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Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets
Bouchy, F.; Vanderburg, A.; Poretti, E. +34 more
Super-Earths belong to a class of planet not found in the Solar system, but which appear common in the Galaxy. Given that some super-Earths are rocky, while others retain substantial atmospheres, their study can provide clues as to the formation of both rocky and gaseous planets, and - in particular - they can help to constrain the role of photoev…
Cosmological test using the Hubble diagram of high-z quasars
Melia, Fulvio
It has been known for over three decades that the monochromatic X-ray and UV luminosities in quasars are correlated, though non-linearly. This offers the possibility of using high-z quasars as standard candles for cosmological testing. In this paper, we use a recently assembled, high-quality catalogue of 1598 quasars extending all the way to redsh…
Machine-learning approaches to exoplanet transit detection and candidate validation in wide-field ground-based surveys
Bouchy, F.; Queloz, D.; Boumis, P. +23 more
Since the start of the Wide-angle Search for Planets (WASP) program, more than 160 transiting exoplanets have been discovered in the WASP data. In the past, possible transit-like events identified by the WASP pipeline have been vetted by human inspection to eliminate false alarms and obvious false positives. The goal of this paper is to assess the…
Anisotropy of the Universe via the Pantheon supernovae sample revisited
Zhao, Dong; Chang, Zhe; Zhou, Yong
We employ the hemisphere comparison (HC) method and the dipole fitting (DF) method to investigate the cosmic anisotropy in the recently released Pantheon sample of type Ia supernovae (SNe Ia) and five combinations among Pantheon. For the HC method, we find that the maximum anisotropy level in the full Pantheon sample is ALmax = 0.361 ± …
The dust content of the Crab Nebula
De Looze, I.; Gomez, H. L.; Barlow, M. J. +7 more
We have modelled the near-infrared to radio images of the Crab Nebula with a Bayesian SED model to simultaneously fit its synchrotron, interstellar (IS), and supernova dust emission. We infer an IS dust extinction map with an average AV = 1.08 ± 0.38 mag, consistent with a small contribution ({≲ }22{{ per cent}}) to the Crab's overall i…
More than just a wrinkle: a wave-like pattern in Ug versus Lz from Gaia data
Schönrich, Ralph; Friske, Jennifer K. S.
We present a newly found wave-like pattern in mean Galactocentric radial velocity {\overline{U}_ g} versus guiding centre radius Rg or angular momentum Lz of stars in the RV subsample of Gaia DR2. The short-wave pattern has a wavelength of order 1.2 kpc in Rg or 285 kpc km s^{-1} in Lz. The pattern shows…
Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM
Dolphin, Andrew E.; Skillman, Evan D.; Williams, Benjamin F. +11 more
We present the star formation history (SFH) of the isolated (D ∼ 970 kpc) Local Group dwarf galaxy Wolf-Lundmark-Melotte (WLM) measured from colour-magnitude diagrams (CMDs) constructed from deep Hubble Space Telescope imaging. Our observations include a central (0.5 r_h) and outer field (0.7 r_h) that reach below the oldest main-sequence turn-off…
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…