Search Publications
A Flare-type IV Burst Event from Proxima Centauri and Implications for Space Weather
Kaplan, David L.; Cairns, Iver H.; Lenc, Emil +10 more
Studies of solar radio bursts play an important role in understanding the dynamics and acceleration processes behind solar space weather events, and the influence of solar magnetic activity on solar system planets. Similar low-frequency bursts detected from active M-dwarfs are expected to probe their space weather environments and therefore the ha…
The Next Generation Virgo Cluster Survey (NGVS). XIV. The Discovery of Low-mass Galaxies and a New Galaxy Catalog in the Core of the Virgo Cluster
Jordán, Andrés; Zhang, Hongxin; Emsellem, Eric +28 more
The Next Generation Virgo Cluster Survey (NGVS) was designed to provide a deep census of baryonic structures in the Virgo cluster. The survey covers the 104 deg2 area from the core of Virgo out to one virial radius, in the u*griz bandpasses, to a point-source depth of g ∼ 25.9 mag (10σ) and a single pixel surface brightness limit of &mi…
Large-scale Structures in the CANDELS Fields: The Role of the Environment in Star Formation Activity
Papovich, Casey; Ferguson, Henry C.; Giavalisco, Mauro +14 more
We present a robust method, weighted von Mises kernel density estimation, along with boundary correction to reconstruct the underlying number density field of galaxies. We apply this method to galaxies brighter than Hubble Space Telescope $/{\rm{F}}160{\rm{w}}\leqslant 26$ AB mag in the redshift range 0.4 ≤ z ≤ 5 in the five CANDELS fields (GOODS-…
Temperatures and Metallicities of M Dwarfs in the APOGEE Survey
Hogg, David W.; Mann, Andrew W.; Burgasser, Adam +1 more
M dwarfs have enormous potential for our understanding of structure and formation on both Galactic and exoplanetary scales through their properties and compositions. However, current atmosphere models have limited ability to reproduce spectral features in stars at the coolest temperatures (Teff < 4200 K) and to fully exploit the info…
The First Ultracompact Roche Lobe-Filling Hot Subdwarf Binary
Duev, Dmitry A.; Riddle, Reed; Szkody, Paula +29 more
We report the discovery of the first short-period binary in which a hot subdwarf star (sdOB) filled its Roche lobe and started mass transfer to its companion. The object was discovered as part of a dedicated high-cadence survey of the Galactic plane named the Zwicky Transient Facility and exhibits a period of P = 39.3401(1) minutes, making it the …
Birds of a Feather? Magellan/IMACS Spectroscopy of the Ultra-faint Satellites Grus II, Tucana IV, and Tucana V
Bechtol, K.; Smith, M.; Lidman, C. +55 more
We present Magellan/IMACS spectroscopy of three recently discovered ultra-faint Milky Way satellites, Grus II, Tucana IV, and Tucana V. We measure systemic velocities of Vhel = 110.0 ± 0.5 km s-1, Vhel = 15.9-1.7+1.8 km s-1, and Vhel=-36.2-2.2+2.5 km…
Constraining the Milky Way Mass Profile with Phase-space Distribution of Satellite Galaxies
Li, Ting S.; Wang, Wenting; Han, Jiaxin +3 more
We estimate the Milky Way (MW) halo properties using satellite kinematic data including the latest measurements from Gaia DR2. With a simulation-based 6D phase-space distribution function (DF) of satellite kinematics, we can infer halo properties efficiently and without bias, and handle the selection function and measurement errors rigorously in t…
TESS Spots a Hot Jupiter with an Inner Transiting Neptune
Torres, Guillermo; Vanderburg, Andrew; Latham, David W. +48 more
Hot Jupiters are rarely accompanied by other planets within a factor of a few in orbital distance. Previously, only two such systems have been found. Here, we report the discovery of a third system using data from the Transiting Exoplanet Survey Satellite (TESS). The host star, TOI-1130, is an eleventh magnitude K-dwarf in Gaia G-band. It has two …
Spectral Signatures of Chromospheric Condensation in a Major Solar Flare
Allred, Joel; Graham, David R.; Zangrilli, Luca +3 more
We study the evolution of chromospheric line and continuum emission during the impulsive phase of the X-class SOL2014-09-10T17:45 solar flare. We extend previous analyses of this flare to multiple chromospheric lines of Fe I, Fe II, Mg II, C I, and Si II observed with the Interface Region Imaging Spectrograph, combined with radiative-hydrodynamica…
The Regulation of Galaxy Growth along the Size-Mass Relation by Star Formation, as Traced by Hα in KMOS3D Galaxies at 0.7 ≲ z ≲ 2.7
Übler, Hannah; van Dokkum, Pieter; Momcheva, Ivelina +24 more
We present half-light sizes measured from Hα emission tracing star formation in 281 star-forming galaxies from the KMOS3D survey at 0.7≲ z ≲ 2.7. Sizes are derived by fitting 2D exponential disk models, with bootstrap errors averaging 20%. Hα sizes are a median (mean) of 1.19 (1.26) times larger than those of the stellar continuum—which…