Search Publications
The Local Group as a time machine: studying the high-redshift Universe with nearby galaxies
Conroy, Charlie; Johnson, Benjamin D.; Weisz, Daniel R. +3 more
We infer the UV luminosities of Local Group galaxies at early cosmic times (z ∼ 2 and z ∼ 7) by combining stellar population synthesis modelling with star formation histories derived from deep colour-magnitude diagrams constructed from Hubble Space Telescope (HST) observations. Our analysis provides a basis for understanding high-z galaxies - incl…
Why is Non-Thermal Line Broadening of Spectral Lines in the Lower Transition Region of the Sun Independent of Spatial Resolution?
Peter, H.; De Pontieu, B.; Pereira, T. M. D. +2 more
Spectral observations of the solar transition region (TR) and corona show broadening of spectral lines beyond what is expected from thermal and instrumental broadening. The remaining non-thermal broadening is significant (5-30 km s-1) and correlated with intensity. Here we study spectra of the TR Si iv 1403 Å line obtained at high resol…
PHAT Stellar Cluster Survey. II. Andromeda Project Cluster Catalog
Gouliermis, Dimitrios A.; Skillman, Evan D.; Williams, Benjamin F. +12 more
We construct a stellar cluster catalog for the Panchromatic Hubble Andromeda Treasury (PHAT) survey using image classifications collected from the Andromeda Project citizen science website. We identify 2753 clusters and 2270 background galaxies within ∼0.5 deg2 of PHAT imaging searched, or ∼400 kpc2 in deprojected area at the…
An X-ray spectroscopic search for dark matter in the Perseus cluster with Suzaku
Maeda, Yoshitomo; Iizuka, Ryo; Mitsuda, Kazuhisa +2 more
We present the results from deep Suzaku observations of the central region of the Perseus cluster. Bulbul et al. (2014, ApJ, 789, 13) reported the detection by XMM-Newton instruments of an unidentified X-ray emission line at an energy around 3.5 keV in spectra for the Perseus and other clusters. They argued for a possibility of the decay of steril…
Evidence of Thermal Conduction Suppression in a Solar Flaring Loop by Coronal Seismology of Slow-mode Waves
Sun, Xudong; Ofman, Leon; Davila, Joseph M. +2 more
Analysis of a longitudinal wave event observed by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory is presented. A time sequence of 131 Å images reveals that a C-class flare occurred at one footpoint of a large loop and triggered an intensity disturbance (enhancement) propagating along it. The spatial features and temp…
Constraining globular cluster formation through studies of young massive clusters - V. ALMA observations of clusters in the Antennae
Cabrera-Ziri, I.; Bastian, N.; Larsen, S. S. +9 more
Some formation scenarios that have been put forward to explain multiple populations within globular clusters (GCs) require that the young massive cluster have large reservoirs of cold gas within them, which is necessary to form future generations of stars. In this paper, we use deep observations taken with Atacama Large Millimeter/submillimeter Ar…
Star formation in Herschel's Monsters versus semi-analytic models
Berta, S.; Pozzi, F.; Franceschini, A. +9 more
We present a direct comparison between the observed star formation rate functions (SFRFs) and the state-of-the-art predictions of semi-analytic models (SAMs) of galaxy formation and evolution. We use the PACS Evolutionary Probe Survey and Herschel Multi-tiered Extragalactic Survey data sets in the COSMOS and GOODS-South fields, combined with broad…
The Lyα Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage
Martin, Crystal L.; Henry, Alaina; Danforth, Charles W. +3 more
We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. We detect Lyα emission from eight ULIRGs an…
Current Sheets in the Earth Magnetotail: Plasma and Magnetic Field Structure with Cluster Project Observations
Nakamura, Rumi; Zelenyi, Lev; Artemyev, Anton +2 more
Thin current sheets having kinetic scales are an important plasma structure, where the magnetic energy dissipation and charged particle acceleration are the most effective. It is believed that such current sheets are self-consistently formed by the specific nonadiabatic dynamics of charged particles and play a critical role in many space plasma an…
No evidence for significant age spreads in young massive LMC clusters
Bastian, N.; Niederhofer, F.; Silva-Villa, E. +1 more
Recent discoveries have put the picture of stellar clusters being simple stellar populations into question. In particular, the color-magnitude diagrams of intermediate age (1-2 Gyr) massive clusters in the Large Magellanic Cloud (LMC) show features that could be interpreted as age spreads of 100-500 Myr. If multiple generations of stars are presen…