Search Publications
Constraining the very heavy elemental abundance peak in the chemically peculiar star χ Lupi, with new atomic data for Os II and Ir II
Leckrone, D. S.; Lundberg, H.; Wahlgren, G. M. +2 more
The determination of elemental abundances plays an important role in understanding the atmospheric processes that lead to anomalies in spectra of chemically peculiar stars. Ongoing study of the HgMn star χ Lupi has defined much of the elemental abundance distribution but progress is dependent upon the availability and accuracy of the atomic data. …
Mid-infrared selection of AGN
Siebenmorgen, R.; Schartel, N.; Haas, M. +6 more
Since a large fraction of active galactic nuclei (AGN) is missed in common UV-excess surveys and is even hard to find in radio, near-IR and X-ray surveys, we have used a new AGN selection technique which is expected to be not affected by extinction. Within the scientific verification of the ISOCAM Parallel Survey at 6.7 µm we have discovered…
A spectral and spatial analysis of η Carinae's diffuse X-ray emission using CHANDRA
Weis, K.; Bomans, D. J.; Davidson, K. +1 more
The luminous unstable star (star system) η Carinae is surrounded by an optically bright bipolar nebula, the Homunculus and a fainter but much larger nebula, the so-called outer ejecta. As images from the EINSTEIN and ROSAT satellites have shown, the outer ejecta is also visible in soft X-rays, while the central source is present in the harder X-ra…
XMM-Newton observations of the young open cluster Blanco 1. I. X-ray spectroscopy and photometry
Harnden, F. R., Jr.; Micela, G.; Sciortino, S. +2 more
We present an X-ray study of the high metallicity young open cluster Blanco 1 based on XMM-Newton data. X-ray spectroscopy of cluster members is presented for the first time as well as new X-ray distribution functions of late-type stars. We detected all known dF and dG stars in the EPIC field and 80% and 90% of dK and dM stars, respectively. The X…
An XMM-Newton study of the RGH 80 galaxy group
Böhringer, H.; Matsushita, K.; Xue, Y. -J.
We present an X-ray study of the galaxy group RGH 80, observed by XMM-Newton. The X-ray emission of the gas is detected out to ∼462 h-150 kpc, corresponding to ∼0.45 r200. The group is relatively gas rich and luminous with respect to its temperature of 1.01 ± 0.01 keV. Using the deprojected spectral analysis, we fi…
Very cold cores in the Taurus Molecular Ring as seen by ISO
Lemke, D.; Haas, M.; Onishi, T. +2 more
Three prominent cold objects of the
INTEGRAL observations of the PSR B1259-63/SS2883 system after the 2004 periastron passage
Mereghetti, S.; Rodriguez, J.; Walter, R. +3 more
The millisecond pulsar
The XMM-Newton view of the X-ray halo and jet of NGC 6251
Cheung, C. C.; Tavecchio, F.; Mushotzky, R. F. +3 more
We present an XMM-Newton observation of the radio jet and diffuse halo of the nearby radio galaxy NGC 6251. The EPIC spectrum of the galaxy's halo is best-fitted by a thermal model with temperature kT ∼ 1.6 keV and sub-solar abundances. Interestingly, an additional hard X-ray component is required to fit the EPIC spectra of the halo above 3 keV, a…
The evolution and simulation of the outburst from XZ Tauri - A possible EXor?
Ray, T. P.; Coffey, D.; Downes, T. P.
We report on multi-epoch HST/WFPC2 images of the XZ Tauri binary, and its outflow, covering the period from 1995 to 2001. Data from 1995 to 1998 have already been published in the literature. Additional images, from 1999, 2000 and 2001 are presented here. These reveal not only further dynamical and morphological evolution of the XZ Tauri outflow b…
X-ray sources and their optical counterparts in the globular cluster M 22
Rizzi, L.; Webb, N. A.; Barret, D. +3 more
Using XMM-Newton EPIC imaging data, we have detected 50 low-luminosity X-ray sources in the field of view of M 22, where 5±3 of these sources are likely to be related to the cluster. Using differential optical photometry, we have identified probable counterparts to those sources belonging to the cluster. Using X-ray spectroscopic and timing studie…