ASTRO: Arp 90

Arp 90/NGC 5929-30 is an interacting pair of galaxies about 120 million
light-years away in the constellation of Bootes. Arp put it in his
classification for spirals with high surface brightness companions on
the arms. He recorded this comment: "Absorption lanes around
companion." This pair should be visible in an 8" telescope for those
going after these visually. It was discovered by William Herschel in
1828 using a 18.7" speculum mirrored reflector.

NGC 5929, on the right, is classed as Sab Pec and is a Seyfert 2 galaxy.
NGC 5930, on the left, is classed as SAB(rs)b pec at NED and SBb/P by
the NGC project. Several notes at NED say 5930 has a starburst nucleus
though this isn't mentioned in the classification at NED. Both the
Seyfert 2 status of NGC 5930 and the starburst core of NGC 5930 can be
an indication of interaction though either can occur without it. Here
it appears interaction is involved.

"Behind" Arp 90 off its lower left side is a small blue blob. Is it a
plume or a separate galaxy. It appears to be a low surface brightness
galaxy in my and the SDSS image but NED shows nothing at this position.
Thus it is marked with a question mark on the annotated image.

To the northeast of Arp 90 is UGC 09857 at 110 million light-years by
redshift. This difference is rather insignificant and can easily
represent relative motion of related galaxies. It is classed as IBm.
Is it naturally irregular or has it had a nasty encounter with Arp 90?
I found nothing on it either way. It sure is interesting looking. Wish
we could see these from a closer vantage point.

The annotated image shows some interesting things. Arp is a strong
believer that quasars aren't distant massive black holes on a feeding
frenzy in distant galaxies but are nearby objects ejected from galaxies.
This puts him in the near crackpot category of many astronomers. His
theory goes that as time passes their red shift increases. Why requires
rewriting physics. Read the Kanipe-Webb book on the Arp Atlas for the
details. He cites several galaxies in which the redshift of the quasars
in the field increases with angular distance from the galaxy. That
appears to be the case here. The one nearest Arp 90 has the lowest
redshift value (converts to distance as 6.2 billion light-years)
increasing (using today's accepted distance conversion of redshift) to
8.1, 10.5 and finally 11.3 billion light years. One minor hitch is one
to the east that's even further from Arp 90 but is only 9.2 billion
light years distant. Of course Arp says those distances are false as
all are about the same distance as Arp 90. The odd one is explained
that the ones with higher redshift are really further from Arp 90 but
only appear closer when projected onto a 2 dimensional image plane. Of
course by that logic nearly any distance could be supported. You could
just as easily say the one at 6.2 is really the furthest as it is was
ejected away or toward us and thus the distance we see is greatly
foreshortened. From what I read in Kanipe and Webb's book this didn't
seem a problem to Arp.

In any case, after several fields without any quasars there are at least
7 in this image ranging out past 11 billion light-years by established
redshift theory.

There are a lot of galaxies, many fall into two very precise distance
measurements. One set at 1.0 billion light-years and another nearly
twice that at 1.9 billion light-years. The latter pretty much covers
the entire field. Also noted in the annotated image is the center
position of the galaxy cluster Abell 2080. It is listed as 30 minutes
in diameter. It would extend from its position near the eastern edge of
my image to the middle of the image. That doesn't fit the distribution
of either of the two distance groups in my image. The catalog gives
little other help just saying it is "distant class" 6. All that means
is the 10th brightest member has a magnitude between 17.3 and 18.0.
Most of both the 1 and 1.9 billion light-year groups fit that range but
extend beyond the 30 minute diameter. So which galaxies in the image
are part of the group? I have no idea.

Arp's image
http://ned.ipac.caltech.edu/level5/A...big_arp90.jpeg

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

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".

