Search Publications
ALMA 200 pc Resolution Imaging of Smooth Cold Dusty Disks in Typical z ∼ 3 Star-forming Galaxies
Daddi, E.; Elbaz, D.; Franco, M. +14 more
We present high-fidelity, 30 mas (200 pc) resolution ALMA rest-frame 240 µm observations of cold dust emission in three typical main-sequence star-forming galaxies (SFGs) at z ∼ 3 in the Hubble Ultra-Deep Field (HUDF). The cold dust is distributed within the smooth disklike central regions of star formation 1-3 kpc in diameter, despite their…
No evidence for intermediate-mass black holes in the globular clusters ω Cen and NGC 6624
Dreizler, S.; Usher, C.; Kamann, S. +8 more
We compare the results of a large grid of N-body simulations with the surface brightness and velocity dispersion profiles of the globular clusters ω Cen and NGC 6624. Our models include clusters with varying stellar-mass black hole retention fractions and varying masses of a central intermediate-mass black hole (IMBH). We find that an ∼ 45 000 M
Two new free-floating or wide-orbit planets from microlensing
Kaspi, Shai; Maoz, Dan; Han, Cheongho +57 more
Planet formation theories predict the existence of free-floating planets that have been ejected from their parent systems. Although they emit little or no light, they can be detected during gravitational microlensing events. Microlensing events caused by rogue planets are characterized by very short timescales tE (typically below two da…
Searching for Highly Magnified Stars at Cosmological Distances: Discovery of a Redshift 0.94 Blue Supergiant in Archival Images of the Galaxy Cluster MACS J0416.1-2403
Filippenko, Alexei V.; Foley, Ryan J.; Kelly, Patrick L. +12 more
Individual highly magnified stars have been recently discovered at lookback times of more than half the age of the universe, in lensed galaxies that straddle the critical curves of massive galaxy clusters. Having established their detectability, it is now important to carry out systematic searches for them in order to establish their frequency, an…
The evolutionary status of Cataclysmic Variables: eclipse modelling of 15 systems
Knigge, C.; Gänsicke, B. T.; Dhillon, V. S. +13 more
We present measurements of the component masses in 15 Cataclysmic Variables (CVs) - 6 new estimates and 9 improved estimates. We provide new calibrations of the relationship between superhump period excess and mass ratio, and use this relation to estimate donor star masses for 225 superhumping CVs. With an increased sample of donor masses we revis…
The evolution of galaxy shapes in CANDELS: from prolate to discy
Faber, S. M.; Lin, Lin; Zhang, Haowen +9 more
We model the projected b/a-log a distributions of CANDELS star-forming main-sequence galaxies, where a (b) is the half-light semimajor (semiminor) axis of the galaxy images measured by GALFIT. We find that smaller a galaxies are rounder at all stellar masses M* and redshifts, so we include a when analysing b/a distributions. Approximati…
CLEAR. I. Ages and Metallicities of Quiescent Galaxies at 1.0 < z < 1.8 Derived from Deep Hubble Space Telescope Grism Data
Papovich, Casey; Dickinson, Mark; Giavalisco, Mauro +14 more
We use deep Hubble Space Telescope spectroscopy to constrain the metallicities and (light-weighted) ages of massive ({log}{M}* /{M}⊙ ≳ 10) galaxies selected to have quiescent stellar populations at 1.0 < z < 1.8. The data include twelve-orbit depth coverage with the WFC3/G102 grism covering ∼8000 < λ < 11,500 Å at…
SkyMapper stellar parameters for Galactic Archaeology on a grand-scale
Wolf, C.; Yong, D.; Casagrande, L. +3 more
The SkyMapper photometric surveys provides uvgriz photometry for several millions sources in the Southern sky. We use DR1.1 to explore the quality of its photometry, and develop a formalism to homogenize zero-points across the sky using stellar effective temperatures. Physical flux transformations, and zero-points appropriate for this release are …
The wide binary fraction of solar-type stars: emergence of metallicity dependence at a < 200 au
Rix, Hans-Walter; El-Badry, Kareem
We combine a catalogue of wide binaries constructed from Gaia DR2 with [Fe/H] abundances from wide-field spectroscopic surveys to quantify how the binary fraction varies with metallicity over separations 50 ≲ s/au ≲ 50 000. At a given distance, the completeness of the catalogue is independent of metallicity, making it straightforward to constrain …
A hypervelocity star with a Magellanic origin
Boubert, Douglas; Erkal, Denis; Evans, N. Wyn +2 more
Using proper motion measurements from Gaia Data Release 2, we probe the origin of 26 previously known hypervelocity stars (HVSs) around the Milky Way. We find that a significant fraction of these stars have a high probability of originating in the Milky Way Galaxy, but there is one obvious outlier. HVS3 is highly likely to be coming almost from th…