dark matter can be found. Dark matter is a confusing area of astrophysics but it is generally agreed upon that dark matter is a requirement of the existence of galaxies.
This was one of those cases where discovery began with the phrase "huh, that looks weird".
"Conventional telescopes are good at finding small, faint objects".
The galaxy NGC 1052-DF2, or DF2 for short, reportedly has 400 times less dark matter than expected for an object of its size.
"It stood out to us because of the remarkable contrast between its appearance in Dragonfly images and Sloan Digital Sky Survey data", the authors of the paper describing the object write.
Closer observations using the Hubble and 10-meter Keck telescopes showed that the object, now termed NGC1052-DF2, was a member of a recently discovered class of objects called ultra-diffuse galaxies.
"This thing is astonishing: a very big blob so sparse that you see the galaxies behind it". It's a literally a transparent galaxy. Using observations from the Hubble Space Telescope and the Dragonfly Telephoto Array, the team discovered that the galaxy appeared dramatically different than others they had seen. The galaxy was then renamed NGC1052-DF2.
The answers were pretty surprising. The stars were moving very slowly, which seemed odd to the scientists since they expected to see speeds up to three times greater. Utilizing the quantity of light given off by the galaxy created a quote of the overall mass of celebrities in the galaxy that was likewise in the neighborhood of 108. Either there's a lot of mass out there in the universe that we can't detect directly, mass scientists call dark matter, or there's no dark matter out there, but there is something missing from our laws of gravity and motion. If dark matter were one of the unexplained effects of the gravity that differentiates it from regular matter, the effect of it would be visible in the galaxy.
"In modern galaxy formation theory, our understanding is that galaxies form in a dark matter halo", says Stanford University's Risa Wechsler.
According to the release, the results show that dark matter is separable from galaxies. The image also served as a confirmation that galaxies are interconnected through a cosmic web of dark matter. Mysterious "dark matter" makes up the rest. We don't see any indication of these effects, so modified gravity ideas must be wrong. The leading theory-that dark matter consists of so-called weakly interacting massive particles, each slightly heavier than a proton-would not be able to explain the existence of many dark matter-less galaxies.
Lying some 63 million light-years from the Milky Way, the elliptical galaxy NGC1052-DF2 seems to be completely made up of normal matter, defying all expectations.
"We really thought that this is the essence of what a galaxy is, that galaxies are built from, initially, a bunch of dark matter and that all the stars and all the planets and everything else is just a little frost on top", van Dokkum added.
These ideas, however, still do not explain how this galaxy formed. But how it formed is a complete mystery.
But each of these would have to be examined in detail to determine if it could form the distinct features of NGC1052-DF2. Yet according to Pieter van Dokkum from Yale University, this galaxy has nearly none.