ASTRO: Arp 316 -- Hickson 44

Arp 316 consists of 3 galaxies NGC 3187, NGC 3190 and NGC 3193 and is
located between two stars of the sickle of Leo. NGC 3185 is part of the
Hickson 44 group but apparently not part of Arp 316. Arp classifies it
under "Group Character: Groups of galaxies. A redundant classification.
Reminds me of when I was in college working for an accounting firm.
Bookkeeping was done by IBM punch cards on a mechanical rather than
computer system. The firm with the equipment forced all users to the
same expense categories. There were 9 possible classifications in three
levels defined by the numbers 1-9. Each refined the previous category.
9 was Other, 9 under that was Miscellaneous and 9 under that was Misc.
I was told that I could never use account 999 for obvious reasons. So
they did Arp one better with redundant classes.

The main galaxies of the group are NGC 3185 at the bottom. It is
classed as SB(r)a and is thought to be about 70 million light-years away.

NGC 3187 is the wide armed spiral SBc pec and is thought to be about 85
million light-years away. Note how the upper arm has lots of fine
detail but the bottom one looks all "windswept" and fuzzy. Must have
happened in the tidal interaction that gave it such wide arms in the
first place though I can't recall seeing this effect before. Notes
indicate it is interacting with NGC 3190 and maybe NGC 3185.

The big spiral in the center with the very weird dust lanes is NGC 3189
(lower part) and NGC 3190, rest of it. Most sources just use the NGC
3190 designation however. It is classed as Sa pec Liner and is thought
to be 73 million light-years away. Note the two planes to its dust
lanes. There's the main lane which at the NW end suddenly seems to
separate and go off at a different angle for a short ways. Then toward
the other end it splits with a fine lane resuming about the same plane
as the odd piece at the other end. But they don't point at each other,
just that they seem to be at about the same angle in relation to the
main band. Very odd. Lots of tidal spray around the galaxy as well.

The upper galaxy is NGC 3193 E2 LINER and has a red shift distance of 79
million light-years but there are indications it is really about 96
million light-years away.

This group, including NGC 3185, is also known as Hickson 44.

Blue spiral toward the SE corner is LSBC D500-05 an Sc spiral, LSBC
stands for Low Surface Brightness Catalog. The galaxy is listed with a
red shift that puts it about 200 million light-years away. Thus it must
be a rather large galaxy.

Blue galaxy well west of NGC 3190, half way to the edge of the image is
LEDA 086788 an Sc galaxy at about 100 million light-years which puts it
at least in the vicinity of Arp 316.

The tiny SO like galaxy between NGC 3190 and NGC 3193 is SDSS
J101811.88+215130.0. I find no info on it other than the note
"candidate dwarf".

The much larger fuzz blob to the southeast of NGC 3193 is SDSS
J101833.31+215138.2. There's little on it however.

Most of the other blue fuzzies aren't even listed in NED which surprises
me as this is an area covered by the SDSS yet they aren't in it either.

Arp 316 by NED is 78 million light-years by redshift.

This was taken on a night of far better than normal seeing. So I was
able to get a lot of detail in these galaxies. But what really strikes
me about the image is that the spread of faint objects is very uneven.
There's an area around the 3 upper galaxies and one bright star that has
a lot of faint objects in it. But the rest of the image has far less.
You normally don't think of dust in Leo but it seems like something
could be reducing the background except in that one area. Though in
looking at an enlarged image it appears most of the objects in this
"enhanced" area are galaxies. I searched NED for some galaxy clusters
in the area and came up with two but they are centered near NGC 3187 or
a bit above it. Still they show a distance of over 2 billion
light-years which does seem to fit. They are NSC J101747+215255 and
400d J1018+2154. They are likely seeing the same group. There's not
much data on either as to size density or galaxy count. Any other ideas?

Arp's image of the group taken this time with the 48" Schmidt telescope
due to the area being too great for the 200" field of view, is at:
http://nedwww.ipac.caltech.edu/level...ig_arp316.jpeg

The SDSS image:
http://astronomerica.awardspace.com/...3193-90-87.php

14" LX200R @ f/10, L=5x10 RGB=2x10, STL-11000XM, Paramount ME

A few years ago I took the same group using similar exposure time but
using twice as many 5 minute subs. I reprocessed it to the best of my
ability and improved it greatly from the original version but it still
doesn't compare to the 10 minute sub version I find there's a big gain
using the 10 minute subs. I need to retake all my old stuff done with 5
minute subs. OK, seeing was not as good for the 5 minute sub image but
it doesn't explain the loss of faint objects. I'm considering trying 20
minute subs to see if there's a similar gain. If so I'll have to again
retake everything. Main problem of longer subs is folks on the lake
with bright lights, especially cars and trucks of ice fishermen in
winter. Those can ruin a frame. Not so bad if I lose 10 minutes but 20
is a worse time loss. Liquid water fishermen also seem to like bright
lights to find fishing bouys. They reflect off the water and hit the
scope even worse than headlights but are far less common. Satellite
trails are another problem as I usually use too few frames for noise
rejection combine methods. That was the main advantage of 5 minute subs
when dithered.

