Search Publications

Cosmological constraints from strong gravitational lensing in clusters of galaxies.

Kneib, J. -P.; Jullo, E.; Richard, J. +4 more

Current efforts in observational cosmology are focused on characterizing the mass-energy content of the Universe. We present results from a geometric test based on strong lensing in galaxy clusters. Based on Hubble Space Telescope images and extensive ground-based spectroscopic follow-up of the massive galaxy cluster Abell 1689, we used a parametr…

Major Galaxy Mergers and the Growth of Supermassive Black Holes in Quasars

Schawinski, Kevin; Natarajan, Priyamvada; Urry, C. Megan +3 more

Despite observed strong correlations between central supermassive black holes (SMBHs) and star formation in galactic nuclei, uncertainties exist in our understanding of their coupling. We present observations of the ratio of heavily obscured to unobscured quasars as a function of cosmic epoch up to z ≅ 3 and show that a simple physical model descr…

Direct Imaging of Bridged Twin Protoplanetary Disks in a Young Multiple Star

Pyo, Tae-Soo; Tamura, Motohide; Hayashi, Masahiko +10 more

Studies of the structure and evolution of protoplanetary disks are important for understanding star and planet formation. Here we present the direct image of an interacting binary protoplanetary system. Both circumprimary and circumsecondary disks are resolved in the near-infrared. There is a bridge of infrared emission connecting the two disks an…

Observing Supernova 1987A with the Refurbished Hubble Space Telescope

Smith, Nathan; Pun, Chun S. J.; France, Kevin +18 more

Observations with the Hubble Space Telescope (HST), conducted since 1990, now offer an unprecedented glimpse into fast astrophysical shocks in the young remnant of supernova 1987A. Comparing observations taken in 2010 with the use of the refurbished instruments on HST with data taken in 2004, just before the Space Telescope Imaging Spectrograph fa…