Rick,

UGC 09857 is most interesting indeed. It looks as if there is a large dust
cloud that covers part of the galaxy.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ter.com...
Arp 90/NGC 5929-30 is an interacting pair of galaxies about 120 million
light-years away in the constellation of Bootes. Arp put it in his
classification for spirals with high surface brightness companions on
the arms. He recorded this comment: "Absorption lanes around
companion." This pair should be visible in an 8" telescope for those
going after these visually. It was discovered by William Herschel in
1828 using a 18.7" speculum mirrored reflector.

NGC 5929, on the right, is classed as Sab Pec and is a Seyfert 2 galaxy.
NGC 5930, on the left, is classed as SAB(rs)b pec at NED and SBb/P by
the NGC project. Several notes at NED say 5930 has a starburst nucleus
though this isn't mentioned in the classification at NED. Both the
Seyfert 2 status of NGC 5930 and the starburst core of NGC 5930 can be
an indication of interaction though either can occur without it. Here
it appears interaction is involved.

"Behind" Arp 90 off its lower left side is a small blue blob. Is it a
plume or a separate galaxy. It appears to be a low surface brightness
galaxy in my and the SDSS image but NED shows nothing at this position.
Thus it is marked with a question mark on the annotated image.

To the northeast of Arp 90 is UGC 09857 at 110 million light-years by
redshift. This difference is rather insignificant and can easily
represent relative motion of related galaxies. It is classed as IBm.
Is it naturally irregular or has it had a nasty encounter with Arp 90?
I found nothing on it either way. It sure is interesting looking. Wish
we could see these from a closer vantage point.

The annotated image shows some interesting things. Arp is a strong
believer that quasars aren't distant massive black holes on a feeding
frenzy in distant galaxies but are nearby objects ejected from galaxies.
This puts him in the near crackpot category of many astronomers. His
theory goes that as time passes their red shift increases. Why requires
rewriting physics. Read the Kanipe-Webb book on the Arp Atlas for the
details. He cites several galaxies in which the redshift of the quasars
in the field increases with angular distance from the galaxy. That
appears to be the case here. The one nearest Arp 90 has the lowest
redshift value (converts to distance as 6.2 billion light-years)
increasing (using today's accepted distance conversion of redshift) to
8.1, 10.5 and finally 11.3 billion light years. One minor hitch is one
to the east that's even further from Arp 90 but is only 9.2 billion
light years distant. Of course Arp says those distances are false as
all are about the same distance as Arp 90. The odd one is explained
that the ones with higher redshift are really further from Arp 90 but
only appear closer when projected onto a 2 dimensional image plane. Of
course by that logic nearly any distance could be supported. You could
just as easily say the one at 6.2 is really the furthest as it is was
ejected away or toward us and thus the distance we see is greatly
foreshortened. From what I read in Kanipe and Webb's book this didn't
seem a problem to Arp.

In any case, after several fields without any quasars there are at least
7 in this image ranging out past 11 billion light-years by established
redshift theory.

There are a lot of galaxies, many fall into two very precise distance
measurements. One set at 1.0 billion light-years and another nearly
twice that at 1.9 billion light-years. The latter pretty much covers
the entire field. Also noted in the annotated image is the center
position of the galaxy cluster Abell 2080. It is listed as 30 minutes
in diameter. It would extend from its position near the eastern edge of
my image to the middle of the image. That doesn't fit the distribution
of either of the two distance groups in my image. The catalog gives
little other help just saying it is "distant class" 6. All that means
is the 10th brightest member has a magnitude between 17.3 and 18.0.
Most of both the 1 and 1.9 billion light-year groups fit that range but
extend beyond the 30 minute diameter. So which galaxies in the image
are part of the group? I have no idea.

Arp's image
http://ned.ipac.caltech.edu/level5/A...big_arp90.jpeg

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

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".

I looked at the 2MASS IR bands where it is virtually invisible. I was
hoping if there were dust that would see through it to some extent but
it vanished almost entirely. POSSII IR very faint but shows same
general shape. This guy is super blue yet isn't hiding and new star
formation it would seem. Very odd.

