Search Publications
A single fast radio burst localized to a massive galaxy at cosmological distance
Shimwell, T. W.; Treu, T.; Kerr, M. +51 more
Fast radio bursts (FRBs) are brief radio emissions from distant astronomical sources. Some are known to repeat, but most are single bursts. Nonrepeating FRB observations have had insufficient positional accuracy to localize them to an individual host galaxy. We report the interferometric localization of the single-pulse FRB 180924 to a position 4 …
A noninteracting low-mass black hole-giant star binary system
Bieryla, Allyson; Latham, David W.; Berlind, Perry +14 more
Black hole binary systems with companion stars are typically found via their x-ray emission, generated by interaction and accretion. Noninteracting binaries are expected to be plentiful in the Galaxy but must be observed using other methods. We combine radial velocity and photometric variability data to show that the bright, rapidly rotating giant…
A three-dimensional map of the Milky Way using classical Cepheid variable stars
Udalski, Andrzej; Mróz, Przemek; Szymański, Michał K. +9 more
The Milky Way is a barred spiral galaxy, with physical properties inferred from various tracers informed by the extrapolation of structures seen in other galaxies. However, the distances of these tracers are measured indirectly and are model-dependent. We constructed a map of the Milky Way in three dimensions, based on the positions and distances …
Measurement and implications of Saturn's gravity field and ring mass
Iess, L.; Tortora, P.; Zannoni, M. +10 more
The interior structure of Saturn, the depth of its winds, and the mass and age of its rings constrain its formation and evolution. In the final phase of the Cassini mission, the spacecraft dived between the planet and its innermost ring, at altitudes of 2600 to 3900 kilometers above the cloud tops. During six of these crossings, a radio link with …
A planetesimal orbiting within the debris disc around a white dwarf star
Reffert, Sabine; Toonen, Silvia; Villaver, Eva +29 more
Many white dwarf stars show signs of having accreted smaller bodies, implying that they may host planetary systems. A small number of these systems contain gaseous debris discs, visible through emission lines. We report a stable 123.4-minute periodic variation in the strength and shape of the Ca II emission line profiles originating from the debri…
A radio ridge connecting two galaxy clusters in a filament of the cosmic web
Brunetti, G.; Enßlin, T. A.; Shimwell, T. W. +26 more
Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intracluster gas. We observed a ridge of radio emission connecting the merging galaxy clusters Abell 0399 and Abell 0401 with the Low-Frequency Array (LOFAR…
Gravitational lensing reveals ionizing ultraviolet photons escaping from a distant galaxy
Mahler, Guillaume; Chisholm, John; Rigby, Jane R. +7 more
During the epoch of reionization, neutral gas in the early Universe was ionized by hard ultraviolet radiation emitted by young stars in the first galaxies. To do so, ionizing ultraviolet photons must escape from the host galaxy. We present Hubble Space Telescope observations of the gravitationally lensed post-reionization galaxy PSZ1-ARC G311.6602…
A giant exoplanet orbiting a very-low-mass star challenges planet formation models
Schmitt, J. H. M. M.; Rebolo, R.; del Burgo, C. +179 more
Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet …
Gas flow and accretion via spiral streamers and circumstellar disks in a young binary protostar
Caselli, P.; Segura-Cox, D.; Zhao, B. +4 more
The majority of stars are part of gravitationally bound stellar systems, such as binaries. Observations of protobinary systems constrain the conditions that lead to stellar multiplicity and subsequent orbital evolution. We report high-angular resolution observations of the circumbinary disk around [BHB2007] 11, a young binary protostar system. The…
A loud quasi-periodic oscillation after a star is disrupted by a massive black hole
Steiner, James F.; Remillard, Ronald A.; Homan, Jeroen +9 more
The tidal forces close to massive black holes can rip apart stars that come too close to them. As the resulting stellar debris spirals toward the black hole, the debris heats up and emits x-rays. We report observations of a stable 131-second x-ray quasi-periodic oscillation from the tidal disruption event ASASSN-14li. Assuming the black hole mass …