Search Publications

The Complete Light-curve Sample of Spectroscopically Confirmed SNe Ia from Pan-STARRS1 and Cosmological Constraints from the Combined Pantheon Sample
DOI: 10.3847/1538-4357/aab9bb Bibcode: 2018ApJ...859..101S

Berger, E.; Kirshner, R. P.; Rest, A. +37 more

We present optical light curves, redshifts, and classifications for 365 spectroscopically confirmed Type Ia supernovae (SNe Ia) discovered by the Pan-STARRS1 (PS1) Medium Deep Survey. We detail improvements to the PS1 SN photometry, astrometry, and calibration that reduce the systematic uncertainties in the PS1 SN Ia distances. We combine the subs…

2018 The Astrophysical Journal
Planck eHST 2313
Milky Way Cepheid Standards for Measuring Cosmic Distances and Application to Gaia DR2: Implications for the Hubble Constant
DOI: 10.3847/1538-4357/aac82e Bibcode: 2018ApJ...861..126R

Casertano, Stefano; Filippenko, Alexei V.; Riess, Adam G. +9 more

We present Hubble Space Telescope (HST) photometry of a selected sample of 50 long-period, low-extinction Milky Way Cepheids measured on the same WFC3 F555W-, F814W-, and F160W-band photometric system as extragalactic Cepheids in Type Ia supernova host galaxies. These bright Cepheids were observed with the WFC3 spatial scanning mode in the optical…

2018 The Astrophysical Journal
Gaia eHST 601
New Parallaxes of Galactic Cepheids from Spatially Scanning the Hubble Space Telescope: Implications for the Hubble Constant
DOI: 10.3847/1538-4357/aaadb7 Bibcode: 2018ApJ...855..136R

Casertano, Stefano; Anderson, Jay; Filippenko, Alexei V. +8 more

We present new measurements of the parallax of seven long-period (≥10 days) Milky Way (MW) Cepheid variables (SS CMa, XY Car, VY Car, VX Per, WZ Sgr, X Pup, and S Vul) using one-dimensional astrometric measurements from spatial scanning of Wide-Field Camera 3 on the Hubble Space Telescope (HST). The observations were obtained at ∼6 month intervals…

2018 The Astrophysical Journal
Gaia INTEGRAL eHST 449
The Dearth of z ∼ 10 Galaxies in All HST Legacy Fields—The Rapid Evolution of the Galaxy Population in the First 500 Myr
DOI: 10.3847/1538-4357/aab03f Bibcode: 2018ApJ...855..105O

Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D. +2 more

We present an analysis of all prime HST legacy fields spanning >800 arcmin2 in the search for z ∼ 10 galaxy candidates and the study of their UV luminosity function (LF). In particular, we present new z ∼ 10 candidates selected from the full Hubble Frontier Field (HFF) data set. Despite the addition of these new fields, we find a low…

2018 The Astrophysical Journal
eHST 369
ALMA Survey of Lupus Protoplanetary Disks. II. Gas Disk Radii
DOI: 10.3847/1538-4357/aab890 Bibcode: 2018ApJ...859...21A

Guidi, G.; Testi, L.; Hogerheijde, M. +10 more

We present Atacama Large Millimeter/Sub-Millimeter Array (ALMA) Band 6 observations of a complete sample of protoplanetary disks in the young (∼1-3 Myr) Lupus star-forming region, covering the 1.33 mm continuum and the 12CO, 13CO, and C18O J = 2-1 lines. The spatial resolution is ∼0.″25 with a medium 3σ continuum s…

2018 The Astrophysical Journal
eHST 342
The Binary Neutron Star Event LIGO/Virgo GW170817 160 Days after Merger: Synchrotron Emission across the Electromagnetic Spectrum
DOI: 10.3847/2041-8213/aab2ad Bibcode: 2018ApJ...856L..18M

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…

2018 The Astrophysical Journal
eHST 334
The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at z ∼ 3
DOI: 10.3847/1538-4357/aaed28 Bibcode: 2018ApJ...869..123S

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…

2018 The Astrophysical Journal
eHST 297
Full-data Results of Hubble Frontier Fields: UV Luminosity Functions at z ∼ 6-10 and a Consistent Picture of Cosmic Reionization
DOI: 10.3847/1538-4357/aaa544 Bibcode: 2018ApJ...854...73I

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…

2018 The Astrophysical Journal
eHST 288
H- Opacity and Water Dissociation in the Dayside Atmosphere of the Very Hot Gas Giant WASP-18b
DOI: 10.3847/2041-8213/aab272 Bibcode: 2018ApJ...855L..30A

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 …

2018 The Astrophysical Journal
eHST 236
Type Ia Supernova Distances at Redshift >1.5 from the Hubble Space Telescope Multi-cycle Treasury Programs: The Early Expansion Rate
DOI: 10.3847/1538-4357/aaa5a9 Bibcode: 2018ApJ...853..126R

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…

2018 The Astrophysical Journal
eHST 225