Search Publications
Machine Learning Analysis of Jupiter's Far-Ultraviolet Auroral Morphology
Milan, S. E.; Nichols, J. D.; Kamran, A.
We present the first principal component analysis of Jupiter's far-ultraviolet auroras, in order to identify the most repeatable sources of variation in the auroral morphology. We show that the most recurrent source of variance is emission just poleward of the statistical oval on the dawnside. Further significant repeatable sources of variance are…
Kinematics of subclusters in star cluster complexes: imprint of their parental molecular clouds
Fujii, M. S.
Star cluster complexes such as the Carina Nebula could have formed in turbulent giant molecular clouds. We perform a series of N-body simulations starting from subclustering initial conditions based on hydrodynamic simulations of turbulent molecular clouds. These simulations finally result in the formation of star cluster complexes consisting of s…
Non-thermal emission from massive star-forming regions: a possible SNR candidate G351.7-1.2?
Vig, S.; Ghosh, S. K.; Lal, D. V. +3 more
We present low-frequency wideband observations (300-500 MHz) of the star-forming complex G351.7-1.2 using upgraded Giant Metrewave Radio Telescope (uGMRT), India. Combining this with the optical, infrared, and submillimetre data, we analyse the large-scale diffuse radio emission associated with the region that exhibits a broken shell morphology. T…
Water and OH Emission from the Inner Disk of a Herbig Ae/Be Star
Najita, Joan R.; Brittain, Sean D.; Carr, John S. +2 more
We report the detection of hot H2O and OH emission from the Herbig Ae/Be star HD 101412 using the Cryogenic Infrared Echelle Spectrograph on the Very Large Telescope. Previous studies of Herbig Ae/Be stars have shown the presence of OH around some of these sources, but H2O has proven more elusive. While marginal water emissio…
Solar Wind Dynamic Pressure Upstream From Saturn: Estimation From Magnetosheath Properties and Comparison With SKR
Thomsen, M. F.; Jackman, C. M.; Lamy, L.
An analytical method is developed by which measurements made by the Cassini spacecraft in Saturn's magnetosheath can be used to infer the upstream solar wind parameters, specifically the solar wind speed (Vsw) and the dynamic pressure (Pd). The method is validated by comparing the results with other estimates of these parameters, includ…
Characterization of Low-mass K2 Planet Hosts Using Near-infrared Spectroscopy
Vanderburg, Andrew; Montet, Benjamin T.; Christiansen, Jessie L. +3 more
We present moderate resolution near-infrared spectra in the H, J, and K band of M-dwarf hosts to candidate transiting exoplanets discovered by NASA’s K2 mission. We employ known empirical relationships between spectral features and physical stellar properties to measure the effective temperature, radius, metallicity, and luminosity of our sample. …
Deuterated methanol toward NGC 7538-IRS1
Fedele, D.; Favre, C.; Lefloch, B. +7 more
We investigate the deuteration of methanol towards the high-mass star-forming region NGC 7538-IRS1. We carried out a multi-transition study of CH3OH, 13CH3OH, and the deuterated flavors, CH2DOH and CH3OD, between 1.0 and 1.4 mm with the IRAM-30 m antenna. In total, 34 13CH3
Variability of Precipitating Ion Fluxes During the September 2017 Event at Mars
Holmström, M.; Leblanc, F.; Luhmann, J. +15 more
In this work, we study the influence of the September 2017 solar event on the precipitating heavy ion fluxes toward Mars' atmosphere as seen by Mars Atmosphere and Volatile EvolutioN/Solar Wind Ion Analyzer, an energy and angular ion spectrometer and by Mars Atmosphere and Volatile EvolutioN/Suprathermal and Thermal Ion Composition instrument, an …
Awakening of the Fast-spinning Accreting Be/X-Ray Pulsar A0538-66
Mereghetti, Sandro; Santangelo, Andrea; Ducci, Lorenzo
A0538-66 is a Be/X-ray binary (Be/XRB) hosting a 69 ms pulsar It emitted bright X-ray outbursts with peak luminosity up to ∼1039 erg s-1 during the first years after its discovery in 1977. Since then, it was always seen in quiescence or during outbursts with L x ≲ 4 × 1037 erg s-1. In 2018 we …
A Multi-epoch X-Ray Study of the Spiral Galaxy NGC 7331
Kong, Albert K. H.; Jin, Ruolan
X-ray point sources in galaxies are dominated by X-ray binaries (XRBs) that are variables or transients, and whether their variability would alter the X-ray luminosity functions (XLFs) is still in debate. Here we report on NGC 7331 as an example to test this with seven Chandra observations. Their detection limit is 7 × 1037 erg s-1…