Search Publications
Origin of the Excess of High-energy Retrograde Stars in the Galactic Halo
Matsuno, Tadafumi; Aoki, Wako; Suda, Takuma
We report on the very low α-element abundances of a group of metal-poor stars with high orbital energy and with large retrograde motion in the Milky Way halo, whose excess has been reported recently from metallicity and kinematics. We constructed a sample of halo stars with measured abundances and precise kinematics, including ∼880 stars with [Fe/…
The Foundation Supernova Survey: Measuring Cosmological Parameters with Supernovae from a Single Telescope
Berger, E.; Kirshner, R. P.; Rest, A. +27 more
Measurements of the dark energy equation-of-state parameter, w, have been limited by uncertainty in the selection effects and photometric calibration of z < 0.1 Type Ia supernovae (SNe Ia). The Foundation Supernova Survey is designed to lower these uncertainties by creating a new sample of z < 0.1 SNe Ia observed on the Pan-STARRS system. He…
The Recent Burstiness of Star Formation in Galaxies at z ∼ 4.5 from Hα Measurements
Tacchella, Sandro; Larson, Kirsten L.; Faisst, Andreas L. +2 more
The redshift range z = 4-6 marks a transition phase between primordial and mature galaxy formation in which galaxies considerably increase their stellar mass, metallicity, and dust content. The study of galaxies in this redshift range is therefore important to understanding early galaxy formation and the fate of galaxies at later times. Here, we i…
The Precision of Mass Measurements Required for Robust Atmospheric Characterization of Transiting Exoplanets
Fortney, Jonathan J.; Batalha, Natalie M.; Batalha, Natasha E. +4 more
Two of Transiting Exoplanet Survey Satellite’s major science goals are to measure masses for 50 planets smaller than 4 Earth radii and to discover high-quality targets for atmospheric characterization efforts. It is important that these two goals are linked by quantifying what precision of mass constraint is required to yield robust atmospheric pr…
TESS Spots a Compact System of Super-Earths around the Naked-eye Star HR 858
Vanderburg, Andrew; Bieryla, Allyson; Latham, David W. +48 more
Transiting Exoplanet Survey Satellite (TESS) observations have revealed a compact multiplanet system around the sixth-magnitude star HR 858 (TIC 178155732, TOI 396), located 32 pc away. Three planets, each about twice the size of Earth, transit this slightly evolved, late F-type star, which is also a member of a visual binary. Two of the planets m…
Space Densities and Emissivities of Active Galactic Nuclei at z > 4
Dickinson, M.; Fiore, F.; Castellano, M. +11 more
The study of the space density of bright active galactic nuclei (AGNs) at z > 4 has been subject to extensive effort given its importance in the estimation of cosmological ionizing emissivity and growth of supermassive black holes. In this context we have recently derived high space densities of AGNs at z ∼ 4 and -25 < M 1450 <…
The East Asian Observatory SCUBA-2 Survey of the COSMOS Field: Unveiling 1147 Bright Sub-millimeter Sources across 2.6 Square Degrees
Thomson, A. P.; Ivison, R. J.; Smail, Ian +28 more
We present sensitive 850 µm imaging of the Cosmological Evolution Survey (COSMOS) field using 640 hr of new and archival observations taken with SCUBA-2 at the East Asian Observatory’s James Clerk Maxwell Telescope. The SCUBA-2 COSMOS survey (S2COSMOS) achieves a median noise level of σ 850µm = 1.2 mJy beam-1 over…
The Ophiuchus DIsk Survey Employing ALMA (ODISEA): Disk Dust Mass Distributions across Protostellar Evolutionary Classes
Ansdell, Megan; Williams, Jonathan P.; Casassus, Simon +5 more
As protostars evolve from optically faint/infrared-bright (Class I) sources to optically bright/infrared-faint (Class II) the solid material in their surrounding disks accumulates into planetesimals and protoplanets. The nearby, young Ophiuchus star-forming region contains hundreds of protostars in a range of evolutionary states. Using the Atacama…
Age Determination in Upper Scorpius with Eclipsing Binaries
Howell, Steve B.; Isaacson, Howard T.; Livingston, John H. +4 more
The Upper Scorpius OB association is the nearest region of recent massive star formation and thus an important benchmark for investigations concerning stellar evolution and planet formation timescales. We present nine eclipsing binaries (EBs) in Upper Scorpius, three of which are newly reported here and all of which were discovered from K2 photome…
ALMA Unveils Widespread Molecular Gas Clumps in the Ram Pressure Stripped Tail of the Norma Jellyfish Galaxy
Fumagalli, Michele; Brinks, Elias; Combes, Françoise +8 more
We present the first high-resolution map of the cold molecular gas distribution as traced by CO(2-1) emission with ALMA in a long ram pressure stripped tail. The Norma cluster galaxy ESO 137-001 is undergoing a strong interaction with the surrounding intracluster medium and is one of the nearest jellyfish galaxies with a long multiphase and multic…