Search Publications
Photolytic Hazes in the Atmosphere of 51 Eri b
Morley, C. V.; Zahnle, K.; Moses, J. I. +1 more
We use a 1D model to address photochemistry and possible haze formation in the irradiated warm Jupiter, 51 Eridani b. The intended focus was to be carbon, but sulfur photochemistry turns out to be important. The case for organic photochemical hazes is intriguing but falls short of being compelling. If organic hazes form, they are likeliest to do s…
Data-driven Radiative Hydrodynamic Modeling of the 2014 March 29 X1.0 Solar Flare
Liu, Wei; Allred, Joel C.; Kleint, Lucia +2 more
Spectroscopic observations of solar flares provide critical diagnostics of the physical conditions in the flaring atmosphere. Some key features in observed spectra have not yet been accounted for in existing flare models. Here we report a data-driven simulation of the well-observed X1.0 flare on 2014 March 29 that can reconcile some well-known spe…
Suprathermal particle energization in dipolarization fronts: Particle-in-cell simulations
Angelopoulos, V.; Fu, Huishan; Lu, San
Within dipolarization fronts (DFs) in the Earth's magnetotail, significant magnetic energy is converted to plasma energy, and a significant portion of the electrons and ions therein are accelerated to suprathermal energies. The mechanism that produces these suprathermal particles while simultaneously reducing magnetic field energy is poorly unders…
The Characteristics of Solar X-Class Flares and CMEs: A Paradigm for Stellar Superflares and Eruptions?
Toriumi, Shin; Guedel, Manuel; Harra, Louise K. +10 more
This paper explores the characteristics of 42 solar X-class flares that were observed between February 2011 and November 2014, with data from the Solar Dynamics Observatory (SDO) and other sources. This flare list includes nine X-class flares that had no associated CMEs. In particular our aim was to determine whether a clear signature could be ide…
SN Refsdal: Photometry and Time Delay Measurements of the First Einstein Cross Supernova
Sharon, K.; Molino, A.; Zitrin, A. +16 more
We present the first year of Hubble Space Telescope imaging of the unique supernova (SN) “Refsdal,” a gravitationally lensed SN at z = 1.488 ± 0.001 with multiple images behind the galaxy cluster MACS J1149.6+2223. The first four observed images of SN Refsdal (images S1-S4) exhibited a slow rise (over ∼150 days) to reach a broad peak brightness ar…
Infrared Color Selection of Massive Galaxies at z > 3
Daddi, E.; Elbaz, D.; Shu, X. +29 more
We introduce a new color selection technique to identify high-redshift, massive galaxies that are systematically missed by Lyman-break selection. The new selection is based on the H160 (H) and Infrared Array Camera (IRAC) 4.5 µm bands, specifically H-[4.5]\gt 2.25 mag. These galaxies, called “HIEROs,” include two major populations…
Ionospheric plasma of comet 67P probed by Rosetta at 3 au from the Sun
Wurz, P.; Altwegg, K.; Glassmeier, K. -H. +23 more
We propose to identify the main sources of ionization of the plasma in the coma of comet 67P/Churyumov-Gerasimenko at different locations in the coma and to quantify their relative importance, for the first time, for close cometocentric distances (<20 km) and large heliocentric distances (>3 au). The ionospheric model proposed is used as an …
The Age of the Young Bulge-like Population in the Stellar System Terzan 5: Linking the Galactic Bulge to the High-z Universe
Dalessandro, E.; Massari, D.; Rich, R. M. +4 more
The Galactic bulge is dominated by an old, metal-rich stellar population. The possible presence and the amount of a young (a few gigayears old) minor component is one of the major issues debated in the literature. Recently, the bulge stellar system Terzan 5 was found to harbor three sub-populations with iron content varying by more than one order …
The Distance to M51
Dolphin, Andrew E.; Skillman, Evan D.; Berg, Danielle +2 more
Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies ha…
Far-infrared Line Spectra of Active Galaxies from the Herschel/PACS Spectrometer: The Complete Database
Spinoglio, Luigi; Fernández-Ontiveros, Juan Antonio; Malkan, Matthew A. +3 more
We present a coherent database of spectroscopic observations of far-IR fine-structure lines from the Herschel/Photoconductor Array Camera and Spectrometer archive for a sample of 170 local active galactic nuclei (AGNs), plus a comparison sample of 20 starburst galaxies and 43 dwarf galaxies. Published Spitzer/IRS and Herschel/SPIRE line fluxes are…