Search Publications
Unveiling short-period binaries in the inner VVV bulge
Minniti, D.; Contreras Ramos, R.; Saito, R. K. +5 more
Most of our knowledge of the structure of the Milky Way has come from the study of variable stars. Among these variables, mimicking the periodic variation of pulsating stars, are eclipsing binaries. These stars are important in astrophysics because they allow us to directly measure the radii and masses of the components, as well as the distance to…
Element Abundance Analysis of the Metal-rich Stellar Halo and High-velocity Thick Disk in the Galaxy
Shi, Jianrong; Ma, Jun; Du, Cuihua +3 more
Based on the second Gaia data release (DR2) and APOGEE (DR16) spectroscopic surveys, we define two kinds of star samples: high-velocity thick disk (HVTD) with vφ > 90 km s-1 and metal-rich stellar halo (MRSH) with vφ < 90 km s-1. Due to high-resolution spectra data from APOGEE (DR16), we can accura…
Investigation of the in-flight anomalies of the LISA Pathfinder Test Mass release mechanism
Bortoluzzi, D.; Mendes, J.; Vignotto, D. +1 more
The LISA Pathfinder mission was flown to test some key technologies for the in-flight detection of gravitational waves. The mechanism developed to initialise the science phase, releasing the test mass into a geodesic trajectory, produced unexpected test mass states, requiring dedicated in-flight and on-ground test campaigns. Due to the limited inf…
A spectroscopically confirmed Gaia-selected sample of 318 new young stars within ∼200 pc
Zhou, George; Nordlander, Thomas; Žerjal, Maruša +7 more
In the Gaia era, the majority of stars in the Solar neighbourhood have parallaxes and proper motions precisely determined while spectroscopic age indicators are still missing for a large fraction of low-mass young stars. In this work, we select 756 overluminous late K and early M young star candidates in the southern sky and observe them over 64 n…
Search for age pattern across spiral arms of the Milky Way
Xu, Ye; Hou, Li-Gang; He, Zhi-Hong
The age pattern across spiral arms is one of the key observational features utilised to study the dynamic nature of the Galaxy's spiral structure. With the most updated samples of high-mass star formation region (HMSFR) masers, O stars and open clusters, we investigated their distributions and kinematic properties in the vicinity of the Sun. We fo…
Serendipitous discovery of a dusty disc around WDJ181417.84-735459.83
Cooper, W. J.; Marocco, F.; Koester, D. +8 more
Spectroscopic observations of white dwarfs reveal that many of them are polluted by exoplanetary material, whose bulk composition can be uniquely probed this way. We present a spectroscopic and photometric analysis of the DA white dwarf WDJ181417.84-735459.83, an object originally identified to have a strong infrared (IR) excess in the 2MASS and W…
Modeling Stellar Abundance Patterns Resulting from the Addition of Earth-like Planetary Material
Cowley, Charles R.; Bord, Donald J.; Yüce, Kutluay
We model the observed precision differential abundance patterns of three G-type dwarfs, assuming a mass of planetary or disk material was added to or subtracted from the atmosphere of the star. The two-parameter model is fit by linear regression. The stellar abundance patterns are corrected for Galactic chemical evolution (GCE). The differential a…
Detection of volatiles undergoing sublimation from 67P/Churyumov-Gerasimenko coma particles using ROSINA/COPS. I. The ram gauge
Altwegg, K.; Balsiger, H.; Rubin, M. +5 more
Context. The ESA Rosetta mission has allowed for an extensive in situ study of the comet 67P/Churyumov-Gerasimenko. In measurements performed by the ram gauge of the COmet Pressure Sensor (COPS), observed features are seen to deviate from the nominal ram gauge signal. This effect is attributable to the sublimation of the volatile fraction of comet…
uGMRT detection of cluster radio emission in low-mass Planck Sunyaev-Zel'dovich clusters
Raychaudhury, Somak; Paul, Surajit; Dabhade, Pratik +5 more
Low-mass (M500 < 5 × 1014 M⊙) galaxy clusters have been largely unexplored in radio observations, because of the inadequate sensitivity of existing telescopes. However, the upgraded Giant Metrewave Radio Telescope (uGMRT) and the Low Frequency ARray (LoFAR), with unprecedented sensitivity at low frequencies, hav…
The role of magnetospheric plasma in solar wind-magnetosphere coupling: A review
Walsh, Brian M.; Zou, Ying
A variety of magnetospheric plasma populations have been proposed to impact solar wind-magnetosphere coupling. These magnetospheric populations could mass load the dayside magnetopause and include the plasmaspheric plume, plasma cloak, ion plasma sheet, and dayside ion outflow. Each has different densities, ion composition, and spatial/temporal oc…