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helium sedimentation primordial

Primordial and recycled helium isotope signatures in the ...

Aug 16, 2019  Helium isotopes provide a window into the very deepest and oldest parts of Earth's voluminous mantle. However, several processes tend to obscure the helium isotope signal from reservoirs in basaltic lavas that have erupted at the surface. Timmerman et al. identified a set of diamonds that formed deep within Earth and were rapidly erupted, which have avoided near-surface

Big Bang nucleosynthesis - Wikipedia

Primordial nucleosynthesis is believed by most cosmologists to have taken place in the interval from roughly 10 seconds to 20 minutes after the Big Bang, and is calculated to be responsible for the formation of most of the universe's helium as the isotope helium-4 (4 He), along with small amounts of the hydrogen isotope deuterium (2 H or D ...

The UV Upturn In Elliptical Galaxies And Environmental ...

Jan 01, 2012  An extremely high abundance of helium (Y 0.4) allows for a working hypothesis, but its origin is unclear. Peng Nagai (2009) proposed that primordial helium sedimentation in dark haloes over cosmic timescales may lead to extreme helium abundances in galaxy cluster centers.

(PDF) The Primordial Helium Abundance: Toward ...

Feb 02, 2000  An accurate measuremen t of the primordial helium abundance would b e an imp ortan t test of standard big b ang n ucleosyn thesis (Olive, Steigman

The Ultraviolet Upturn in Elliptical Galaxies and ...

Aug 01, 2011  It is suspected that the ultraviolet (UV) upturn phenomenon in elliptical galaxies and extended horizontal-branch stars in globular clusters have a common origin. An extremely high abundance of helium (Y ~ 0.4) allows for a working hypothesis, but its origin is unclear. Peng Nagai proposed that primordial helium sedimentation in dark halos over cosmic timescales may lead to extreme helium ...

(PDF) Helium Sedimentation and the Ultraviolet Upturn in ...

Helium Sedimentation and the Ultraviolet Upturn in Brightest Cluster Galaxies. ... In this work, we propose that the sedimentation process can greatly enhance the He abundance in BCGs. Our model ...

THE ULTRAVIOLET UPTURN IN ELLIPTICAL GALAXIES AND ...

stars in globular clusters have a common origin. An extremely high abundance of helium (Y ∼ 0.4) allows for a working hypothesis, but its origin is unclear. Peng Nagai proposed that primordial helium sedimentation in dark halos over cosmic timescales may lead to extreme helium abundances in galaxy cluster centers. In this scenario,

[1107.0005] The UV Upturn in Elliptical galaxies and ...

Jun 30, 2011  An extremely high abundance of helium (Y~0.4) allows for a working hypothesis, but its origin is unclear. Peng Nagai (2009) proposed that primordial helium sedimentation in dark haloes over cosmic timescales may lead to extreme helium abundances in galaxy cluster centers.

The diffusion of helium through sedimentary rocks ...

Source of helium Two classes of helium can be envisaged: primordial helium, and radiogenic helium produced since the formation of the earth. In view of the wide cosmic abundance of helium it is clear that primordial helium did exist in the early stages of the earth's formation and a portion of this helium is still present. ... The sedimentation ...

(PDF) A measurement of the primordial helium abundance ...

However, a proper treatment of gravitational sedimentation of helium was not considered in their computations, so their estimation is too lower than the recent measurements of the primordial ...

Helium-3 the Mantle: Primordial Signal or Cosmic Dust?

been2 x 10-15 cm3 cm-2year` over the past 40 million years [variation from 1 x 105to5 X 10-15cm3cm-2year-] (17). UsinganETflux of50Ggyear-1, basedon siderophiles (8) andanIDP3Heconcentra- tion of 4 x 10` cm3 g` (18), the total 3Hedelivered to the Earth is 2 x 106 cm3 year-1. Siderophiles, ofcourse, survive at- mospheric entry but some of the volatiles are lost by fragmentation andmelting dur-

HELIUM SEDIMENTATION AND THE ULTRAVIOLET UPTURN

in Equation (2) further suppresses the sedimentation process. Substituting Equation (6) into Equation (1) and integrating over time, we obtain Y = Y 0e4Δt/3τ, where Y 0 is the primordial He mass fraction and τ 10Gyr(f gas/0.1)(T/10keV)−3/2(1+ 1.5dlnT/dlnr)−1 is the sedimentation timescale (Chuzhoy Loeb 2004). Note that the gas ...

