Search Publications
Galaxy Merger Candidates in High-redshift Cluster Environments
Cooper, M. C.; Demarco, R.; Lidman, C. +14 more
We compile a sample of spectroscopically and photometrically selected cluster galaxies from four high-redshift galaxy clusters (1.59< z< 1.71) from the Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS), and a comparison field sample selected from the UKIDSS Deep Survey. Using near-infrared imaging from the Hubble Space Telescope…
ZFIRE: The Evolution of the Stellar Mass Tully-Fisher Relation to Redshift ∼2.2
Kewley, Lisa J.; Kacprzak, Glenn G.; Glazebrook, Karl +8 more
Using observations made with MOSFIRE on Keck I as part of the ZFIRE survey, we present the stellar mass Tully-Fisher relation at 2.0< z< 2.5. The sample was drawn from a stellar-mass-limited, {K}s-band-selected catalog from ZFOURGE over the CANDELS area in the COSMOS field. We model the shear of the Hα emission line to derive rota…
Onset of a Large Ejective Solar Eruption from a Typical Coronal-jet-base Field Configuration
Moon, Yong-Jae; Joshi, Navin Chandra; Magara, Tetsuya +2 more
Utilizing multiwavelength observations and magnetic field data from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), SDO/Helioseismic and Magnetic Imager (HMI), the Geostationary Operational Environmental Satellite (GOES), and RHESSI, we investigate a large-scale ejective solar eruption of 2014 December 18 from active regio…
Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar SDSS J2222+2745
Rigby, Jane R.; Whitaker, Katherine E.; Sharon, Keren +7 more
SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spect…
The Architecture of the GW Ori Young Triple-star System and Its Disk: Dynamical Masses, Mutual Inclinations, and Recurrent Eclipses
Torres, Guillermo; Latham, David W.; Wilner, David J. +15 more
We present spatially and spectrally resolved Atacama Large Millimeter/submillimeter Array (ALMA) observations of gas and dust orbiting the pre-main-sequence hierarchical triple-star system GW Ori. A forward modeling of the 13CO and C18O J = 2-1 transitions permits a measurement of the total stellar mass in this system, 5.29+/…
The Coldest Place in the Universe: Probing the Ultra-cold Outflow and Dusty Disk in the Boomerang Nebula
Sahai, R.; Vlemmings, W. H. T.; Nyman, L. -Å.
Our Cycle 0 ALMA observations confirmed that the Boomerang Nebula is the coldest known object in the universe, with a massive high-speed outflow that has cooled significantly below the cosmic background temperature. Our new CO 1-0 data reveal heretofore unseen distant regions of this ultra-cold outflow, out to ≳120,000 au. We find that in the ultr…
Chemical Complexity in the Eu-enhanced Monometallic Globular NGC 5986
Caldwell, Nelson; Rich, R. Michael; Johnson, Christian I. +4 more
NGC 5986 is a poorly studied but relatively massive Galactic globular cluster that shares several physical and morphological characteristics with “iron-complex” clusters known to exhibit significant metallicity and heavy-element dispersions. In order to determine whether NGC 5986 joins the iron-complex cluster class, we investigated the chemical c…
The Role of Pebble Fragmentation in Planetesimal Formation. II. Numerical Simulations
Blum, Jürgen; Johansen, Anders; Wahlberg Jansson, Karl +1 more
Some scenarios for planetesimal formation go through a phase of collapse of gravitationally bound clouds of millimeter- to centimeter-size pebbles. Such clouds can form, for example, through the streaming instability in protoplanetary disks. We model the collapse process with a statistical model to obtain the internal structure of planetesimals wi…
The First ALMA Observation of a Solar Plasmoid Ejection from an X-Ray Bright Point
Shimojo, Masumi; White, Stephen M.; Hudson, Hugh S. +2 more
Eruptive phenomena such as plasmoid ejections or jets are important features of solar activity and have the potential to improve our understanding of the dynamics of the solar atmosphere. Such ejections are often thought to be signatures of the outflows expected in regions of fast magnetic reconnection. The 304 Å EUV line of helium, formed at arou…
A Rogues’ Gallery of Andromeda's Dwarf Galaxies. I. A Predominance of Red Horizontal Branches
Lewis, Geraint F.; Dolphin, Andrew E.; Skillman, Evan D. +11 more
We present homogeneous, sub-horizontal branch photometry of 20 dwarf spheroidal satellite galaxies of M31 observed with the Hubble Space Telescope. Combining our new data for 16 systems with archival data in the same filters for another four, we show that Andromeda dwarf spheroidal galaxies favor strikingly red horizontal branches or red clumps do…