The XMM Cluster Survey: Present status and latest results

The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM‐ Newton Science Archive. Our recent first data release (XCS‐DR1) contains 503 optically confirmed groups and clusters, among which 256 new to the literature and 357 whose X‐ray emission was detected for the first time. We discuss their properties and provide an update on the work being done. As examples of the applications of XCS‐DR1, we mention the 17 fossil groups/clusters identified with the help of the Sloan Digital Sky Survey. Their brightest galaxies have stellar populations and star‐formation histories which are similar to normal brightest cluster galaxies, but their stellar masses are significantly larger and correspond to a much bigger fraction of the total group/cluster optical luminosity. We also highlight the 15 clusters expected tobe also detected by the Planck satellite, and characterize the expected overlap between the final XCS and Planck cluster catalogues. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98104/1/462_ftp.pd

Black Hole Results from XMM-Newton

XMM-Newton is one of the most successful science missions of the  European Space Agency. Since 2003 every year about 300 articles are published in refereed journals making directly use of XMM-Newton data. All XMM-Newton calls for observing proposals are highly oversubscribed by factors of six and more. In the following some scientic highlights of XMM-Newton observations of black holes are summarized

Understanding the Exotic Distributions of Invasive Species

Invasive species are organisms whose introduction and spread in exotic ranges result in a multitude of ecological impacts. Understanding the factors that constrain the exotic distributions of invasive species is of considerable interest. Biotic associations formed with taxa in the invaded community may be particularly important in shaping invader distributions. These associations emerge from interactions between the traits of the invasive species and some subset of the traits present in the invaded community. Focusing on how organism traits influence the outcomes of biotic interactions may inform predictions of invader distributions. This kind of trait-based approach may be most easily applied to systems where invaders specialize on particular hosts because such associations imply a close correspondence between the traits of the invader and hosts. This dissertation focuses on the South American cactus moth (Cactoblastis cactorum, Lepidoptera: Pyralidae), an invasive consumer in North America whose larvae infest prickly-pear cacti (Opuntia spp.). Chapter One is a brief introduction providing background and context to the presented research. In Chapter Two, I quantify Opuntia morphological and tissue macronutrient traits hypothesized to correlate with patterns of C. cactorum host use. Tissue macronutrient traits appear important in predicting C. cactorum infestation whereas a model containing Opuntia morphological traits had poor predictive ability. Chapter Three describes a method that uses host Opuntia identity and availability to estimate habitat suitability in order to predict the North American distribution of C. cactorum. I then simulate C. cactorum dispersal relative to scenarios of habitat suitability and Opuntia availability. Chapter Four alters the model in Chapter Three so that habitat suitability for C. cactorum is determined by the availability of trait-based groupings of Opuntia hosts. I then simulate C. cactorum dispersal via a different method from that described in Chapter Three. In Chapters Three and Four, I evaluate the degree of similarity among model predictions and the relative contribution of modeling constraints in generating variation in this similarity. Chapters Three and Four predictions were most affected by estimates of abiotic suitability and dispersal constraints, respectively. Chapter Five is a short summary of my results and a discussion of their more general applicability

Technology needs of advanced Earth observation spacecraft

Remote sensing missions were synthesized which could contribute significantly to the understanding of global environmental parameters. Instruments capable of sensing important land and sea parameters are combined with a large antenna designed to passively quantify surface emitted radiation at several wavelengths. A conceptual design for this large deployable antenna was developed. All subsystems required to make the antenna an autonomous spacecraft were conceptually designed. The entire package, including necessary orbit transfer propulsion, is folded to package within the Space Transportation System (STS) cargo bay. After separation, the antenna, its integral feed mast, radiometer receivers, power system, and other instruments are automatically deployed and transferred to the operational orbit. The design resulted in an antenna with a major antenna dimension of 120 meters, weighing 7650 kilograms, and operating at an altitude of 700 kilometers

Proving strong magnetic fields near to the central black hole in the quasar PG0043+039 via cyclotron lines

The optical luminous quasar PG0043+039 has not been detected before in deep X-ray observations indicating the most extreme optical-to-X-ray slope index ${\alpha}_{ox}$ of all quasars. This study aims to detect PG0043+039 in a deep X-ray exposure. Furthermore, we wanted to check out whether this object shows specific spectral properties in other frequency bands. We took deep X-ray (XMM-Newton), far-ultraviolet (HST), and optical (HET, SALT telescopes) spectra of PG0043+039 simultaneously in July 2013. We just detected PG0043+039 in our deep X-ray exposure. The steep ${\alpha}_{ox} = -2.37 {\pm} 0.05$ gradient is consistent with an unusual steep gradient $F_{\nu} {\sim} {\nu}^{\alpha}$ with ${\alpha} = -2.67 {\pm} 0.02$ seen in the UV/far-UV continuum. The optical/UV continuum flux has a clear maximum near 2500 {\AA}. The UV spectrum is very peculiar because it shows broad humps in addition to known emission lines. A modeling of these observed humps with cyclotron lines can explain their wavelength positions, their relative distances, and their relative intensities. We derive plasma temperatures of T ${\sim}$ 3keV and magnetic field strengths of B ${\sim}$ 2 ${\times} 10^8$ G for the line-emitting regions close to the black hole.Comment: 4 pages, 3 figures, Astronomy & Astrophysics in pres