation able to better encompass the physics of these unique systems. We combine CO(1-0) data from the …
Limitations in the determination of surface emission distributions on comets through modelling of observational data - A case study based on Rosetta observations
Thomas, Nicolas; Marschall, Raphael; Wu, Jong-Shinn +1 more
The European Space Agency's (ESA) Rosetta mission has returned a vast data set of measurements of the inner gas coma of comet 67/Churyumov-Gerasimenko. These measurements have been used by different groups to determine the distribution of the gas sources at the nucleus surface. The solutions that have been found differ from each other substantiall…
Heliospheric Maps from Cassini INCA Early in the Cruise to Saturn
Mitchell, D. G.; Krimigis, S.; Clark, G. +8 more
We present new energetic neutral atom (ENA) maps from the Ion and Neutral Camera (INCA) instrument on Cassini from the year 2000, prior to Cassini's encounter with Jupiter. These maps are the first produced for the year 2000 and are the only maps with comprehensive spatial coverage from the peak of solar cycle 23. These ENA maps span the energy ra…
CMEchaser, Detecting Line-of-Sight Occultations Due to Coronal Mass Ejections
Zucca, Pietro; Shaifullah, Golam; Tiburzi, Caterina
We present a python-based tool to detect the occultation of back-ground sources by foreground solar coronal mass ejections. The tool takes as input standard celestial coordinates of the source and translates those to the helioprojective plane, and is thus well suited for use with a wide variety of background astronomical sources. This tool provide…
Dying of the Light: An X-Ray Fading Cold Quasar at z ∼ 0.405
Kirkpatrick, Allison; Trump, Jonathan R.; LaMassa, Stephanie +11 more
Cold quasars are a rare subpopulation observed to host unobscured, X-ray luminous active galactic nuclei (AGN) while also retaining a cold gas supply fueling high star formation rates. These objects are interpreted as AGN early in their evolution. We present new SOFIA HAWC+ far-infrared observations, far-ultraviolet to far-infrared (FUV-FIR) photo…
Broad-band spectral analysis of LMXB XTE J1710-281 with Suzaku
Jain, Chetana; Dutta, Anjan; Sharma, Rahul +1 more
This work presents the broad-band time-averaged spectral analysis of neutron star (NS) low-mass X-ray binary, XTE J1710-281 by using the Suzaku archival data. The source was in a hard or an intermediate spectral state during this observation. This is the first time that a detailed spectral analysis of the persistent emission spectra of XTE J1710-2…
Shapes of stellar activity cycles
Hackman, T.; Käpylä, M. J.; Olspert, N. +4 more
Context. Magnetic activity cycles are an important phenomenon both in the Sun and other stars. The shape of the solar cycle is commonly characterised by a fast rise and a slower decline, but not much attention has been paid to the shape of cycles in other stars.
Aims: Our aim is to study whether the asymmetric shape of the solar cycle is comm…
A Search for Polarized Thermal Emission from Directly Imaged Exoplanets and Brown Dwarf Companions to Nearby Stars
Jensen-Clem, Rebecca; De Rosa, Robert J.; Hinkley, Sasha +15 more
Aerosols in the atmospheres of cloudy gas giant exoplanets and brown dwarfs scatter and polarize these objects' thermal emission. If such an object has an oblate shape or nonuniform cloud distribution, the net degree of linear polarization can show an increase ranging from several tenths of a percent to a few percent. Modern high-contrast imaging …