Search Publications
FRiED: A Novel Three-dimensional Model of Coronal Mass Ejections
Isavnin, A.
We present a novel three-dimensional (3D) model of coronal mass ejections (CMEs) that unifies all key evolutionary aspects of CMEs and encapsulates their 3D magnetic field configuration. This fully analytic model is capable of reproducing the global geometrical shape of a CME with all major deformations taken into account, I.e., deflection, rotati…
Longitudinal Properties of a Widespread Solar Energetic Particle Event on 2014 February 25: Evolution of the Associated CME Shock
Lario, D.; Anderson, B. J.; Kwon, R. -Y. +8 more
We investigate the solar phenomena associated with the origin of the solar energetic particle (SEP) event observed on 2014 February 25 by a number of spacecraft distributed in the inner heliosphere over a broad range of heliolongitudes. These include spacecraft located near Earth; the twin Solar TErrestrial RElations Observatory spacecraft, STEREO…
On the Fermi-GBM Event 0.4 s after GW150914
Burgess, J. M.; Greiner, J.; Savchenko, V. +1 more
In view of the recent report by Connaughton et al., we analyze continuous time-tagged event (TTE) data of Fermi-gamma-ray burst monitor (GBM) around the time of the gravitational-wave event GW 150914. We find that after proper accounting for low-count statistics, the GBM transient event at 0.4 s after GW 150914 is likely not due to an astrophysica…
Comet 67P/Churyumov-Gerasimenko: Close-up on Dust Particle Fragments
Langevin, Y.; Altwegg, K.; Krüger, H. +44 more
The COmetary Secondary Ion Mass Analyser instrument on board ESA's Rosetta mission has collected dust particles in the coma of comet 67P/Churyumov-Gerasimenko. During the early-orbit phase of the Rosetta mission, particles and particle agglomerates have been imaged and analyzed in the inner coma at distances between 100 km and 10 km off the cometa…
The H I Content of the Universe Over the Past 10 GYRS
Prochaska, J. Xavier; Rafelski, Marc; Neeleman, Marcel +4 more
We use the Hubble Space Telescope (HST) archive of ultraviolet (UV) quasar spectroscopy to conduct the first blind survey for damped Lyα absorbers (DLAs) at low redshift (z\lt 1.6). Our statistical sample includes 463 quasars with spectral coverage spanning a total redshift path {{Δ }}z=123.3 or an absorption path {{Δ }}X=229.7. Within this survey…
ALFALFA Discovery of the Most Metal-poor Gas-rich Galaxy Known: AGC 198691
McQuinn, Kristen B. W.; Cannon, John M.; Skillman, Evan D. +12 more
We present spectroscopic observations of the nearby dwarf galaxy AGC 198691. This object is part of the Survey of H I in Extremely Low-Mass Dwarfs project, which is a multi-wavelength study of galaxies with H I masses in the range of 106-107.2 M ⊙, discovered by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We hav…
Star-forming Brightest Cluster Galaxies at 0.25 < z < 1.25: A Transitioning Fuel Supply
Schrabback, T.; Zenteno, A.; Desai, S. +23 more
We present a multiwavelength study of the 90 brightest cluster galaxies (BCGs) in a sample of galaxy clusters selected via the Sunyaev Zel’dovich effect by the South Pole Telescope, utilizing data from various ground- and space-based facilities. We infer the star-formation rate (SFR) for the BCG in each cluster—based on the UV and IR continuum lum…
Multiple Populations in the Old and Massive Small Magellanic Cloud Globular Cluster NGC 121
Dalessandro, E.; Mucciarelli, A.; Origlia, L. +3 more
We used a combination of optical and near-UV Hubble Space Telescope photometry and FLAMES/ESO-VLT high-resolution spectroscopy to characterize the stellar content of the old and massive globular cluster (GC) NGC 121 in the Small Magellanic Cloud (SMC). We report on the detection of multiple stellar populations, the first case in the SMC stellar cl…
Discovery of Rotational Modulations in the Planetary-mass Companion 2M1207b: Intermediate Rotation Period and Heterogeneous Clouds in a Low Gravity Atmosphere
Showman, Adam P.; Apai, Dániel; Marley, Mark S. +2 more
Rotational modulations of brown dwarfs have recently provided powerful constraints on the properties of ultra-cool atmospheres, including longitudinal and vertical cloud structures and cloud evolution. Furthermore, periodic light curves directly probe the rotational periods of ultra-cool objects. We present here, for the first time, time-resolved …
IC 751: A New Changing Look AGN Discovered by NuSTAR
Harrison, F. A.; Boggs, S.; Stern, D. +12 more
We present results of five Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the type 2 active galactic nucleus (AGN) in IC 751, three of which were performed simultaneously with XMM-Newton or Swift/X-Ray Telescope. We find that the nuclear X-ray source underwent a clear transition from a Compton-thick ({N}{{H}}≃ 2× {10}