A cosmic dragonfly

A galaxy, known as Dragonfly 44, first detected in 2015 using the Dragonfly Telephoto Array in New Mexico by Professor Peter van Dokkum is now claimed to be made of 99.99% dark matter.1 It is a galaxy where very few stars can be seen. It took a two-hour exposure using one of the very biggest telescopes on Earth, one of the Gemini telescopes at the W. M. Keck Observatory in Mauna Kea, Hawaii, to get a picture of this wispy galaxy as shown in Fig. 1 below.

cosmic-dragonfly

Figure 1: Astronomers photographed the ultradiffuse galaxy Dragonfly 44 using the Gemini Multi-Object Spectrograph (GMOS) on the 8-meter Gemini North telescope in Mauna Kea, Hawaii. Credit: Pieter van Dokkum, Roberto Abraham, Gemini Observatory/AURA

Professor van Dokkum from the Astronomy Department and the Physics Department of Yale University is not only an astrophysicist but also a photographer of insects, particularly dragonflies.It is a strange coincidence, or is it, to find that one of his particular interests in the cosmos are these ultradiffuse, or “fluffy” galaxies. One of them is named Dragonfly 44, which van Dokkum and team determined to be at a distance of 300 million light-years from Earth, in the Coma Cluster.3  That distance is easily close enough for a big telescope to see, which can see galaxies at billions of light-year distances but no one had previously noticed these fluffy galaxies before even though they are ‘so close’.

Dragonfly 44 was like “a dirty smudge on a photo of deep space.”1 And it was one of the largest and brightest galaxies of those they found. From its distance its size was determined and it was concluded that it is as big as our Milky Way galaxy, yet it only emits about 1 percent as much light. So I suppose to van Dokkum the galaxy is reminiscent of the very fragile, lightweight and transparent wings of dragonflies he likes to photograph.

Dragonfly 44 is one of 47 ultradiffuse galaxies found. When first noticed in 2015, these were a big surprise but now after ‘counting’ the stars in these galaxies, from the light they emit, and measuring their sizes, it was realized that they must be very massive. “It looks like the universe is able to make unexpected galaxies,” van Dokkum said.3

Prof. van Dokkum and his team realized that there was something very odd about Dragonfly 44. A galaxy that big couldn’t possibly hold itself together with so few stars. There wouldn’t be enough gravity, and the stars would drift apart. Thus from the motions of the stars in the spheroidal galaxy they determined that it must comprise almost exclusively of dark matter and that was estimated to be 99.99%.

That calculation is based on assuming that the galaxy is many billions of years old since all galaxies allegedly formed only a billion years or so after the big bang. Therefore it follows that the galaxy is stable and the stars are in equilibrium; that is, they are not flying apart. If they were flying apart the galaxy would have eviscerated a long time ago in a big bang universe.

That leaves only one explanation: “dark matter was responsible for holding the galaxy together, and this particular galaxy seemed like it contained a ton of it, so they set out to determine exactly how much.” Thus they concluded “only 0.01 percent of the galaxy is made of ordinary, visible matter: stuff that is made of atoms containing protons, neutrons and electrons.”1

Think if it! You have a claim that a galaxy is made of nearly 100% dark invisible matter. It won’t be long before we will have claims of galaxies with only 0.001% normal matter and eventually of galaxies that contain no normal matter at all.4 What will they see? Absolutely nothing at all. But this is the result of the initial assumptions, a belief that the Universe is the product only of matter, energy and the laws of physics. There was no Creator. Well, if there was a Creator He has had nothing to do with the Universe since He lit the fuse of the big bang, as some theorists would reason. Instead it is the laws of physics that they pay homage to.

It is a requirement also of big bang cosmologies that the physics we determine locally is the same everywhere in the Universe. But that may not necessarily be the case. That assumption could lead to this dilemma as the physics used may be wrong, but the ruling paradigm limits any investigation to the contrary. It even makes much more sense, and perhaps even better physics, to assume that the galaxies don’t need to be in equilibrium because they were created not so long ago. If they are not dynamically stable no dark matter needs to be assumed.

dmgogDark matter is the unknown ‘god of the gaps’5 used to fill in where the physics fails. And this is despite the fact that there is still no direct local laboratory evidence for the existence of any type of dark matter.6 It is used to connect the ruling paradigm to the observations that are otherwise impossible to reconcile in a universe that evolved out of the hot big bang fireball. Not so long ago I reported that some astronomers were suggesting the possibility of dark galaxies containing dark stars with dark planets and even dark intelligent life.7 Here we are ‘seeing’ more of that ‘darkness’. When the Creator is ignored the madness never ends.

References

  1. H. Weitering, This weird galaxy is actually 99.99 percent dark matter, August 26, 2016.
  2. Professor Peter Van Dokkum’s Yale University home page, accessed August 29, 2016.
  3. S. Hall, Cluster Filled with Dark Matter May House ‘Failed Galaxies’, February 20, 2015.
  4. J.G. Hartnett, Why is Dark Matter everywhere in the cosmos? March 31, 2015.
  5. J.G. Hartnett, Is Dark Matter the unknown god? Creation 37(2):22–24, April 2015
  6. J.G. Hartnett, Dark matter search comes up empty, July 24, 2016.
  7. J.G. Hartnett, Where materialism logically leads, May 31, 2016.

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4 thoughts on “A cosmic dragonfly

  1. So is it possible to check if it´s in equillibrium or not? Because if not, then that’s more evidence that the Universe is young.

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      • Is there any measurement of the velocities of the stars in Dragonfly 44? If the total visible mass is about 1% of the visible mass of a normal galaxy, then the velocities to remain bound would be about 10% of the usual velocities, i.e., about 20 km/sec. Is there any reason why that couldn’t be the case?

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      • From their paper on the ArXiv.org preprint server they measured a stellar velocity dispersion of about 47 km/s, which implies a dynamical mass of Mdyn(<r1/2) = 0.7 x 10^10 M_solar within its half-light radius of r1/2 = 4.6 kpc. The mass-to-light ratio there is M/L = 48 M_solar/L_solar, and therefore the dark matter fraction is 98% within r1/2. Based on that 2% of the matter is visible within the 4.6 kpc radius.

        The abstract then concludes with:

        “We estimate the total dark halo mass of Dragonfly 44 by comparing the amount of dark matter within r = 4.6 kpc to enclosed mass profiles of NFW halos. The enclosed mass suggests a total mass of ∼ 10^12 M_solar, similar to the mass of the Milky Way.”

        So that must mean there exists a lot more dark matter (100 times in fact) outside the half-light radius, which quite obviously cannot be detected even dynamically. Thus this is where they get their 99.99% dark matter fraction from when the dynamically measured dark matter fraction inside the half-light radius was calculated at ‘only’ 98%.

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