Search Publications
Cosmology from Gravitational Lens Time Delays and Planck Data
Treu, T.; Blandford, R. D.; Auger, M. W. +11 more
Under the assumption of a flat ΛCDM cosmology, recent data from the Planck satellite point toward a Hubble constant that is in tension with that measured by gravitational lens time delays and by the local distance ladder. Prosaically, this difference could arise from unknown systematic uncertainties in some of the measurements. More interestingly—…
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. I. First Results from a New Reverberation Mapping Campaign
Kaspi, Shai; Netzer, Hagai; Du, Pu +8 more
We report first results from a large project to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). Such objects may be different from other AGNs in being powered by slim accretion disks and showing saturated accretion luminosities, but both are not yet fully understood. The results are part of a large reverberation …
Lyα Transit Spectroscopy and the Neutral Hydrogen Tail of the Hot Neptune GJ 436b
Loyd, R. O. Parke; France, Kevin; Kulow, Jennifer R. +1 more
To date, more than 750 planets have been discovered orbiting stars other than the Sun. Two sub-classes of these exoplanets, "hot Jupiters" and their less massive counterparts "hot Neptunes," provide a unique opportunity to study the extended atmospheres of planets outside of our solar system. We describe here the first far-ultraviolet transit stud…
A Census of Star-forming Galaxies in the Z ~ 9-10 Universe based on HST+Spitzer Observations over 19 Clash Clusters: Three Candidate Z ~ 9-10 Galaxies and Improved Constraints on the Star Formation Rate Density at Z ~ 9.2
Kelson, D. D.; Infante, L.; Zheng, W. +34 more
We utilize a two-color Lyman-break selection criterion to search for z ~ 9-10 galaxies over the first 19 clusters in the CLASH program. A systematic search yields three z ~ 9-10 candidates. While we have already reported the most robust of these candidates, MACS1149-JD, two additional z ~ 9 candidates are also found and have H 160-band …
Physical Properties of Emission-line Galaxies at z ~ 2 from Near-infrared Spectroscopy with Magellan FIRE
Hathi, Nimish P.; Martin, Crystal L.; Bunker, Andrew J. +16 more
We present results from near-infrared spectroscopy of 26 emission-line galaxies at z ~ 2.2 and z ~ 1.5 obtained with the Folded-port InfraRed Echellette (FIRE) spectrometer on the 6.5 m Magellan Baade telescope. The sample was selected from the WFC3 Infrared Spectroscopic Parallels survey, which uses the near-infrared grism of the Hubble Space Tel…
The Long Lives of Giant Clumps and the Birth of Outflows in Gas-rich Galaxies at High Redshift
Amram, Philippe; Daddi, Emanuele; Juneau, Stéphanie +13 more
Star-forming disk galaxies at high redshift are often subject to violent disk instability, characterized by giant clumps whose fate is yet to be understood. The main question is whether the clumps disrupt within their dynamical timescale (<=50 Myr), like the molecular clouds in today's galaxies, or whether they survive stellar feedback for more…
Lens Models and Magnification Maps of the Six Hubble Frontier Fields Clusters
Coe, Dan; Sharon, Keren; Johnson, Traci L. +3 more
We present strong-lensing models as well as mass and magnification maps for the cores of the six Hubble Space Telescope (HST) Frontier Fields galaxy clusters. Our parametric lens models are constrained by the locations and redshifts of multiple image systems of lensed background galaxies. We use a combination of photometric redshifts and spectrosc…
The Typecasting of Active Galactic Nuclei: Mrk 590 no Longer Fits the Role
Martini, P.; Peterson, B. M.; Pogge, R. W. +9 more
We present multiwavelength observations that trace more than 40 yr in the life of the active galactic nucleus (AGN) in Mrk 590, traditionally known as a classic Seyfert 1 galaxy. From spectra recently obtained from Hubble Space Telescope, Chandra, and the Large Binocular Telescope, we find that the activity in the nucleus of Mrk 590 has diminished…
A Substantial Population of Massive Quiescent Galaxies at z ~ 4 from ZFOURGE
Papovich, Casey; Dickinson, Mark; Inami, Hanae +21 more
We report the likely identification of a substantial population of massive M ~ 1011 M ⊙ galaxies at z ~ 4 with suppressed star formation rates (SFRs), selected on rest-frame optical to near-IR colors from the FourStar Galaxy Evolution Survey (ZFOURGE). The observed spectral energy distributions show pronounced breaks, sampled…
Validation of Kepler's Multiple Planet Candidates. II. Refined Statistical Framework and Descriptions of Systems of Special Interest
Torres, Guillermo; Marcy, Geoffrey W.; Lissauer, Jack J. +11 more
We extend the statistical analysis performed by Lissauer et al. in 2012, which demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) represents true transiting planets, and we develop therefrom a procedure to validate large numbers of planet candidates in multis as bona fide exoplanets. We show that t…