Search Publications
High resolution X-ray spectroscopy of zeta Puppis with the XMM-Newton reflection grating spectrometer
Mewe, R.; Güdel, M.; Leutenegger, M. A. +5 more
We present the first high resolution X-ray spectrum of the bright O4Ief supergiant star zeta Puppis, obtained with the Reflection Grating Spectrometer on-board XMM-Newton. The spectrum exhibits bright emission lines of hydrogen-like and helium-like ions of nitrogen, oxygen, neon, magnesium, and silicon, as well as neon-like ions of iron. The lines…
Central Structural Parameters of Early-Type Galaxies as Viewed with Nicmos on the Hubble Space Telescope
Ravindranath, Swara; Filippenko, Alexei V.; Ho, Luis C. +2 more
We present surface photometry for the central regions of a sample of 33 early-type (E, S0, and S0/a) galaxies observed at 1.6 µm (H band) using the Hubble Space Telescope. Dust absorption has less of an impact on the galaxy morphologies in the near-infrared than found in previous work based on observations at optical wavelengths. When presen…
The Formation of a Prominence in Active Region NOAA 8668. I. SOHO/MDI Observations of Magnetic Field Evolution
Qiu, Jiong; Wang, Haimin; Chae, Jongchul +3 more
We have studied the evolution of the photospheric magnetic field in active region NOAA 8668 for 3 days while the formation of a reverse S-shaped filament proceeded. From a set of full-disk line-of-sight magnetograms taken by the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO), we have found a large canceling m…
CHIANTI-An Atomic Database for Emission Lines. IV. Extension to X-Ray Wavelengths
Young, P. R.; Del Zanna, G.; Dere, K. P. +1 more
CHIANTI provides a database of atomic energy levels, wavelengths, radiative transition probabilities, and electron excitation data for a large number of ions of astrophysical interest. It also includes a suite of Interactive Data Language programs to calculate optically thin synthetic spectra and to perform spectral analysis and plasma diagnostics…
Mayall II=G1 in M31: Giant Globular Cluster or Core of a Dwarf Elliptical Galaxy?
Djorgovski, S. G.; Jablonka, P.; Sarajedini, A. +3 more
Mayall II=G1 is one of the brightest globular clusters belonging to M31, the Andromeda galaxy. Our observations with the Wide Field and Planetary Camera (WFPC2) on board the Hubble Space Telescope (HST) provide photometric data for the I versus V-I and V versus V-I color-magnitude diagrams. They reach stars with magnitudes fainter than V=27 mag, w…
A Multiwavelength Study of the Young Star Clusters and Interstellar Medium in the Antennae Galaxies
Whitmore, Bradley C.; Fall, S. Michael; Zhang, Qing
We report on a multiwavelength study of the relationship between young star clusters in the Antennae galaxies (NGC 4038/9) and their interstellar environment, with the goal of understanding the formation and feedback effects of star clusters in merging galaxies. This is possible for the first time because various new observations (from X-rays to r…
Near-Sun and near-Earth manifestations of solar eruptions
Kaiser, M. L.; Gopalswamy, N.; Bougeret, J. -L. +1 more
We compare the near-Sun and near-Earth manifestations of solar eruptions that occurred during November 1994 to June 1998. We compared white-light coronal mass ejections, metric type II radio bursts, and extreme ultraviolet wave transients (near the Sun) with interplanetary (IP) signatures such as decameter-hectometric type II bursts, kilometric ty…
Complex resonance absorption structure in the X-ray spectrum of IRAS 13349+2438
Kaastra, J. S.; Clavel, J.; Behar, E. +8 more
The luminous infrared-loud quasar
XMM-Newton observations of M 87 and its X-ray halo
Böhringer, H.; Dos Santos, S.; Guainazzi, M. +10 more
We report performance verification observations of the giant elliptical galaxy M 87 in the Virgo Cluster with the MOS, pn, and optical monitor instruments on board of XMM-Newton. With the energy sensitive imaging instruments MOS and pn we obtain the first spatially constrained X-ray spectra of the nucleus and the jet of the galaxy. The good photon…
First light measurements with the XMM-Newton reflection grating spectrometers: Evidence for an inverse first ionisation potential effect and anomalous Ne abundance in the Coronae of HR 1099
Kaastra, J. S.; Mewe, R.; Audard, M. +15 more
The RS CVn binary system HR 1099 was extensively observed by the XMM-Newton observatory in February 2000 as its first-light target. A total of 570 ks of exposure time was accumulated with the Reflection Grating Spectrometers (RGS). The integrated X-ray spectrum between 5-35 Å is of unprecedented quality and shows numerous features attributed to tr…