Search Publications
The Profile of the Galactic Halo from Pan-STARRS1 3π RR Lyrae
Rix, Hans-Walter; Chambers, Ken; Magnier, Eugene +11 more
We characterize the spatial density of the Pan-STARRS1 (PS1) sample of Rrab stars to study the properties of the old Galactic stellar halo. This sample, containing 44,403 sources, spans galactocentric radii of 0.55 kpc ≤ R gc ≤ 141 kpc with a distance precision of 3% and thus is able to trace the halo out to larger distances than most p…
Incompressive Energy Transfer in the Earth’s Magnetosheath: Magnetospheric Multiscale Observations
Russell, C. T.; Torbert, R. B.; Matthaeus, W. H. +14 more
Using observational data from the Magnetospheric Multiscale mission in the Earth’s magnetosheath, we estimate the energy cascade rate at three ranges of length scale, employing a single data interval, using different techniques within the framework of incompressible magnetohydrodynamic (MHD) turbulence. At the energy-containing scale, the energy b…
Resolving Quiescent Galaxies at z ≳ 2. I. Search for Gravitationally Lensed Sources and Characterization of Their Structure, Stellar Populations, and Line Emission
Ellis, Richard S.; Belli, Sirio; Newman, Andrew B. +1 more
Quiescent galaxies at z ≳ 2 are compact and have weak or absent emission lines, making it difficult to spatially resolve their kinematics and stellar populations using ground-based spectroscopy. Gravitationally lensed examples provide a promising route forward, but such objects are very rare. We describe a search in the fields of 232 galaxy cluste…
Rings and Gaps in Protoplanetary Disks: Planets or Snowlines?
Williams, Jonathan P.; van der Marel, Nienke; Bruderer, Simon
High-resolution Atacama Large Millimeter/submillimeter Array observations of protoplanetary disks have revealed that many, if not all, primordial disks consist of ring-like dust structures. The origin of these dust rings remains unclear, but a common explanation is the presence of planetary companions that have cleared gaps along their orbit and t…
Transverse Wave Induced Kelvin-Helmholtz Rolls in Spicules
De Pontieu, B.; Schmit, D.; Pereira, T. M. D. +2 more
In addition to their jet-like dynamic behavior, spicules usually exhibit strong transverse speeds, multi-stranded structure, and heating from chromospheric to transition region temperatures. In this work we first analyze Hinode and IRIS observations of spicules and find different behaviors in terms of their Doppler velocity evolution and collectiv…
ALMA 26 Arcmin2 Survey of GOODS-S at One Millimeter (ASAGAO): Average Morphology of High-z Dusty Star-forming Galaxies in an Exponential Disk (n ≃ 1)
Ouchi, Masami; Ivison, R. J.; Dunlop, J. S. +23 more
We present morphological properties of dusty star-forming galaxies at z = 1-3 determined with the high-resolution (FWHM ∼ 0.″19) Atacama Large Milllimeter/submillimeter Array (ALMA) 1 mm map of our ASAGAO survey covering a 26 arcmin2 area in GOODS-S. In conjunction with the ALMA archival data, our sample consists of 45 ALMA sources with…
Characterizing TW Hydra
Lee, Jae-Joon; Kim, Hwihyun; Jaffe, Daniel T. +5 more
At 60 pc, TW Hydra (TW Hya) is the closest example of a star with a gas-rich protoplanetary disk, though TW Hya may be relatively old (3-15 Myr). As such, TW Hya is especially appealing for testing our understanding of the interplay between stellar and disk evolution. We present a high-resolution near-infrared spectrum of TW Hya obtained with the …
Periastron Observations of TeV Gamma-Ray Emission from a Binary System with a 50-year Period
Maraschi, L.; Covino, S.; Antonelli, L. A. +211 more
We report on observations of the pulsar/Be star binary system PSR J2032+4127/MT91 213 in the energy range between 100 {GeV} and 20 {TeV} with the Very Energetic Radiation Imaging Telescope Array and Major Atmospheric Gamma Imaging Cherenkov telescope arrays. The binary orbit has a period of approximately 50 years, with the most recent periastron o…
Element Abundance Ratios in the Quiet Sun Transition Region
Young, P. R.
Element abundance ratios of magnesium to neon (Mg/Ne) and neon to oxygen (Ne/O) in the transition region of the quiet Sun have been derived by re-assessing previously published data from the Coronal Diagnostic Spectrometer on board the Solar and Heliospheric Observatory in the light of new atomic data. The quiet Sun Mg/Ne ratio is important for as…
Interrogating Seyferts with NebulaBayes: Spatially Probing the Narrow-line Region Radiation Fields and Chemical Abundances
Kewley, Lisa J.; Blanc, Guillermo A.; Hopkins, Andrew M. +4 more
NebulaBayes is a new Bayesian code that implements a general method of comparing observed emission-line fluxes to photoionization model grids. The code enables us to extract robust, spatially resolved measurements of abundances in the extended narrow-line regions (ENLRs) produced by Active Galactic Nuclei (AGN). We observe near-constant ionization…