Search Publications
Ion-Ion Equilibration and Particle Distributions in a 3000 km s-1 Shock in SN 1006
Raymond, J. C.; Laming, J. M.; Blair, W. P. +1 more
SN 1006 is the most attractive target for investigating the physics of collisionless shock waves faster than 2000 {km} {{{s}}}-1. We obtained UV and optical spectra and an Hα image of a 3000 {km} {{{s}}}-1 shock driven by a clump of ejecta that has overtaken the blast wave. It is 500 km s-1 faster than the filament…
Clues to the Formation of Spiral Structure in M51 from the Ages and Locations of Star Clusters
Calzetti, Daniela; Schinnerer, Eva; Whitmore, Bradley C. +8 more
We determine the spatial distributions of star clusters at different ages in the grand-design spiral galaxy M51 using a new catalog based on multi-band images taken with the Hubble Space Telescope (HST). These distributions, when compared with the spiral structure defined by molecular gas, dust, young and old stars, show the following sequence in …
Dynamics of Large-scale Coronal Structures as Imaged during the 2012 and 2013 Total Solar Eclipses
Morgan, Huw; Habbal, Shadia R.; Druckmüller, Miloslav +2 more
White light images acquired at the peak of solar activity cycle 24, during the total solar eclipses of 2012 November 13 and 2013 November 3, serendipitously captured erupting prominences accompanied by CMEs. Application of state-of-the-art image processing techniques revealed the intricate details of two “atypical” large-scale structures, with str…
The Multiplicity of M Dwarfs in Young Moving Groups
Yee, Jennifer C.; Montet, Benjamin T.; Bowler, Brendan P. +12 more
We image 104 newly identified low-mass (mostly M-dwarf) pre-main sequence (PMS) members of nearby young moving groups (YMGs) with Magellan Adaptive Optics (MagAO) and identify 27 stellar binaries with instantaneous projected separation as small as 40 mas. Fifteen were previously unknown. The total number of multiple systems in this sample includin…
A Redshift Survey of the Nearby Galaxy Cluster Abell 2199: Comparison of the Spatial and Kinematic Distributions of Galaxies with the Intracluster Medium
Hwang, Ho Seong; Park, Changbom; Song, Hyunmi +1 more
We present the results from an extensive spectroscopic survey of the central region of the nearby galaxy cluster Abell 2199 (A2199) at z = 0.03. By combining 775 new redshifts from the MMT/Hectospec observations with the data in the literature, we construct a large sample of 1624 galaxies with measured redshifts at R< 30\prime , whic…
3D Magnetohydrodynamic Models of Nonthermal Photon Emission in the Binary System γ 2 Velorum
Reimer, A.; Reimer, O.; Kissmann, R. +1 more
Recent reports claiming an association of the massive star binary system {γ }2 Velorum (WR 11) with a high-energy γ-ray source observed by Fermi-LAT contrast the so far exclusive role of η Carinae as the hitherto only detected γ-ray emitter in the source class of particle-accelerating colliding-wind binary (CWB) systems. We offer suppor…
Fan Loops Observed by IRIS, EIS, and AIA
Solanki, Sami K.; Polito, Vanessa; Gupta, G. R. +3 more
A comprehensive study of the physical parameters of active region fan loops is presented using the observations recorded with the Interface Region Imaging Spectrometer (IRIS), the EUV Imaging Spectrometer (EIS) on board Hinode, and the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Obs…
OH Survey along Sightlines of Galactic Observations of Terahertz C+
Wang, Shen; Heiles, Carl; Li, Di +9 more
We have obtained OH spectra of four transitions in the {}2{{{\Pi }}}3/2 ground state, at 1612, 1665, 1667, and 1720 MHz, toward 51 sightlines that were observed in the Herschel project Galactic Observations of Terahertz C+. The observations cover the longitude range of (32°, 64°) and (189°, 207°) in the northern Galactic plan…
Explosive Chromospheric Evaporation and Warm Rain in a C3.1 Flare Observed by IRIS, Hinode/EIS, and RHESSI
Brosius, Jeffrey W.; Inglis, Andrew R.
IRIS and EIS observed a GOES C3.1 flare in stare mode on 2014 March 15. The GOES flare started at 00:21:35 and peaked at 00:26:30 UT. The IRIS slit pointed near the center of the flare, while the EIS slit pointed 35\prime\prime to its west. About 4 minutes before the GOES flare start, the IRIS C II and Si IV intensities became (and rema…
Carbon Abundances in Starburst Galaxies of the Local Universe
Leitherer, Claus; Wofford, Aida; Kewley, Lisa +2 more
The cosmological origin of carbon, the fourth most abundant element in the universe, is not well known and a matter of heavy debate. We investigate the behavior of C/O to O/H in order to constrain the production mechanism of carbon. We measured emission-line intensities in the spectral range from 1600 to 10000 Å on Space Telescope Imaging Spectrog…