Search Publications
The stellar mass of the Gaia-Sausage/Enceladus accretion remnant
Bovy, Jo; Lane, James M. M.; Mackereth, J. Ted
The Gaia-Sausage/Enceladus (GS/E) structure is an accretion remnant that comprises a large fraction of the Milky Way's stellar halo. We study GS/E using high-purity samples of kinematically selected stars from APOGEE DR16 and Gaia. Employing a novel framework to account for kinematic selection biases using distribution functions, we fit density pr…
Local stellar formation history from the 40 pc white dwarf sample
Tremblay, P. -E.; McCleery, J.; Cukanovaite, E. +4 more
We derive the local stellar formation history from the Gaia-defined 40 pc white dwarf sample. This is currently the largest volume-complete sample of white dwarfs for which spectroscopy is available, allowing for classification of the chemical abundances at the photosphere, and subsequently accurate determination of the atmospheric parameters. We …
The impact of early massive mergers on the chemical evolution of Milky Way-like galaxies: insights from NIHAO-UHD simulations
Buck, Tobias; Minchev, Ivan; Macciò, Andrea V. +3 more
Recent observations of the Milky Way (MW) found an unexpected steepening of the star-forming gas metallicity gradient around the time of the Gaia-Sausage-Enceladus (GSE) merger event. Here, we investigate the influence of early (tmerger ≲ 5 Gyr) massive ($M_{\rm {gas}}^{\rm {merger}}/M_{\rm {gas}}^{\rm {main}}(t_{\rm {merger}})\gtrsim 1…
The ALMA REBELS Survey: the first infrared luminosity function measurement at z ∼ 7
Inami, H.; Schneider, R.; Oesch, P. A. +18 more
We present the first observational infrared luminosity function (IRLF) measurement in the Epoch of Reionization (EoR) based on a ultraviolet (UV)-selected galaxy sample with the Atacama Large Millimeter Array (ALMA) spectroscopic observations. Our analysis is based on the ALMA large program Reionization Era Bright Emission Line Survey (REBELS), wh…
The merger fraction of ultramassive white dwarfs
Toonen, Silvia; Bergeron, P.; Kilic, Mukremin +6 more
We search for merger products among the 25 most massive white dwarfs in the Montreal White Dwarf Database 100 pc sample through follow-up spectroscopy and high-cadence photometry. We find an unusually high fraction, 40 per cent, of magnetic white dwarfs among this population. In addition, we identify four outliers in transverse velocity and detect…
The UV luminosity functions of bright z > 8 galaxies: determination from 0.41 deg2 of HST observations along 300 independent sightlines
Treu, Tommaso; Trenti, Michele; Morishita, Takahiro +2 more
We determine the bright end of the rest-frame UV luminosity function (UVLF) at z = 8-10 by selecting bright z ≳ 8 photometric candidates from the largest systematic compilation of HST (pure-)parallel observations to date, the Super-Brightest-of-Reionizing-Galaxies (SuperBoRG) data set. The data set includes ~300 independent sightlines from WFC3 ob…
JWST observations of dust reservoirs in type IIP supernovae 2004et and 2017eaw
Temim, Tea; Van Dyk, Schuyler D.; Filippenko, Alexei V. +37 more
Supernova (SN) explosions have been sought for decades as a possible source of dust in the Universe, providing the seeds of galaxies, stars, and planetary systems. SN 1987A offers one of the most promising examples of significant SN dust formation, but until the James Webb Space Telescope (JWST), instruments have traditionally lacked the sensitivi…
Beyond the bulge-halo conspiracy? Density profiles of early-type galaxies from extended-source strong lensing
Massey, Richard; Lagattuta, David J.; Robertson, Andrew +9 more
Observations suggest that the dark matter and stars in early-type galaxies 'conspire' to produce a surprisingly simple distribution of total mass, ρ(r) ∝ ρ-γ, with γ ≈ 2. We measure the distribution of mass in 48 early-type galaxies that gravitationally lens a resolved background source. By fitting the source light in every pixel of ima…
Potential signature of a quadrupolar hubble expansion in Pantheon+supernovae
Dhawan, Suhail; Cowell, Jessica A.; Macpherson, Hayley J.
The assumption of isotropy - that the Universe looks the same in all directions on large scales - is fundamental to the standard cosmological model. It is therefore critical to empirically test in which regimes this assumption holds. Anisotropies in the cosmic expansion are expected due to non-linear structures in the late Universe. However, the e…
On the origin of the Galactic thin and thick discs, their abundance gradients and the diagnostic potential of their abundance ratios
Cristallo, Sergio; de Laverny, Patrick; Recio-Blanco, Alejandra +8 more
Using a semi-analytical model of the evolution of the Milky Way, we show how secular evolution can create distinct overdensities in the phase space of various properties (e.g. age versus metallicity or abundance ratios versus age) corresponding to the thin and thick discs. In particular, we show how key properties of the Solar vicinity can be obta…