Search Publications
Observing the release of twist by magnetic reconnection in a solar filament eruption
Zhang, Jun; Bi, Yi; Xue, Zhike +9 more
Magnetic reconnection is a fundamental process of topology change and energy release, taking place in plasmas on the Sun, in space, in astrophysical objects and in the laboratory. However, observational evidence has been relatively rare and typically only partial. Here we present evidence of fast reconnection in a solar filament eruption using hig…
Early and Extended Helium Reionization over More Than 600 Million Years of Cosmic Time
Hennawi, Joseph F.; Worseck, Gábor; Prochaska, J. Xavier +1 more
We measure the effective optical depth of He II Lyα absorption {τ }{eff,{He}{{II}}} at 2.3\lt z\lt 3.5 in 17 UV-transmitting quasars observed with UV spectrographs on the Hubble Space Telescope. The median {τ }{eff,{He}{{II}}} values increase gradually from 1.95 at z=2.7 to 5.17 at z=3.4, but with a strong sightline-to-sightl…
Radio AGN in the local universe: unification, triggering and evolution
Tadhunter, Clive
Associated with one of the most important forms of active galactic nucleus (AGN) feedback, and showing a strong preference for giant elliptical host galaxies, radio AGN (L_{1.4 GHz} > 10^{24} W Hz^{-1}) are a key sub-class of the overall AGN population. Recently their study has benefitted dramatically from the availability of high-quality data …
The Evolution of Galaxy Number Density at z < 8 and Its Implications
Conselice, Christopher J.; Mortlock, Alice; Wilkinson, Aaron +1 more
The evolution of the number density of galaxies in the universe, and thus also the total number of galaxies, is a fundamental question with implications for a host of astrophysical problems including galaxy evolution and cosmology. However, there has never been a detailed study of this important measurement, nor a clear path to answer it. To addre…
Origins of volatile elements (H, C, N, noble gases) on Earth and Mars in light of recent results from the ROSETTA cometary mission
Mousis, Olivier; Morbidelli, Alessandro; Altwegg, Kathrin +6 more
Recent measurements of the volatile composition of the coma of Comet 67P/Churyumov-Gerasimenko (hereafter 67P) allow constraints to be set on the origin of volatile elements (water, carbon, nitrogen, noble gases) in inner planets' atmospheres. Analyses by the ROSINA mass spectrometry system onboard the Rosetta spacecraft indicate that 67P ice has …
High-mass X-ray binaries in the Small Magellanic Cloud
Haberl, F.; Sturm, R.
Aims: The last comprehensive catalogue of high-mass X-ray binaries in the Small Magellanic Cloud (SMC) was published about ten years ago. Since then new such systems were discovered, mainly by X-ray observations with Chandra and XMM-Newton. For the majority of the proposed HMXBs in the SMC no X-ray pulsations were discovered as yet, and unles…
The Angular Momentum Distribution and Baryon Content of Star-forming Galaxies at z ∼ 1-3
Wuyts, E.; Lutz, D.; Wuyts, S. +25 more
We analyze the angular momenta of massive star-forming galaxies (SFGs) at the peak of the cosmic star formation epoch (z ∼ 0.8-2.6). Our sample of ∼360 log(M */M ⊙) ∼ 9.3-11.8 SFGs is mainly based on the KMOS3D and SINS/zC-SINF surveys of Hα kinematics, and collectively provides a representative subset of the massi…
The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using Only Population II Distance Indicators
Kollmeier, Juna A.; Madore, Barry F.; Freedman, Wendy L. +15 more
We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3% measurement of the Hubble constant (H 0) using alternative methods to the traditional Cepheid distance scale. We aim to establish a completely independent route to H 0 using RR Lyrae variables, the tip of the red giant branch (TRG…
The Redshift Distribution of Dusty Star-forming Galaxies from the SPT Survey
Menten, K. M.; Béthermin, M.; Murphy, E. J. +28 more
We use the Atacama Large Millimeter/submillimeter Array (ALMA) in Cycle 1 to determine spectroscopic redshifts of high-redshift dusty star-forming galaxies (DSFGs) selected by their 1.4 mm continuum emission in the South Pole Telescope (SPT) survey. We present ALMA 3 mm spectral scans between 84 and 114 GHz for 15 galaxies and targeted ALMA 1 mm o…
Modeling Dust Evolution in Galaxies with a Multiphase, Inhomogeneous ISM
Jenkins, Edward B.; Klessen, Ralf S.; Zhukovska, Svitlana +1 more
We develop a model of dust evolution in a multiphase, inhomogeneous interstellar medium (ISM) using hydrodynamical simulations of giant molecular clouds in a Milky Way-like spiral galaxy. We improve the treatment of dust growth by accretion in the ISM to investigate the role of the temperature-dependent sticking coefficient and ion-grain interacti…