Search Publications
Modeling the Surface X-ray Emission and Viewing Geometry of PSR J0821-4300 in Puppis A
Gotthelf, E. V.; Halpern, J. P.; Perna, R.
We present a model for the unusual X-ray pulse profiles of PSR J0821-4300, the compact central object in supernova remnant Puppis A. We show that a pair of thermal, antipodal hot spots on the neutron star (NS) surface is able to fully account for the pulsar's double blackbody spectrum and energy-dependent pulse profile, including the observed 180°…
Evidence for Gamma-ray Emission from the Low-mass X-ray Binary System First J102347.6+003841
Cheng, K. S.; Takata, J.; Kong, A. K. H. +6 more
The low-mass X-ray binary (LMXB) system FIRST J102347.6+003841 hosts a newly born millisecond pulsar (MSP) PSR J1023+0038 that was revealed as the first and only known rotation-powered MSP in a quiescent LMXB. While the system is shown to have an accretion disk before 2002, it remains unclear how the accretion disk has been removed in order to rev…
Solar Magnetic Tracking. III. Apparent Unipolar Flux Emergence in High-resolution Observations
Lamb, D. A.; DeForest, C. E.; Hagenaar, H. J. +2 more
Understanding the behavior of weak magnetic fields near the detection limit of current instrumentation is important for determining the flux budget of the solar photosphere at small spatial scales. Using 0farcs3-resolution magnetograms from the Solar Optical Telescope's Narrowband Filter Imager (NFI) on the Hinode spacecraft, we confirm that the p…
A Geometrical Height Scale for Sunspot Penumbrae
Martínez Pillet, V.; Ruiz Cobo, B.; Puschmann, K. G.
Inversions of spectropolarimetric observations of penumbral filaments deliver the stratification of different physical quantities in an optical depth scale. However, without establishing a geometrical height scale, their three-dimensional geometrical structure cannot be derived. This is crucial in understanding the correct spatial variation of phy…
The Evolution and Eddington Ratio Distribution of Compton Thick Active Galactic Nuclei
Ballantyne, D. R.; Draper, A. R.
Previous studies of the active galactic nuclei (AGNs) contribution to the cosmic X-ray background (CXB) consider only observable parameters such as luminosity and absorbing column. Here, for the first time, we extend the study of the CXB to physical parameters including the Eddington ratio of the sources and the black hole mass. In order to calcul…
X-Ray Emission from HESS J1731-347/SNR G353.6-0.7 and Central Compact Source XMMS J173203-344518
Leahy, D. A.; Li, Z.; Tian, W. W. +4 more
We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-Newton and Suzaku X-ray observations and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio supernova remnant (SNR). We find that spatially resolved X-ray spectra can generally…
Analysis of a Global Moreton Wave Observed on 2003 October 28
Magdalenić, J.; Temmer, M.; Veronig, A. M. +2 more
We study the well-pronounced Moreton wave that occurred in association with the X17.2 flare/CME event of 2003 October 28. This Moreton wave is striking for its global propagation and two separate wave centers, which implies that two waves were launched simultaneously. The mean velocity of the Moreton wave, tracked within different sectors of propa…
Multi-transition Study of M51'S Molecular Gas Spiral Arms
Schinnerer, E.; Scoville, N. Z.; Aalto, S. +1 more
Two selected regions in the molecular gas spiral arms in M51 were mapped with the Owens Valley Radio Observatory (OVRO) mm-interferometer in the 12CO(2-1), 13CO(1-0), C18O(1-0), HCN(1-0), and HCO+(1-0) emission lines. The CO data have been combined with the 12CO(1-0) data from Aalto et al. covering the c…
Detection of a Pseudobulge Hidden Inside the "Box-shaped Bulge" of NGC 4565
Kormendy, John; Barentine, John C.
Numerical simulations show that box-shaped bulges of edge-on galaxies are not bulges: they are bars seen side-on. Therefore, the two components that are seen in edge-on Sb galaxies such as NGC 4565 are a disk and a bar. But face-on SBb galaxies always show a disk, a bar, and a (pseudo)bulge. Where is the (pseudo)bulge in NGC 4565? We use archival …
Three-Dimensional Polarimetric Coronal Mass Ejection Localization Tested Through Triangulation
Thompson, William T.; Davila, Joseph M.; Moran, Thomas G.
We have tested the validity of the coronal mass ejection (CME) polarimetric reconstruction technique for the first time using triangulation and demonstrated that it can provide the angle and distance of CMEs to the plane of the sky. In this study, we determined the three-dimensional orientation of the CMEs that occurred on 2007 August 21 and 2007 …