Search Publications
Vigorous convection in a sunspot granular light bridge
Lagg, Andreas; Solanki, Sami K.; Danilovic, Sanja +1 more
Context. Light bridges are the most prominent manifestation of convection in sunspots. The brightest representatives are granular light bridges composed of features that appear to be similar to granules.
Aims: An in-depth study of the convective motions, temperature stratification, and magnetic field vector in and around light bridge granules…
Two-zero Majorana textures in the light of the Planck results
Meloni, Davide; Meroni, Aurora; Peinado, Eduardo
The recent results of the Planck experiment put a stringent constraint on the sum of the light neutrino masses, Σimi<0.23 eV (95% C.L.). On the other hand, two-zero Majorana mass matrix textures predict strong correlations among the atmospheric angle sin2θ23 and Σ. We use the Planck result to show that, for the …
Mud volcanism and morphology of impact craters in Utopia Planitia on Mars: Evidence for the ancient ocean
Hiesinger, H.; Erkeling, G.; Reiss, D. +1 more
Results of our detailed geological mapping and interpretation of the nature and relative and absolute model ages of units and structures in the SW portion of Utopia Planitia (20-45°N, 100-120°E) suggest the following. (1) The size-frequency distribution (SFD) of craters that both are buried by materials of the Vastitas Borealis units (VB) and supe…
"Direct" Gas-phase Metallicities, Stellar Properties, and Local Environments of Emission-line Galaxies at Redshifts below 0.90
Shimasaku, Kazuhiro; Hayashi, Masao; Malkan, Matthew A. +3 more
Using deep narrow-band (NB) imaging and optical spectroscopy from the Keck telescope and MMT, we identify a sample of 20 emission-line galaxies at z = 0.065-0.90 where the weak auroral emission line, [O III] λ4363, is detected at >=3σ. These detections allow us to determine the gas-phase metallicity using the "direct" method. With electron temp…
High-resolution Ultraviolet Radiation Fields of Classical T Tauri Stars
France, Kevin; Bergin, Edwin A.; Roueff, Evelyne +2 more
The far-ultraviolet (FUV; 912-1700 Å) radiation field from accreting central stars in classical T Tauri systems influences the disk chemistry during the period of giant planet formation. The FUV field may also play a critical role in determining the evolution of the inner disk (r < 10 AU), from a gas- and dust-rich primordial disk to a transiti…
Formation of pebble-pile planetesimals
Johansen, Anders; Wahlberg Jansson, Karl
Asteroids and Kuiper belt objects are remnant planetesimals from the epoch of planet formation. The first stage of planet formation is the accumulation of dust and ice grains into mm- and cm-sized pebbles. These pebbles can clump together through the streaming instability and form gravitationally bound pebble clouds. Pebbles inside such a cloud wi…
Delayed Star Formation in Isolated Dwarf galaxies: Hubble Space Telescope Star Formation History of the Aquarius Dwarf Irregular
Dolphin, Andrew E.; Skillman, Evan D.; Leaman, Ryan +4 more
We have obtained deep images of the highly isolated (d = 1 Mpc) Aquarius dwarf irregular galaxy (DDO 210) with the Hubble Space Telescope Advanced Camera for Surveys. The resulting color-magnitude diagram (CMD) reaches more than a magnitude below the oldest main-sequence turnoff, allowing us to derive the star formation history (SFH) over the enti…
Tracing the Cosmic Metal Evolution in the Low-redshift Intergalactic Medium
Shull, J. Michael; Danforth, Charles W.; Tilton, Evan M.
Using the Cosmic Origins Spectrograph aboard the Hubble Space Telescope, we measured the abundances of six ions (C III, C IV, Si III, Si IV, N V, and O VI) in the low-redshift (z <= 0.4) intergalactic medium (IGM). Both C IV and Si IV have increased in abundance by a factor of ~10 from z ≈ 5.5 to the present. We derive ion mass densities, ρ
Degree-scale Cosmic Microwave Background Polarization Measurements from Three Years of BICEP1 Data
Ade, P. A. R.; Bock, J. J.; Chiang, H. C. +31 more
BICEP1 is a millimeter-wavelength telescope designed specifically to measure the inflationary B-mode polarization of the cosmic microwave background at degree angular scales. We present results from an analysis of the data acquired during three seasons of observations at the South Pole (2006-2008). This work extends the two-year result published i…
Physical properties of fullerene-containing Galactic planetary nebulae
Otsuka, Masaaki; Peeters, E.; Bernard-Salas, J. +2 more
We searched the Spitzer Space Telescope data archive for Galactic planetary nebulae (PNe), which show the characteristic 17.4 and 18.9 µm features due to C60, also known as buckminsterfullerene. Out of 338 objects with Spitzer/Infrared Spectrograph data, we found eleven C60-containing PNe, six of which (Hen2-68, IC2501,…