Search Publications

Host-galaxy Properties of 32 Low-redshift Superluminous Supernovae from the Palomar Transient Factory
DOI: 10.3847/0004-637X/830/1/13 Bibcode: 2016ApJ...830...13P

Gal-Yam, A.; Filippenko, A. V.; Nugent, P. E. +9 more

We present ultraviolet through near-infrared photometry and spectroscopy of the host galaxies of all superluminous supernovae (SLSNe) discovered by the Palomar Transient Factory prior to 2013 and derive measurements of their luminosities, star formation rates, stellar masses, and gas-phase metallicities. We find that Type I (hydrogen-poor) SLSNe (…

2016 The Astrophysical Journal
eHST 206
ALMA Imaging and Gravitational Lens Models of South Pole Telescope—Selected Dusty, Star-Forming Galaxies at High Redshifts
DOI: 10.3847/0004-637X/826/2/112 Bibcode: 2016ApJ...826..112S

Béthermin, M.; Weiss, A.; Greve, T. R. +18 more

The South Pole Telescope has discovered 100 gravitationally lensed, high-redshift, dusty, star-forming galaxies (DSFGs). We present 0.″5 resolution 870 µ {{m}} Atacama Large Millimeter/submillimeter Array imaging of a sample of 47 DSFGs spanning z=1.9{--}5.7, and construct gravitational lens models of these sources. Our visibility-based lens…

2016 The Astrophysical Journal
eHST 202
The Evolution of Normal Galaxy X-Ray Emission through Cosmic History: Constraints from the 6 MS Chandra Deep Field-South
DOI: 10.3847/0004-637X/825/1/7 Bibcode: 2016ApJ...825....7L

Lehmer, B. D.; Hornschemeier, A. E.; Yukita, M. +17 more

We present measurements of the evolution of normal-galaxy X-ray emission from z\quad ≈ 0-7 using local galaxies and galaxy samples in the ≈6 Ms Chandra Deep Field-South (CDF-S) survey. The majority of the CDF-S galaxies are observed at rest-frame energies above 2 keV, where the emission is expected to be dominated by X-ray binary (XRB) populations…

2016 The Astrophysical Journal
eHST 199
The Lyman-Continuum Photon Production Efficiency ξ ion of z ∼ 4-5 Galaxies from IRAC-based Hα Measurements: Implications for the Escape Fraction and Cosmic Reionization
DOI: 10.3847/0004-637X/831/2/176 Bibcode: 2016ApJ...831..176B

Bouwens, R. J.; Franx, M.; Labbé, I. +5 more

Galaxies represent one of the preferred candidate sources to drive the reionization of the universe. Even as gains are made in mapping the galaxy UV luminosity density to z\gt 6, significant uncertainties remain regarding the conversion to the implied ionizing emissivity. The relevant unknowns are the Lyman-continuum (LyC) photon production effici…

2016 The Astrophysical Journal
eHST 198
The COS-Halos Survey: Origins of the Highly Ionized Circumgalactic Medium of Star-Forming Galaxies
DOI: 10.3847/1538-4357/833/1/54 Bibcode: 2016ApJ...833...54W

Tripp, Todd M.; Prochaska, J. Xavier; Cantalupo, Sebastiano +6 more

The total contribution of diffuse halo gas to the galaxy baryon budget strongly depends on its dominant ionization state. In this paper, we address the physical conditions in the highly ionized circumgalactic medium (CGM) traced by {{O}} {{VI}} absorption lines observed in COS-Halos spectra. We analyze the observed ionic column densities, absorpti…

2016 The Astrophysical Journal
eHST 194
The MUSCLES Treasury Survey. III. X-Ray to Infrared Spectra of 11 M and K Stars Hosting Planets
DOI: 10.3847/0004-637X/824/2/102 Bibcode: 2016ApJ...824..102L

Redfield, Seth; Brown, Alexander; France, Kevin +8 more

We present a catalog of panchromatic spectral energy distributions (SEDs) for 7 M and 4 K dwarf stars that span X-ray to infrared wavelengths (5 Å -5.5 µm). These SEDs are composites of Chandra or XMM-Newton data from 5-∼50 Å, a plasma emission model from ∼50-100 Å, broadband empirical estimates from 100-1170 Å, Hubble Space Telescope data f…

2016 The Astrophysical Journal
XMM-Newton eHST 194
The Influence of Nonuniform Cloud Cover on Transit Transmission Spectra
DOI: 10.3847/0004-637X/820/1/78 Bibcode: 2016ApJ...820...78L

Line, Michael R.; Parmentier, Vivien

We model the impact of nonuniform cloud cover on transit transmission spectra. Patchy clouds exist in nearly every solar system atmosphere, brown dwarfs, and transiting exoplanets. Our major findings suggest that fractional cloud coverage can exactly mimic high mean molecular weight atmospheres and vice versa over certain wavelength regions, in pa…

2016 The Astrophysical Journal
eHST 193
Hubble Imaging of the Ionizing Radiation from a Star-forming Galaxy at Z=3.2 with fesc>50%
DOI: 10.3847/0004-637X/825/1/41 Bibcode: 2016ApJ...825...41V

Giavalisco, M.; Castellano, M.; Pentericci, L. +20 more

Star-forming galaxies are considered to be the leading candidate sources dominating cosmic reionization at z\gt 7: the search for analogs at moderate redshift showing Lyman continuum (LyC) leakage is currently an active line of research. We have observed a star-forming galaxy at z = 3.2 with Hubble/WFC3 in the F336W filter, corresponding to the 73…

2016 The Astrophysical Journal
eHST 185
An HST/COS Survey of the Low-redshift Intergalactic Medium. I. Survey, Methodology, and Overall Results
DOI: 10.3847/0004-637X/817/2/111 Bibcode: 2016ApJ...817..111D

Savage, Blair D.; Shull, J. Michael; Danforth, Charles W. +12 more

We use high-quality, medium-resolution Hubble Space Telescope/Cosmic Origins Spectrograph (HST/COS) observations of 82 UV-bright active galactic nuclei (AGNs) at redshifts zAGN < 0.85 to construct the largest survey of the low-redshift intergalactic medium (IGM) to date: 5138 individual extragalactic absorption lines in H I and 25 di…

2016 The Astrophysical Journal
eHST 180
Detection of H2O and Evidence for TiO/VO in an Ultra-hot Exoplanet Atmosphere
DOI: 10.3847/2041-8205/822/1/L4 Bibcode: 2016ApJ...822L...4E

Nikolov, Nikolay; Drummond, Benjamin; Gibson, Neale P. +7 more

We present a primary transit observation for the ultra-hot (T eq ∼ 2400 K) gas giant expolanet WASP-121b, made using the Hubble Space Telescope Wide Field Camera 3 in spectroscopic mode across the 1.12-1.64 µm wavelength range. The 1.4 µm water absorption band is detected at high confidence (5.4σ) in the planetary atmosphere…

2016 The Astrophysical Journal
eHST 178