Rick

Mighty detail in these galaxies, very impressive.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
. com...
Arp 316 consists of 3 galaxies NGC 3187, NGC 3190 and NGC 3193 and is
located between two stars of the sickle of Leo. NGC 3185 is part of the
Hickson 44 group but apparently not part of Arp 316. Arp classifies it
under "Group Character: Groups of galaxies. A redundant classification.
Reminds me of when I was in college working for an accounting firm.
Bookkeeping was done by IBM punch cards on a mechanical rather than
computer system. The firm with the equipment forced all users to the
same expense categories. There were 9 possible classifications in three
levels defined by the numbers 1-9. Each refined the previous category.
9 was Other, 9 under that was Miscellaneous and 9 under that was Misc.
I was told that I could never use account 999 for obvious reasons. So
they did Arp one better with redundant classes.

The main galaxies of the group are NGC 3185 at the bottom. It is
classed as SB(r)a and is thought to be about 70 million light-years away.

NGC 3187 is the wide armed spiral SBc pec and is thought to be about 85
million light-years away. Note how the upper arm has lots of fine
detail but the bottom one looks all "windswept" and fuzzy. Must have
happened in the tidal interaction that gave it such wide arms in the
first place though I can't recall seeing this effect before. Notes
indicate it is interacting with NGC 3190 and maybe NGC 3185.

The big spiral in the center with the very weird dust lanes is NGC 3189
(lower part) and NGC 3190, rest of it. Most sources just use the NGC
3190 designation however. It is classed as Sa pec Liner and is thought
to be 73 million light-years away. Note the two planes to its dust
lanes. There's the main lane which at the NW end suddenly seems to
separate and go off at a different angle for a short ways. Then toward
the other end it splits with a fine lane resuming about the same plane
as the odd piece at the other end. But they don't point at each other,
just that they seem to be at about the same angle in relation to the
main band. Very odd. Lots of tidal spray around the galaxy as well.

The upper galaxy is NGC 3193 E2 LINER and has a red shift distance of 79
million light-years but there are indications it is really about 96
million light-years away.

This group, including NGC 3185, is also known as Hickson 44.

Blue spiral toward the SE corner is LSBC D500-05 an Sc spiral, LSBC
stands for Low Surface Brightness Catalog. The galaxy is listed with a
red shift that puts it about 200 million light-years away. Thus it must
be a rather large galaxy.

Blue galaxy well west of NGC 3190, half way to the edge of the image is
LEDA 086788 an Sc galaxy at about 100 million light-years which puts it
at least in the vicinity of Arp 316.

The tiny SO like galaxy between NGC 3190 and NGC 3193 is SDSS
J101811.88+215130.0. I find no info on it other than the note
"candidate dwarf".

The much larger fuzz blob to the southeast of NGC 3193 is SDSS
J101833.31+215138.2. There's little on it however.

Most of the other blue fuzzies aren't even listed in NED which surprises
me as this is an area covered by the SDSS yet they aren't in it either.

Arp 316 by NED is 78 million light-years by redshift.

This was taken on a night of far better than normal seeing. So I was
able to get a lot of detail in these galaxies. But what really strikes
me about the image is that the spread of faint objects is very uneven.
There's an area around the 3 upper galaxies and one bright star that has
a lot of faint objects in it. But the rest of the image has far less.
You normally don't think of dust in Leo but it seems like something
could be reducing the background except in that one area. Though in
looking at an enlarged image it appears most of the objects in this
"enhanced" area are galaxies. I searched NED for some galaxy clusters
in the area and came up with two but they are centered near NGC 3187 or
a bit above it. Still they show a distance of over 2 billion
light-years which does seem to fit. They are NSC J101747+215255 and
400d J1018+2154. They are likely seeing the same group. There's not
much data on either as to size density or galaxy count. Any other ideas?

Arp's image of the group taken this time with the 48" Schmidt telescope
due to the area being too great for the 200" field of view, is at:
http://nedwww.ipac.caltech.edu/level...ig_arp316.jpeg

The SDSS image:
http://astronomerica.awardspace.com/...3193-90-87.php

14" LX200R @ f/10, L=5x10 RGB=2x10, STL-11000XM, Paramount ME

A few years ago I took the same group using similar exposure time but
using twice as many 5 minute subs. I reprocessed it to the best of my
ability and improved it greatly from the original version but it still
doesn't compare to the 10 minute sub version I find there's a big gain
using the 10 minute subs. I need to retake all my old stuff done with 5
minute subs. OK, seeing was not as good for the 5 minute sub image but
it doesn't explain the loss of faint objects. I'm considering trying 20
minute subs to see if there's a similar gain. If so I'll have to again
retake everything. Main problem of longer subs is folks on the lake
with bright lights, especially cars and trucks of ice fishermen in
winter. Those can ruin a frame. Not so bad if I lose 10 minutes but 20
is a worse time loss. Liquid water fishermen also seem to like bright
lights to find fishing bouys. They reflect off the water and hit the
scope even worse than headlights but are far less common. Satellite
trails are another problem as I usually use too few frames for noise
rejection combine methods. That was the main advantage of 5 minute subs
when dithered.

Rick