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Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Fri Mar 13, 2009 4:58 am
by neufer
http://apod.nasa.gov/apod/ap090313.html
http://en.wikipedia.org/wiki/Hickson_Compact_Group wrote:
A Hickson Compact Group (abberviation: HCG) is a collection of galaxies designated as published by Paul Hickson in 1982.
According to Hickson: “Most compact groups contain a high fraction of galaxies having morphological or kinematical peculiarities, nuclear radio and infrared emission, and starburst or active galactic nuclei (AGN) activity. They contain large quantities of diffuse gas and are dynamically dominated by dark matter. They most likely form as subsystems within looser associations and evolve by gravitational processes. Strong galaxy interactions result and merging is expected to lead to the ultimate demise of the group. Compact groups are surprisingly numerous, and may play a significant role in galaxy evolution.”>>
Sorta sounds like The Asterisk* 8) :
1) morphological or kinematical peculiarities,
2) large quantities of diffuse gas,
3) dynamically dominated by dark matter,
4) form as subsystems within looser associations,
5) strong interactions, and
6) merging is expected to lead to the ultimate demise of the group.
Hickson group and...
Posted: Fri Mar 13, 2009 3:28 pm
by Phil R
I noticed a distant galaxy on the lower left of todays (03/13/09)apod pic. Has it been identified and/ or measured for distance?
Re: Hickson group and...
Posted: Fri Mar 13, 2009 5:29 pm
by JAlanScott
This photo is very interesting. I can see several hundred distant galaxies that are very faint. I do not know how to identify any of them, but in the upper left hand corner on the high res photo there appears to be a very tight cluster of galaxies positioned just above what appears to be a binary star in our own Milky Way.
Re: Hickson group and...
Posted: Fri Mar 13, 2009 5:30 pm
by aristarchusinexile
Watch out for those oncoming headlights!
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Fri Mar 13, 2009 5:36 pm
by aristarchusinexile
"I'm leaving on a jet plain..."
Well, okay, there's no jet in the photo, and I don't know why that thought came to me, except hoping Harry might look in.
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Fri Mar 13, 2009 10:18 pm
by bhrobards
How does one know that the structure between the elipticals is a spiral?
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Fri Mar 13, 2009 10:51 pm
by bystander
bhrobards wrote:How does one know that the structure between the elipticals is a spiral?
elipticals
usually don't have dust lanes, spirals
almost always do.
Trio of Galaxies Mix It Up (Hubble 2009 March 03)
Posted: Fri Mar 13, 2009 11:06 pm
by bystander
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Sat Mar 14, 2009 1:19 am
by BMAONE23
This
zoomable image really shows the strange blue masses above the local binary system to be IMO a nonstructired galaxy in early development. Gived Deeper imaging of this area, I would suspect that it would reveal it to be the blue star forming regions of a faint spiral galaxy.
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Sat Mar 14, 2009 6:53 am
by bystander
APOD wrote:Three galaxies are revealed to be strongly interacting: a dusty spiral galaxy stretched and distorted between a pair of large elliptical galaxies. The close encounter will trigger furious star formation. On a cosmic timescale, the gravitational tug of war will eventually result in the merger of the trio into a large single galaxy.
Maybe when they merge they will look like
Dusty Elliptical Galaxy Centaurus A: NGC 5128.
http://asterisk.apod.com/vie ... 11&t=15277
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Sat Mar 14, 2009 9:00 pm
by bongman
Kinda off topic here but that picture of Centaurus A, is that a blue jet exiting it (from center to the upper left of the picture) or something either compleatly unrelated to this galaxy or possibly not even there other then in this picture
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Sat Mar 14, 2009 11:36 pm
by bystander
bongman wrote:Kinda off topic here but that picture of Centaurus A, is that a blue jet exiting it (from center to the upper left of the picture) or something either compleatly unrelated to this galaxy or possibly not even there other then in this picture
Black hole outflows from Centaurus A detected
Jets and lobes emanating a from central black hole have been imaged at sub-millimeter wavelengths for the first time.
Provided by ESO, Garching, Germany
Astronomy.com - 2009 Jan 28
See also:
http://www.spitzer.caltech.edu/Media/re ... ease.shtml
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Sun Mar 15, 2009 1:04 am
by neufer
bystander wrote:Black hole outflows from Centaurus A detected
Jets and lobes emanating a from central black hole have been imaged at sub-millimeter wavelengths for the first time.
Provided by ESO, Garching, Germany
Astronomy.com - 2009 Jan 28
Stunning picture!:
(Should be an APOD like
http://antwrp.gsfc.nasa.gov/apod/ap080110.html )
http://www.spitzer.caltech.edu/Media/releases/ssc2004-09/release.shtml wrote:
Located 11 million light-years away, Centaurus A is a type of galaxy known as "elliptical." It is one of the brightest sources of radio waves in the sky, which suggests the presence of a supermassive black hole at its center. About 200 million years ago, this galaxy is believed to have consumed a smaller spiral galaxy -- the contents of which appear to be churning inside Centaurus A's core, triggering new generations of star birth. The model predicts that the leftover galaxy will ultimately flatten into a plane before being entirely devoured by Centaurus A. Warped discs like this are the "smoking guns" of galactic cannibalism, providing proof that one galaxy once made a meal of another. Such galactic feeding has long thought to be a mechanism by which giant elliptical galaxies form and grow, and likely provides the fuel that drives the strong radio activity surrounding Centaurus A's central black hole.
Galactic "cannibalism" seems a little strong!
(After all, they
aren't really the same "species" of galaxy.)
How about galaxiaphagy?
(
Do the strong jets imply that Centaurus A is galactose intolerant?)
<<Cannibalism (from Spanish caníbal) is the act or practice of humans eating other humans. The ritualistic eating of human flesh is also known as anthropophagy, from Greek: ἄνθρωπος, anthropos, "human being"; and φαγειν, phagein, "to eat". While taken as a synonym for human cannibalism, this term also applies when a non-human life-form consumes human flesh. In zoology, the term "cannibalism" is extended to refer to any species consuming members of its own kind (see cannibalism (zoology)).>> - from Wikipedia
Re: Hickson Compact Group 90 (APOD 2009 March 13)
Posted: Sun Mar 15, 2009 6:17 am
by bystander
neufer wrote:Galactic "cannibalism" seems a little strong!
(After all, they aren't really the same "species" of galaxy.)
How about galaxiaphagy?
Galactic genecide or galacticide?
