ASTRO: Arp 151 You can't get much stranger than this

Arp 151 is a rather odd object. It appears to be a compact galaxy with
a long jet (40") that has a bright knot in the middle of it. Or maybe
it is a chain of three galaxies as the Vorontso-Velyaminov Interacting
Galaxy Catalog indicates saying it is VV144a, b, and c. But gives the
exact same coordinates for each entry! All point to the lower compact
object. Arp put it in his class Galaxies (not classifiable as E or S):
with jets. He said nothing about it however. It appears in many
catalogs as many different types of objects. NED says it is a Seyfert 1
galaxy. It's in the 2MASS survey as an infra red object. The Markarian
catalog lists it as an ultra violet excess galaxy. It is in the Second
Byurakan Survey of Emission Line Objects as an emission line source.
The SDSS lists it as a quasar. That one surprised me greatly. The
Luyten Blue Star Catalogue lists it as a blue star! It is in several x
ray catalogs as an X ray source and some catalogs actually consider it a
galaxy. Talk about an identity crisis! A note at NED says this galaxy
was the first Luyten blue "star" recognized to be a galaxy. I assume
this refers to the blue knot in its center.

It's red shift distance is about 300 million light-years. NED classes
it as an S0 peculiar Seyfert 1 galaxy. If it is a quasar it must be the
closest one as I can't recall any less than a billion light-years away,
maybe nearly 2 billion. It is located in Ursa Major, about a quarter of
the way from M97 to M109.

The SDSS lists the knot a bit less than half way along the "jet" as a
separate galaxy SDSS J112535.23+542314.3 and not part of a galaxy.
They show a red shift distance only 4 million light-years closer than
Arp 151. So is it a knot or a separate galaxy? Is Arp 151 eating it
for lunch and the "jet" a resulting tidal plume of stars possibly drawn
way from the galaxy with only the core remaining to appear like a knot
that by coincidence of perspective seems to lie on the "jet"? Looking
closely there appears to be another knot at the north western end of the
Jet. It is far fainter than the one near the middle. It carries the
designation 2MFGC 08934 and is an IR source as 2MASX J11253416+5423312.
So is it a three galaxy chain as some papers indicate? Also I seem to
see a faint hint of a "jet" or plume going to the southeast of the main
condensation as well.

The obvious round "bubble" centered on a point half way between the blue
knot and the northwest end of the "jet" caught me by surprise. I only
see hints of it in Arp's image. Slightly stronger hints are seen in the
POSS 2 plates. I was about ready to put down to some sort of reflection
from the star to the north when I saw it clearly on the SDSS image. It
is real but not mentioned in the few papers I looked at on this galaxy.
Is it part of the galaxy, an unknown planetary nebula seen in front of
the galaxy or something else? I find nothing on it. The color is wrong
for a planetary so I'll go with part of the galaxy for now.

This has to be one complex object that is not getting much study. Is
there a fourth galaxy involved here? Just to the west of the northern
end of Arp 151, and well shown in Arp's image is a small, 20th
magnitude, galaxy, SDSS J112531.90+542321.8. With no red shift data
it's distance is unknown.

My processing of this one was severely hurt by the halos from the 8th
magnitude F0 star just to the north. This was the image that finally
got me to start saving for new filters that didn't have this halo
problem as the Astrodon Generation 1 filters that came with the camera
(used) when I bought it over 5 years ago do. I didn't get them until
months later unfortunately. Anyway that star cast a lot of noise about
this area creating a processing nightmare. The galaxy to the west,
2MASX J11252180+5423201 appears to have some tidal plumes about it. But
those may be noise from the glare of the star as it has a red shift
distance of nearly 1 billion light-years and thus not involved with Arp
151 in any way. Though the SDSS image does seem to show some fuzz to
the eastern side of it. They too were bothered by halos from the star,
just not as severe as mine.

There appear to be two galaxy groups in the image, one with a distance
of a bit over 900 million light-years is centered near the left edge of
the image. It's coordinates match that of a galaxy. I've marked them
at G/GC 0.91/0.93 indicating the distance to the galaxy and cluster
respectively. The galaxy is SDSS J112701.15+542238.4. It is also in
the 2MASX catalog as an IR source. The cluster is SDSS-C4-DR3 3275.
NED lists it as having 12 members. I see 13 in my image alone at about
this distance. With the center of the cluster near the left edge I'd
expect a lot more east of my image. There's three more galaxies in the
image at 640 million light-years, also along the left edge. They must
be in some group as well. Again I didn't go searching farther east than
my image to try and find it.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp151.jpeg

14"LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Attached a
My full image
My image enlarged and cropped to 0.67" per pixel
My annotated image
SDSS image showing the "bubble"

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Oops, I attached the wrong cropped image. Here's the enlarged one



