Arp 273 - November 15 2008

[Sputnick]

http://apod.nasa.gov/apod/ap081115.html

Such a beautiful photo -
If these Galaxies are enveloped in Dark Matter - the envelopes will be interacting .. possibly exchanging energies - are these exchanges being searched for?

[astrolabe]

Hello Sputnick,

What energies?

[astrolabe]

Hello All,

The larger galaxy appears to be tethering the object just outside it's edge at about 4:00. Any comments?

[apodman]

The larger galaxy appears to be tethering the object just outside it's edge at about 4:00.

Referring to the large photo, I see 3 bright spots. From left to right, I see the first as within the galaxy's arm, near where an interior wisp or spur of the galaxy meets the arm; I see the second as a star, unrelated to the galaxy; and, I see the third as a much more distant galaxy, also unrelated.

[astrolabe]

Hello apodman,

Oh................that darn flea must've found it's way back onto my monitor again. DANG!

[BMAONE23]

Presuming that the bright source @ 4:00 is a foreground star, are you refering to the arc just above that bright point?
If so, there is another in the diffraction spike of the red foreground star (near the smaller galaxy) and another in the very faint tidal trail at the 9:30 position about twice the distance from the center to the end of the apparent bright arm.

[astrolabe]

Hello BMAONE23,

Yes, but I was thinking that the arc was more the tail end of the arm extending perpendicularly (almost as hard to type as pronounce!) from Arp 273's center.

[Chris Peterson]

Presuming that the bright source @ 4:00 is a foreground star, are you refering to the arc just above that bright point?
If so, there is another in the diffraction spike of the red foreground star (near the smaller galaxy) and another in the very faint tidal trail at the 9:30 position about twice the distance from the center to the end of the apparent bright arm.

Every one of those faint, fuzzy, not quite star-like objects in the picture is a distant galaxy, unrelated to the foreground galaxies. I counted up to ten of them before I quit.

[DavidLeodis]

Presuming that the bright source @ 4:00 is a foreground star, are you refering to the arc just above that bright point?
If so, there is another in the diffraction spike of the red foreground star (near the smaller galaxy) and another in the very faint tidal trail at the 9:30 position about twice the distance from the center to the end of the apparent bright arm.

Every one of those faint, fuzzy, not quite star-like objects in the picture is a distant galaxy, unrelated to the foreground galaxies. I counted up to ten of them before I quit.

Yes there are lots of probable galaxies that are particularly noticeable in the large version that is brought up by clicking on the image that is brought up through the 'this colorful skyscape' link. Some of those galaxies have a fascinating apperance. It's quite awe inspiring that most of the 'stars' are likely to be galaxies. The Universe is a wondrous delight.

[neufer]

http://apod.nasa.gov/apod/ap081115.html
If these Galaxies are enveloped in Dark Matter - the envelopes will be interacting .. possibly exchanging energies - are these exchanges being searched for?

. "No matter how much you push the envelope, it's still stationery."

After due consideration I find Sputnick's question to be deeply thought provoking.

I would think that spherically symmetrical [density ~ A/(B + C * r^2)] envelopes of galactic dark matter would indeed be the first things to interact with the primary result being that the smaller galaxy would drain off more dark matter from the large galaxy (than it would lose to it). Among other things, this would probably cause the smaller galaxy to rotate faster (which should be observable).

Still, the two major dynamic feature IMO would be:

1) very strong tidal forces on the smaller galaxy and
2) the free streaming of stars that approach the gravitationally neutral Lagrange point L1.

[astrolabe]

Hello neufer,

http://apod.nasa.gov/apod/ap081115.html
If these Galaxies are enveloped in Dark Matter - the envelopes will be interacting .. possibly exchanging energies - are these exchanges being searched for?

. "No matter how much you push the envelope, it's still stationery."

After due consideration I find Sputnick's question to be deeply thought provoking.

I would think that spherically symmetrical [density ~ A/(B + C * r^2)] envelopes of galactic dark matter would indeed be the first things to interact with the primary result being that the smaller galaxy would drain off more dark matter from the large galaxy (than it would lose to it). Among other things, this would probably cause the smaller galaxy to rotate faster (which should be observable).

Still, the two major dynamic feature IMO would be:

1) very strong tidal forces on the smaller galaxy and
2) the free streaming of stars that approach the gravitationally neutral Lagrange point L1.

Okay, I guess, but I find the line of logic in Sputnick's post from start to finish somewhat disturbing. and sets up arguments the will end up in the Cafe again.

[apodman]

... the Café again

Not the briar patch!

[astrolabe]

Hello apodman,

Absolutely! And with TAR BABY no less.

[astrolabe]

Hello All,

My use of the term TAR BABY was in bad taste, unfair, and inappropriate, my apologies.

[BMAONE23]

Perhaps you should have said "STAR BABY"

[astrolabe]

Hello BMAONE23,

Yes, of coures. Why didn't I think of that. You people are quicker than most normal human beings.

[apodman]

You people are quicker than most normal human beings.

Yes, and with exactly 2000 members registered in this forum as of today, there are also more of us than there are "normal" human beings (to serve you better).

[astrolabe]

Hello apodman,

I wonder if ole' "2K" has posted yet.

[apodman]

I wonder if ole' "2K" has posted yet.

That would be reboots on the anticrepuscular thread ...
http://asterisk.apod.com/vie ... 689#p98689

[Sputnick]

Hello Sputnick,

What energies?

Theoretically (using that term loosely of course) the energies generated from the 'friction' or other interaction of Dark Matter as it encounters itself. I think measurements will reveal heat slightly higher than the Cosmic Background Radiation .. unless of course the standard measure for CBM is Dark Matter heated by those interactions .. standard measurements possibly having been made inside a 'river' of CBR which may be carrying our local group of galaxies along with its close neighbours towards the Great Attractor. I think the measurements will vary according to the amount of interaction.

[Sputnick]

Hello All,

My use of the term TAR BABY was in bad taste, unfair, and inappropriate, my apologies.

I've been tarred and feathered so often I'm becoming comfortable with the costume .. convenient for Hallowe'en - and if I can rearrange my feathers, and find a way to inject helium into the tar, I might be gifted with flight. Watch for a strange apparaition appearing among the moons of the PLANET Pluto.

[astrolabe]

Hello Sputnick,

I wll, wouldn't mind going there myself. I know I've got some tar and feather's left over somewhere. if when we get there we'll have to have a chat.

[Sputnick]

Hello Sputnick,

I wll, wouldn't mind going there myself. I know I've got some tar and feather's left over somewhere. if when we get there we'll have to have a chat.

Tar and feathers you scraped off from yourself? Or simply what you have kept around to fix your nest?

[astrolabe]

Hello Sputnick,

Scraped 'em off myself- from myself, even threw in a little egg for good measure. Oh, the perils of not being perfect!

[Sputnick]

Hello Sputnick,

Scraped 'em off myself- from myself, even threw in a little egg for good measure. Oh, the perils of not being perfect!

Ain't love grand! What a time we shall have exploring Pluto.