Search Publications
The Major Geoeffective Solar Eruptions of 2012 March 7: Comprehensive Sun-to-Earth Analysis
Gontikakis, C.; Patsourakos, S.; Tsinganos, K. +33 more
During the interval 2012 March 7-11 the geospace experienced a barrage of intense space weather phenomena including the second largest geomagnetic storm of solar cycle 24 so far. Significant ultra-low-frequency wave enhancements and relativistic-electron dropouts in the radiation belts, as well as strong energetic-electron injection events in the …
The Evolution of the Intracluster Medium Metallicity in Sunyaev Zel’dovich-selected Galaxy Clusters at 0 < z < 1.5
Hlavacek-Larrondo, J.; Bleem, L. E.; Stalder, B. +16 more
We present the results of an X-ray spectral analysis of 153 galaxy clusters observed with the Chandra, XMM-Newton, and Suzaku space telescopes. These clusters, which span 0 < z < 1.5, were drawn from a larger, mass-selected sample of galaxy clusters discovered in the 2500 square degree South Pole Telescope Sunyaev Zel’dovich (SPT-SZ) survey.…
The Relationship Between Molecular Gas, H I, and Star Formation in the Low-mass, Low-metallicity Magellanic Clouds
Bot, Caroline; Bolatto, Alberto D.; Leroy, Adam K. +14 more
The Magellanic Clouds provide the only laboratory to study the effects of metallicity and galaxy mass on molecular gas and star formation at high (∼⃒20 pc) resolution. We use the dust emission from HERITAGE Herschel data to map the molecular gas in the Magellanic Clouds, avoiding the known biases of CO emission as a tracer of {{{H}}}2. U…
Subproton-scale Cascades in Solar Wind Turbulence: Driven Hybrid-kinetic Simulations
Rincon, F.; Califano, F.; Cerri, S. S. +2 more
A long-lasting debate in space plasma physics concerns the nature of subproton-scale fluctuations in solar wind (SW) turbulence. Over the past decade, a series of theoretical and observational studies were presented in favor of either kinetic Alfvén wave (KAW) or whistler turbulence. Here, we investigate numerically the nature of the subproton-sca…
The Lyman Continuum Escape Fraction of the Cosmic Horseshoe: A Test of Indirect Estimates
Lewis, Geraint F.; Pettini, Max; Siana, Brian +6 more
High-redshift star-forming galaxies are likely responsible for the reionization of the universe, yet direct detection of their escaping ionizing (Lyman continuum [LyC]) photons has proven to be extremely challenging. In this study, we search for escaping LyC of the Cosmic Horseshoe, a gravitationally lensed, star-forming galaxy at z = 2.38 with a …
Disappearance of the Progenitor of Supernova iPTF13bvn
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Foley, Ryan J. +13 more
Supernova (SN) iPTF13bvn in NGC 5806 was the first Type Ib SN to have been tentatively associated with a progenitor in pre-explosion images. We performed deep ultraviolet (UV) and optical Hubble Space Telescope observations of the SN site ∼740 days after explosion. We detect an object in the optical bands that is fainter than the pre-explosion obj…
An Enhanced Rate of Tidal Disruptions in the Centrally Overdense E+A Galaxy NGC 3156
Stone, Nicholas C.; van Velzen, Sjoert
Time domain optical surveys have discovered roughly a dozen candidate stellar tidal disruption flares in the last five years, and future surveys like the Large Synoptic Survey Telescope will likely find hundreds to thousands more. These tidal disruption events (TDEs) present an interesting puzzle: a majority of the current TDE sample is hosted by …
The Relation between Solar Eruption Topologies and Observed Flare Features. II. Dynamical Evolution
Pariat, E.; DeLuca, E. E.; McKillop, S. +4 more
A long-established goal of solar physics is to build understanding of solar eruptions and develop flare and coronal mass ejection (CME) forecasting models. In this paper, we continue our investigation of nonlinear forces free field (NLFFF) models by comparing topological properties of the solutions to the evolution of the flare ribbons. In particu…
The Very Massive Star Content of the Nuclear Star Clusters in NGC 5253
Crowther, P. A.; Calzetti, D.; Smith, L. J. +1 more
The blue compact dwarf galaxy NGC 5253 hosts a very young starburst containing twin nuclear star clusters, separated by a projected distance of 5 pc. One cluster (#5) coincides with the peak of the Hα emission and the other (#11) with a massive ultracompact H II region. A recent analysis of these clusters shows that they have a photometric age of …
Discovery of a Substellar Companion to the Nearby Debris Disk Host HR 2562
Matthews, Brenda C.; Duchêne, Gaspard; Esposito, Thomas M. +54 more
We present the discovery of a brown dwarf companion to the debris disk host star HR 2562. This object, discovered with the Gemini Planet Imager (GPI), has a projected separation of 20.3 ± 0.3 au (0\buildrel{\prime\prime}\over{.} 618+/- 0\buildrel{\prime\prime}\over{.} 004) from the star. With the high astrometric precision afforded by GPI, we have…