Search Publications
Plasma Diagnostics of Coronal Dimming Events
Veronig, Astrid M.; Temmer, Manuela; Dissauer, Karin +1 more
Coronal mass ejections are often associated with coronal dimmings, i.e., transient dark regions that are most distinctly observed in Extreme Ultra-violet wavelengths. Using Atmospheric Imaging Assembly (AIA) data, we apply Differential Emission Measure diagnostics to study the plasma characteristics of six coronal dimming events. In the core dimmi…
X-Ray and Optical Studies of the Redback System PSR J2129-0429
Ray, Paul S.; Kerr, Matthew; Hessels, Jason W. T. +6 more
PSR J2129-0429 is a 7.62 ms eclipsing millisecond pulsar (MSP) with a non-degenerate binary companion star that is likely in an early stage of the recycling process. It has one of the largest companion masses of a so-called “redback” (0.4 M ⊙) and has an unusually high surface magnetic field (1.6 × 109 G) for an MSP. We prese…
3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?
Grappin, Roland; Alexandrova, Olga; Verdini, Andrea +1 more
We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method allows nonaxisymmetric structures. These results are probably contaminated by the wind expansio…
ZFOURGE: Using Composite Spectral Energy Distributions to Characterize Galaxy Populations at 1 < z < 4
Papovich, Casey; Kacprzak, Glenn G.; Glazebrook, Karl +12 more
We investigate the properties of galaxies as they shut off star formation over the 4 billion years surrounding peak cosmic star formation. To do this, we categorize ∼7000 galaxies from 1 < z < 4 into 90 groups based on the shape of their spectral energy distributions (SEDs) and build composite SEDs with R ∼ 50 resolution. These composite SED…
Y Dwarf Trigonometric Parallaxes from the Spitzer Space Telescope
Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R. +12 more
Y dwarfs provide a unique opportunity to study free-floating objects with masses <30 M Jup and atmospheric temperatures approaching those of known Jupiter-like exoplanets. Obtaining distances to these objects is an essential step toward characterizing their absolute physical properties. Using Spitzer’s Infrared Array Camera (IRAC) [4…
The Discovery of a Gravitationally Lensed Supernova Ia at Redshift 2.22
Stern, D.; Huang, X.; Amanullah, R. +33 more
We present the discovery and measurements of a gravitationally lensed supernova (SN) behind the galaxy cluster MOO J1014+0038. Based on multi-band Hubble Space Telescope and Very Large Telescope (VLT) photometry of the supernova, and VLT spectroscopy of the host galaxy, we find a 97.5% probability that this SN is a SN Ia, and a 2.5% chance of a CC…
Beta Dips in the Gaia Era: Simulation Predictions of the Galactic Velocity Anisotropy Parameter (β) for Stellar Halos
Bell, Eric F.; Hattori, Kohei; Quinn, Thomas R. +7 more
The velocity anisotropy parameter, β, is a measure of the kinematic state of orbits in the stellar halo, which holds promise for constraining the merger history of the Milky Way (MW). We determine global trends for β as a function of radius from three suites of simulations, including accretion-only and cosmological hydrodynamic simulations. We fin…
A Complete Census of Luminous Stellar Variability on Day to Decade Timescales
Dolphin, Andrew E.; van Dokkum, Pieter; Conroy, Charlie +6 more
Stellar photometric variability offers a novel probe of the interior structure and evolutionary state of stars. Here we present a census of stellar variability on day to decade timescales across the color-magnitude diagram (CMD) for 73,000 stars brighter than M I,814 = -5 in the Whirlpool Galaxy (M51). Our Cycle 24 Hubble Space Telescop…
Prospects for Backtracing 1I/‘Oumuamua and Future Interstellar Objects
Zhang, Qicheng
1I/‘Oumuamua is the first of likely many small bodies of extrasolar origin to be found in the solar system. These interstellar objects (ISOs) are hypothesized to have formed in extrasolar planetary systems prior to being ejected into interstellar space and subsequently arriving at the solar system. This paper discusses necessary considerations for…
The H 0 Tension in Non-flat QCDM Cosmology
Huang, Zhiqi; Miao, Haitao
The recent local measurement of the Hubble constant leads to a more than 3σ tension with Planck + ΛCDM. In this article we study the H 0 tension in non-flat QCDM cosmology, where Q stands for a minimally coupled and slowly or moderately rolling quintessence field ϕ with a smooth potential V(φ ), and CDM refers to cold dark matter. By ge…