Search Publications
Sun-to-Earth MHD Simulation of the 2000 July 14 “Bastille Day” Eruption
Downs, Cooper; Riley, Pete; Linker, Jon A. +6 more
Solar eruptions are the main driver of space-weather disturbances at Earth. Extreme events are of particular interest, not only because of the scientific challenges they pose, but also because of their possible societal consequences. Here we present a magnetohydrodynamic (MHD) simulation of the 2000 July 14 “Bastille Day” eruption, which produced …
Size-Luminosity Relations and UV Luminosity Functions at z = 6-9 Simultaneously Derived from the Complete Hubble Frontier Fields Data
Ouchi, Masami; Shimasaku, Kazuhiro; Oguri, Masamune +3 more
We construct z ∼ 6-7, 8, and 9 faint Lyman break galaxy samples (334, 61, and 37 galaxies, respectively) with accurate size measurements with the software glafic from the complete Hubble Frontier Fields (HFF) cluster and parallel fields data. These are the largest samples hitherto and reach down to the faint ends of recently obtained deep luminosi…
The Large-scale Structure of the Halo of the Andromeda Galaxy. II. Hierarchical Structure in the Pan-Andromeda Archaeological Survey
Lewis, Geraint F.; Dotter, Aaron; Babul, Arif +29 more
The Pan-Andromeda Archaeological Survey is a survey of >400 square degrees centered on the Andromeda (M31) and Triangulum (M33) galaxies that has provided the most extensive panorama of an L ⋆ galaxy group to large projected galactocentric radii. Here, we collate and summarize the current status of our knowledge of the substructures …
The Disk Substructures at High Angular Resolution Project (DSHARP). III. Spiral Structures in the Millimeter Continuum of the Elias 27, IM Lup, and WaOph 6 Disks
Hughes, A. Meredith; Wilner, David J.; Andrews, Sean M. +13 more
We present an analysis of Atacama Large Millimeter/submillimeter Array 1.25 mm continuum observations of spiral structures in three protoplanetary disks from the Disk Substructures at High Angular Resolution Project. The disks around Elias 27, IM Lup, and WaOph 6 were observed at a resolution of ∼40-60 mas (∼6-7 au). All three disks feature m = 2 …
One Large Blob and Many Streams Frosting the nearby Stellar Halo in Gaia DR2
Helmi, Amina; Veljanoski, Jovan; Koppelman, Helmer
We explore the phase-space structure of nearby halo stars identified kinematically from the Gaia second data release (DR2). We focus on their distribution in velocity and in “integrals of motion” space, as well as on their photometric properties. Our sample of stars selected to be moving at a relative velocity of at least 210 km s-1, wi…
Gaia Proper Motions and Orbits of the Ultra-faint Milky Way Satellites
Simon, Joshua D.
The second data release from the Gaia mission (DR2) provides a comprehensive and unprecedented picture of the motions of astronomical sources in the plane of the sky, extending from the solar neighborhood to the outer reaches of the Milky Way. I present proper-motion measurements based on Gaia DR2 for 17 ultra-faint dwarf galaxies within 100 kpc o…
Measuring Dark Energy Properties with Photometrically Classified Pan-STARRS Supernovae. II. Cosmological Parameters
Berger, E.; Kirshner, R. P.; Rest, A. +25 more
We use 1169 Pan-STARRS supernovae (SNe) and 195 low-z (z < 0.1) SNe Ia to measure cosmological parameters. Though most Pan-STARRS SNe lack spectroscopic classifications, in a previous paper we demonstrated that photometrically classified SNe can be used to infer unbiased cosmological parameters by using a Bayesian methodology that marginalizes …
Deep Learning Based Solar Flare Forecasting Model. I. Results for Line-of-sight Magnetograms
Xu, Long; Huang, Xin; Wang, Huaning +3 more
Solar flares originate from the release of the energy stored in the magnetic field of solar active regions, the triggering mechanism for these flares, however, remains unknown. For this reason, the conventional solar flare forecast is essentially based on the statistic relationship between solar flares and measures extracted from observational dat…
The Opacity of the Intergalactic Medium Measured along Quasar Sightlines at z ∼ 6
Hennawi, Joseph F.; Davies, Frederick B.; Eilers, Anna-Christina
We publicly release a new sample of 34 medium resolution quasar spectra at 5.77 ≤ z em ≤ 6.54 observed with the Echellette Spectrograph and Imager on the Keck telescope. This quasar sample represents an ideal laboratory to study the intergalactic medium (IGM) during the end stages of the epoch of reionization, and constrain the timing a…
Light Curves of Hydrogen-poor Superluminous Supernovae from the Palomar Transient Factory
Cenko, S. B.; Sollerman, J.; Spyromilio, J. +24 more
We investigate the light-curve properties of a sample of 26 spectroscopically confirmed hydrogen-poor superluminous supernovae (SLSNe-I) in the Palomar Transient Factory survey. These events are brighter than SNe Ib/c and SNe Ic-BL, on average, by about 4 and 2 mag, respectively. The peak absolute magnitudes of SLSNe-I in rest-frame g band span -2…