Search Publications

Subwavelength Resolution Imaging of the Solar Deep Interior

Duvall, Thomas L., Jr.; Hanasoge, Shravan M.

We derive expectations for signatures in the measured travel times of waves that interact with thermal anomalies and jets. A series of numerical experiments that involve the dynamic linear evolution of an acoustic wave field in a solarlike stratified spherical shell in the presence of fully three-dimensional time-stationary perturbations are perfo…

Evidence for Nonlinear Growth of Structure from an X-Ray-Selected Cluster Survey using a Novel Joint Analysis of the Chandra and XMM-Newton Archives

Kahn, S. M.; Peterson, J. R.; Gupta, R. R. +2 more

We present a large X-ray-selected serendipitous cluster survey based on a novel joint analysis of archival Chandra and XMM-Newton data. The survey provides enough depth to reach clusters of flux of ≈10^-14ergcm^-2s^-1 near z≈ 1 and simultaneously a large-enough sample to find evidence for the strong evolution of clust…

Erratum: "Suzaku Observations of Local Ultraluminous Infrared Galaxies" (2009, ApJ, 691, 261)

Sanders, D. B.; Nakagawa, Takao; Veilleux, Sylvain +7 more

We report the results from our analysis of {\it Suzaku} XIS (0.5-10 keV) and HXD/PIN (15-40 keV) observations of five well-known local ULIRGs: {\em IRAS} F05189-2524, {\em IRAS} F08572+3915, Mrk 273, PKS 1345+12, and Arp 220. The XIS observations of F05189-2524 and Mrk 273 reveal strong iron lines consistent with Fe K$\alpha$ and changes in spectr…

XMM Observations of Two Quadrupolar Outflows

Simon, Theodore

X-ray images of two small dark clouds, L1455 and L723, have been obtained with the EPIC cameras on board the XMM-Newton telescope. Both regions contain multiple independent but overlapping bipolar flows in high-velocity CO, a collection of Herbig-Haro objects, and a number of filaments and knots of H₂ emission. The field of view in each…

Erratum: "Abell 851 and the Role of Starbursts in Cluster Galaxy Evolution" (2009, ApJ, 693, 152)

Smail, Ian; Fritz, Jacopo; Dressler, Alan +5 more

The Unusual Spectral Energy Distribution of LBQS 0102-2713

Boller, Th.; Heftrich, T.; Linguri, K. +1 more

We have studied the spectral energy distribution of the quasar LBQS 0102-2713. The available multiwavelength data in the observers frame are one optical spectrum between 3200 and 7400 Å, seven Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra between 1700 and 2300 Å, one GALEX NUV flux density and a K_S magnitude obtai…

Improved Cosmological Constraints from New, Old, and Combined Supernova Data Sets

Perdereau, O.; Frye, B. L.; Suntzeff, N. B. +67 more

We present a new compilation of Type Ia supernovae (SNe Ia), a new data set of low-redshift nearby-Hubble-flow SNe, and new analysis procedures to work with these heterogeneous compilations. This "Union" compilation of 414 SNe Ia, which reduces to 307 SNe after selection cuts, includes the recent large samples of SNe Ia from the Supernova Legacy S…

Constraints on the Self-Interaction Cross Section of Dark Matter from Numerical Simulations of the Merging Galaxy Cluster 1E 0657-56

Gonzalez, Anthony H.; Markevitch, Maxim; Clowe, Douglas +2 more

We compare recent results from X-ray, strong lensing, weak lensing, and optical observations with numerical simulations of the merging galaxy cluster 1E 0657-56. X-ray observations reveal a bullet-like subcluster with a prominent bow shock, which gives an estimate for the merger velocity of 4700 km s^-1, while lensing results show that t…

Confirmation of the Remarkable Compactness of Massive Quiescent Galaxies at z ~ 2.3: Early-Type Galaxies Did not Form in a Simple Monolithic Collapse

van Dokkum, Pieter G.; Franx, Marijn; Illingworth, Garth D. +9 more

Using deep near-infrared spectroscopy, Kriek et al. found that ~45% of massive galaxies at z ~ 2.3 have evolved stellar populations and little or no ongoing star formation. Here we determine the sizes of these quiescent galaxies using deep, high-resolution images obtained with HST/NIC2 and laser guide star (LGS)-assisted Keck/adaptive optics (AO).…

Submillimeter Galaxies at z ~ 2: Evidence for Major Mergers and Constraints on Lifetimes, IMF, and CO-H₂ Conversion Factor

Smail, I.; Lutz, D.; Cimatti, A. +17 more

We report subarcsecond resolution IRAM PdBI millimeter CO interferometry of four z ~ 2 submillimeter galaxies (SMGs), and sensitive CO(3-2) flux limits toward three z ~ 2 UV/optically selected star-forming galaxies. The new data reveal for the first time spatially resolved CO gas kinematics in the observed SMGs. Two of the SMGs show double or mult…