Search Publications

A Detailed Study of the Most Relaxed SPT-selected Galaxy Clusters: Properties of the Cool Core and Central Galaxy
DOI: 10.3847/1538-4357/aaf394 Bibcode: 2019ApJ...870...85M

Schrabback, T.; Hlavacek-Larrondo, J.; Bayliss, M. +14 more

We present a multi-wavelength analysis of the four most relaxed clusters in the South Pole Telescope 2500 deg2 survey, which lie at 0.55 < z < 0.75. This study, which utilizes new, deep data from the Chandra X-ray Observatory and Hubble Space Telescope, along with ground-based spectroscopy from Gemini and Magellan, improves signif…

2019 The Astrophysical Journal
eHST 20
Frequency-Distance Structure of Solar Radio Sources Observed by LOFAR
DOI: 10.3847/1538-4357/ab03d8 Bibcode: 2019ApJ...873...48G

Browning, Philippa; Gordovskyy, Mykola; Kontar, Eduard +1 more

Low-frequency radio observations make it possible to study the solar corona at distances up to 2-3 R . Frequency of plasma emission is a proxy for electron density of the emitting plasma and, therefore, observations of solar radio bursts can be used to probe the density structure of the outer corona. In this study, positions of solar r…

2019 The Astrophysical Journal
SOHO 20
Radius Inflation at Low Rossby Number in the Hyades Cluster
DOI: 10.3847/1538-4357/ab21cf Bibcode: 2019ApJ...879...39J

Stassun, Keivan G.; Somers, Garrett; Jaehnig, Karl

Radius inflation continues to be explored as a peculiar occurrence among magnetically active, low-mass stars. Recently, Somers & Stassun showed that radius inflation among low-mass stars in the young open cluster M45 (Pleiades Cluster) is correlated to the rotation rate: faster rotators are more inflated. Here we extend that work to a sample o…

2019 The Astrophysical Journal
Gaia 20
The Dynamics, Structure, and Fate of a Young Cluster during Gas Dispersal: Hectoschelle, Chandra, Spitzer, and Gaia Observations of Cep OB3b
DOI: 10.3847/1538-4357/aaf4c1 Bibcode: 2019ApJ...871...46K

Jeffries, R. D.; Megeath, S. T.; Gutermuth, R. A. +5 more

We present a study of the kinematics and structure of the Cep OB3b cluster based on new spectra obtained with the Hectoschelle spectrograph on the MMT and data from Spitzer, Chandra, and Gaia. At a distance of 819 ± 16 pc, Cep OB3b is one of the closest examples of a young (∼3-5 Myr), large (∼3000 total members) cluster at the late stages of gas d…

2019 The Astrophysical Journal
Gaia 20
Models of the Mass-ejection Histories of Pre-planetary Nebulae. III. The Shaping of Lobes by Post-AGB Winds
DOI: 10.3847/1538-4357/ab16f5 Bibcode: 2019ApJ...877...30B

Frank, Adam; Balick, Bruce; Liu, Baowei

We develop a physical framework for interpreting high-resolution images and kinematics of pre-planetary nebulae (“prePNe”). We use hydrodynamical models to infer the historical properties of fast collimated nuclear flows (“jet”) that successfully form hollow, candle-shaped lobes over ≈103 yr, including the density, momenta, and geometry…

2019 The Astrophysical Journal
eHST 20
Near-term interstellar probe: First step
DOI: 10.1016/j.actaastro.2019.06.013 Bibcode: 2019AcAau.162..284M

Wimmer-Schweingruber, Robert F.; McNutt, Ralph L.; Gruntman, Mike +9 more

Exploration of the heliosphere and the far reaches of our solar system by the Voyagers and New Horizons and near-Earth observations of the Kuiper Belt and exoplanetary systems have all profoundly changed how we view our own home in space. An Interstellar Probe escaping beyond the solar-system boundaries with new observational techniques would be a…

2019 Acta Astronautica
Ulysses 20
Quantifying the thermal Sunyaev-Zel'dovich effect and excess millimetre emission in quasar environments
DOI: 10.1093/mnras/stz2751 Bibcode: 2019MNRAS.490.2315H

Hilton, Matt; Sifón, Cristóbal; Battaglia, Nicholas +23 more

In this paper, we probe the hot, post-shock gas component of quasar-driven winds through the thermal Sunyaev-Zel'dovich (tSZ) effect. Combining data sets from the Atacama Cosmology Telescope, the Herschel Space Observatory, and the Very Large Array, we measure average spectral energy distributions of 109 829 optically selected, radio quiet quasars…

2019 Monthly Notices of the Royal Astronomical Society
Herschel 20
The effect of tides on the Sculptor dwarf spheroidal galaxy
DOI: 10.1093/mnras/stz1342 Bibcode: 2019MNRAS.487.5692I

Iorio, G.; Battaglia, G.; Sollima, A. +1 more

Dwarf spheroidal galaxies (dSphs) appear to be some of the most dark matter (DM)-dominated objects in the Universe. Their dynamical masses are commonly derived using the kinematics of stars under the assumption of equilibrium. However, these objects are satellites of massive galaxies (e.g. the Milky Way) and thus can be influenced by their tidal f…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 20
The Interplay of the Solar Wind Core and Suprathermal Electrons: A Quasilinear Approach for Firehose Instability
DOI: 10.3847/1538-4357/aaf72d Bibcode: 2019ApJ...871..237S

Lazar, M.; Poedts, S.; Yoon, P. H. +1 more

In the solar wind an equipartition of kinetic energy densities can be easily established between thermal and suprathermal electrons and the instability conditions are markedly altered by the interplay of these two populations. The new thresholds derived here for the periodic branch of firehose instability shape the limits of temperature anisotropy…

2019 The Astrophysical Journal
Cluster Ulysses 20
Transfer of Twists from a Mini-filament to Large-scale Loops by Magnetic Reconnection
DOI: 10.3847/1538-4357/ab55d7 Bibcode: 2019ApJ...887..239Y

Li, Ting; Xue, Zhike; Yan, Xiaoli +4 more

With high spatial and temporal resolution, Hα data from the New Vacuum Solar Telescope, X-ray images from the X-ray telescope on board Hinode and simultaneous observations from the Solar Dynamics Observatory, we present multiwavelength observations of the interaction between a mini-filament (MF) and its overlying large-scale active-region loops (A…

2019 The Astrophysical Journal
Hinode 20