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Hot Interstellar Gas and Stellar Energy Feedback in the Antennae Galaxies
Guerrero, Martín A.; Chu, You-Hua; Gruendl, Robert A. +3 more
We have analyzed Chandra archival observations of the Antennae galaxies to study the distribution and physical properties of its hot interstellar gas. Eleven distinct diffuse X-ray emission regions are selected according to their underlying interstellar structures and star formation activity. The X-ray spectra of these regions are used to determin…
Coronal response of Bi-directional Jets
Doyle, J. G.; Madjarska, M. S.; Dammasch, I. E. +1 more
EUV bi-directional jets are a prominent class of phenomena characterizing the solar transition region. Using simultaneously obtained SUMER observations in the chromospheric Si ii 1251.16 Å and C i 1251.17 Å, transition region N v 1238.8 Å and coronal Mg x 625 Å lines we show an example of a bi-directional jet observed in the chromospheric and the …
Models for Solar Magnetic Loops. IV. On the Relation between Coronal and Footpoint Plasma in Active Region Loops
Landi, E.; Feldman, U.
In the present work we analyze several SUMER intensity maps of active region solar loops in order to compare the relative brightnesses of the footpoints and the coronal section of active region loops. We find that the former are barely distinguishable from the background emission of the active region, while the coronal emission of loops is confine…
Astrometric Control of the Inertiality of the Hipparcos Catalog
Bobylev, V. V.
Based on the most complete list of the results of an individual comparison of the proper motions for stars of various programs common to the Hipparcos catalog, each of which is an independent realization of the inertial reference frame with regard to stellar proper motions, we redetermined the vector omega of residual rotation of the ICRS system r…
Period-luminosity relation for M-type semiregular variables from Hipparcos parallaxes
Yeşilyaprak, C.; Aslan, Z.
We have studied the period-luminosity (P-L) relationships of oxygen-rich semiregular (SR) variables in several wavelength bands using Hipparcos parallaxes with an accuracy of better than 10 per cent. We have shown that there is a clear dependence on period of absolute magnitude in the U,B,V,R,IC,J,H,K,L,M,N, [12], [25], [60] and [100] b…
Discovery of high-amplitude X-ray variability in the Seyfert-LINER transition galaxy NGC7589
Watson, M. G.; Osborne, J. P.; Yuan, W. +3 more
We present the first result of a programme to search for large flux variations in the X-ray sources of the XMM Serendipitous Survey compared to previous ROSAT observations. An increase in X-ray flux by a factor >10 was discovered from the nucleus of the galaxy NGC7589 on a time-scale of less than 5yr. The 0.4-10keV XMM spectrum can be approxima…
XMM-Newton observations of the dwarf nova YZ Cnc in quiescence
Ramsay, G.; Hakala, P.; Wheatley, P. +2 more
We present results from the XMM-Newton observations of the dwarf nova YZ Cnc in a quiescent state. We have performed a detailed time series analysis of the resulting light curves. Unusually, we do not detect any orbital modulation in the UV, with only marginal evidence for X-ray modulation on this period. Although there are peaks in the X-ray peri…
Ionospheric plasma density structures associated with magnetopause motion: a case study using the Cluster spacecraft and the EISCAT Svalbard Radar
Pitout, F.; Lucek, E.; Escoubet, C.
Available from http://www.copernicus.org/site/EGU/annales/22/7/2369.htm?FrameEngine=false;
The nuclear radio-optical properties of intermediate-redshift FR II radio galaxies and quasars
Macchetto, F. D.; Capetti, A.; Chiaberge, M. +1 more
We extend the study of the nuclei of 3CR objects as seen with the HST to higher-redshift FR II radio sources (0.4<z<0.6). Our results reflect what has been found for FR II of lower redshift. The position of the nuclei in the plane formed by optical and radio luminosities is related to their optical spectral classification: the nuclei of both…
Mid- and Far-Infrared Infrared Space Observatory Limits on Dust Disks around Millisecond Pulsars
Lazio, T. Joseph W.; Fischer, J.
We report 60 and 90 µm observations of seven millisecond pulsars with the Infrared Space Observatory. The pulsar PSR B1257+12 is orbited by three planets, and other millisecond pulsars may be orbited by dust disks that represent planets that failed to form or their residue. We do not detect any infrared emission from the seven pulsars in our…