Search Publications
Missions
Journals
Publication Years
The Sloan Digital Sky Survey Reverberation Mapping Project: Accretion and Broad Emission Line Physics from a Hypervariable Quasar
Trump, Jonathan R.; Green, Paul J.; Brandt, W. N. +18 more
We analyze extensive spectroscopic and photometric data of the hypervariable quasar SDSS J141324+530527 (RMID 017) at z = 0.456, an optical “changing-look” quasar from the Sloan Digital Sky Survey Reverberation Mapping project that increased in optical luminosity by a factor ≃10 between 2014 and 2017. The observed broad emission lines all respond …
A Giant Intragroup Nebula Hosting a Damped {Ly}\alpha Absorber at z = 0.313
Johnson, Sean D.; Zahedy, Fakhri S.; Chen, Hsiao-Wen +5 more
This Letter reports the discovery of spatially extended line-emitting nebula, reaching to ≈100 physical kpc (pkpc) from a damped {Ly}α absorber (DLA) at z DLA = 0.313 along the sightline toward quasi-stellar object (QSO) PKS 1127-145 (z QSO = 1.188). This DLA was known to be associated with a galaxy group of dynamical mass M …
A solution to the proplyd lifetime problem
Hacar, Alvaro; Rosotti, Giovanni P.; Clarke, Cathie J. +2 more
Protoplanetary discs (PPDs) in the Orion Nebula Cluster (ONC) are irradiated by UV fields from the massive star θ1C. This drives thermal winds, inducing mass-loss rates of up to \dot{M}_wind∼ 10^{-7} M_⊙ yr-1 in the `proplyds' (ionized PPDs) close to the centre. For the mean age of the ONC and reasonable initial PPD masses, s…
Chronostar: a novel Bayesian method for kinematic age determination - I. Derivation and application to the β Pictoris moving group
Federrath, Christoph; Žerjal, Maruša; Ireland, Michael J. +3 more
Gaia DR2 provides an unprecedented sample of stars with full 6D phase-space measurements, creating the need for a self-consistent means of discovering and characterizing the phase-space overdensities known as moving groups or associations. Here we present Chronostar, a new Bayesian analysis tool that meets this need. Chronostar uses the Expectatio…
Intermittency in Solar Wind Turbulence From Fluid to Kinetic Scales
Bruno, Roberto
Solar wind is a highly turbulent medium exhibiting fluctuations ranging from the solar sidereal rotation period to proton and electron gyroperiods. Their amplitudes show remarkable scalings with frequency across more than seven decades, suggesting a self-similar nature for these fluctuations. However, these fluctuations are not globally scale inva…
Chemical Abundance Signature of J0023+0307: A Second-generation Main-sequence Star with [Fe/H] < -6
Hansen, Terese T.; Ezzeddine, Rana; Frebel, Anna +4 more
We present a chemical abundance analysis of the faint halo metal-poor main-sequence star J0023+0307, with [Fe/H] < -6.3, based on a high-resolution (R ∼ 35,000) Magellan/MIKE spectrum. The star was originally found to have [Fe/H] < -6.6 based on a Ca II K measurement in an R ∼ 2500 spectrum. No iron lines could be detected in our MIKE spectr…
The bimodal [Mg/Fe] versus [Fe/H] bulge sequence as revealed by APOGEE DR14
Schultheis, M.; Minniti, D.; Recio-Blanco, A. +5 more
Context. The Galactic bulge has a bimodal metallicity distribution function: different kinematic, spatial, and, potentially, age distributions characterize the metal-poor and metal-rich components. Despite this observed dichotomy, which argues for different formation channels for those stars, the distribution of bulge stars in the α-abundance vers…
Magnetic Turbulence Spectra and Intermittency in the Heliosheath and in the Local Interstellar Medium
Pogorelov, Nikolai V.; Fraternale, Federico; Richardson, John D. +1 more
The understanding of inertial-scale dynamics in the heliosheath is not yet thorough. Magnetic field fluctuations across the inner heliosheath (IHS) and the local interstellar medium (LISM) are here considered to provide accurate and highly resolved statistics over different plasma conditions between 88 and 136 au. By using the unique in situ 48 s …
Mutual orbit orientations of transneptunian binaries
Buie, M. W.; Roe, H. G.; Trujillo, C. A. +8 more
We present Keplerian orbit solutions for the mutual orbits of 17 transneptunian binary systems (TNBs). For ten of them, the orbit had not previously been known: 60458 2000 CM114, 119979 2002 WC19, 160091 2000 OL67, 160256 2002 PD149, 469514 2003 QA91, 469705 ǂKá̦gára, 508788 2000 CQ114
The Galactic spiral structure as revealed by O- and early B-type stars
Wang, H. -F.; Huang, Y.; Chen, B. -Q. +7 more
We investigate the morphology and kinematics of the Galactic spiral structure based on a new sample of O- and early B-type stars. We select 6858 highly confident OB star candidates from the combined data of the VST Photometric H α Survey Data Release 2 (VPHAS+ DR2) and the Gaia Data Release 2 (Gaia DR2). Together with the O-B2 stars from the liter…