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Structure Properties of Supergranulation and Granulation
Kosovichev, A. G.; Pietropaolo, E.; Duvall, T. L., Jr. +3 more
We investigate spatial dislocation ordering of the solar structures associated with supergranulation and granulation scales. The supergranular and granular structures are automatically segmented from time-distance divergence maps and from broad-band images, respectively. The spatial dislocation ordering analysis is accomplished by applying the sta…
Origin of diffuse C II 158 micron and Si II 35 micron emission in the Carina nebula
Onaka, T.; Shibai, H.; Mizutani, M.
We present the results of mapping observations with ISO of [O I] 63 µm, 145 µm, [N II] 122 µm, [C II] 158 µm, [Si II] 35 µm, and H_2 9.66 µm line emissions for the Carina nebula, an active star-forming region in the Galactic plane. The observations were made for the central 40 arcmin × 20 arcmin area of the nebu…
WZ Sagittae: Hubble Space Telescope Spectroscopy of the Cooling of the White Dwarf after the 2001 Outburst
Szkody, Paula; Sion, Edward M.; Gänsicke, Boris T. +1 more
Following an outburst in 2001 July, the UV flux of WZ Sge has declined slowly toward preoutburst levels. Here we describe new 1150-1710 Å Hubble Space Telescope STIS spectra of WZ Sge obtained between 2002 April and 2003 March to follow the decline. A combined analysis of these and spectra obtained in the fall of 2001 show that if logg=8.5, then t…
An Unusual Discontinuity in the X-Ray Surface Brightness Profile of NGC 507: Evidence of an Abundance Gradient?
Churazov, E.; Vikhlinin, A.; Markevitch, M. +5 more
We present results from a 45 ks Chandra ACIS-I observation of the nearby (z=0.01646) NGC 507 group. The X-ray surface brightness profile of the outer region of the group is well described by an isothermal β-profile consistent with earlier ROSAT observations. We find a sharp edge or discontinuity in the radial surface brightness profile 55 kpc east…
Probing Warm-Hot Intergalactic Medium Associated with the Virgo Cluster Using an Oxygen Absorption Line
Kelley, Richard L.; Kilbourne, Caroline A.; Ohashi, Takaya +8 more
To detect a warm-hot intergalactic medium (WHIM) associated with the large-scale structure of the universe, we observed a quasar behind the Virgo cluster with XMM-Newton. With 54ks exposure, we marginally detected an O VIII Kα absorption line at 650.9+0.8-1.9eV in the RGS spectra, with a statistical confidence of 96.4%. The o…
XMM-Newton Observations of NGC 507: Supersolar Metal Abundances in the Hot Interstellar Medium
Fabbiano, Giuseppina; Kim, Dong-Woo
We present the results of the X-ray XMM-Newton observations of NGC 507, a dominant elliptical galaxy in a small group of galaxies, and report supersolar metal abundances of both Fe and α-elements in the hot interstellar medium (ISM) of this galaxy. These results are robust in that we considered all possible systematic effects in our analysis. We f…
The Fundamental Plane Evolution of Active Galactic Nucleus Host Galaxies
van der Marel, Roeland P.; Urry, C. Megan; Lira, Paulina +2 more
We measured the stellar velocity dispersions of 15 active galactic nucleus (AGN) host galaxies at redshifts as high as ~0.34. Combining these with published velocity dispersion measurements from the literature, we study the fundamental plane of AGN host galaxies and its evolution. BL Lac object hosts and radio galaxies seem to lie on the same fund…
Tracing the ``Acoustic'' Solar Cycle: A Direct Comparison of BiSON and GOLF Low-l p-Mode Variations
Jiménez-Reyes, S. J.; García, R. A.; Chaplin, W. J. +1 more
We present a detailed, comparative study of low angular degree solar p-mode variations extracted by analyses of two sets of observational data. These were collected by the ground-based Birmingham Solar-Oscillations Network (BiSON) and the Global Oscillations at Low Frequency (GOLF) instrument on board the ESA/NASA SOHO satellite. The ~5.5 yr perio…
Confronting the Superbubble Model with X-Ray Observations of 30 Doradus C
Wang, Q. Daniel; Smith, David A.
We present an analysis of XMM-Newton observations of the superbubble 30 Dor C and compare the results with the predictions from the standard wind-blown bubble model. We find that the observed X-ray spectra cannot be fitted satisfactorily with the model alone and that there is evidence for nonthermal X-ray emission, which is particularly important …
Compressive fluctuations in high-latitude solar wind
Bavassano, B.; Pietropaolo, E.; Bruno, R.
. Solar wind compressive fluctuations at MHD scales have been extensively studied in the past using data from spacecraft on the ecliptic plane. In the present study, based on plasma and magnetic field measurements by Ulysses, a statistical analysis of the compressive fluctuations observed in the high-latitude solar wind is performed. Data are from…