Search Publications
Stellar Kinematics of z ~ 2 Galaxies and the Inside-out Growth of Quiescent Galaxies
van Dokkum, Pieter G.; Franx, Marijn; Bezanson, Rachel +6 more
Using stellar kinematics measurements, we investigate the growth of massive, quiescent galaxies from z ~ 2 to today. We present X-Shooter spectra from the UV to NIR and dynamical mass measurements of five quiescent massive (>1011 M ⊙) galaxies at z ~ 2. This triples the sample of z > 1.5 galaxies with well-constrained (…
The SL2S Galaxy-scale Lens Sample. IV. The Dependence of the Total Mass Density Profile of Early-type Galaxies on Redshift, Stellar Mass, and Size
Treu, Tommaso; Gavazzi, Raphaël; Marshall, Philip J. +4 more
We present optical and near-infrared spectroscopy obtained at Keck, Very Large Telescope, and Gemini for a sample of 36 secure strong gravitational lens systems and 17 candidates identified as part of the Strong Lensing Legacy Survey. The deflectors are massive early-type galaxies in the redshift range zd = 0.2-0.8, while the lensed sou…
Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations
von Braun, Kaspar; White, Russel; Goldfinger, P. J. +13 more
Based on CHARA Array measurements, we present the angular diameters of 23 nearby, main-sequence stars, ranging from spectral types A7 to K0, 5 of which are exoplanet host stars. We derive linear radii, effective temperatures, and absolute luminosities of the stars using Hipparcos parallaxes and measured bolometric fluxes. The new data are combined…
Discovery, Progenitor and Early Evolution of a Stripped Envelope Supernova iPTF13bvn
Kulkarni, S. R.; Cenko, S. Bradley; Wheeler, J. Craig +26 more
The intermediate Palomar Transient Factory reports our discovery of a young supernova, iPTF13bvn, in the nearby galaxy, NGC 5806 (22.5 Mpc). Our spectral sequence in the optical and infrared suggests a Type Ib classification. We identify a blue progenitor candidate in deep pre-explosion imaging within a 2σ error circle of 80 mas (8.7 pc). The cand…
The Structure of the Milky Way's Hot Gas Halo
Bregman, Joel N.; Miller, Matthew J.
The Milky Way's million degree gaseous halo contains a considerable amount of mass that, depending on its structural properties, can be a significant mass component. In order to analyze the structure of the Galactic halo, we use XMM-Newton Reflection Grating Spectrometer archival data and measure O VII Kα absorption-line strengths toward 26 active…
Spectroscopic analysis of DA white dwarfs with 3D model atmospheres
Steffen, M.; Ludwig, H. -G.; Tremblay, P. -E. +1 more
We present the first grid of mean three-dimensional (3D) spectra for pure-hydrogen (DA) white dwarfs based on 3D model atmospheres. We use CO5BOLD radiation-hydrodynamics 3D simulations instead of the mixing-length theory for the treatment of convection. The simulations cover the effective temperature range of 6000 < Teff …
HST Spectral Mapping of L/T Transition Brown Dwarfs Reveals Cloud Thickness Variations
Burrows, Adam; Apai, Dániel; Radigan, Jacqueline +3 more
Most directly imaged giant exoplanets are fainter than brown dwarfs with similar spectra. To explain their relative underluminosity, unusually cloudy atmospheres have been proposed. However, with multiple parameters varying between any two objects, it remained difficult to observationally test this idea. We present a new method, sensitive time-res…
Interstellar Water Chemistry: From Laboratory to Observations
van Dishoeck, Ewine F.; Neufeld, David A.; Herbst, Eric
Water is observed throughout the universe, from diffuse interstellar clouds to protoplanetary disks around young stars, and from comets in our own solar system and exoplanetary atmospheres to galaxies at high redshifts. This review summarizes the spectroscopy and excitation of water in interstellar space as well as the basic chemical processes tha…
Spiral Arms in the Asymmetrically Illuminated Disk of MWC 758 and Constraints on Giant Planets
Kuzuhara, M.; Tamura, M.; Ishii, M. +71 more
We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and Disks with Subaru, and 1.1 µm Hubble Space Telescope/NICMOS data. While submillimeter studies suggested there is a dust-depleted cavity with r = …
The Era of Star Formation in Galaxy Clusters
Chary, R. -R.; Stern, D.; Pope, A. +17 more
We analyze the star formation properties of 16 infrared-selected, spectroscopically confirmed galaxy clusters at 1 < z < 1.5 from the Spitzer/IRAC Shallow Cluster Survey (ISCS). We present new spectroscopic confirmation for six of these high-redshift clusters, five of which are at z > 1.35. Using infrared luminosities measured with deep S…