Search Publications
The Phase Space of z∼1.2 SpARCS Clusters: Using Herschel to Probe Dust Temperature as a Function of Environment and Accretion History
Muzzin, A.; van der Burg, R. F. J.; Wilson, G. +5 more
We present a five-band Herschel study (100-500 µm) of three galaxy clusters at z∼ 1.2 from the Spitzer Adaptation of the Red-Sequence Cluster Survey. With a sample of 120 spectroscopically confirmed cluster members, we investigate the role of environment on galaxy properties utilizing the projected cluster phase space (line-of-sight velocity…
Galaxies Probing Galaxies at High Resolution: Co-rotating Gas Associated with a Milky Way Analog at z=0.4
Moustakas, John; Coil, Alison L.; Tremonti, Christy A. +5 more
We present results on gas flows in the halo of a Milky-Way-like galaxy at z = 0.413 based on high-resolution spectroscopy of a background galaxy. This is the first study of circumgalactic gas at high spectral resolution toward an extended background source (I.e., a galaxy rather than a quasar). Using long-slit spectroscopy of the foreground galaxy…
The Hot Companion and Circumbinary Disk of the Be Star HR 2142
Gies, Douglas R.; Wang, Luqian; Peters, Geraldine J. +1 more
We present a spectroscopic investigation of the Be+sdO binary system HR 2142 that is based upon large sets of ultraviolet observations from the International Ultraviolet Explorer (IUE) and ground-based Hα observations. We measured radial velocities for the Be star component from these spectra and computed a revised orbit. In order to search for th…
A New γ-Ray Loud, Eclipsing Low-mass X-Ray Binary
Strader, Jay; Udalski, Andrzej; Chomiuk, Laura +5 more
We report the discovery of an eclipsing low-mass X-ray binary at the center of the 3FGL error ellipse of the unassociated Fermi/Large Area Telescope γ-ray source 3FGL J0427.9-6704. Photometry from OGLE and the SMARTS 1.3 m telescope and spectroscopy from the SOAR telescope have allowed us to classify the system as an eclipsing low-mass X-ray binar…
The Fe II Emission in Active Galactic Nuclei: Excitation Mechanisms and Location of the Emitting Region
Garcia-Rissmann, A.; Sigut, T. A. A.; Rodríguez-Ardila, A. +2 more
We present a study of Fe II emission in the near-infrared region (NIR) for 25 active galactic nuclei (AGNs) to obtain information about the excitation mechanisms that power it and the location where it is formed. We employ an NIR Fe II template derived in the literature and find that it successfully reproduces the observed Fe II spectrum. The Fe I…
Suprathermal Electron Strahl Widths in the Presence of Narrow-band Whistler Waves in the Solar Wind
Fazakerley, A. N.; Maksimovic, M.; Alexandrova, O. +2 more
We perform the first statistical study of the effects of the interaction of suprathermal electrons with narrow-band whistler mode waves in the solar wind (SW). We show that this interaction does occur and that it is associated with enhanced widths of the so-called strahl component. The latter is directed along the interplanetary magnetic field awa…
Sun-to-Earth Characteristics of the 2012 July 12 Coronal Mass Ejection and Associated Geo-effectiveness
Möstl, Christian; Wang, Rui; Yang, Zhongwei +2 more
We analyze multi-spacecraft observations associated with the 2012 July 12 coronal mass ejection (CME), covering the source region on the Sun from the Solar Dynamics Observatory, stereoscopic imaging observations from the Solar Terrestrial Relations Observatory (STEREO), magnetic field characteristics from Mercury Surface, Space Environment, Geoche…
Stellar Populations and Star Formation History of the Metal-poor Dwarf Galaxy DDO 68
Cignoni, M.; Tosi, M.; van der Marel, R. P. +6 more
We present the star formation history (SFH) of the extremely metal-poor dwarf galaxy DDO 68, based on our photometry with the Advanced Camera for Surveys. With a metallicity of only 12+{log}({{O}}/{{H}})=7.15 and a very isolated location, DDO 68 is one of the most metal-poor galaxies known. It has been argued that DDO 68 is a young system that sta…
Confirming the Existence of a Quiescent Galaxy Population out to z=3: A Stacking Analysis of Mid-, Far-Infrared and Radio Data
Casey, Caitlin M.; Schinnerer, Eva; Zirm, Andrew W. +15 more
We performed a comprehensive stacking analysis on ∼14,200 quiescent galaxy (QG) candidates at z = 0-3 across mid-, far-infrared (MIR and FIR), and radio wavelengths. Identified via their rest-frame NUV - r and r - J colors, the QG candidates ({M}\star ={10}9.8{{{--}}12.2} {M}⊙ ) have drastically different IR and ra…
The Age, Mass, and Size Distributions of Star Clusters in M51
Schinnerer, Eva; Whitmore, Bradley C.; Chandar, Rupali +4 more
We present a new catalog of 3816 compact star clusters in the grand design spiral galaxy M51 based on observations taken with the Hubble Space Telescope. The age distribution of the clusters declines starting at very young ages, and can be represented by a power law, {dN}/dτ \propto {τ }γ , with γ =-0.65+/- 0.15. No significant changes …