Search Publications
A Detection of an X-ray Wind and an Ionized Disk in the Chandra HETGS Observation of the Seyfert 2 Galaxy IRAS 18325-5926
Lee, Julia C.; Canizares, Claude R.; Iwasawa, Kazushi +1 more
We analyze the Chandra High Energy Transmission Grating Spectrometer observation of the Seyfert 2 AGN IRAS 18325-5926. We detect a v = -360+41 -66 km s-1 blueshifted ionized absorber in the X-ray spectrum, with photoionization parameter log ξ = 2.0+0.1 -0.1 and hydrogen column density N H…
Hubble Space Telescope Pixel Analysis of the Interacting Face-on Spiral Galaxy NGC 5194 (M51A)
Lee, Joon Hyeop; Kyeong, Jaemann; Kim, Sang Chul +3 more
A pixel analysis is carried out on the interacting face-on spiral galaxy NGC 5194 (M51A), using the Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) images in the F435W, F555W, and F814W (BVI) bands. After 4 × 4 binning of the HST/ACS images to secure a sufficient signal-to-noise ratio for each pixel, we derive several quantities des…
Transition Region Emission from Solar Flares during the Impulsive Phase
Raymond, J. C.; Ciaravella, A.; Giordano, S. +4 more
There are relatively few observations of UV emission during the impulsive phases of solar flares, so the nature of that emission is poorly known. Photons produced by solar flares can resonantly scatter off atoms and ions in the corona. Based on off-limb measurements by the Solar and Heliospheric Observatory/Ultraviolet Coronagraph Spectrometer, we…
Suzaku Observation of a New Merging Group of Galaxies at a Filamentary Junction
Yoshitake, Hiroshi; Kawahara, Hajime; Nishimichi, Takahiro +1 more
We report on a new merging group of galaxies, Suzaku J1552+2739, at z ~ 0.08 revealed by a Suzaku observation. The group was found by observing a junction of galaxy filaments optically identified in the Sloan Digital Sky Survey spectroscopic data. Suzaku J1552+2739 exhibits an irregular morphology and presents several peaks in its X-ray image. A b…
Measurement of Intermittency of Anisotropic Magnetohydrodynamic Turbulence in High-speed Solar Wind
Wu, D. J.; Yang, L.; Luo, Q. Y.
We investigate the intermittency of anisotropic magnetohydrodynamic (MHD) turbulence in high-speed solar wind. Using the data recorded by the Ulysses spacecraft, we apply the Castaing function to model the probability density functions of the fluctuating magnetic field and calculate the magnetic structure functions (SFs) Sp of the order…
Deconvolution of Images from BLAST 2005: Insight into the K3-50 and IC 5146 Star-forming Regions
France, Kevin; Devlin, Mark J.; Halpern, Mark +26 more
We present an implementation of the iterative flux-conserving Lucy-Richardson (L-R) deconvolution method of image restoration for maps produced by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Compared to the direct Fourier transform method of deconvolution, the L-R operation restores images with better-controlled background no…
Oxidizing Proto-atmosphere on Titan: Constraint from N2 Formation by Impact Shock
Mousis, Olivier; Sekine, Yasuhito; Matsui, Takafumi +1 more
Titan is the only satellite that possesses a thick atmosphere, composed mainly of N2 and CH4. However, its origin and evolution remain largely unknown. Knowledge of the acquirement of a N2 atmosphere on Titan would provide insights into nitrogen evolution in planetary atmospheres as well as the formation of satelli…
A Search for Young Stars in the S0 Galaxies of a Super-group at z = 0.37
Tran, Kim-Vy H.; Moustakas, John; Gonzalez, Anthony H. +3 more
We analyze Galaxy Evolution Explorer UV data for a system of four gravitationally bound groups at z = 0.37, SG1120, which is destined to merge into a Coma-mass cluster by z = 0, to study how galaxy properties may change during cluster assembly. Of the 38 visually classified S0 galaxies, with masses ranging from log (M *)[M sun
Redshifts, Widths, and Radiances of Spectral Lines Emitted by the Solar Transition Region
Doschek, G. A.; Dammasch, I. E.; Feldman, U.
A long-standing problem in understanding the physics of the transition region has been the ubiquitous redshifts of transition region ultraviolet spectral lines relative to chromospheric emission lines, a result known since the Skylab era. Extended spectral scans performed for various regions of the solar disk by the Solar Ultraviolet Measurements …
The mm-colors of a Young Binary Disk System in the Orion Nebula Cluster
Testi, L.; Williams, J. P.; Ricci, L. +2 more
We present new Expanded Very Large Array (EVLA) continuum observations at 7 mm of the 253-1536 binary disk system in the Orion Nebula Cluster. The measured fluxes were combined with data in the submillimeter to derive the millimeter spectral index of each individual disk component. We show how these observations can be used to test the models of d…