These are Hubble Space Telescope images of 2 massive clusters of galaxies named MOO J1014 +0038 (left panel) and SPT-CL J2106-5844 (best panel). Billions of years ago the stars were shed from their parent galaxies and now drift through intergalactic area.
Hubble Space Telescope Finds that Ghost Light Among Galaxies Stretches Far Back in Time.
In giant clusters of hundreds or thousands of galaxies, innumerable stars wander amongst the galaxies like lost souls, emitting a ghostly haze of light. These stars are not gravitationally tied to any one galaxy in a cluster.
There are lots of stars wandering about within giant clusters of hundreds or thousands of galaxies. These stars are not gravitationally connected to any one galaxy in a cluster. Image of galaxy clusters MOO J1014 +0038 (left panel) and SPT-CL J2106-5844 (best panel) recorded by Hubbles Wide Field Camera 3, with color secret, compass arrows, and scale bar for reference.This image shows near-infrared wavelengths of light. Stars can be scattered outside of their stellar birthplace when a galaxy moves through gaseous material in the area in between galaxies, as it orbits the center of the cluster. If the wandering stars were produced through a comparatively current pinball video game amongst galaxies, they do not have enough time to scatter throughout the whole gravitational field of the cluster and therefore would not trace the circulation of the clusters dark matter.
Thanks to Hubble, astronomers now know about whole households of stars– and most likely their planetary systems– that do not even have a galaxy to call home. There are many stars roaming about inside huge clusters of hundreds or thousands of galaxies. These stars are not gravitationally tied to any one galaxy in a cluster.
Jointly, the dim dispersed glow from these wayward stars forms a background called intracluster light that is evidence they are lurking around. Although the very first clues was available in 1951, Hubble can quickly identify this light even though its 1/10,000 th the glow of the night sky as seen from the ground-based telescopes. Billions of years ago galaxies would have been smaller than seen today, and they probably shed stars pretty easily since of a weaker gravitational pull. (The escape velocity from our Milky Way is over 1 million miles per hour). Understanding the origin of intracluster light could provide astronomers brand-new insights into the assembly history of whole galaxy clusters.
The irritating concern for astronomers has been: how did the stars get so spread throughout the cluster in the very first place? Numerous contending theories include the possibility that the stars were removed out of a clusters galaxies, or they were considered after mergers of galaxies, or they were present early in a clusters formative years many billions of years back.
A current infrared survey from NASAs Hubble Space Telescope, which tried to find this so-called “intracluster light” sheds new light on the mystery. The new Hubble observations suggest that these stars have actually been roaming around for billions of years, and are not an item of more current dynamical activity inside a galaxy cluster that would remove them out of typical galaxies.
The study consisted of 10 galaxy clusters as far as nearly 10 billion light-years. Because the faint intracluster light is 10,000 times dimmer than the night sky as seen from the ground, these measurements must be made from area.
The survey reveals that the portion of the intracluster light relative to the overall light in the cluster remains continuous, examining billions of years back into time. “This suggests that these stars were currently homeless in the early phases of the clusters development,” stated James Jee of Yonsei University in Seoul, South Korea. His results were published in the January 5 problem of Nature magazine.
Image of galaxy clusters MOO J1014 +0038 (left panel) and SPT-CL J2106-5844 (right panel) caught by Hubbles Wide Field Camera 3, with color secret, compass arrows, and scale bar for reference.This image reveals near-infrared wavelengths of light. When collecting the light, the color secret shows which filters were utilized. The color of each filter name is the color utilized to represent the wavelength that goes through that filter.The compass graphic points to the objects orientation on the celestial sphere. North indicate the north celestial pole which is not a fixed point in the sky, but it currently lies near the star Polaris, in the circumpolar constellation Ursa Minor. Celestial coordinates are analogous to a terrestrial map, though east and west are shifted since we are looking up rather than down.The scale bar is labeled in light-years (ly) and parsecs (pc). A light-year is the distance that light travels in one Earth-year. (It takes 100,000 years for light to travel a distance equal to the length of the bar.) One light-year is equal to about 5.88 trillion miles or 9.46 trillion kilometers.A parsec is likewise a measure of length or distance. One parsec is approximately 3.26 light-years across.Note that the range in parsecs and light-years revealed on this scale bar uses to the galaxy cluster, not to foreground or background objects.Credit: Science: NASA, ESA, STScI, James Jee (Yonsei University), Image Processing: Joseph DePasquale (STScI).
Stars can be spread outside of their galactic birth place when a galaxy moves through gaseous product in the space in between galaxies, as it orbits the center of the cluster. In the process, drag pushes gas and dust out of the galaxy.
” We do not exactly understand what made them homeless. Existing theories can not describe our outcomes, however in some way they were produced in big quantities in the early universe,” stated Jee. “In their early developmental years, galaxies might have been quite small and they bled stars pretty easily due to the fact that of a weaker gravitational grasp.”.
” If we determine the origin of intracluster stars, it will assist us comprehend the assembly history of an entire galaxy cluster, and they can act as visible tracers of dark matter covering the cluster,” said Hyungjin Joo of Yonsei University, the very first author of the paper. Dark matter is the invisible scaffolding of deep space, which holds galaxies, and clusters of galaxies, together.
If the roaming stars were produced through a comparatively recent pinball game amongst galaxies, they do not have adequate time to spread throughout the whole gravitational field of the cluster and for that reason would not trace the circulation of the clusters dark matter. If the stars were born in the clusters early years, they will have totally dispersed throughout the cluster. This would enable astronomers to utilize the wayward stars to map out the dark matter distribution throughout the cluster.
This strategy is new and complementary to the traditional approach of dark matter mapping by measuring how the whole cluster warps light from background items due to a phenomenon called gravitational lensing.
Intracluster light was first found in the Coma cluster of galaxies in 1951 by Fritz Zwicky, who reported that a person of his most intriguing discoveries was observing luminous, faint intergalactic matter in the cluster. Since the Coma cluster, consisting of a minimum of 1,000 galaxies, is one of the nearby clusters to Earth (330 million light-years), Zwicky was able to find the ghost light even with a modest 18-inch telescope.
NASAs James Webb Space Telescopes near-infrared capability and level of sensitivity will considerably extend the search for intracluster stars deeper into the universe, and for that reason need to help solve the mystery.
Reference: “Intracluster light is already plentiful at redshift beyond unity” by Hyungjin Joo and M. James Jee, 4 January 2023, Nature.DOI: 10.1038/ s41586-022-05396-4.
The Hubble Space Telescope is a job of worldwide cooperation between NASA and ESA. NASAs Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, performs Hubble and Webb science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.