Guts of the universe's 1st stars found in distant gas clouds

[Admin]

Astronomers have found the fingerprints of material dispersed by the supernova deaths of the universe's first stars in distant gas clouds.

Guts of the universe's 1st stars found in distant gas clouds : Read more

 

[rod]

The space.com report stated. "The chemical fingerprints seen in the three clouds spotted by the study team match the template for enrichment by the first supernovas. This fingerprint has, according to Saccardi, also been observed in many old stars in our Milky Way galaxy, which researchers consider to be second-generation stars that formed directly from the "ashes" of the first ones. "These faraway clouds in the early universe have a very low iron content but plenty of carbon and other light elements," Saccardi added. "Indeed, in the Milky Way, several ancient stars show a small iron content and a large excess of carbon and other light elements as our gas clouds."

That is exciting and good but not the same as actually seeing Population III stars. The metals are interpreted within a model for Pop III supernovae.

Ref - Evidence of First Stars-enriched Gas in High-redshift Absorbers*, https://iopscience.iop.org/article/10.3847/1538-4357/acc39f, 03-May-2023. “Abstract The first stars were born from chemically pristine gas. They were likely massive, and thus they rapidly exploded as supernovae, enriching the surrounding gas with the first heavy elements. In the Local Group, the chemical signatures of the first stellar population were identified among low-mass, long-lived, very metal-poor ([Fe/H] < −2) stars, characterized by high abundances of carbon over iron ([C/Fe] > +0.7): the so-called carbon-enhanced metal-poor stars. Conversely, a similar carbon excess caused by first-star pollution was not found in dense neutral gas traced by absorption systems at different cosmic time. Here we present the detection of 14 very metal-poor, optically thick absorbers at redshift z ∼ 3–4. Among these, 3 are carbon-enhanced and reveal an overabundance with respect to Fe of all the analyzed chemical elements (O, Mg, Al, and Si)..."

My observation. *The chemically pristine gas* has not been seen in nature, always some metal content is observed. From the paper, "1. Introduction Cosmological simulations show that the first (Population III) stars are likely more massive than present-day “normal” stars, with a characteristic mass of ∼10Msun and a maximum mass possibly extending up to ∼1000Msun (e.g., Hosokawa et al. 2011; Hirano et al. 2014). Among such a variety of stellar masses there are many channels to produce supernovae (SNe) and thus to contaminate the surrounding environment with the heavy elements newly produced by Population III stars. "

My note, other models now use 10,000 and 100,000 solar mass Population III stars as seeds to create SMBHs in galaxies. Redshift ranges used in the paper are some 3 to 4.5 z. At redshift 4.5, the universe age after BB is 1.352 Gyr, light time or look back distance = 12.370 Gly, and comoving radial distance = 24.957 Gly. Using H0 = 69 km/s/Mpc, space is expanding at 1.7611313E+00 or 1.76 x c velocity. Plenty of variables and parameters used to interpret the metals found in the gases as arising from a population of primordial supernovae created by Population III stars.

 

[murgatroyd]

What generation star is our Sun? Third generation ... or has there been more than one generation in between the original Pop III stars and the Sun?

 

[rod]

What generation star is our Sun? Third generation ... or has there been more than one generation in between the original Pop III stars and the Sun?

I used Google search and 3rd generation was the answer. For the BB model, the universe is 13.8 billion years old and the Sun is claimed to be born about 4.6 billion years ago, so we have 9.2 billion years for evolutionary events to unfold Many reports I read say the Sun was born in a stellar nursery, so with many other stars, not just an isolated solar nebula model. Example, Sculpted by starlight: A meteorite witness to the solar system's birth, https://www.sciencedaily.com/releases/2021/07/210706115405.htm

One problem is the mix of s-process and r-process elements found on Earth and in the solar system compared to the Sun's mix said to be found like oxygen (not the same as Earth), and the original stellar nursery for the Sun. Other reports indicate lithium and some other elements in Earth found their way here via novae. The Little Stars That Can, Sky & Telescope 145(4):36-40,2023 by Ken Croswell.

My note, how many of the elements found on Earth were created by the r-process and s-process is difficult to determine using the BB cosmology and stellar evolution r-process and s-process. This report indicated the oxygen we breathe today evolved from 160 million different supernovae events. “In fact, with every breath you take, you inhale oxygen forged in 160 million different massive stars that went supernova, according to Matteucci and Donatella Romano (Italian National Institute for Astrophysics, Bologna).”

My observation. Novae creating elements like lithium or others in our galaxy is difficult to document and calculate the total mass or amount contribution. “The Nova Rate Exactly how much nova nucleosynthesis contributes to the galaxy depends on how many novae occur each year — a number no one knows. “There’s a lot of uncertainty in estimating the nova rate for our galaxy,” says Allen Shafter (San Diego State University), who has spent most of his career trying to do just that.”

If the Sun is a 3rd generation star, difficult to see the first stars apparently which are the 1st generation, Population III stars

 

[murgatroyd]

Thank you rod