Search Publications
The VLT-FLAMES Tarantula Survey. XVII. Physical and wind properties of massive stars at the top of the main sequence
Crowther, P. A.; Herrero, A.; Simón-Díaz, S. +12 more
The evolution and fate of very massive stars (VMS) is tightly connected to their mass-loss properties. Their initial and final masses differ significantly as a result of mass loss. VMS have strong stellar winds and extremely high ionising fluxes, which are thought to be critical sources of both mechanical and radiative feedback in giant H ii regio…
How the Geysers, Tidal Stresses, and Thermal Emission across the South Polar Terrain of Enceladus are Related
Nimmo, Francis; Porco, Carolyn; DiNino, Daiana
We present the first comprehensive examination of the geysering, tidal stresses, and anomalous thermal emission across the south pole of Enceladus and discuss the implications for the moon's thermal history and interior structure. A 6.5 yr survey of the moon's south polar terrain (SPT) by the Cassini imaging experiment has located ~100 jets or gey…
What is the Physical Origin of Strong Lyα Emission? II. Gas Kinematics and Distribution of Lyα Emitters
Ono, Yoshiaki; Ouchi, Masami; Shibuya, Takatoshi +8 more
We present a statistical study of velocities of Lyα, interstellar (IS) absorption, and nebular lines and gas covering fraction for Lyα emitters (LAEs) at z ~= 2. We make a sample of 22 LAEs with a large Lyα equivalent width (EW) of >~ 50 Å based on our deep Keck/Low Resolution Imaging Spectrometer (LRIS) observations, in conjunction with spectr…
Circulation of Heavy Ions and Their Dynamical Effects in the Magnetosphere: Recent Observations and Models
Dandouras, Iannis; Malova, Helmi V.; Grigorenko, Elena E. +13 more
Knowledge of the ion composition in the near-Earth's magnetosphere and plasma sheet is essential for the understanding of magnetospheric processes and instabilities. The presence of heavy ions of ionospheric origin in the magnetosphere, in particular oxygen (O+), influences the plasma sheet bulk properties, current sheet (CS) thickness …
X-ray emission from star-forming galaxies - III. Calibration of the LX-SFR relation up to redshift z ≈ 1.3
Sunyaev, R.; Lehmer, B. D.; Morrison, G. E. +2 more
We investigate the relation between total X-ray emission from star-forming galaxies and their star formation activity. Using nearby late-type galaxies and ultraluminous infrared galaxies from Paper I and star-forming galaxies from Chandra Deep Fields (CDFs), we construct a sample of 66 galaxies spanning the redshift range z ≈ 0-1.3 and the star fo…
Evidence of nonthermal particles in coronal loops heated impulsively by nanoflares
Golub, L.; Tian, H.; De Pontieu, B. +21 more
The physical processes causing energy exchange between the Sun’s hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that is highly sensitive to the coronal heating mechanism. High-resolution observations with the Interface Region…
An Interface Region Imaging Spectrograph First View on Solar Spicules
Golub, L.; Tian, H.; De Pontieu, B. +17 more
Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere remains unknown. Here we give a first glimpse of what quiet-Sun spicules look like when observed with NASA's recently launched…
CANDELS/GOODS-S, CDFS, and ECDFS: Photometric Redshifts for Normal and X-Ray-Detected Galaxies
Barro, Guillermo; Ferguson, Henry C.; Grazian, Andrea +29 more
We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). This work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revis…
Anomalous expansion of coronal mass ejections during solar cycle 24 and its space weather implications
Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji +3 more
The familiar correlation between the speed and angular width of coronal mass ejections (CMEs) is also found in solar cycle 24, but the regression line has a larger slope: for a given CME speed, cycle 24 CMEs are significantly wider than those in cycle 23. The slope change indicates a significant change in the physical state of the heliosphere, due…
Strongest model-independent bound on the lifetime of Dark Matter
Tram, Thomas; Lesgourgues, Julien; Mangano, Gianpiero +2 more
Dark Matter is essential for structure formation in the late Universe so it must be stable on cosmological time scales. But how stable exactly? Only assuming decays into relativistic particles, we report an otherwise model independent bound on the lifetime of Dark Matter using current cosmological data. Since these decays affect only the low ℓ mul…