Cosmology Views

NGC 1316: After Galaxies Collide

This is the title for the Astronomy Picture of the Day on 2005 April 4.


APOD-link

Excerpt from its description:

How did this strange-looking galaxy form? Astronomers turn detectives when trying to figure out the cause of unusual jumbles of stars, gas, and dust like NGC 1316. A preliminary inspection indicates that NGC 1316 is an enormous elliptical galaxy that includes dark dust lanes usually found in a spiral. The above image taken by the Hubble Space Telescope shows details, however, that help in reconstructing the history of this gigantic jumble. Close inspection finds fewer low mass globular clusters of stars toward NGC 1316's center. Such an effect is expected in galaxies that have undergone collisions or merging with other galaxies in the past few billion years. After such collisions, many star clusters would be destroyed in the dense galactic center. The dark knots and lanes of dust indicate that one or more of the devoured galaxies were spiral galaxies. NGC 1316 spans about 60,000 light years and lies about 75 million light years away toward the constellation of the Furnace.

(Excerpt end)

observation:

stronomers see "nusual jumbles of stars, gas, and dust " and HST also provided detailed images of globular clusters.

This galaxy suggests astronomers are just clueless about elliptical galaxies.

There is no attempt to understand the galaxy. Instead the focus is on its periphery.

They claim this giant elliptical has absorbed other galaxies in the past.

Apparently, those visible dusy lanes on the OUTSIDE are considered remnants of those merged galaxies, now gone, whose GC stars went to the INSIDE, where they were "destroyed in the dense galactic center."


APOD provides only " a brief explanation written by a professional astronomer."

NASA hosts APOD and other sites. Another NASA page has this same title.

NASA offers a wider view revealing there is a large, spiral galaxy, NGC 1317,  very near the elliptical NGC 1316 shown in APOD.

Here is that story and image

Excerpt:

An example of violence on a cosmic scale, enormous elliptical galaxy NGC 1316 lies about 75 million light-years away toward Fornax. Investigating the startling sight, astronomers suspect the giant galaxy of colliding with smaller neighbor NGC 1317 seen just above, causing far flung loops and shells of stars. Light from their close encounter would have reached Earth some 100 million years ago. In the deep, sharp image, the central regions of NGC 1316 and NGC 1317 appear separated by over 100,000 light-years. Complex dust lanes visible within also indicate that NGC 1316 is itself the result of a merger of galaxies in the distant past. Found on the outskirts of the Fornax galaxy cluster, NGC 1316 is known as Fornax A. One of the visually brightest of the Fornax cluster galaxies it is one of the strongest and largest radio sources with radio emission extending well beyond this telescopic field-of-view, over several degrees on the sky.

(Excerpt end)

Observation:

APOD neglected to mention NGC 1316 "is one of the strongest and largest radio sources [covering 6 degrees on the sky]."

There is an unjustified conclusion here: "example of violence on a cosmic scale." There is nothing here to justify that "example."


APOD provides a link to a study of the globular clusters around NGC 1316:

excerpt:

Recent observations of globular clusters (GCs) in intermediate-age (2--4 Gyr old), early-type merger remnants have provided the hitherto `missing link' between young merger remnants and `normal' elliptical galaxies in the form of a GC subsystem with colors and luminosities consistent with population synthesis model predictions for those ages and ∼ solar metallicity. Here we present new, deep observations of the GC system of the intermediate-age merger remnant NGC 1316, using the ACS camera aboard Hubble Space Telescope, which allowed us to create luminosity functions (LFs) as a function of galactocentric radius. We find that the inner 50% of the `red' GC system shows a clear turnover in its LF, at about 1 mag fainter than that of the `old' blue GCs. This constitutes direct, dynamical evidence that metal-rich GC populations formed during a gas-rich merger can evolve into the `red', metal-rich GC populations that are ubiquitous in `normal' giant ellipticals.

(Excerpt end)

Observation:

The NGC 1516  globular cluster star populations do not conform to "`normal' elliptical galaxies in the form of a GC subsystem"

These deviations conclude:  "This constitutes direct, dynamical evidence" of their claimed merger of different globular clusters from another galaxy.

Cosmologists have no historical evidence for:

a) how specific metallicity changes by age.

We have no history of metallicity changes in our Sun, let alone any other star. "solar metallicity" is mentioned.

Perhaps GC stars evolve differently than stars in spiral galaxies.

b) whether metallicity in a GC is related only to its parent galaxy.

The assumption here is: if the GC metallicity does not match that expected, then the GC came from another galaxy.

There is no evidence for that direct connection. It just assumes stars can never have an unexpected change in metallicity, because it is "well established" the stellar surface is driven by metals in the dust cloud at the time of the star's formation.

Oddly, supernovae are assumed to distribute metals into space but that interstellar "pollution" is ignored in these metallicity conclusions.

Sometimes, a metallicity analysis requires the frequency of supernovae in the vicinity to anticipate that pollution of metals.

One can be astounded by how cosmologists make baseless assumptions so lacking in evidence, and then make unfounded conclusions on the observed data.

Stories about galaxies like this one, which is a "startling sight," only reveal how cosmology lacks a foundation in science by evidence. Guesses about stars in globular clusters lead to a laughable conclusion of "violence on a cosmic scale."