Globular clusters at the core of NGC 1275: NASA/ESA Hubble Space Telescope has provided intriguing new clues to cataclysmic events in the history of the peculiar galaxy NGC 1275, located approximately 200 million light-years from Earth.

Name: IRAS 03164+4119, NGC 1275, Perseus A
Type: Unspecified : Galaxy
Category: Galaxies
Constellation: Perseus
Release date: 16 January 1992, 06:00
Credit: J. Holtzman/NASA/ESA

Quasar 1208+101 (gravitational lens candidate): An image of the gravitational lens candidate taken with NASA/ESA Hubble Space Telescope's Wide Field and Planetary Camera (WFPC) in PC mode, on 23 December 1991. The HST picture shows that the quasar actually consists of two images. HST observations to be made this winter will show whether this is a gravitational lens or a chance superposition of a star in our own galaxy and a quasar. The bar in the lower left represents one arc second (the diameter of a penny seen at about two miles or 3.2 kilometres) which is the typical resolution of ground-based telescopes. This image is being presented on Monday, January 13th at the 179th meeting of the American Astronomical Society in Atlanta, Georgia.

Name: QSO B1208+101
Type: Early Universe : Galaxy : Activity : AGN : Quasar
Category: Quasars and Black Holes
Distance: z=3.82 (redshift)
Release date: 13 January 1992, 06:00
Credit: John Bachall (IAS Princeton), Dan Maoz (IAS, Princeton), Donald Schneider (IAS, Princeton) Brian Yanny (IAS, Princeton), Rodger Doxsey (STScI) Neta Bahcall (Princeton), Qfer Lahav (Cambridge, England).

NASA/ESA Hubble Space Telescope colour images of gravitational lenses: NASA/ESA Hubble Space Telescope (HST) colour views of the distant quasar 1208+101 indicate that its image has been split in two by a gravitational lensing. The quasar was first observed with HST's Wide Field/Planetary Camera in July 1991 as part of the Snapshot Survey for gravitational lenses. The Snapshot Survey consists of short (about four minute) exposures of several hundred very bright, very distant quasars with the Wide Field/Planetary Camera. Current theories of gravitational lensing suggest that several of these quasars should be seen as multiple images with separations smaller than can be seen in ground-based observations. Gravitational lensing is a phenomenon by which the pull of a massive object, such as a galaxy, can bend light from another, more distant, object as the light passes near or through it, focusing the light in multiple identical images. The high spatial resolution capability of HST allows searches for multiple images at separations of only 0.2 arc seconds; this is about five times smaller than can be done with ground-based instrumentation.

Name: QSO B1208+101
Type: Early Universe : Galaxy : Activity : AGN : Quasar
Category: Quasars and Black Holes
Release date: 13 January 1992, 06:00
Credit: Professor John Bahcall, Dr. Donald Schneider, Dr. Dan Mayoz, all of the Institute for Advanced Study

Intergalactic absorbtion clouds: [Top Diagram]The transparent block schematically represents a column of space between a distant quasar and a telescope on earth. As the quasar's light travels across space, invisible, intervening clouds of hydrogen gas absorb certain frequencies of the light. This creates complex "thickets" of absorption features, schematically shown in the spectrum below the box. Ground-based observations have shown that the number of these clouds rapidly rises as one looks back in time. [Bottom Diagram]Hubble Space Telescope dramatically changed this picture in 1991 when independent observations made with the HST's Faint Object Spectrograph (OS) and Goddard High Resolution Spectrograph (GHRS) detected more than a dozen hydrogen clouds within less than a billion light-years of our galaxy. Until the launch of HST, it was impossible detect these clouds because the recession velocity of the nearby clouds is so low that the hydrogen absorption features occur in the far ultraviolet part of the spectrum, which is inaccessible with ground-based telescopes.

Name: Intergalactic Absorption
Type: Unspecified : Nebula : Type : Interstellar Medium
Category: Nebulae
Release date: 13 January 1992, 06:00
Credit: STScI Astronomy Visualization Laboratory

NASA/ESA Hubble Space Telescope yields clear view of optical jet in galaxy M87: A NASA/ESA Hubble Space Telescope href="http://www.spacetelescope.org/about/index.html">HST) view of a 4,000 light-year long jet of plasma emanating from the bright nucleus of the giant elliptical galaxy M87. This ultraviolet light image was made with the European Space Agency's Faint Object Camera (FOC), one of two imaging systems aboard HST. This photo is being presented on Thursday, January 16th at the 179th meeting of the American Astronomical Society meeting in Atlanta, Georgia. M87 is a giant elliptical galaxy with an estimated mass of 300 billion suns. Located 52 million light-years away at the heart of the neighboring Virgo cluster of galaxies, M87 is the nearest example of an active galactic nucleus with a bright optical jet. The jet appears as a string of knots within a widening cone extending out from the core of M87. The FOC image reveals unprecedented detail in these knots, resolving some features as small as ten light-years across. According to one theory, the jet is most likely powered by a 3 billion solar mass black hole at the nucleus of M87. Magnetic fields generated within a spinning accretion disk surrounding the black hole, spiral around the edge of the jet. The fields confine the jet to a long narrow tube of hot plasma and charged particles. High speed electrons and protons which are accelerated near the black hole race along the tube at nearly the speed of light. When electrons are caught up in the magnetic field they radiate in a process called synchrotron radiation. The Faint Object Camera image clearly resolves these localized electron acceleration, which seem to trace out the spiral pattern of the otherwise invisible magnetic field lines. A large bright knot located midway along the jet shows where the blue jet disrupts violently and becomes more chaotic. Farther out from the core the jet bends and dissipates as it rams into a wall of gas, invisible but present throughout the galaxy which the jet has plowed in front of itself. HST is ideally suited for studying extragalactic jets. The Telescope's UV sensitivity allows it to clearly separate a jet from the stellar background light of its host galaxy. What's more, the FOC's high angular resolution is comparable to sub arc second resolution achieved by large radio telescope arrays.

Name: Messier 87, NGC 4486, Virgo Galaxy
Type: Local Universe : Galaxy : Type : EllipticalLocal Universe : Galaxy : Activity : AGN
Category: Quasars and Black Holes
Constellation: Virgo
Distance: 55 million light years
Release date: 16 January 1992, 06:00
Credit: F. Duccio Macchetto/NASA/ESA