Search Publications
The Gaia DR2 halo white dwarf population: the luminosity function, mass distribution, and its star formation history
Rebassa-Mansergas, Alberto; Raddi, Roberto; Torres, Santiago +1 more
We analyse the volume-limited nearly complete 100 pc sample of 95 halo white dwarf candidates identified by the second data release of Gaia. Based on a detailed population synthesis model, we apply a method that relies on Gaia astrometry and photometry to accurately derive the individual white dwarf parameters. This method is tested with 25 white …
SN 2017gci: a nearby Type I Superluminous Supernova with a bumpy tail
Sollerman, J.; Gromadzki, M.; Jerkstrand, A. +27 more
We present and discuss the optical spectrophotometric observations of the nearby (z = 0.087) Type I superluminous supernova (SLSN I) SN 2017gci, whose peak K-corrected absolute magnitude reaches Mg = -21.5 mag. Its photometric and spectroscopic evolution includes features of both slow- and of fast-evolving SLSN I, thus favoring a contin…
Exploiting timing capabilities of the CHEOPS mission with warm-Jupiter planets
Alonso, R.; Deleuil, M.; Erikson, A. +75 more
We present 17 transit light curves of seven known warm-Jupiters observed with the CHaracterising ExOPlanet Satellite (CHEOPS). The light curves have been collected as part of the CHEOPS Guaranteed Time Observation (GTO) program that searches for transit-timing variation (TTV) of warm-Jupiters induced by a possible external perturber to shed light …
The nature of the extreme X-ray variability in the NLS1 1H 0707-495
Chainakun, P.; Fabian, A. C.; Pinto, C. +11 more
We examine archival XMM-Newton data on the extremely variable narrow-line Seyfert 1 active galactic nucleus (AGN) 1H 0707-495. We construct fractional excess variance (Fvar) spectra for each epoch, including the recent 2019 observation taken simultaneously with eROSITA. We explore both intrinsic and environmental absorption origins for …
Strong lens modelling: comparing and combining Bayesian neural networks and parametric profile fitting
Li, Nan; Dye, Simon; Maresca, Jacob +1 more
The vast quantity of strong galaxy-galaxy gravitational lenses expected by future large-scale surveys necessitates the development of automated methods to efficiently model their mass profiles. For this purpose, we train an approximate Bayesian convolutional neural network (CNN) to predict mass profile parameters and associated uncertainties, and …
Giant white-light flares on fully convective stars occur at high latitudes
Davenport, James R. A.; Pineda, J. Sebastian; Poppenhaeger, Katja +7 more
White-light flares are magnetically driven localized brightenings on the surfaces of stars. Their temporal, spectral, and statistical properties present a treasury of physical information about stellar magnetic fields. The spatial distributions of magnetic spots and associated flaring regions help constrain dynamo theories. Moreover, flares are th…
Deep Extragalactic VIsible Legacy Survey (DEVILS): consistent multiwavelength photometry for the DEVILS regions (COSMOS, XMMLSS, and ECDFS)
Häußler, B.; Bowler, R. A. A.; Lidman, C. +23 more
The Deep Extragalactic VIsible Legacy Survey (DEVILS) is an ongoing high-completeness, deep spectroscopic survey of ~60 000 galaxies to Y < 21.2 mag, over ~6 deg2 in three well-studied deep extragalactic fields: D10 (COSMOS), D02 (XMMLSS), and D03 (ECDFS). Numerous DEVILS projects all require consistent, uniformly derived and state-o…
A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) - IV. Candidate exoplanets around stars in open clusters: frequency and age-planetary radius distribution
Deleuil, M.; Bedin, L. R.; Piotto, G. +7 more
The knowledge of the ages of stars hosting exoplanets allows us to obtain an overview on the evolution of exoplanets and understand the mechanisms affecting their life. The measurement of the ages of stars in the Galaxy is usually affected by large uncertainties. An exception are the stellar clusters: For their coeval members, born from the same m…
The GOGREEN survey: transition galaxies and the evolution of environmental quenching
Cooper, M. C.; Muzzin, Adam; Forrest, Ben +25 more
We measure the rate of environmentally driven star formation quenching in galaxies at z ~ 1, using eleven massive ($M\approx 2\times 10^{14}\, \mathrm{M}_\odot$) galaxy clusters spanning a redshift range 1.0 < z < 1.4 from the GOGREEN sample. We identify three different types of transition galaxies: 'green valley' (GV) galaxies identified fr…
A multiband map of the natural night sky brightness including Gaia and Hipparcos integrated starlight
Masana, Eduard; Carrasco, Josep Manel; Bará, Salvador +1 more
The natural night sky brightness is a relevant input for monitoring the light pollution evolution at observatory sites, by subtracting it from the overall sky brightness determined by direct measurements. It is also instrumental for assessing the expected darkness of the pristine night skies. The natural brightness of the night sky is determined b…