Search Publications
Elucidating ΛCDM: Impact of Baryon Acoustic Oscillation Measurements on the Hubble Constant Discrepancy
Halpern, M.; Weiland, J. L.; Hinshaw, G. +3 more
We examine the impact of baryon acoustic oscillation (BAO) scale measurements on the discrepancy between the value of the Hubble constant (H 0) inferred from the local distance ladder and that from Planck cosmic microwave background (CMB) data. While the BAO data alone cannot constrain H 0, we show that combining the latest B…
H- Opacity and Water Dissociation in the Dayside Atmosphere of the Very Hot Gas Giant WASP-18b
Fortney, Jonathan J.; Stevenson, Kevin B.; Désert, Jean-Michel +7 more
We present one of the most precise emission spectra of an exoplanet observed so far. We combine five secondary eclipses of the hot Jupiter WASP-18b (T day ∼ 2900 K) that we secured between 1.1 and 1.7 µm with the Wide Field Camera 3 instrument on board the Hubble Space Telescope. Our extracted spectrum (S/N = 50, R ∼ 40) does not …
Type Ia Supernova Distances at Redshift >1.5 from the Hubble Space Telescope Multi-cycle Treasury Programs: The Early Expansion Rate
Dickinson, Mark; Ferguson, Henry C.; Grogin, Norman A. +31 more
We present an analysis of 15 Type Ia supernovae (SNe Ia) at redshift z> 1 (9 at 1.5< z< 2.3) recently discovered in the CANDELS and CLASH Multi-Cycle Treasury programs using WFC3 on the Hubble Space Telescope. We combine these SNe Ia with a new compilation of ∼1050 SNe Ia, jointly calibrated and corrected for simulated survey biases to pr…
Extremely Irradiated Hot Jupiters: Non-oxide Inversions, H- Opacity, and Thermal Dissociation of Molecules
Lothringer, Joshua D.; Barman, Travis; Koskinen, Tommi
Extremely irradiated hot Jupiters, exoplanets reaching dayside temperatures >2000 K, stretch our understanding of planetary atmospheres and the models we use to interpret observations. While these objects are planets in every other sense, their atmospheres reach temperatures at low pressures comparable only to stellar atmospheres. In order to u…
The ATLAS All-Sky Stellar Reference Catalog
Wolf, C.; Smartt, S. J.; Stalder, B. +6 more
The Asteroid Terrestrial-impact Last Alert System (ATLAS) observes most of the sky every night in search of dangerous asteroids. Its data are also used to search for photometric variability, where sensitivity to variability is limited by photometric accuracy. Since each exposure spans 7.°6 corner to corner, variations in atmospheric transparency i…
Three Hypervelocity White Dwarfs in Gaia DR2: Evidence for Dynamically Driven Double-degenerate Double-detonation Type Ia Supernovae
Foley, Ryan J.; Boubert, Douglas; Smith, Nathan +23 more
Double detonations in double white dwarf (WD) binaries undergoing unstable mass transfer have emerged in recent years as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. One potential outcome of this “dynamically driven double-degenerate double-detonation” (D6) scenario is that the companion WD survives the expl…
The HDUV Survey: A Revised Assessment of the Relationship between UV Slope and Dust Attenuation for High-redshift Galaxies
van Dokkum, Pieter G.; Illingworth, Garth D.; Labbé, Ivo +13 more
We use a newly assembled sample of 3545 star-forming galaxies with secure spectroscopic, grism, and photometric redshifts at z = 1.5-2.5 to constrain the relationship between UV slope (β) and dust attenuation (L IR/L UV ≡ IRX). Our sample significantly extends the range of L UV and β probed in previous UV-selected …
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6
Ono, Yoshiaki; Ouchi, Masami; Goto, Tomotsugu +44 more
We present new measurements of the quasar luminosity function (LF) at z ∼ 6 over an unprecedentedly wide range of the rest-frame ultraviolet luminosity M 1450 from -30 to -22 mag. This is the fifth in a series of publications from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multiban…
The Sausage Globular Clusters
Myeong, G. C.; Evans, N. W.; Belokurov, V. +2 more
The Gaia Sausage is an elongated structure in velocity space discovered by Belokurov et al. using the kinematics of metal-rich halo stars. They showed that it could be created by a massive dwarf galaxy (∼5 × 1010 {M}⊙ ) on a strongly radial orbit that merged with the Milky Way at a redshift z ≲ 3. This merger would also have …
A Decline in the X-Ray through Radio Emission from GW170817 Continues to Support an Off-axis Structured Jet
Berger, E.; Chornock, R.; Fong, W. +17 more
We present new observations of the binary neutron star merger GW170817 at Δt ≈ 220-290 days post-merger, at radio (Karl G. Jansky Very Large Array; VLA), X-ray (Chandra X-ray Observatory), and optical (Hubble Space Telescope; HST) wavelengths. These observations provide the first evidence for a turnover in the X-ray light curve, mirroring a declin…