Search Publications
A Catalog of Stellar Unified Properties (CATSUP) for 951 FGK-Stars within 30 pc
Smith, Graeme H.; Shkolnik, Evgenya L.; Somers, Garrett +6 more
Almost every star in our Galaxy is likely to harbor a terrestrial planet, but accurate measurements of an exoplanet’s mass and radius demand accurate knowledge of the properties of its host star. The imminent TESS and CHEOPS missions are slated to discover thousands of new exoplanets. Along with WFIRST, which will directly image nearby planets, th…
MC2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9
Koekemoer, Anton M.; Seitz, Stella; Gruen, Daniel +6 more
The second most significant detection of the Planck Sunyaev-Zel’dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is located ∼ 400 {kpc} NW of the X-ray peak and the other ∼ 2.8 Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key miss…
Star Formation at z = 2.481 in the Lensed Galaxy SDSS J1110+6459. II. What is Missed at the Normal Resolution of the Hubble Space Telescope?
Rigby, J. R.; Sharon, K.; Gladders, M. D. +6 more
For lensed galaxy SGAS J111020.0+645950.8 at redshift z = 2.481, which is magnified by a factor of 28 ± 8, we analyze the morphology of star formation, as traced by rest-frame ultraviolet emission, in both the highly magnified source plane and simulations of how this galaxy would appear without lensing magnification. Were this galaxy not lensed, b…
Milky Way Tomography with K and M Dwarf Stars: The Vertical Structure of the Galactic Disk
Yanny, Brian; Ferguson, Deborah; Gardner, Susan
We use the number density distributions of K and M dwarf stars with vertical height from the Galactic disk, determined using observations from the Sloan Digital Sky Survey, to probe the structure of the Milky Way disk across the survey’s footprint. Using photometric parallax as a distance estimator we analyze a sample of several million disk stars…
The Formation and Physical Origin of Highly Ionized Cooling Gas
Heckman, Timothy M.; Bordoloi, Rongmon; Wagner, Alexander Y. +1 more
We present a simple model that explains the origin of warm, diffuse gas seen primarily as highly ionized absorption-line systems in the spectra of background sources. We predict the observed column densities of several highly ionized transitions such as O VI, O vii, Ne viii, N v, and Mg x, and we present a unified comparison of the model predictio…
Hints for Small Disks around Very Low Mass Stars and Brown Dwarfs
Pascucci, Ilaria; Henning, Thomas; Ménard, François +6 more
The properties of disks around brown dwarfs and very low mass stars (hereafter VLMOs) provide important boundary conditions on the process of planet formation and inform us about the numbers and masses of planets than can form in this regime. We use the Herschel Space Observatory PACS spectrometer to measure the continuum and [O I] 63 µm lin…
Detection of Interstellar Ortho-D2H+ with SOFIA
Caselli, Paola; Menten, Karl M.; Okada, Yoko +9 more
We report on the detection of the ground-state rotational line of ortho-D2H+ at 1.477 THz (203 µm) using the German REceiver for Astronomy at Terahertz frequencies (GREAT) on board the Stratospheric Observatory For Infrared Astronomy (SOFIA). The line is seen in absorption against far-infrared continuum from the protost…
Non-local Thermodynamic Equilibrium Stellar Spectroscopy with 1D and >3D< Models. II. Chemical Properties of the Galactic Metal-poor Disk and the Halo
Kovalev, Mikhail; Hansen, Camilla Juul; Bergemann, Maria +5 more
From exploratory studies and theoretical expectations it is known that simplifying approximations in spectroscopic analysis (local thermodynamic equilibrium (LTE), 1D) lead to systematic biases of stellar parameters and abundances. These biases depend strongly on surface gravity, temperature and, in particular, for LTE versus non-LTE (NLTE), on me…
Theory and Transport of Nearly Incompressible Magnetohydrodynamics Turbulence. III. Evolution of Power Anistropy in Magnetic Field Fluctuations throughout the Heliosphere
Bruno, R.; Zank, G. P.; Shiota, D. +3 more
A theoretical model that describes the evolution of the power anisotropy in the energy-containing and inertial ranges throughout the heliosphere is developed for three possibilities: (i) no in situ sources of turbulence; (ii) stream-shear sources of 2D and slab turbulence; and (iii) a fully driven turbulence model that includes both stream-shear d…
The Origin of Solar Filament Plasma Inferred from In Situ Observations of Elemental Abundances
Chen, Y.; Li, B.; Song, H. Q. +6 more
Solar filaments/prominences are one of the most common features in the corona, which may lead to energetic coronal mass ejections (CMEs) and flares when they erupt. Filaments are about 100 times cooler and denser than the coronal material, and physical understanding of their material origin remains controversial. Two types of scenarios have been p…