Rick

On 6/14/2011 8:08 AM, Stefan Lilge wrote:
Rick,

UGC 09857 is most interesting indeed. It looks as if there is a large dust
cloud that covers part of the galaxy.

Stefan

"Rick schrieb im Newsbeitrag
ter.com...
Arp 90/NGC 5929-30 is an interacting pair of galaxies about 120 million
light-years away in the constellation of Bootes. Arp put it in his
classification for spirals with high surface brightness companions on
the arms. He recorded this comment: "Absorption lanes around
companion." This pair should be visible in an 8" telescope for those
going after these visually. It was discovered by William Herschel in
1828 using a 18.7" speculum mirrored reflector.

NGC 5929, on the right, is classed as Sab Pec and is a Seyfert 2 galaxy.
NGC 5930, on the left, is classed as SAB(rs)b pec at NED and SBb/P by
the NGC project. Several notes at NED say 5930 has a starburst nucleus
though this isn't mentioned in the classification at NED. Both the
Seyfert 2 status of NGC 5930 and the starburst core of NGC 5930 can be
an indication of interaction though either can occur without it. Here
it appears interaction is involved.

"Behind" Arp 90 off its lower left side is a small blue blob. Is it a
plume or a separate galaxy. It appears to be a low surface brightness
galaxy in my and the SDSS image but NED shows nothing at this position.
Thus it is marked with a question mark on the annotated image.

To the northeast of Arp 90 is UGC 09857 at 110 million light-years by
redshift. This difference is rather insignificant and can easily
represent relative motion of related galaxies. It is classed as IBm.
Is it naturally irregular or has it had a nasty encounter with Arp 90?
I found nothing on it either way. It sure is interesting looking. Wish
we could see these from a closer vantage point.

The annotated image shows some interesting things. Arp is a strong
believer that quasars aren't distant massive black holes on a feeding
frenzy in distant galaxies but are nearby objects ejected from galaxies.
This puts him in the near crackpot category of many astronomers. His
theory goes that as time passes their red shift increases. Why requires
rewriting physics. Read the Kanipe-Webb book on the Arp Atlas for the
details. He cites several galaxies in which the redshift of the quasars
in the field increases with angular distance from the galaxy. That
appears to be the case here. The one nearest Arp 90 has the lowest
redshift value (converts to distance as 6.2 billion light-years)
increasing (using today's accepted distance conversion of redshift) to
8.1, 10.5 and finally 11.3 billion light years. One minor hitch is one
to the east that's even further from Arp 90 but is only 9.2 billion
light years distant. Of course Arp says those distances are false as
all are about the same distance as Arp 90. The odd one is explained
that the ones with higher redshift are really further from Arp 90 but
only appear closer when projected onto a 2 dimensional image plane. Of
course by that logic nearly any distance could be supported. You could
just as easily say the one at 6.2 is really the furthest as it is was
ejected away or toward us and thus the distance we see is greatly
foreshortened. From what I read in Kanipe and Webb's book this didn't
seem a problem to Arp.

In any case, after several fields without any quasars there are at least
7 in this image ranging out past 11 billion light-years by established
redshift theory.

There are a lot of galaxies, many fall into two very precise distance
measurements. One set at 1.0 billion light-years and another nearly
twice that at 1.9 billion light-years. The latter pretty much covers
the entire field. Also noted in the annotated image is the center
position of the galaxy cluster Abell 2080. It is listed as 30 minutes
in diameter. It would extend from its position near the eastern edge of
my image to the middle of the image. That doesn't fit the distribution
of either of the two distance groups in my image. The catalog gives
little other help just saying it is "distant class" 6. All that means
is the 10th brightest member has a magnitude between 17.3 and 18.0.
Most of both the 1 and 1.9 billion light-year groups fit that range but
extend beyond the 30 minute diameter. So which galaxies in the image
are part of the group? I have no idea.

Arp's image
http://ned.ipac.caltech.edu/level5/A...big_arp90.jpeg

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

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".





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