The primordial helium abundance determination from metal ...

The advantages of measuring the helium abundance in metal-poor emission-line galaxies are emphasized. Recent results are reviewed and seem to converge to a primordial helium abundance Y p = 0.24±0.01. There is little evidence so far for a relation between the helium abundance and the oxygen abundance whereas nitrogen seems to correlate better with the observed helium.

Why Helium Could Be The Next Commodity To Boom

Our helium comes from two main sources: Primordial, which is part of the original formation of the planet, or from radioactive decay of uranium and thorium in the earth’s crust. Most of our ...

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of this sedimentation of heavy ions toward the central region, given that the cluster has survived for a sufficiently long time in the universe, m will no longer be a constant in the cluster. If the intracluster gas is entirely composed of hydrogen and helium with their primordial abundances, the value of m will

Elements of the past: Big Bang Nucleosynthesis and ...

By this extrapolation, we obtain an estimate for the primordial helium-4 abundance. All investigations of this type result in a primordial helium-4 mass fraction of 24 per cent, with an uncertainty of little more than one per cent. ... a cosmic analogue to the more familiar phenomenon of sedimentation: if you let a mixture of water and sand ...

Big Bang nucleosynthesis - Wikipedia

Primordial nucleosynthesis is believed by most cosmologists to have taken place in the interval from roughly 10 seconds to 20 minutes after the Big Bang, and is calculated to be responsible for the formation of most of the universe's helium as the isotope helium-4 (4 He), along with small amounts of the hydrogen isotope deuterium (2 H or D ...

'Space Force': the truth behind the helium-3 plot twist

Jun 03, 2020  Helium-3 is primordial, dating back to a planetary body’s earliest days. On Earth, it formed in the mantle of the planet, above the core and below the crust.

PROVEN AND HYPOTHETICAL HELIUM RESOURCES IN UTAH

Helium (He) is a colorless, odorless, chemically inert element of the noble gas family with two stable isotopes: the lighter, rarer primordial helium-3 (3He) and the heavier, more com-mon radiogenic helium-4 (4He) that has historically been a byproduct of natural gas production (figure 1) (Anderson, 1998; Gilfillan and others, 2008).

Cosmological helium production simplified

Bernstein, Brown, and Feinberg: Cosmological helium production simplified the neutron to proton number densities at such early times is given by the simple Boltzmann factor n„(T) nz(T) Twhere Am is the neutron-proton mass difFerence, Am =m„—m-1.29 MeV. (1.2) (1.3) At the initial temperature of 100 MeV, the neutron- proton ratio is very close to unity. It proves convenient

arXiv:astro-ph/9907402v1 28 Jul 1999 - CiteSeerX

It is however of primordial importance to derive ... The additional energy provided by helium sedimentation (or that of any other element) has been estimated by Hubbard et al. (1999). The resulting model ages therefore provide an ... helium and heavy elements, I also introduce an equivalent helium mass mixing ratio, YZ ∼ Y +Z

Bio - Dr. ERIC R SWITZER - NASA

The Sciences and Exploration Directorate is the largest Earth and space science research organization in the world. Its scientists advance understanding of the Earth and its life-sustaining environment, the Sun, the solar system, and the wider universe beyond. The Directorate is part of Goddard Space Flight Center (GSFC) in Greenbelt, Maryland.

Primordial helium abundance determination using sulphur as ...

The primordial helium abundance Y P is calculated using sulphur as metallicity tracer in the classical methodology (with Y P as an extrapolation of Y to zero metals). The calculated value, Y P , S = 0.244 ± 0.006, is in good agreement with the estimate from the Planck experiment, as well as, determinations in the literature using oxygen as the ...

THE ULTRAVIOLET UPTURN IN ELLIPTICAL GALAXIES AND ...

Aug 04, 2011  An extremely high abundance of helium (Y ~ 0.4) allows for a working hypothesis, but its origin is unclear. Peng Nagai proposed that primordial helium sedimentation in dark halos over cosmic timescales may lead to extreme helium abundances in galaxy cluster centers.

new determination of the primordial helium abundance using ...

ABSTRACT. The precision measurement of the primordial helium abundance Y p is a powerful probe of the early Universe. The most common way to determine Y p is the analyses of observations of metal-poor H ii regions found in blue compact dwarf galaxies. We present the spectroscopic sample of 100 H ii regions collected from the Sloan Digital Sky Survey. . The final analysed sample consists of our ...

