Search Publications
Constraining the properties of HD 206893 B. A combination of radial velocity, direct imaging, and astrometry data
Aigrain, S.; Rouan, D.; Meunier, N. +25 more
Context. High contrast imaging enables the determination of orbital parameters for substellar companions (planets, brown dwarfs) from the observed relative astrometry and the estimation of model and age-dependent masses from their observed magnitudes or spectra. Combining astrometric positions with radial velocity gives direct constraints on the o…
Investigating ULX accretion flows and cyclotron resonance in NGC 300 ULX1
Haberl, F.; Buchner, J.; Vasilopoulos, G. +2 more
Aims: We investigate accretion models for the newly discovered pulsating ultraluminous X-ray source (ULX) NGC 300 ULX1.
Methods: We analyzed broadband XMM-Newton and NuSTAR observations of NGC 300 ULX1, performing phase-averaged and phase-resolved spectroscopy. Using the Bayesian framework, we compared two physically motivated models for…
Prolonged sub-luminous state of the new transitional pulsar candidate CXOU J110926.4‑650224
Rea, Nanda; Coti Zelati, Francesco; Torres, Diego F. +12 more
We report on a multi-wavelength study of the unclassified X-ray source CXOU J110926.4‑650224 (J1109). We identified the optical counterpart as a blue star with a magnitude of ∼20.1 (3300–10500 Å). The optical emission was variable on timescales from hundreds to thousands of seconds. The spectrum showed prominent emission lines with variable profil…
Measuring the local matter density using Gaia DR2
Widmark, A.
Aims: We determine the total dynamical matter density in the solar neighbourhood using the second Gaia data release (DR2).
Methods: The dynamical matter density distribution is inferred in a framework of a Bayesian hierarchical model, which accounts for position and velocity of all individual stars, as well as the full error covariance m…
A new weak-field magnetic DA white dwarf in the local 20 pc volume. The frequency of magnetic fields in DA stars
Bagnulo, S.; Landstreet, J. D.
We report the discovery of a new magnetic DA white dwarf (WD), WD 0011 - 721, which is located within the very important 20 pc volume-limited sample of the closest WDs to the Sun. This star has a mean field modulus ⟨|B|⟩ of 343 kG, and from the polarisation signal we deduce a line-of-sight field component of 75 kG. The magnetic field is sufficient…
Characterising the surface magnetic fields of T Tauri stars with high-resolution near-infrared spectroscopy
Hussain, G. A. J.; Kochukhov, O.; Lavail, A.
Aims: In this paper, we aim to characterise the surface magnetic fields of a sample of eight T Tauri stars from high-resolution near-infrared spectroscopy. Some stars in our sample are known to be magnetic from previous spectroscopic or spectropolarimetric studies. Our goals are firstly to apply Zeeman broadening modelling to T Tauri stars wi…
Globular cluster candidates in the Galactic bulge: Gaia and VVV view of the latest discoveries
Minniti, D.; Rejkuba, M.; Zoccali, M. +7 more
Context. Thanks to the recent wide-area photometric surveys, the number of star cluster candidates have risen exponentially in the last few years. Most detections, however, are based only on the presence of an overdensity of stars in a given region or an overdensity of variable stars, regardless of their distance. As candidates, their detection ha…
Spatial distribution of stellar mass and star formation activity at 0.2 < z < 1.2 across and along the main sequence
Popesso, P.; Oesch, P. A.; Illingworth, G. D. +5 more
High-resolution multi-wavelength photometry is crucial to explore the spatial distribution of star formation in galaxies and understand how these evolve. To this aim, in this paper we exploit the deep, multi-wavelength Hubble Space Telescope (HST) data available in the central parts of the Great Observatories Origins Deep Survey (GOODS) fields and…
Extreme starlight polarization in a region with highly polarized dust emission
Tassis, Konstantinos; Hensley, Brandon S.; Blinov, Dmitry +2 more
Context. Galactic dust emission is polarized at unexpectedly high levels, as revealed by Planck.
Aims: The origin of the observed ≃20% polarization fractions can be identified by characterizing the properties of optical starlight polarization in a region with maximally polarized dust emission.
Methods: We measure the R-band linear polari…
Mass discrepancy analysis for a select sample of Type II-Plateau supernovae
Bersten, Melina C.; Martinez, Laureano
The detailed study of supernovae (SNe) and their progenitors allows a better understanding of the evolution of massive stars and how these end their lives. Despite its importance, the range of physical parameters for the most common type of explosion, the type II supernovae (SNe II), is still unknown. In particular, previous studies of type II-Pla…