--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Rick,

I won't argue with you if you say this is strange ;-)
I'd like to have this one at 10mio lightyears instead of 300mio.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ster.com...
Arp 151 is a rather odd object. It appears to be a compact galaxy with
a long jet (40") that has a bright knot in the middle of it. Or maybe
it is a chain of three galaxies as the Vorontso-Velyaminov Interacting
Galaxy Catalog indicates saying it is VV144a, b, and c. But gives the
exact same coordinates for each entry! All point to the lower compact
object. Arp put it in his class Galaxies (not classifiable as E or S):
with jets. He said nothing about it however. It appears in many
catalogs as many different types of objects. NED says it is a Seyfert 1
galaxy. It's in the 2MASS survey as an infra red object. The Markarian
catalog lists it as an ultra violet excess galaxy. It is in the Second
Byurakan Survey of Emission Line Objects as an emission line source.
The SDSS lists it as a quasar. That one surprised me greatly. The
Luyten Blue Star Catalogue lists it as a blue star! It is in several x
ray catalogs as an X ray source and some catalogs actually consider it a
galaxy. Talk about an identity crisis! A note at NED says this galaxy
was the first Luyten blue "star" recognized to be a galaxy. I assume
this refers to the blue knot in its center.

It's red shift distance is about 300 million light-years. NED classes
it as an S0 peculiar Seyfert 1 galaxy. If it is a quasar it must be the
closest one as I can't recall any less than a billion light-years away,
maybe nearly 2 billion. It is located in Ursa Major, about a quarter of
the way from M97 to M109.

The SDSS lists the knot a bit less than half way along the "jet" as a
separate galaxy SDSS J112535.23+542314.3 and not part of a galaxy.
They show a red shift distance only 4 million light-years closer than
Arp 151. So is it a knot or a separate galaxy? Is Arp 151 eating it
for lunch and the "jet" a resulting tidal plume of stars possibly drawn
way from the galaxy with only the core remaining to appear like a knot
that by coincidence of perspective seems to lie on the "jet"? Looking
closely there appears to be another knot at the north western end of the
Jet. It is far fainter than the one near the middle. It carries the
designation 2MFGC 08934 and is an IR source as 2MASX J11253416+5423312.
So is it a three galaxy chain as some papers indicate? Also I seem to
see a faint hint of a "jet" or plume going to the southeast of the main
condensation as well.

The obvious round "bubble" centered on a point half way between the blue
knot and the northwest end of the "jet" caught me by surprise. I only
see hints of it in Arp's image. Slightly stronger hints are seen in the
POSS 2 plates. I was about ready to put down to some sort of reflection
from the star to the north when I saw it clearly on the SDSS image. It
is real but not mentioned in the few papers I looked at on this galaxy.
Is it part of the galaxy, an unknown planetary nebula seen in front of
the galaxy or something else? I find nothing on it. The color is wrong
for a planetary so I'll go with part of the galaxy for now.

This has to be one complex object that is not getting much study. Is
there a fourth galaxy involved here? Just to the west of the northern
end of Arp 151, and well shown in Arp's image is a small, 20th
magnitude, galaxy, SDSS J112531.90+542321.8. With no red shift data
it's distance is unknown.

My processing of this one was severely hurt by the halos from the 8th
magnitude F0 star just to the north. This was the image that finally
got me to start saving for new filters that didn't have this halo
problem as the Astrodon Generation 1 filters that came with the camera
(used) when I bought it over 5 years ago do. I didn't get them until
months later unfortunately. Anyway that star cast a lot of noise about
this area creating a processing nightmare. The galaxy to the west,
2MASX J11252180+5423201 appears to have some tidal plumes about it. But
those may be noise from the glare of the star as it has a red shift
distance of nearly 1 billion light-years and thus not involved with Arp
151 in any way. Though the SDSS image does seem to show some fuzz to
the eastern side of it. They too were bothered by halos from the star,
just not as severe as mine.

There appear to be two galaxy groups in the image, one with a distance
of a bit over 900 million light-years is centered near the left edge of
the image. It's coordinates match that of a galaxy. I've marked them
at G/GC 0.91/0.93 indicating the distance to the galaxy and cluster
respectively. The galaxy is SDSS J112701.15+542238.4. It is also in
the 2MASX catalog as an IR source. The cluster is SDSS-C4-DR3 3275.
NED lists it as having 12 members. I see 13 in my image alone at about
this distance. With the center of the cluster near the left edge I'd
expect a lot more east of my image. There's three more galaxies in the
image at 640 million light-years, also along the left edge. They must
be in some group as well. Again I didn't go searching farther east than
my image to try and find it.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp151.jpeg

14"LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Attached a
My full image
My image enlarged and cropped to 0.67" per pixel
My annotated image
SDSS image showing the "bubble"

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".