What percentage of Helium-3 is primordial vs produced in stars

My question is 2-fold: 1. Is the primordial amounts of $^3$ He significant or insignificant compared to what stars produce and eject by coronal mass ejections or blowing up into nebulas, and .... The $^3$ He composition of CMEs can vary significantly, see: "Unusual composition of the solar wind in the 2-3 May 1998 CME observed with SWICS on ACE" (Jan 1999), by G. Gloeckler, L. A. Fisk, S ...

THE HELIUM CONTENT OF GLOBULAR CLUSTERS: NGC 6121

studies available in the literature. This is a rare direct measurement of the (primordial) He abundance for stars belonging to the Na-rich/O-poor population of GC stars in a temperature regime where the He content is not altered by sedimentation or extreme mixing as suggested for the hottest, late helium flash HB stars. Our results support

Primordial Nucleosynthesis: Successes and Challenges - G ...

As gas cycles through generations of stars, hydrogen is burned to helium-4 (and beyond), increasing the 4 He abundance above its primordial value. The 4 He mass fraction in the Universe at the present epoch, Y 0 , has received a significant contribution from post-BBN, stellar nucleosynthesis, so

What is the primordial helium? - Answers

Helium-4 mostly arises from alpha decay of heavy radioactive elements. Helium-3 is primordial helium, and is extremely rare on Earth. Whether or not a minute proportion of the Earth's total helium ...

Cosmological helium production simplified

Bernstein, Brown, and Feinberg: Cosmological helium production simplified the neutron to proton number densities at such early times is given by the simple Boltzmann factor n„(T) nz(T) Twhere Am is the neutron-proton mass difFerence, Am =m„—m-1.29 MeV. (1.2) (1.3) At the initial temperature of 100 MeV, the neutron- proton ratio is very close to unity. It proves convenient

The Primordial Lithium Problem Answers in Genesis

Jan 15, 2015  The Problem. According to the big bang model, nuclear reactions in the first few minutes after the big bang produced the three lightest elements: hydrogen, helium, and lithium. Much later, stars produced all the other elements, including the carbon upon which all life is based, the nitrogen and oxygen in the air we breathe, the calcium in our bones, and the iron in our blood.

Helium Hydride: The First Molecule? Answers in Genesis

May 22, 2019  Conclusion. Let me recap: This study produced the first unambiguous detection of helium hydride in space. Helium hydride is believed to be the first molecule to have formed in the big bang universe. The formation of this molecule is important to the big bang model, because it was a crucial step in the development of molecular hydrogen, which in turn was a critical step in the formation of the ...

Geochemistry and Geology of Helium - ScienceDirect

Jan 01, 1971  Cosmogenic Helium Cosmogenic or primordial helium was first detected in the sun's spectrum by Lockyer in 1868 (see [38]). A look a t the cosmic abundance of elements in Fig. 1. reveals that helium is a major constituent of most stars. ... t is the time measured from beginning of sedimentation, and C , and fl determined by the abundances and ...

Helium-3 anomalies and crust-mantle interaction in Italy ...

Dec 01, 1985  The distribution of primordial 3 He in the crust of Italy has been investigated through a survey of groundwaters, hot-springs, exploration and production geothermal wells. The mantle-derived component varies from 0% to > 60% and reaches a maximum at Vulcano in the Eolian Islands. 3 He anomalies occur where the conductive heat flow is relatively high, but the relationships between heat

Gravitational di usion in the intra-cluster medium

From (6) the helium velocity is V − Vp =(3 =4− 1)~g~~ ˝ p ˇ−0:56gg~~ ˝ p: (7) The relative sedimentation speed of heavy elements, Vi − Vp, can easily be related to that of helium V − Vp. Heavy elements experience an upward proton drag and in-ward helium drag forces. According to (2), ˝ij / Z−2 i

Hydrogen-Helium Abundance - HyperPhysics Concepts

Hydrogen-Helium Abundance Hydrogen and helium account for nearly all the nuclear matter in today's universe. This is consistent with the standard or "big bang" model.The process of forming the hydrogen and helium and other trace constituents is often called "big bang nucleosynthesis".Schramm's figures for relative abundances indicate that helium is about 25% by mass and hydrogen about 73% with ...