Earlier this year, JWST researchers reported measurements built on: Last year’s confirmation Based on Webb’s data, Hubble’s measurements of the expansion rate were accurate, at least for the first few rungs of the cosmic distance ladder. But especially when measuring the brightness of more distant stars, there was still the potential for undetected errors to increase the deeper we looked into the universe (that is, further back in time).
Three views of NGC 4258 (Messier 106). The images on the left and center show the galaxy in visible light, and the image on the right is in infrared from JWST.
Credit: ESA/WEBB, NASA, CSA
The additional observations of a total of 1,000 Cepheid variable stars in five host galaxies 130 million light-years away correlate with Hubble data, and JWST makes Hubble’s own images of stars more blurred and overlapping. It helped me see beyond the dust. . This allowed astronomers to more easily distinguish between individual stars. the result further confirmed The accuracy of Hubble data has improved, allowing astronomers to confidently eliminate measurement errors.
Important cross-check
This latest study serves as an important cross-check to April’s paper, using three different measurements to determine the distance to galaxies known to be the host of supernovae. “Hubble’s cross-check may sound mundane, but Hubble’s results show that the current rate of expansion of the universe (as measured by Hubble) and predictions from the standard model LambdaCDM (calibrated by the Cosmic Microwave Background Radiation) “This shows serious tensions in the universe,” lead author Adam Rees of the Johns Hopkins Space Science Telescope Institute told Ars. “So Webb’s confirmation of Hubble means we really do sense something is wrong with the universe.”
The new study includes data from two independent groups working to refine the Hubble constant, and includes about one-third of the total galaxy sample collected by Hubble. The authors used the known distance to galaxy NGC-4258 (also known as Messier 106) as a reference point. They used pulsating stars known as Cepheid variables to calculate the distances, and cross-checked that study with complementary distance measurements based on carbon-rich stars and red giants. The final value of the Hubble constant was 72.6 km/s/Mpc, which is very close to Hubble’s value of 72.8 km/s/Mpc.
