Astronomers have identified a rare gravitational lens in the shape of Cruz and Einstein. The phenomenon allowed them to accurately analyze a young elliptical galaxy called J1453g. The galaxy appears as it did about 8 billion years ago, when the universe was less than 6 billion years old. Apesar from the initial phase of development, the stellar composition in its center resembles that of today’s Via Láctea.
J1453g acts as a lens for a more distant quasar. The quasar, dominated by an active supermassive black hole, has its light magnified and multiplied into four images that form the cross. Essa rare configuration offered researchers a unique opportunity to study the stars in the core of the elliptical galaxy in a remote era.
Gravitational lens forms cross in the sky
The effect occurs because the galaxy J1453g’s gravity bends spacetime, as predicted by the Albert Einstein theory of general relativity. Light from the background quasar follows different paths as it passes through the distortion. Como result, the same distant object appears several times in the same observed image of Terra.
This is the first gravitational lens at great cosmic distance that astronomers have been able to weigh accurately. The mass within the radius of Einstein has been estimated to be around 2 x 10^10 solar masses. The galaxy J1453g has redshift 1.055, which corresponds to about 5.5 billion years after Big Bang.
The observation combined spectroscopy data and images with adaptive optics from the ERIS instrument no. Very Large Telescope. The system also stands out for the small angle of separation between the images of the quasar, the smallest recorded so far in quadruple lenses.
- The galaxy J1453g serves as a lens for a quasar at redshift 2.82
- The system has the smallest radius of Einstein known among quadruple quasars
- The lens mass is one of the smallest ever measured in distant elliptical galaxies
- The analysis focused on the galaxy’s stellar core, a region dominated by stars
Stellar composition surprises researchers
Galaxy J1453g was still in its early stages of formation. However, the stars in the center show characteristics similar to those of mature Via Láctea. Essa similarity includes the distribution of stellar masses, which follows a pattern close to that of our galaxy’s initial mass function.
The team leader, Quirino D’Amato, of Instituto Nacional of Astrofísica of Itália, highlighted the find. The discovery made it possible to study the nature of stars at the center of an elliptical galaxy in an era when it was still young. The observed composition contrasts with models that predicted rapid and different formation of galactic bulges in primordial phases.
The data suggest that galaxy growth may occur more gradually or involve early disruptive events. Isso challenges classical views that nuclei evolve quickly and remain stable afterwards.
Implications for galaxy formation models
The measurement accuracy came from the exceptional system configuration. The J1453g galaxy allows direct access to the initial mass function of stars in the core, something rare in such distant objects. The researchers excluded initial mass functions with many low-mass stars.
This analysis paves the way for refining theoretical models about galactic evolution. The processes of star formation and mass accumulation in the young universe appear more complex than previously imagined. Observações future telescopes like James Webb can complement the data obtained.
Gravitational lensing not only amplifies the quasar’s light but also serves as a tool for probing the inner regions of distant galaxies. Fenômenos similar ones have already helped study ancient galaxies, but the combination of low lensing mass and high redshift makes this case unique.
Technical details of the observation
The background quasar has redshift 2.82, which places it at an even earlier time. The lens galaxy, in turn, makes it possible to measure properties that would be inaccessible without the magnification effect. Astronomers used Bayesian analysis based on standard scaling relationships to determine stellar characteristics.
The image obtained shows four images of the quasar around the center of the galaxy J1453g. Essa geometry confirms the precise alignment required to form a Cruz of Einstein. The phenomenon occurs when the background object lies within the tangential caustic curve of the lens.
Researchers from several institutions participated in the work, with emphasis on INAF at Itália. The study explores how low-mass elliptical galaxies behave on cosmological scales.
The discovery reinforces the value of gravitational lensing as tools for extragalactic astronomy. Elas allow you to observe details that telescopes alone could not reach due to the distance and limited brightness of the objects.
What is a Cruz of Einstein
The phenomenon was predicted by the theory of general relativity. A massive object, such as a galaxy, bends spacetime and bends the path of light from more distant sources. Quando The alignment is perfect, the light can create multiple images of the same object.
In the case of crosses, four images appear in symmetrical positions around the lens. Anéis and Einstein are another possible configuration, but less common in isolated galaxies. The effect has already been observed in other systems, but J1453g stands out due to its combination of properties.
This configuration not only creates a striking visual image but also provides quantitative data on the mass and distribution of matter in the lens galaxy. Inclui both visible matter and dark matter, although the focus here was on the stellar component.
The work was recently published and is already generating discussions in the scientific community about the evolution of galaxies. Modelos Futures will need to incorporate the possibility of nuclei with a mature composition even in young galaxies.