2002/07/26 by R. D. Blandford, Roger Blandford
Physics and Astronomy · #Accretion (finance) #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Cosmology #Equipartition theorem #Galaxy #Gamma-ray bursts and supernovae #Luminosity #Magnetic field #Opacity #Physics #Space Science #Stars #astro-ph
paper · pdf · doi:10.1098/rsta.2002.1055
published as Phil.Trans.Roy.Soc.Lond. A360 (2002) 2091-2103 · 12 pages
openalex publication_date 2002/07/26 · arxiv created 2003/02/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Recent X-ray observations have had a major impact on topics ranging from proto-stars to cosmology. They have also drawn attention to important and general physical processes that currently limit our understanding of thermal and non-thermal X-ray sources. These include unmeasured atomic astrophysics data (wavelengths, oscillator strengths, etc.), basic hydromagnetic processes (e.g. shock structure, reconnection), plasma processes (such as electron-ion equipartition and heat conduction) and radiative transfer (in discs and accretion columns). Progress on these problems will probably come from integrative studies that draw upon observations, throughout the electromagnetic spectrum, of different classes of source. X-ray observations are also giving a new perspective on astronomical subjects, like the nature of galactic nuclei and the evolution of stellar populations. In addition, they are helping us to address central cosmological questions, including the measurement of the matter content of the Universe, understanding its overall luminosity density, describing its chemical evolution and locating the first luminous objects. X-ray astronomy has a healthy future with several international space missions under construction and in development.