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We present XMM-Newton Reflection Grating Spectrometer observations of X-ray clusters and groups of galaxies. We demonstrate the failure of the standard cooling-flow model to describe the soft X-ray spectrum of clusters of galaxies. We also emphasize several new developments in the study of the soft X-ray spectrum of cooling flows. Although there is some uncertainty in the expected mass deposition rate for any individual cluster, we show that high resolution RGS spectra robustly demonstrate that the expected line emission from the isobaric cooling-flow model is absent below 1/3 of the background temperature rather than below a fixed temperature in all clusters. Furthermore, we demonstrate that the best-resolved cluster spectra are inconsistent with the predicted shape of the differential luminosity distribution and the measured distribution is tilted to higher temperatures. These observations create several fine-tuning challenges for current theoretical explanations for the soft X-ray cooling-flow problem. Comparisons between these observations and other X-ray measurements are discussed.
High-energy astrophysics is a relatively young scientific field, made possible by space-borne telescopes. During the half-century history of x-ray astronomy, the sensitivity of focusing x-ray telescopes-through finer angular resolution and increased
We examine high signal to noise XMM-Newton European Photon Imaging Camera (EPIC) and Reflection Grating Spectrometer (RGS) observations to determine the physical characteristics of the gas in the cool core and outskirts of the nearby rich cluster A31
Past X-ray observations by ASCA suggest that warm absorbers (O VII and O VIII edges) are apparently rare in high luminosity AGNs (quasars) while they are more common in low luminosity AGNs (Seyferts). However, this could be a selection effect if high
High-resolution spectroscopy of the core of the Perseus Cluster of galaxies, using the $Hitomi$ satellite above 2 keV and the $XMM$-$Newton$ Reflection Grating Spectrometer at lower energies, provides reliable constraints on the abundances of O, Ne,
Context : The peculiar hot star Theta Car in the open cluster IC2602 is a blue straggler as well as a single-line binary of short period (2.2d). Aims : Its high-energy properties are not well known, though X-rays can provide useful constraints on the