Lockman Hole

The Lockman Hole (literally " Lockman Hole" ) is an area of ​​sky in the constellation Ursa Major. Since there are virtually no HI- regions within our own Galaxy in this direction of observation, especially little perturbed observations objects are also possible. Accordingly, it is one of the most accurately screened regions of the sky. From observations of such well-defined regions of the sky - the Lockman Hole, but for example, the Hubble Deep Field - in as many different regions of the spectrum to draw conclusions on the relative and absolute frequencies of the various types of astronomical objects can be drawn on galactic distance scales.

Radio and infrared observations

In the radio range, the Lockman Hole contains around 150 strong sources. Some of these are also sources of strong X-ray radiation, and most of both the radio as detectable in X-rays objects are visible also in light detectable. The majority of them (around 60 percent ) is obviously quasars, the rest mainly to normal galaxies. Infrared observations with the ISO satellite telescope point to the existence of many galaxies in a phase of active star formation.

X-ray observations

In the X-ray range, the Lockman Hole already in the 1990s, the target area was a survey with the help of the satellite ROSAT telescope. Were detected nearly 1200 distinct sources. In subsequent X-ray observations with the XMM-Newton space telescope, these and other objects have been investigated in detail; for example, originated data series that show how to change the X-ray luminosities of different Active Galactic cores on time scales of months to years.

The analysis of observations in the Lockman Hole with the Chandra X-ray satellite gave insight into the different types of supermassive black holes, the energy source of active galaxies, and sets an association between the incidence of material into the central black hole of a galaxy and phases of star formation near.