Search Publications
A Twisted Flux Rope as the Magnetic Structure of a Filament in Active Region 10953 Observed by Hinode
Canou, A.; Amari, T.
The presence of twisted flux ropes (TFRs) in pre-eruptive/flaring magnetic configurations is of main interest for our understanding of the structure and dynamics of the solar corona. On the one hand, their presence is a key ingredient in several theoretical models for the magnetic support of material in filaments, or triggering of coronal mass eje…
Powerful H2 Line Cooling in Stephan's Quintet. I. Mapping the Significant Cooling Pathways in Group-wide Shocks
Yun, M. S.; Boulanger, F.; Reach, W. T. +10 more
We present results from the mid-infrared spectral mapping of Stephan's Quintet using the Spitzer Space Telescope. A 1000 km s-1 collision (t col = 5 × 106 yr) has produced a group-wide shock, and for the first time the large-scale distribution of warm molecular hydrogen emission is revealed, as well as its close as…
A Displaced Supermassive Black Hole in M87
Batcheldor, D.; Axon, D. J.; Robinson, A. +2 more
Isophotal analysis of M87, using data from the Advanced Camera for Surveys, reveals a projected displacement of 6.8 ± 0.8 pc (~0farcs1) between the nuclear point source (presumed to be the location of the supermassive black hole, SMBH) and the photo-center of the galaxy. The displacement is along a position angle of 307° ± 17° and is consistent wi…
Galaxy Clusters at the Edge: Temperature, Entropy, and Gas Dynamics Near the Virial Radius
O'Shea, Brian W.; Burns, Jack O.; Skillman, Samuel W.
Recently, Suzaku has produced temperature and entropy profiles, along with profiles of gas density, gas fraction, and mass, for multiple galaxy clusters out to approximately the virial radius. In this paper, we compare these novel X-ray observations with results from N-body + hydrodynamic adaptive mesh refinement cosmological simulations using the…
Toward a Realistic Thermodynamic Magnetohydrodynamic Model of the Global Solar Corona
Lugaz, Noé; Downs, Cooper; Roussev, Ilia I. +3 more
In this work, we describe our implementation of a thermodynamic energy equation into the global corona model of the Space Weather Modeling Framework and its development into the new lower corona (LC) model. This work includes the integration of the additional energy transport terms of coronal heating, electron heat conduction, and optically thin r…
z ~ 7 Galaxy Candidates from NICMOS Observations Over the HDF-South and the CDF-South and HDF-North Goods Fields
Conselice, Christopher J.; Franx, Marijn; Illingworth, Garth D. +9 more
We use ~88 arcmin2 of deep (gsim26.5 mag at 5σ) NICMOS data over the two GOODS fields and the HDF-South to conduct a search for bright z >~ 7 galaxy candidates. This search takes advantage of an efficient preselection over 58 arcmin2 of NICMOS H 160-band data where only plausible z >~ 7 candidates are followe…
Cavities and Shocks in the Galaxy Group HCG 62 as Revealed by Chandra, XMM-Newton, and Giant Metrewave Radio Telescope Data
Raychaudhury, Somak; Giacintucci, Simona; David, Laurence P. +4 more
We report on the results of an analysis of Chandra, XMM-Newton, and new Giant Metrewave Radio Telescope (GMRT) data of the X-ray bright compact group of galaxies HCG 62, which is one of the few groups known to possess clear, small X-ray cavities in the inner regions. This is part of an ongoing X-ray/low-frequency radio study of 18 groups, initiall…
Galaxy-Scale Strong-Lensing Tests of Gravity and Geometric Cosmology: Constraints and Systematic Limitations
Rappaport, Saul A.; Bolton, Adam S.; Schwab, Josiah
Galaxy-scale strong gravitational lenses with measured stellar velocity dispersions allow a test of the weak-field metric on kiloparsec scales and a geometric measurement of the cosmological distance-redshift relation, provided that the mass-dynamical structure of the lensing galaxies can be independently constrained to a sufficient degree. We com…
The Morphology of Passively Evolving Galaxies at z ~ 2 from Hubble Space Telescope/WFC3 Deep Imaging in the Hubble Ultra Deep Field
Gardner, Jonathan P.; Dickinson, M.; Giavalisco, M. +15 more
We present near-IR images, obtained with the Hubble Space Telescope and the WFC3/IR camera, of six passive and massive galaxies at redshift 1.3 < z < 2.4 (specific star formation rate <10-2 Gyr-1 stellar mass M ~ 1011 M sun), selected from the Great Observatories Origins Deep Survey. These image…
A Detailed Study of Photometric Redshifts for GOODS-South Galaxies
Dickinson, Mark; Ferguson, Henry C.; Giavalisco, Mauro +10 more
We use the deepest and the most comprehensive photometric data currently available for GOODS-South (GOODS-S) galaxies to measure their photometric redshifts. The photometry includes VLT/VIMOS (U band), HST/ACS (F435W, F606W, F775W, and F850LP bands), VLT/ISAAC (J, H, and Ks bands), and four Spitzer/IRAC channels (3.6, 4.5, 5.8, and 8.0 …