Search Publications
Transverse kinematics of the Galactic bar-bulge from VVV and Gaia
Evans, N. Wyn; Sanders, Jason L.; Lucas, Philip +1 more
We analyse the kinematics of the Galactic bar-bulge using proper motions from the ESO public survey Vista Variables in the Via Lactea (VVV) and the second Gaia data release. Gaia has provided some of the first absolute proper motions within the bulge and the near-infrared VVV multi-epoch catalogue complements Gaia in highly extincted low-latitude …
The shapes of the rotation curves of star-forming galaxies over the last ≈10 Gyr
Bacon, Roland; Smail, Ian; Swinbank, A. M. +16 more
We analyse maps of the spatially resolved nebular emission of ≈1500 star-forming galaxies at z ≈ 0.6-2.2 from deep K-band Multi-Object Spectrograph and MUSE observations to measure the average shape of their rotation curves. We use these to test claims for declining rotation curves at large radii in galaxies at z ≈ 1-2 that have been interpreted a…
The Hubble PanCET program: an extensive search for metallic ions in the exosphere of GJ 436 b
Sanz-Forcada, J.; Ehrenreich, D.; Lecavelier des Etangs, A. +15 more
Context. The quiet M2.5 star GJ 436 hosts a warm Neptune that displays an extended atmosphere that dwarfs its own host star. Predictions of atmospheric escape in such planets state that H atoms escape from the upper atmosphere in a collisional regime and that the flow can drag heavier atoms to the upper atmosphere. It is unclear, however, what ast…
Contributions from Accreted Organics to Titan’s Atmosphere: New Insights from Cometary and Chondritic Data
Miller, Kelly E.; Glein, Christopher R.; Waite, J. Hunter, Jr.
Since its discovery in the first half of the 20th century, scientists have puzzled over the origins of Titan’s atmosphere. Current models suggest that atmospheric N2 on Titan may have originated from NH3-bearing ice with N-isotopic ratios similar to those observed in NH2 in cometary comae (14N/15
In Situ Measurements of the Variable Slow Solar Wind near Sector Boundaries
Davies, J. A.; Lavraud, B.; Kilpua, E. +2 more
The release of density structures at the tip of the coronal helmet streamers, likely as a consequence of magnetic reconnection, contributes to the mass flux of the slow solar wind (SSW). In situ measurements in the vicinity of the heliospheric plasma sheet of the magnetic field, protons, and suprathermal electrons reveal details of the processes a…
Particle re-acceleration and Faraday-complex structures in the RXC J1314.4-2515 galaxy cluster
Dallacasa, D.; Vazza, F.; Botteon, A. +9 more
Radio relics are sites of electron (re)acceleration in merging galaxy clusters but the mechanism of acceleration and the topology of the magnetic field in and near relics are yet to be understood. We are carrying out an observational campaign on double relic galaxy clusters starting with RXC J1314.4-2515. With Jansky Very Large Array multiconfigur…
Infrared-excess white dwarfs in the Gaia 100 pc sample
Solano, E.; Rebassa-Mansergas, A.; Torres, S. +3 more
We analyse the 100 pc Gaia white dwarf volume-limited sample by means of VOSA (Virtual Observatory SED Analyser) with the aim of identifying candidates for displaying infrared excesses. Our search focuses on the study of the spectral energy distribution (SED) of 3733 white dwarfs with reliable infrared photometry and GBP - GRP
Plasmoid-mediated reconnection in solar UV bursts
Peter, H.; Chitta, L. P.; Young, P. R. +1 more
Context. Ultraviolet bursts are transients in the solar atmosphere with an increased impulsive emission in the extreme UV lasting for one to several tens of minutes. They often show spectral profiles indicative of a bi-directional outflow in response to magnetic reconnection.
Aims: To understand UV bursts, we study how motions of magnetic ele…
A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators
Duev, Dmitry A.; Riddle, Reed; Szkody, Paula +22 more
Using high-cadence observations from the Zwicky Transient Facility at low Galactic latitudes, we have discovered a new class of pulsating, hot compact stars. We have found four candidates, exhibiting blue colors (g - r ≤ -0.1 mag), pulsation amplitudes of >5%, and pulsation periods of 200-475 s. Fourier transforms of the light curves show only …
X-shooter spectroscopy of young stars with disks. The TW Hydrae association as a probe of the final stages of disk accretion
Alcalá, J. M.; Randich, S.; Scholz, A. +9 more
Context. Measurements of the fraction of disk-bearing stars in clusters as a function of age indicate protoplanetary disk lifetimes ≲10 Myr. However, our knowledge of the time evolution of mass accretion in young stars over the disk lifespans is subject to many uncertainties, especially at the lowest stellar masses (M⋆).
Aims: We i…