Search Publications
Forward seismic modeling of the pulsating magnetic B-type star HD 43317
Aerts, C.; Neiner, C.; Mathis, S. +5 more
The large-scale magnetic fields detected at the surface of about 10% of hot stars extend into the stellar interior, where they may alter the structure. Deep inner regions of stars are only observable using asteroseismology. Here, we investigate the pulsating magnetic B3.5V star
Halometry from astrometry
Van Tilburg, Ken; Weiner, Neal; Taki, Anna-Maria
Halometry—mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo—can be realized via variable weak gravitational lensing of the apparent motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of cata…
Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies. I. Spatially Resolved Mass Outflow Rates for the Seyfert 2 Galaxy Markarian 573
Kraemer, S. B.; Crenshaw, D. M.; Schmitt, H. R. +3 more
We present the first spatially resolved mass outflow rate measurements ({\dot{M}}out}) of the optical emission line gas in the narrow line region (NLR) of a Seyfert 2 galaxy, Markarian 573. Using long slit spectra and [O III] imaging from the Hubble Space Telescope and Apache Point Observatory in conjunction with emission line diagnosti…
Gaia Data Release 2. The first Gaia catalogue of long-period variable candidates
Audard, M.; Rimoldini, L.; Holl, B. +13 more
Context. Gaia Data Release 2 (DR2) provides a unique all-sky catalogue of 550 737 variable stars, of which 151 761 are long-period variable (LPV) candidates with G variability amplitudes larger than 0.2 mag (5-95% quantile range). About one-fifth of the LPV candidates are Mira candidates, the majority of the rest are semi-regular variable candidat…
Confirmation of double peaked Lyα emission at z = 6.593. Witnessing a galaxy directly contributing to the reionisation of the Universe
Sobral, David; Stefanon, Mauro; Gronke, Max +3 more
Distant luminous Lyman-α emitters (LAEs) are excellent targets for spectroscopic observations of galaxies in the epoch of reionisation (EoR). We present deep high-resolution (R = 5000) VLT/X-shooter observations, along with an extensive collection of photometric data of COLA1, a proposed double peaked LAE at z = 6.6. We rule out the possibility th…
Neutral gas properties of Lyman continuum emitting galaxies: Column densities and covering fractions from UV absorption lines
Rigby, J. R.; Chisholm, J.; Schaerer, D. +3 more
Context. The processes allowing the escape of ionizing photons from galaxies into the intergalactic medium are poorly known.
Aims: To understand how Lyman continuum (LyC) photons escape galaxies, we constrain the H I covering fractions and column densities using ultraviolet (UV) H I and metal absorption lines of 18 star-forming galaxies that …
An Unusual Energetic Particle Flux Enhancement Associated with Solar Wind Magnetic Island Dynamics
Chen, Y.; Zank, G. P.; Zhao, L. -L. +4 more
The possibility that charged particles are accelerated statistically in a “sea” of small-scale interacting magnetic flux ropes in the supersonic solar wind is gaining credence. In this Letter, we extend the Zank et al. statistical transport theory for a nearly isotopic particle distribution by including an escape term corresponding to particle los…
TOPoS. IV. Chemical abundances from high-resolution observations of seven extremely metal-poor stars
Steffen, M.; Ludwig, H. -G.; Bonifacio, P. +15 more
Context. Extremely metal-poor (EMP) stars provide us with indirect information on the first generations of massive stars. The TOPoS survey has been designed to increase the census of these stars and to provide a chemical inventory that is as detailed as possible.
Aims: Seven of the most iron-poor stars have been observed with the UVES spectro…
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE). II. Constraining the quenching time in the stripped galaxy NGC 4330
Ferrarese, L.; Buat, V.; Boquien, M. +24 more
The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band Hα + [NII] imaging survey carried out with MegaCam at the Canada-France-Hawaii Telescope. During pilot observations taken in the spring of 2016 we observed NGC 4330, an intermediate mass (M* ≃ 109.8 M⊙) edge-on star forming…
The first all-sky view of the Milky Way stellar halo with Gaia+2MASS RR Lyrae
Belokurov, V.; Koposov, S. E.; Iorio, G. +3 more
We exploit the first Gaia data release to study the properties of the Galactic stellar halo as traced by RR Lyrae. We demonstrate that it is possible to select a pure sample of RR Lyrae using only photometric information available in the Gaia+2MASS catalogue. The final sample contains about 21 600 RR Lyrae covering an unprecedented fraction ( ∼ 60…