Search Publications
HARPS-N radial velocities confirm the low densities of the Kepler-9 planets
Poretti, E.; Sozzetti, A.; Piotto, G. +20 more
We investigated the discrepancy between planetary mass determinations using the transit timing variations (TTVs) and radial velocities (RVs), by analysing the multiplanet system Kepler-9. Despite being the first system characterized with TTVs, there are several discrepant solutions in the literature, with those reporting lower planetary densities …
The HST Large Programme on NGC 6752 - II. Multiple populations at the bottom of the main sequence probed in NIR
Salaris, M.; Apai, D.; Anderson, J. +12 more
Historically, multiple populations in globular clusters (GCs) have been mostly studied from ultraviolet and optical filters down to stars that are more massive than ∼0.6 M_{\odot }. Here, we exploit deep near-infrared (NIR) photometry from the Hubble Space Telescope to investigate multiple populations among M-dwarfs in the GC NGC 6752. We discover…
Evolution of galactic planes of satellites in the EAGLE simulation
Frenk, Carlos S.; Cautun, Marius; Shao, Shi
We study the formation of planes of dwarf galaxies around Milky Way (MW)-mass haloes in the EAGLE galaxy formation simulation. We focus on satellite systems similar to the one in the MW: spatially thin or with a large fraction of members orbiting in the same plane. To characterize the latter, we introduce a robust method to identify the subsets of…
SOFIA mid-infrared observations of Supernova 1987A in 2016 - forward shocks and possible dust re-formation in the post-shocked region
Matsuura, Mikako; Barlow, M. J.; Meixner, Margaret +10 more
The equatorial ring of Supernova (SN) 1987A has been exposed to forward shocks from the SN blast wave, and it has been suggested that these forward shocks have been causing ongoing destruction of dust in the ring. We obtained Stratospheric Observatory For Infrared Astronomy The Faint Object InfraRed CAmera for the SOFIA Telescope (FORCAST) 11.1, 1…
NGTS-7Ab: an ultrashort-period brown dwarf transiting a tidally locked and active M dwarf
Jackman, James A. G.; Wheatley, Peter J.; Moyano, Maximiliano +36 more
We present the discovery of NGTS-7Ab, a high-mass brown dwarf transiting an M dwarf with a period of 16.2 h, discovered as part of the Next Generation Transit Survey (NGTS). This is the shortest period transiting brown dwarf around a main or pre-main sequence star to date. The M star host (NGTS-7A) has an age of roughly 55 Myr and is in a state of…
Yule-Simpson's paradox in Galactic Archaeology
Guiglion, G.; Anders, F.; Chiappini, C. +7 more
Simpson's paradox, or Yule-Simpson effect, arises when a trend appears in different subsets of data but disappears or reverses when these subsets are combined. We describe here seven cases of this phenomenon for chemo-kinematical relations believed to constrain the Milky Way disc formation and evolution. We show that interpreting trends in relatio…
ASKAP detection of periodic and elliptically polarized radio pulses from UV Ceti
Kaplan, David L.; Lenc, Emil; Phillips, Chris +9 more
Active M dwarfs are known to produce bursty radio emission, and multiwavelength studies have shown that solar-like magnetic activity occurs in these stars. However, coherent bursts from active M dwarfs have often been difficult to interpret in the solar activity paradigm. We present Australian Square Array Pathfinder (ASKAP) observations of UV Cet…
The chemical composition of HIP 34407/HIP 34426 and other twin-star comoving pairs
Lambert, D. L.; Endl, M.; Meléndez, J. +4 more
We conducted a high-precision elemental abundance analysis of the twin-star comoving pair HIP 34407/HIP 34426. With mean error of 0.013 dex in the differential abundances (Δ[X/H]), a significant difference was found: HIP 34407 is more metal rich than HIP 34426. The elemental abundance differences correlate strongly with condensation temperature, w…
The diverse galaxy counts in the environment of high-redshift massive black holes in Horizon-AGN
Somerville, Rachel S.; Volonteri, Marta; Habouzit, Mélanie +4 more
High-redshift quasars are believed to reside in highly biased regions of the Universe, where black hole growth is sustained by an enhanced number of mergers and by being at the intersection of filaments bringing fresh gas. This assumption should be supported by an enhancement of the number counts of galaxies in the field of view of quasars. While …
The power spectrum of the Lyman-α Forest at z < 0.5
Hennawi, Joseph F.; Tripp, Todd M.; Prochaska, J. Xavier +7 more
We present new measurements of the flux power-spectrum P(k) of the z < 0.5 H I Lyman-α Forest spanning scales k ∼ 0.001-0.1 s km^{-1}. These results were derived from 65 far-ultraviolet quasar spectra (resolution R ∼ 18 000) observed with the Cosmic Origin Spectrograph (COS) on board the Hubble Space Telescope. The analysis required careful mas…