Exploring the Observed Flow of Galaxies in the Expanding Universe

In summary, skepticism about "dark flow" is still advisable, as it has not gained a lot of adherents since 2008 and the scientific community is not fully convinced of its validity. Only academic sources should be trusted, as popularization and public relations media may exaggerate or omit important reservations. Further research and analysis is needed in order to determine the credibility of this alleged drift in a limited patch of galaxies.
  • #1
WORMHOLE7777
1
0
Anybody out there with info? What part of the expandable universe have the galaxys been observed to be flowing to a pecticular direction. Been looking for information site on topic. Thanks
 
Space news on Phys.org
  • #2
skepticism about "dark flow" is still advisable.
Here was Ned Wright's comment when Kashlinsky's paper came out:
=quote http://www.astro.ucla.edu/~wright/cosmolog.htm =
Dark Flow Detected - Not!

24 Sep 2008 - Kashlinsky et al. (2008) have claimed a detection of a bulk flow in the motion of many distant X-ray emitting clusters of galaxies. Unfortunately this paper and the companion paper have several errors so their conclusions cannot be trusted. A technical discussion of these errors can be found here.
=endquote=

Only academic sources are to be trusted because they have some self-critical ethic. Popularization and public relations media ("discovery channel") will say unbalanced hype, omitting reservations, and quote scientists' oversimple soundbites, if they think it will excite viewers and boost ratings.

I think if you look at academic sources on "dark flow" (a jazzy name for a possible drift in a large but limited patch of galaxies) you will find it has NOT gained a lot of adherents since 2008. The jury is still out, so to speak. That is my take. But I could be wrong! You can judge for yourself by looking at Kashlinsky's publication record and checking to see how many other people have cited his papers on this alleged drift.

Here are the 4 papers by Kashlinsky that are about the alleged drift. Two in 2008 and then two more around January 2010 with a "new measurement" of the "dark flow".

1. arXiv:1001.1261 [pdf, ps, other]
The error budget of the Dark Flow measurement
F. Atrio-Barandela, A. Kashlinsky, H. Ebeling, D. Kocevski, A. Edge
Comments: ApJ, in press
Subjects: Cosmology and Extragalactic Astrophysics (astro-ph.CO)

2. arXiv:0910.4958 [pdf, ps, other]
A new measurement of the bulk flow of X-ray luminous clusters of galaxies
A. Kashlinsky (GSFC), F. Atrio-Barandela (U Salamanca, Spain), H. Ebeling (IfA, Hawaii), A. Edge (U of Durham, UK), D. Kocevski (UCD)
Comments: Ap.J. (Letters), Mar 20/2010. Replaced with published version
Journal-ref: ApJ, (2010), 712, L81-l85
Subjects: Cosmology and Extragalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)

5. arXiv:0809.3734 [pdf, ps, other]
A measurement of large-scale peculiar velocities of clusters of galaxies: results and cosmological implications
A. Kashlinsky (GSFC), F. Atrio-Barandela (U of Salamanca), D. Kocevski (UC Davis), H. Ebeling (U of Hawaii)
Comments: Ap.J. (Letters), in press. 20 Oct issue (Vol. 686)
Subjects: Astrophysics (astro-ph)

6. arXiv:0809.3733 [pdf, ps, other]
A measurement of large-scale peculiar velocities of clusters of galaxies: technical details
A. Kashlinsky (GSFC), F. Atrio-Barandela (U of Salamanca), D. Kocevski (UC Davis), H. Ebeling (U of Hawaii)
Comments: Minor changes to match the published version - Ap.J., 1 Feb 2009 issue
Subjects: Astrophysics (astro-ph)

Here is the list of all his publications with live links to the PDF (and the html summaries called "abstracts")
http://arxiv.org/find/grp_physics/1/au:+kashlinsky/0/1/0/all/0/1

You have to judge for yourself. A key factor is the "cited by" link on the HTML abstract page. You can see how many other scientists have cited his two recent "dark flow" papers: the "new measurement" one labeled 0910.4958 and the "error budget" one labeled 1001.1261
If there is a big dropoff in citations, then probably the scientific community is not buying it. If citations remain high then there is a chance the idea is going somewhere (other than out into the popular media.)
 
Last edited:
  • #3
I second that motion, marcus. Bold claims require bold evidence. The OP needs citations to assert this claim.
 

1. What is the expanding universe?

The expanding universe is a theory in astrophysics that describes the continuous expansion of the universe since its beginning. This means that the distance between galaxies is increasing, and the universe is becoming larger over time.

2. How does the expansion of the universe affect the flow of galaxies?

The expansion of the universe affects the flow of galaxies by causing them to move away from each other at an accelerating rate. This is due to the increasing distance between galaxies as the universe expands.

3. What is the observed flow of galaxies in the expanding universe?

The observed flow of galaxies in the expanding universe is known as the Hubble flow. This refers to the velocity at which galaxies are moving away from each other, which is proportional to their distance from each other.

4. How do scientists study the observed flow of galaxies in the expanding universe?

Scientists study the observed flow of galaxies in the expanding universe through various methods, including observations from telescopes, computer simulations, and mathematical models. These methods help us understand the distribution, movement, and evolution of galaxies in the expanding universe.

5. What is the significance of studying the observed flow of galaxies in the expanding universe?

Studying the observed flow of galaxies in the expanding universe allows us to better understand the structure and evolution of the universe. It also helps us test and refine theories about the nature of the universe and its expansion. Additionally, this research can provide insights into the origin of the universe and the role of dark matter and dark energy in its expansion.

Similar threads

Replies
1
Views
1K
Replies
15
Views
727
  • Cosmology
Replies
5
Views
1K
Replies
9
Views
1K
Replies
12
Views
1K
Replies
15
Views
1K
Replies
2
Views
1K
Replies
22
Views
1K
Replies
65
Views
4K
  • Cosmology
Replies
11
Views
2K
Back
Top