Search Publications
Direct Simulation Monte Carlo modelling of the major species in the coma of comet 67P/Churyumov-Gerasimenko
Altwegg, K.; Huang, Z.; Erard, S. +26 more
We analyse the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) - the Double Focusing Mass Spectrometer data between 2014 August and 2016 February to examine the effect of seasonal variations on the four major species within the coma of 67P/Churyumov-Gerasimenko (H2O, CO2, CO, and O2), resulting f…
Magnetar-like Activity from the Central Compact Object in the SNR RCW103
Rea, N.; Esposito, P.; De Luca, A. +4 more
The 6.67 hr periodicity and the variable X-ray flux of the central compact object (CCO) at the center of the supernova remnant RCW 103, named 1E 161348-5055, have been always difficult to interpret within the standard scenarios of an isolated neutron star (NS) or a binary system. On 2016 June 22, the Burst Alert Telescope (BAT) on board Swift dete…
Three-dimensional direct simulation Monte-Carlo modeling of the coma of comet 67P/Churyumov-Gerasimenko observed by the VIRTIS and ROSINA instruments on board Rosetta
Altwegg, K.; Huang, Z.; Erard, S. +26 more
Context. Since its rendezvous with comet 67P/Churyumov-Gerasimenko (67P), the Rosetta spacecraft has provided invaluable information contributing to our understanding of the cometary environment. On board, the VIRTIS and ROSINA instruments can both measure gas parameters in the rarefied cometary atmosphere, the so-called coma, and provide compleme…
Morphology and Molecular Gas Fractions of Local Luminous Infrared Galaxies as a Function of Infrared Luminosity and Merger Stage
Sanders, D. B.; Kim, D. -C.; Mirabel, I. F. +8 more
We present a new, detailed analysis of the morphologies and molecular gas fractions (MGFs) for a complete sample of 65 local luminous infrared galaxies from Great Observatories All-Sky Luminous Infrared Galaxies (LIRG) Survey using high resolution I-band images from The Hubble Space Telescope, the University of Hawaii 2.2 m Telescope and the Pan-S…
Simulations of the Mg II k and Ca II 8542 lines from an Alfvén Wave-heated Flare Chromosphere
Kerr, Graham S.; Fletcher, Lyndsay.; Russell, Alexander J. B. +1 more
We use radiation hydrodynamic simulations to examine two models of solar flare chromospheric heating: Alfvén wave dissipation and electron beam collisional losses. Both mechanisms are capable of strong chromospheric heating, and we show that the distinctive atmospheric evolution in the mid-to-upper chromosphere results in Mg II k-line emission tha…
Global Sausage Oscillation of Solar Flare Loops Detected by the Interface Region Imaging Spectrograph
Reeves, Katharine K.; Chen, Bin; He, Jiansen +4 more
An observation from the Interface Region Imaging Spectrograph reveals coherent oscillations in the loops of an M1.6 flare on 2015 March 12. Both the intensity and Doppler shift of Fe xxi 1354.08 Å show clear oscillations with a period of ∼25 s. Remarkably similar oscillations were also detected in the soft X-ray flux recorded by the Geostationary …
Comet 67P/Churyumov-Gerasimenko preserved the pebbles that formed planetesimals
Rodriguez, J.; Colangeli, L.; Della Corte, V. +16 more
Solar system formation models predict that the building blocks of planetesimals were mm- to cm-sized pebbles, aggregates of ices and non-volatile materials, consistent with the compact particles ejected by comet 67P/Churyumov-Gerasimenko (67P hereafter) and detected by GIADA (Grain Impact Analyzer and Dust Accumulator) on-board the Rosetta spacecr…
Jellyfish: the origin and distribution of extreme ram-pressure stripping events in massive galaxy clusters
Ebeling, Harald; McPartland, Conor; Roediger, Elke +1 more
We investigate the observational signatures and physical origin of ram-pressure stripping (RPS) in 63 massive galaxy clusters at z = 0.3-0.7, based on images obtained with the Hubble Space Telescope. Using a training set of a dozen `jellyfish' galaxies identified earlier in the same imaging data, we define morphological criteria to select 211 addi…
A Keck Adaptive Optics Survey of a Representative Sample of Gravitationally Lensed Star-forming Galaxies: High Spatial Resolution Studies of Kinematics and Metallicity Gradients
Richard, Johan; Stark, Daniel P.; Ellis, Richard S. +4 more
We discuss spatially resolved emission line spectroscopy secured for a total sample of 15 gravitationally lensed star-forming galaxies at a mean redshift of z≃ 2 based on Keck laser-assisted adaptive optics observations undertaken with the recently improved OSIRIS integral field unit (IFU) spectrograph. By exploiting gravitationally lensed sources…
The Bursty Star Formation Histories of Low-mass Galaxies at 0.4 < z < 1 Revealed by Star Formation Rates Measured From Hβ and FUV
Barro, Guillermo; Pérez-González, Pablo G.; Bell, Eric F. +17 more
We investigate the burstiness of star formation histories (SFHs) of galaxies at 0.4 < z < 1 by using the ratio of star formation rates (SFRs) measured from Hβ and FUV (1500 Å) (Hβ-to-FUV ratio). Our sample contains 164 galaxies down to stellar mass (M *) of 108.5 M ⊙ in the CANDELS GOODS-N region, where Team …