Search Publications
The Orbit of the Close Companion of Polaris: Hubble Space Telescope Imaging, 2007 to 2014
Mack, Jennifer; Schaefer, Gail H.; Nelan, Edmund P. +6 more
As part of a program to determine the dynamical masses of Cepheids, we have imaged the nearest and brightest Cepheid, Polaris, with the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 and Wide Field Camera 3. Observations were obtained at three epochs between 2007 and 2014. In these images, as in HST frames obtained in 2005 and 2006, wh…
Magnification Bias of Distant Galaxies in the Hubble Frontier Fields: Testing Wave Versus Particle Dark Matter Predictions
Broadhurst, Tom; Windhorst, Rogier; Schive, Hsi-Yu +4 more
Acting as powerful gravitational lenses, the strong lensing galaxy clusters of the deep Hubble Frontier Fields (HFF) program permit access to lower-luminosity galaxies lying at higher redshifts than hitherto possible. We analyzed the HFF to measure the volume density of Lyman-break galaxies at z > 4.75 by identifying a complete and reliable sam…
Toward a Quantitative Model for Simulation and Forecast of Solar Energetic Particle Production during Gradual Events. I. Magnetohydrodynamic Background Coupled to the SEP Model
Gombosi, T. I.; Taktakishvili, A.; Roussev, I. I. +2 more
Solar energetic particles (SEPs) are an important aspect of space weather. SEP events possess a high destructive potential, since they may cause disruptions of communication systems on Earth and be fatal to crew members on board spacecraft and, in extreme cases, harmful to people on board high-altitude flights. However, currently the research comm…
Constraining the Solar Galactic Reflex Velocity using Gaia Observations of the Sagittarius Stream
Law, David R.; Majewski, Steven R.; Hayes, Christian R.
Because of its particular orientation around the Galaxy—i.e., in a plane nearly perpendicular to the Galactic plane and containing both the Sun and Galactic center—the Sagittarius (Sgr) stream provides a powerful means by which to measure the solar reflex velocity, and thereby infer the velocity of the Local Standard of Rest (LSR), in a way that i…
A Wide-field Map of Intracluster Globular Clusters in Coma
O'Neill, Conor R.; Madrid, Juan P.; Gagliano, Alexander T. +1 more
The large-scale distribution of globular clusters in the central region of the Coma cluster of galaxies is derived through the analysis of Hubble Space Telescope/Advanced Camera for Surveys data. Data from three different HST observing programs are combined in order to obtain a full surface density map of globular clusters in the core of Coma. A t…
Resolved Star Formation Efficiency in the Antennae Galaxies
Leroy, Adam K.; Whitmore, Bradley C.; Johnson, Kelsey E. +3 more
We use Atacama Large Millimeter Array CO(3-2) observations in conjunction with optical observations from the Hubble Space Telescope to determine the ratio of stellar to gas mass for regions in the Antennae Galaxies. We adopt the term “instantaneous mass ratio” {IMR}(t)={M}stars}/({M}gas}+{M}stars}), which is equiva…
Predicting the COSIE-C Signal from the Outer Corona up to 3 Solar Radii
Telloni, Daniele; Andretta, Vincenzo; Del Zanna, Giulio +2 more
We present estimates of the signal to be expected in quiescent solar conditions, as would be obtained with the COronal Spectrographic Imager in the EUV in its coronagraphic mode (COSIE-C). COSIE-C has been proposed to routinely observe the relatively unexplored outer corona, where we know that many fundamental processes affecting both the lower co…
Objective Lagrangian Vortex Detection in the Solar Photosphere
Silva, Suzana S. A.; Requerey, Iker S.; Rempel, Erico Luiz +2 more
Vortices in the solar photosphere can be linked to a wide range of events, such as small-scale solar eruptions, wave excitation, and heating of the upper part of the solar atmosphere. Despite their importance in solar physics, most of the current studies on photospheric vortices are based on methods that are not invariant under time-dependent tran…
A Two-dimensional Spectroscopic Study of Emission-line Galaxies in the Faint Infrared Grism Survey (FIGS). I. Detection Method and Catalog
Finkelstein, Steven L.; Hathi, Nimish P.; Koekemoer, Anton M. +31 more
We present the results from the application of a two-dimensional emission line detection method, EMission-line two-Dimensional (EM2D), to the near-infrared G102 grism observations obtained with the Wide-Field Camera 3 (WFC3) as part of the Cycle 22 Hubble Space Telescope Treasury Program: the Faint Infrared Grism Survey (FIGS). Using the EM2D meth…
IN-SYNC. VIII. Primordial Disk Frequencies in NGC 1333, IC 348, and the Orion A Molecular Cloud
Da Rio, Nicola; Meyer, Michael R.; Yao, Yuhan +2 more
In this paper, we address two issues related to primordial disk evolution in three clusters (NGC 1333, IC 348, and Orion A) observed by the INfrared Spectra of Young Nebulous Clusters (IN-SYNC) project. First, in each cluster, averaged over the spread of age, we investigate how disk lifetime is dependent on stellar mass. The general relation in IC…