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A Chandra X-Ray Study of Cygnus A. II. The Nucleus
Terashima, Yuichi; Wilson, Andrew S.; Young, Andrew J. +2 more
We report Chandra Advanced CCD Imaging Spectrometer and quasi-simultaneous Rossi X-Ray Timing Explorer (RXTE) observations of the nearby, powerful radio galaxy Cygnus A, with the present paper focusing on the properties of the active nucleus. In the Chandra observation, the hard (>a few keV) X-ray emission is spatially unresolved with a size &l…
A search for solar g modes in the GOLF data
Baudin, F.; García, R. A.; Provost, J. +14 more
With over 5 years of GOLF data having some 90% continuity, a new attempt has been made to search for possible solar g modes. Statistical methods are used, based on the minimum of assumptions regarding the solar physics; namely that mode line-widths are small compared with the inverse of the observing time, and that modes are sought in the frequenc…
Two-dimensional electron density in the solar corona from inversion of white light images - Application to SOHO/LASCO-C2 observations
Lamy, P.; Quémerais, E.
We present here the inversion method which has been developed to derive the electron density in the Solar Corona from LASCO-C2 white light images. We discuss how our inversion scheme can be applied either to images of polarized brightness of the corona or images of total brightness after removal of the dust and stray light components. The outputs …
Hubble Space Telescope/NICMOS Imaging Survey of the Ophiuchus (Lynds 1688) Cluster
Di Francesco, James; Myers, Philip C.; Allen, Lori E. +3 more
We present a catalog of near-infrared photometry of young stars associated with the Ophiuchus molecular cloud based on observations made with the Hubble Space Telescope NICMOS3 camera at 1.1 and 1.6 µm. Our survey covers 0.02 deg2 centered on the dense molecular cores in Lynds 1688. We detect 165 sources at 1.6 µm and 65 sou…
Chandra Discovery of Luminous Supersoft X-Ray Sources in M81
Wu, Kinwah; Tennant, Allyn F.; Swartz, Douglas A. +2 more
A Chandra ACIS-S imaging observation of the nearby galaxy M81 (NGC 3031) reveals nine luminous soft X-ray sources. The local environments, X-ray spectral properties, and X-ray light curves of the sources are presented and discussed in the context of prevailing physical models for supersoft sources. It is shown that the sample falls within expectat…
Spectroscopic Observation of Coronal Waves
Ichimoto, K.; Raju, K. P.; Sakurai, T. +1 more
A time sequence over 80 min of coronal green-line spectra was obtained with a corona- graph at the Norikura Solar Observatory. Doppler velocities, line intensities, and line widths were derived through fitting a single Gaussian to the observed line profiles. Coronal waves have been clearly detected in the Doppler velocity data. The Fourier analysi…
The XMM-Newton serendipitous survey . II. First results from the AXIS high galactic latitude medium sensitivity survey
Pérez-Fournon, I.; Motch, C.; Page, M. J. +25 more
We present the first results on the identifications of a medium sensitivity survey (X-ray flux limit 2x 10-14 erg cm-2 s-1 in the 0.5-4.5 keV band) at high galactic latitude ({\mid}b{\mid}>20deg) carried out with the XMM-Newton X-ray observatory within the AXIS observing programme. This study is being…
Circumnuclear regions in barred spiral galaxies - II. Relations to host galaxies
Knapen, J. H.; Pérez-Ramírez, D.; Laine, S.
We present optical broad- and narrow-band imaging of a sample of a dozen barred galaxies. These images are analysed in conjunction with our previously published near-infrared imaging of their central regions and with literature values for, e.g. bar strengths and the total star formation activity of the galaxies. We present B, I and Hα images, and …
The Spectral Components of SS 433
Wang, Z.; Gies, D. R.; McSwain, M. V. +3 more
We present results from new optical and UV spectroscopy of the unusual binary system SS 433, and we discuss the relationship of the particular spectral components that we observe to the properties of the binary. These spectral components include1. The continuum spectrum, which we associate with flux from the super-Eddington accretion disk and the …
Hubble Space Telescope Spectra of GW Librae: A Hot Pulsating White Dwarf in a Cataclysmic Variable
Szkody, Paula; Howell, Steve B.; Sion, Edward M. +1 more
We have obtained Hubble Space Telescope UV spectra of the white dwarf in GW Lib, the only known nonradially pulsating white dwarf in a cataclysmic variable and the first known DAZQ variable. The UV light curve reveals large-amplitude (10%) pulsations in the UV with the same periods (646, 376, and 237 s) as those seen at optical wavelengths, but th…