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IC Abell 1795:
A Cooling Flow In Galaxy Cluster Abell 1795
Like a spoon moving through hot
soup, the massive elliptical galaxy near the top of
this image has cut a swath across the dense, hot gas in
this crowded galaxy cluster known as Abell 1795.
This smoothed Chandra X-ray Observatory image of the
galaxy cluster A1795 shows a bright filament some
200,000 light years in length. The gas in this
structure is denser and cooler (30 million compared to
50 million degrees) than the surrounding gas. The
filament was most likely caused when an enormous
elliptical galaxy (white spot at the head of the
filament) moved through the cluster core. Hot gas
spread throughout the cluster is drawn by the
gravitational field of the giant galaxy into a cosmic
wake of cooling gas, which appears as the long
string-like feature in the middle of this image.
Most observed galaxies in the universe appear in
groups ranging from simple pairs and trios to complex
clusters of thousands. Scientists find these clusters
immersed in haloes of hot gas. Through time, this
"intracluster" gas loses energy through X-ray
radiation, cools, and flows toward the dense core of a
cluster where it may form stars. This phenomenon is
known as a "cooling flow."
The latest Chandra research on Abell 1795 was
conducted by a team led by Professor Andrew Fabian of
the Institute of Astronomy, Cambridge, England, using
the Advanced CCD Imaging Spectrometer (ACIS) instrument
aboard Chandra. Chandra observed Abell 1795 for 19,594
seconds on December 20, 1999, and then for 19,421
seconds on March 21, 2000.
| Fast Facts for Abell 1795: |
| Credit |
NASA/IoA/AC Fabian et al. |
| Scale |
Image is 75 arcsec on a side. |
| Category |
Groups & Clusters of Galaxies |
| Coordinates (J2000) |
RA 13h 48m 52.70s | Dec +26° 35' 27" |
| Constellation |
Boötes |
| Observation Dates |
December 20, 1999 and March 21, 2000
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| Observation Time |
27 hours |
| Obs. IDs |
493, 494
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| Color Code |
Intensity |
| Instrument |
ACIS |
| Release Date |
December 04, 2000 |
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