Jochen Greiner

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Jochen Greiner (* 20th March 1959 in Berlin ) is a German astrophysicist who deals with gamma-ray astronomy and especially with GRBs tackles (GRB).

After graduating from university in 1977 and after completing military service, Greiner studied physics at the University of Leipzig in 1984, graduating in quantum field theory in 1984. He received his doctorate in 1988 at the Institute for Cosmos Research in Berlin-Adlershof, where he had been a researcher since 1984. Even then he was concerned with GRB in the optical spectral range and X-ray range. The topic of the dissertation was the spatial distribution of old neutron stars in the galaxy with application to GRB sources.

Greiner was at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching from 1990 to 1996 , where he analyzed data from Comptel from the Compton satellite and from ROSAT . From 1997 to 2001 he was at the Astrophysical Institute in Potsdam and then again at the MPE. Since 2004 he has headed the gamma ray group there. He also teaches at the Technical University of Munich , where he completed his habilitation in 1998 (on cosmic gamma X-ray sources with short-term variability).

He is a senior scientist on the Burst Monitor of the Fermi Gamma-ray Space Telescope .

He also developed the GROND (Gamma-Ray Burst Optical / Near-Infrared Detector) at the MPG / ESO 2.2 m telescope of the La Silla Observatory to observe the afterglow of gamma-ray flashes in the optical / infrared. In April 2009 the distance of the gamma-ray flash GRB 090423, which was first discovered by the Swift satellite, was determined in April 2009 (distance over 13 billion light years, redshift about 8). Grond is automatically paired with Swift . He has been active since mid-2007. From Earth it should be possible to observe redshifts up to about 13 (due to the age of the universe of 13.6 billion years, it is hoped to be able to detect gamma-ray bursts of up to about redshifts of 25 to 30 from the first generation of stars, for which new satellite telescopes are necessary).

He also deals with super-soft X-ray sources (possible supernova precursors) and transient X-ray sources such as microquasars , for example GRS 1915 + 105, a microquasar in our galaxy, consisting of a black hole with an accretion disk and jet that sucks off mass from a companion star. The black hole, which was first discovered in 1994 and is around 40,000 light-years away, is unusually massive (around 14 solar masses) and the heaviest star-like black hole in our galaxy to date.

Fonts

  • with Dieter Hartmann, Sylvio Klose Gamma-Ray Bursts: Intensive gamma radiation sources that light up briefly in the sky are a current research focus in relativistic astrophysics , Physikalische Blätter, Volume 57, 2001, pp. 47–52, online
  • with Hartmann, Klose Cosmic Gamma Ray Outbreaks , Part 1,2, Stars and Space, Issue 3 and 4/5, 2001

Web links

Individual evidence

  1. ↑ In cooperation with the Thuringian State Observatory in Tautenburg. The name is borrowed from the Lord of the Rings in addition to the abbreviation function
  2. ↑ Interview with Jochen Greiner about the observation of the most distant gamma-ray flash (MPG), April 30, 2009
  3. ↑ Greiner The heaviest stellar black hole in our Milky Way
  4. ^ Greiner, Mark McCaughrean, Jean-Gabriel Cuby An unusually massive stellar black hole in the Galaxy , Nature, Volume 414, 2001, 522
personal data
SURNAME Greiner, Jochen
BRIEF DESCRIPTION German astrophysicist
DATE OF BIRTH March 20, 1959
PLACE OF BIRTH Berlin