This Hubble Space Telescope image (right) reveals the faint host galaxy that a bright quasar dwells within. The wealth of new detail in this picture helps solve a three-decade old mystery about the true nature of quasars, the most distant and energetic objects in the universe.
The HST image shows clearly that the quasar, called 1229+204, lies in the core of a galaxy that has a common shape consisting of two spiral arms of stars connected by a bar-like feature. The host galaxy is in a spectacular collision with a dwarf galaxy. The collision apparently fuels the quasar "engine" at the galaxy center - presumably a massive black hole - and also triggers many sites of new star-formation.
The image is one of a pair of relatively nearby quasars that were selected as early targets to test the resolution and dynamic range of HST's newly-installed Wide Field and Planetary Camera, which contains special optics to correct for a flaw in Hubble's primary mirror. The observations were made by Dr. John Hutchings of Dominion Astrophysical Observatory in Victoria, British Columbia. "The project was impossible from ground-based telescopes," says Dr. Hutchings, who has been researching quasars for many years. " The sharpness of the Hubble pictures is leading to major new discoveries almost anywhere you point it in the sky."
Quasars are the most distant objects in the universe, and so are among the earliest objects known to have formed in the young universe, more than 12 billion years ago. The most widely accepted notion is that quasars are in galaxies with active, supermassive black holes at their centers. However, because of their enormous distance, the `host' galaxies appear very small and faint, and are very hard to see against the much brighter quasar light at the center. Though a quasar might no be much larger than our solar system it releases as much energy as billions of stars.
Though a previous ground based observation using the Canada-France-Hawaii Telescope (at 0.5 arcsec resolution) first identified the barred spiral galaxy in 1229+204, Hubble shows clearly the galaxy's structure and reveals details of the collision.
Hubble reveals that an extended blue feature on one side of the galaxy is really a string of knots, which are probably massive young star clusters. The star clusters were most likely formed as a result of a collision between the host galaxy and a small gas-rich companion. HST also reveals shell-like structures along the bar that might be produced by gravitational tidal resonance forces between the spiral and its companion.
Credits
Dr. John Hutchings, Dominion Astrophysical Observatory, NASA| About The Object | |
|---|---|
| Object Name | 1229+204 |
| R.A. Position | 12h 32m 3.6s |
| Dec. Position | 20° 9' 29.21" |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
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| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
