Search Publications
The Gemini/NICI Planet-Finding Campaign: The Frequency of Planets around Young Moving Group Stars
Nielsen, Eric L.; Skemer, Andrew; Shkolnik, Evgenya L. +18 more
We report results of a direct imaging survey for giant planets around 80 members of the β Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as part of the Gemini/NICI Planet-Finding Campaign. For this sample, we obtained median contrasts of ΔH = 13.9 mag at 1'' in combined CH4 narrowband ADI+SDI mode and …
The Spin-down of PSR J0821-4300 and PSR J1210-5226: Confirmation of Central Compact Objects as Anti-magnetars
Gotthelf, E. V.; Halpern, J. P.; Alford, J.
Using XMM-Newton and Chandra, we measure period derivatives for the second and third known pulsars in the class of central compact objects (CCOs) in supernova remnants, proving that these young neutron stars have exceptionally weak dipole magnetic field components. For the 112 ms PSR J0821-4300 in Puppis A, \dot{P} = (9.28 +/- 0.36) \times 10^{-18…
ALMA Observations of SPT-discovered, Strongly Lensed, Dusty, Star-forming Galaxies
Sharon, K.; Gladders, M. D.; Menten, K. M. +64 more
We present Atacama Large Millimeter/submillimeter Array (ALMA) 860 µm imaging of four high-redshift (z = 2.8-5.7) dusty sources that were detected using the South Pole Telescope (SPT) at 1.4 mm and are not seen in existing radio to far-infrared catalogs. At 1.''5 resolution, the ALMA data reveal multiple images of each submillimeter source, …
A Herschel and APEX Census of the Reddest Sources in Orion: Searching for the Youngest Protostars
Henning, Thomas; Manoj, P.; Robitaille, Thomas +13 more
We perform a census of the reddest, and potentially youngest, protostars in the Orion molecular clouds using data obtained with the PACS instrument on board the Herschel Space Observatory and the LABOCA and SABOCA instruments on APEX as part of the Herschel Orion Protostar Survey (HOPS). A total of 55 new protostar candidates are detected at 70 &m…
Longitudinal and Radial Dependence of Solar Energetic Particle Peak Intensities: STEREO, ACE, SOHO, GOES, and MESSENGER Observations
Lario, D.; Roelof, E. C.; Ho, G. C. +5 more
Simultaneous measurements of solar energetic particle (SEP) events by two or more of the spacecraft located near 1 AU during the rising phase of solar cycle 24 (i.e., STEREO-A, STEREO-B, and near-Earth spacecraft such as ACE, SOHO, and GOES) are used to determine the longitudinal dependence of 71-112 keV electron, 0.7-3 MeV electron, 15-40 MeV pro…
HerMES: Cosmic Infrared Background Anisotropies and the Clustering of Dusty Star-forming Galaxies
Aussel, H.; Pérez-Fournon, I.; Valtchanov, I. +51 more
We present measurements of the auto- and cross-frequency power spectra of the cosmic infrared background (CIB) at 250, 350, and 500 µm (1200, 860, and 600 GHz) from observations totaling ~70 deg2 made with the SPIRE instrument aboard the Herschel Space Observatory. We measure a fractional anisotropy δI/I = 14% ± 4%, detecting sign…
Hot Spine Loops and the Nature of a Late-phase Solar Flare
Liu, Yang; Aulanier, Guillaume; Sun, Xudong +4 more
The fan-spine magnetic topology is believed to be responsible for many curious features in solar explosive events. A spine field line links distinct flux domains, but direct observation of such a feature has been rare. Here we report a unique event observed by the Solar Dynamic Observatory where a set of hot coronal loops (over 10 MK) connected to…
The Origin and Evolution of Metallicity Gradients: Probing the Mode of Mass Assembly at z ~= 2
Richard, Johan; Ellis, Richard S.; Jones, Tucker +1 more
We present and discuss measurements of the gas-phase metallicity gradient in four gravitationally lensed galaxies at z = 2.0-2.4 based on adaptive optics-assisted imaging spectroscopy with the Keck II telescope. Three galaxies with well-ordered rotation reveal metallicity gradients with lower gas-phase metallicities at larger galactocentric radii.…
Scaling of the Electron Dissipation Range of Solar Wind Turbulence
Belmont, G.; Sahraoui, F.; Huang, S. Y. +4 more
Electron scale solar wind (SW) turbulence has attracted great interest in recent years. Considerable evidence exists that the turbulence is not fully dissipated near the proton scale, but continues cascading down to electron scales. However, the scaling of the magnetic energy spectra as well as the nature of the plasma modes involved at those smal…
A Refined Estimate of the Ionizing Emissivity from Galaxies at z ~= 3: Spectroscopic Follow-up in the SSA22a Field
Siana, Brian; Shapley, Alice E.; Steidel, Charles C. +2 more
We investigate the contribution of star-forming galaxies to the ionizing background at z ~ 3, building on previous work based on narrowband (NB3640) imaging in the SSA22a field. We use new Keck/LRIS spectra of Lyman break galaxies (LBGs) and narrowband-selected Lyα emitters (LAEs) to measure redshifts for 16 LBGs and 87 LAEs at z > 3.055, such …