Search Publications
The Binary Neutron Star Event LIGO/Virgo GW170817 160 Days after Merger: Synchrotron Emission across the Electromagnetic Spectrum
Berger, E.; Chornock, R.; Fong, W. +17 more
We report deep Chandra X-ray Observatory (CXO), Hubble Space Telescope (HST), and Karl J. Jansky Very Large Array (VLA) observations of the binary neutron star event GW170817 at t < 160 days after merger. These observations show that GW170817 has been steadily brightening with time and might have now reached its peak, and constrain the emission…
Disks around T Tauri Stars with SPHERE (DARTTS-S). I. SPHERE/IRDIS Polarimetric Imaging of Eight Prominent T Tauri Disks
Benisty, Myriam; Garufi, Antonio; Pinte, Christophe +7 more
We present the first part of our Disks ARound T Tauri Stars with SPHERE (DARTTS-S) survey: observations of eight T Tauri stars that were selected based on their strong (sub)millimeter excesses using SPHERE/IRDIS polarimetric differential imaging in the J and H bands. All observations successfully detect the disks, which appear vastly different in …
In Disguise or Out of Reach: First Clues about In Situ and Accreted Stars in the Stellar Halo of the Milky Way from Gaia DR2
Haywood, M.; Gómez, A.; Lehnert, M. D. +3 more
We investigate the nature of the double color-magnitude sequence observed in the Gaia DR2 HR diagram of stars with high transverse velocities. The stars in the reddest-color sequence are likely dominated by the dynamically hot tail of the thick disk population. Information from Nissen & Schuster and from the APOGEE survey suggests that stars i…
The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at z ∼ 3
Pettini, Max; Shapley, Alice E.; Steidel, Charles C. +5 more
We present results of a deep spectroscopic survey quantifying the statistics of the escape of ionizing radiation from star-forming galaxies at z ∼ 3. We measure the ratio of ionizing to non-ionizing UV flux density < {f}900{/f}1500{> }obs}, where f 900 is the mean flux density evaluated over the ra…
The White Dwarf Initial-Final Mass Relation for Progenitor Stars from 0.85 to 7.5 M ⊙
Choi, Jieun; Ramirez-Ruiz, Enrico; Tremblay, P. -E. +2 more
We present the initial-final mass relation (IFMR) based on the self-consistent analysis of Sirius B and 79 white dwarfs from 13 star clusters. We have also acquired additional signal on eight white dwarfs previously analyzed in the NGC 2099 cluster field, four of which are consistent with membership. These re-observed white dwarfs have masses rang…
Full-data Results of Hubble Frontier Fields: UV Luminosity Functions at z ∼ 6-10 and a Consistent Picture of Cosmic Reionization
Ono, Yoshiaki; Ouchi, Masami; Shimasaku, Kazuhiro +3 more
We present UV luminosity functions of dropout galaxies at z∼ 6{--}10 with the complete Hubble Frontier Fields data. We obtain a catalog of ∼450 dropout-galaxy candidates (350, 66, and 40 at z∼ 6{--}7, 8, and 9, respectively), with UV absolute magnitudes that reach ∼ -14 mag, ∼2 mag deeper than the Hubble Ultra Deep Field detection limits. We caref…
Revised Radii of Kepler Stars and Planets Using Gaia Data Release 2
van Saders, Jennifer L.; Huber, Daniel; Berger, Travis A. +1 more
One bottleneck for the exploitation of data from the Kepler mission for stellar astrophysics and exoplanet research has been the lack of precise radii and evolutionary states for most of the observed stars. We report revised radii of 177,911 Kepler stars derived by combining parallaxes from the Gaia Data Release 2 with the DR25 Kepler Stellar Prop…
Evidence for a Systematic Offset of -80 µas in the Gaia DR2 Parallaxes
Torres, Guillermo; Stassun, Keivan G.
We reprise the analysis of Stassun & Torres, comparing the parallaxes of the eclipsing binaries reported in that paper to the parallaxes newly reported in the Gaia second data release (DR2). We find evidence for a systematic offset of -82 ± 33 µas, in the sense of the Gaia parallaxes being too small, for brightnesses (G ≲ 12) and for dis…
Kinematic Evidence for an Embedded Protoplanet in a Circumstellar Disk
Pinte, C.; Ménard, F.; Duchêne, G. +6 more
Disks of gas and dust surrounding young stars are the birthplace of planets. However, the direct detection of protoplanets forming within disks has proved elusive to date. We present the detection of a large, localized deviation from Keplerian velocity in the protoplanetary disk surrounding the young star HD 163296. The observed velocity pattern i…
A Kinematical Detection of Two Embedded Jupiter-mass Planets in HD 163296
Foreman-Mackey, Daniel; Bae, Jaehan; Bergin, Edwin A. +2 more
We present the first kinematical detection of embedded protoplanets within a protoplanetary disk. Using archival Atacama Large Millimetre Array (ALMA) observations of HD 163296, we demonstrate a new technique to measure the rotation curves of CO isotopologue emission to sub-percent precision relative to the Keplerian rotation. These rotation curve…