Frontiers of Space And Ground-Based Astronomy

The Astrophysics of the 21st Century

  • W. Wamsteker
  • M. S. Longair
  • Y. Kondo

Part of the Astrophysics and Space Science Library book series (ASSL, volume 187)

Table of contents

  1. Front Matter
    Pages i-xxiii
  2. Achievements of the Present Generation of Space Observatories

    1. Front Matter
      Pages 1-3
    2. D. A. Kniffen, E. Chipman, N. Gehrels
      Pages 5-16
    3. K. Bennett, COMPTEL Collaboration
      Pages 17-22
    4. J. Ballet, P. Laurent, F. Lebrun, J. Paul, J. P. Roques, P. Mandrou et al.
      Pages 23-33
    5. E. Churazov, M. Gilfanov, R. Sunyaev, S. Grebenev, M. Markevich, M. Pavlinsky et al.
      Pages 35-46
    6. J. TrÜmper
      Pages 47-51
    7. Willem Wamsteker
      Pages 77-86
    8. H. S. Stockman
      Pages 87-94
    9. M. A. C. Perryman, The ESA Hipparcos Science Team
      Pages 95-104
  3. Achievements of the Present Generation of Ground-Based Telescopes

    1. Front Matter
      Pages 121-121
    2. L. Woltjer
      Pages 123-127
    3. E. E. Becklin
      Pages 129-132

About this book

Introduction

ROSAT Observations G. HASINGER Max-Planck-Institut flir extraterrestrische Physik, D-85740 Garching, Germany Abstract. This review describes the most recent advances in the study of the extragalactic soft X-ray background and what we can learn about its constituents. The deepest pointed observations with the ROSAT PSPC are discussed. The logN-logS relation is presented, which reaches to the faintest X-ray fluxes and to the highest AGN surface densities ever achieved. The N(>S) relation shows a 2 density in excess of 400 deg- at the faintest fluxes and a flattening below the Einstein Deep Survey limit. About 60% of the extragalactic background has been resolved in the deepest field. Detailed source spectra and first optical and radio identifications will be discussed. The results are put into perspective of the higher energy X -ray background. Key words: X-rays, background radiations, active galactic nuclei. 1. Introduction The extragalactic X-ray background (XRB), discovered about 30 years ago, has been studied extensively with many X-ray experiments, in particular with the satel­ lites HEAO I and II (see ego Boldt 1987) and with ROSAT (e. g. Hasinger et aI. , 1993). Figure 1 shows a compilation of some of the most recent spectral measure­ ments for the X-ray background. Over the energy range from 3 to about 100 keY its spectrum can be well approximated by an optically thin thermal bremsstrahlung model with kT ~ 40 keY, while at lower X-ray energies a steepening into a new component has been observed observed (e. g.

Keywords

Cosmology Gravity Observatories Universe astronomy astrophysics

Editors and affiliations

  • W. Wamsteker
    • 1
  • M. S. Longair
    • 2
  • Y. Kondo
    • 3
  1. 1.ESA IUE Observatory VILSPAMadridSpain
  2. 2.Cavendish LaboratoryUniversity of CambridgeCambridgeUK
  3. 3.NASA/GSFCGreenbeltUSA

Bibliographic information

  • DOI https://doi.org/10.1007/978-94-011-0794-5
  • Copyright Information Kluwer Academic Publishers 1994
  • Publisher Name Springer, Dordrecht
  • eBook Packages Springer Book Archive
  • Print ISBN 978-94-010-4341-0
  • Online ISBN 978-94-011-0794-5
  • Series Print ISSN 0067-0057
  • About this book
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