Search Publications
Probing gravitational non-minimal coupling with dark energy surveys
Geng, Chao-Qiang; Lee, Chung-Chi; Wu, Yi-Peng
We investigate observational constraints on a specific one-parameter extension to the minimal quintessence model, where the quintessence field acquires a quadratic coupling to the scalar curvature through a coupling constant
“Dandelion” Filament Eruption and Coronal Waves Associated with a Solar Flare on 2011 February 16
Shibata, Kazunari; Takasao, Shinsuke; Ishii, Takako T. +11 more
Coronal disturbances associated with solar flares, such as Hα Moreton waves, X-ray waves, and extreme ultraviolet (EUV) coronal waves, are discussed herein in relation to magnetohydrodynamic fast-mode waves or shocks in the corona. To understand the mechanism of coronal disturbances, full-disk solar observations with high spatial and temporal reso…
XMM-Newton X-Ray Observations of LkCa 15: A T Tauri Star with a Formative Planetary System
Skinner, Stephen L.; Güdel, Manuel
High-resolution ground-based images of the T Tauri star LkCa 15 have revealed multiple companions that are thought to comprise a formative planetary system. The candidate protoplanets orbit at distances of ∼15-20 au within the dust-depleted inner region of the circumstellar disk. Because of its young age (∼1-4 Myr), LkCa 15 provides a benchmark sy…
Source clustering in the Hi-GAL survey determined using a minimum spanning tree method
Elia, D.; Pezzuto, S.; Schisano, E. +5 more
Aims: The aims are to investigate the clustering of the far-infrared sources from the Herschel infrared Galactic Plane Survey (Hi-GAL) in the Galactic longitude range of -71 to 67 deg. These clumps, and their spatial distribution, are an imprint of the original conditions within a molecular cloud. This will produce a catalogue of over-densiti…
Temperatures and CH4 mixing ratios near the homopause of the 8 µm north polar hot spot of Jupiter
Orton, G. S.; Kim, Sang Joon; Yung, Yuk L. +4 more
We have derived homopause temperatures of 180-250 K for the 8-µm north-polar hot spot (8NPHS) of Jupiter by fitting CH4 emission models to 3 and 8 µm spectra of the 8NPHS obtained 24 days apart in 2013. From the fits, we find that CH4 mixing ratios at the 8NPHS are consistent with those reported by Kim et al. (201…
A counterimage to the gravitational arc in Abell 1201: Evidence for IMF variations, or a 1010 M⊙ black hole?★†
Edge, Alastair C.; Lucey, John R.; Smith, Russell J.
Abell 1201 is a massive galaxy cluster at z = 0.169 with a brightest cluster galaxy (BCG) that acts as a gravitational lens to a background source at z = 0.451. The lensing configuration is unusual, with a single bright arc formed at small radius (∼2 arcsec), where stars and dark matter are both expected to contribute substantially to the total le…
Density Structures, Dynamics, and Seasonal and Solar Cycle Modulations of Saturn's Inner Plasma Disk
André, N.; Persoon, A. M.; Garnier, P. +7 more
We present statistical results from the Cassini Radio and Plasma Wave Science (RPWS) Langmuir probe measurements recorded during the time interval from orbit 3 (1 February 2005) to 237 (29 June 2016). A new and improved data analysis method to obtain ion density from the Cassini LP measurements is used to study the asymmetries and modulations foun…
Proper motions of the HH 1 jet
Velázquez, P. F.; Bally, J.; Raga, A. C. +9 more
We describe a new method for determining proper motions of extended objects, and a pipeline developed for the application of this method. We then apply this method to an analysis of four epochs of [S II] HST images of the HH 1 jet (covering a period of ≈20 yr). We determine the proper motions of the knots along the jet, and make a reconstruction o…
Observations of Phobos by the Mars Express radar MARSIS: Description of the detection techniques and preliminary results
Plettemeier, D.; Orosei, R.; Plaut, J. J. +4 more
The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) (Picardi et al., 2005) is a synthetic aperture low frequency radar altimeter, onboard the ESA Mars Express orbiter, launched in June 2003. It is the first and so far the only spaceborne radar that has observed the Martian moon Phobos. Radar echoes were collected on different f…
Modelled isotopic fractionation and transient diffusive release of methane from potential subsurface sources on Mars
Stevens, Adam H.; Lewis, Stephen R.; Patel, Manish R.
We calculate transport timescales of martian methane and investigate the effect of potential release mechanisms into the atmosphere using a numerical model that includes both Fickian and Knudsen diffusion. The incorporation of Knudsen diffusion, which improves on a Fickian description of transport given the low permeability of the martian regolith…