Search Publications
TOI-674b: An oasis in the desert of exo-Neptunes transiting a nearby M dwarf
Bouchy, F.; Korth, J.; Doyon, R. +59 more
Context. The NASA mission TESS is currently doing an all-sky survey from space to detect transiting planets around bright stars. As part of the validation process, the most promising planet candidates need to be confirmed and characterized using follow-up observations.
Aims: In this article, our aim is to confirm the planetary nature of the t…
The Second Discovery from the COCONUTS Program: A Cold Wide-orbit Exoplanet around a Young Field M Dwarf at 10.9 pc
Siverd, Robert J.; Claytor, Zachary R.; Dupuy, Trent J. +3 more
We present the identification of the second discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) program, the COCONUTS-2 system, composed of the M3 dwarf L 34-26 and the T9 dwarf WISEPA J075108.79-763449.6. Given their common proper motions and parallaxes, these two field objects constitute a physically bound pair with a projected sep…
Photometric Variability as a Proxy for Magnetic Activity and Its Dependence on Metallicity
Amard, Louis; See, Victor; Roquette, Julia +1 more
Understanding how the magnetic activity of low-mass stars depends on their fundamental parameters is an important goal of stellar astrophysics. Previous studies have shown that activity levels are largely determined by the stellar Rossby number, defined as the rotation period divided by the convective turnover time. However, we currently have litt…
Star formation in 'the Brick': ALMA reveals an active protocluster in the Galactic centre cloud G0.253+0.016
Ho, Luis C.; Jackson, James M.; Lu, Xing +16 more
G0.253+0.016, aka 'the Brick', is one of the most massive (>105 M⊙) and dense (>104 cm-3) molecular clouds in the Milky Way's Central Molecular Zone. Previous observations have detected tentative signs of active star formation, most notably a water maser that is associated with a dust continuum sou…
Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES+
Reiners, A.; Lopez, M.; Costille, A. +19 more
Studies of atmospheres of directly imaged extrasolar planets with high-resolution spectrographs have shown that their characterization is predominantly limited by noise on the stellar halo at the location of the studied exoplanet. An instrumental combination of high-contrast imaging and high spectral resolution that suppresses this noise and resol…
An Improved Hertzsprung-Russell Diagram for the Orion Trapezium Cluster
Fang, Min; Pascucci, Ilaria; Apai, Dániel +1 more
We present a study of the Trapezium cluster in Orion. We analyze flux-calibrated Very Large Telescope/Multi-Unit Spectroscopic Explorer spectra of 361 stars to simultaneously measure the spectral types, reddening, and the optical veiling due to accretion. We find that the extinction law from Cardelli et al. with a total-to-selective extinction val…
The Effect of Stream Interaction Regions on ICME Structures Observed in Longitudinal Conjunction
Lugaz, Noé; Scolini, Camilla; Galvin, Antoinette B. +1 more
We study two interplanetary coronal mass ejections (ICMEs) observed at Mercury and at 1 au by spacecraft in longitudinal conjunction, investigating the question: what causes the drastic alterations observed in some ICMEs during propagation, while other ICMEs remain relatively unchanged? Of the two ICMEs, the first one propagated relatively self-si…
Taking snapshots of the jet-ISM interplay: The case of PKS 0023-26
Morganti, Raffaella; Oosterloo, Tom; Tadhunter, Clive +2 more
We present high angular resolution (0.13-0.4 arcsec) ALMA CO(2-1) and 1.7 mm continuum observations of the far-infrared-bright galaxy PKS 0023−26 (z = 0.32), which hosts a young radio source as well as a luminous optical active galactic nucleus (AGN). Although young, the powerful radio source has already grown to a size of a few kiloparsec, making…
The IGRINS YSO Survey. I. Stellar Parameters of Pre-main-sequence Stars in Taurus-Auriga
Johns-Krull, Christopher M.; Hwang, Narae; Lee, Jae-Joon +19 more
We present fundamental parameters for 110 canonical K- and M-type (1.3-0.13 M⊙) Taurus-Auriga young stellar objects (YSOs). The analysis produces a simultaneous determination of effective temperature (Teff), surface gravity (log g), magnetic-field strength (B), and projected rotational velocity ( $v\sin i$ ). Our method emplo…
Towards constraining warm dark matter with stellar streams through neural simulation-based inference
Bertone, Gianfranco; Banik, Nilanjan; Weniger, Christoph +2 more
A statistical analysis of the observed perturbations in the density of stellar streams can in principle set stringent constraints on the mass function of dark matter subhaloes, which in turn can be used to constrain the mass of the dark matter particle. However, the likelihood of a stellar density with respect to the stream and subhaloes parameter…