Deze afbeelding toont de enorme cluster van melkwegstelsels MACS J1149.5+223, waarvan het licht er meer dan 5 miljard jaar over deed om ons te bereiken. De enorme massa van de cluster buigt licht af van verder weg gelegen objecten. Het licht van deze objecten is vergroot en vervormd door zwaartekrachtlenzen. Hetzelfde effect is het creëren van meerdere afbeeldingen van dezelfde verre objecten. Credits: NASA, ESA, S. Rodney (John Hopkins University, VS) en het FrontierSN-team; T. Treu (University of California Los Angeles, VS), P. Kelly (University of California Berkeley, VS) en het GLASS-team; J. Lotz (STScI) en het Frontier Fields-team; M. Postman (STScI) en het CLASH-team; en Z. Levay (STScI)
Onderzoek onder leiding van de Universiteit van Minnesota zou kunnen helpen om de ouderdom van het heelal nauwkeuriger te bepalen.
Een team onder leiding van de Twin Cities van de Universiteit van Minnesota gebruikte een unieke techniek om de uitdijingssnelheid van het heelal te meten, waardoor informatie werd verkregen die de ouderdom van het heelal nauwkeuriger kon bepalen en natuurkundigen en astronomen een beter begrip van de kosmos.
Met behulp van gegevens van een uitvergrote supernova met meerdere beelden heeft een team onder leiding van onderzoekers van de Universiteit van Minnesota Twin Cities met succes een unieke techniek gebruikt om de uitdijingssnelheid van het heelal te meten. Hun gegevens bieden inzicht in een al lang bestaand debat in het veld en kunnen wetenschappers helpen de ouderdom van het heelal nauwkeuriger te bepalen en de kosmos beter te begrijpen.
Het werk is verdeeld in twee artikelen, respectievelijk gepubliceerd in Wetenschapeen van ‘s werelds toonaangevende peer-reviewed academische tijdschriften, en Hij
However, these two measurements differ by about 10 percent, which has caused widespread debate among physicists and astronomers. If both measurements are accurate, that means scientists’ current theory about the makeup of the universe is incomplete.
“If new, independent measurements confirm this disagreement between the two measurements of the Hubble constant, it would become a chink in the armor of our understanding of the cosmos,” said Patrick Kelly, lead author of both papers and an assistant professor in the University of Minnesota School of Physics and Astronomy. “The big question is if there is a possible issue with one or both of the measurements. Our research addresses that by using an independent, completely different way to measure the expansion rate of the Universe.”
The University of Minnesota-led team was able to calculate this value using data from a supernova discovered by Kelly in 2014—the first-ever example of a multiply-imaged supernova, meaning that the telescope captured four different images of the same cosmic event. After the discovery, teams around the world predicted that the supernova would reappear at a new position in 2015, and the University of Minnesota team detected this additional image.
These multiple images appeared because the supernova was gravitationally lensed by a galaxy cluster, a phenomenon in which mass from the cluster bends and magnifies light. By using the time delays between the appearances of the 2014 and 2015 images, the researchers were able to measure the Hubble Constant using a theory developed in 1964 by Norwegian astronomer Sjur Refsdal that had previously been impossible to put into practice.
The researchers’ findings don’t absolutely settle the debate, Kelly said, but they do provide more insight into the problem and bring physicists closer to obtaining the most accurate measurement of the Universe’s age.
“Our measurement is in better agreement with the value from the cosmic microwave background, although—given the uncertainties—it does not rule out the measurement from the local distance ladder,” Kelly said. “If observations of future supernovae that are also gravitationally lensed by clusters yield a similar result, then it would identify an issue with the current supernova value, or our understanding of galaxy-cluster dark matter.”
Using the same data, the researchers found that some current models of galaxy-cluster dark matter were able to explain their observations of the supernovae. This allowed them to determine the most accurate models for the locations of dark matter in the galaxy cluster, a question that has long plagued astronomers.
References:
“Constraints on the Hubble constant from Supernova Refsdal’s reappearance” by Patrick L. Kelly, Steven Rodney, Tommaso Treu, Masamune Oguri, Wenlei Chen, Adi Zitrin, Simon Birrer, Vivien Bonvin, Luc Dessart, Jose M. Diego, Alexei V. Filippenko, Ryan J. Foley, Daniel Gilman, Jens Hjorth, Mathilde Jauzac, Kaisey Mandel, Martin Millon, Justin Pierel, Keren Sharon, Stephen Thorp, Liliya Williams, Tom Broadhurst, Alan Dressler, Or Graur, Saurabh Jha, Curtis McCully, Marc Postman, Kasper Borello Schmidt, Brad E. Tucker and Anja von der Linden, 11 May 2023, Science.
DOI: 10.1126/science.abh1322
“The Magnificent Five Images of Supernova Refsdal: Time Delay and Magnification Measurements” by Patrick L. Kelly, Steven Rodney, Tommaso Treu, Simon Birrer, Vivien Bonvin, Luc Dessart, Ryan J. Foley, Alexei V. Filippenko, Daniel Gilman, Saurabh Jha, Jens Hjorth, Kaisey Mandel, Martin Millon, Justin Pierel, Stephen Thorp, Adi Zitrin, Tom Broadhurst, Wenlei Chen, Jose M. Diego, Alan Dressler, Or Graur, Mathilde Jauzac, Matthew A. Malkan, Curtis McCully, Masamune Oguri, Marc Postman, Kasper Borello Schmidt, Keren Sharon, Brad E. Tucker, Anja von der Linden and Joachim Wambsganss, 11 May 2023, The Astrophysical Journal.
DOI: 10.3847/1538-4357/ac4ccb
This research was funded primarily by