Analysis of Superflare Isotopic Imprints in Lunar and Terrestrial Samples
Analysis of Superflare “Isotopic
Imprints” in Lunar and Terrestrial
Samples
Primary authors : Dr. PAVLOV, Anatoly (Ioffe Institute)
Co-authors : Mr. FROLOV, Dminry (Peter the Great Saint-Petersburg Polytechnic University) ;
Prof. OSTRYAKOV, Valery (Peter the Great Saint-Petersburg Polytechnic University) ; Dr.
VASILYEV, Gennady (Ioffe Institute) ; Dr. STRUMINSKY, Alexei (Space Research
Institute)
Presenter : Dr. STRUMINSKY, Alexei (Space Research Institute)
8 September 2016
Torino, ECRS 2016
Mekhaldi et al, 2015
•
The origin of two large peaks in the atmospheric radiocarbon (14C)
concentration at AD 774/5 and 993/4 is still debated.
•
There is consensus that these features can only be explained by an
increase in the atmospheric 14C production rate due to an extraterrestrial
event.
•
The authors provided evidence that these peaks were most likely
produced by extreme solar events, based on several new annually
resolved 10Be measurements from both Arctic and Antarctic ice cores.
•
Using ice core 36Cl data in pair with 10Be, they showed that these solar
events were characterized by a very hard energy spectrum with high fluxes
of solar protons with energy above 100MeV.
In this work
Model for the Earth
atmosphere (Pavlov,
Ostryakov, Vasiliev,
Frolov)
10
Be
36
Cl
Spectra
of GCR,
solar
protons
14
C
INPUT
OUTPUT
COMPARE
775 AD
METHOD Terrestrial samples
•
We used the standard
GEANT4.10.0 code for simulations
of atmospheric interactions of
high-energy charged particles and
gamma-rays.
•
Production rates for
14
С
,
10
Ве
and
36
Cl were calculated for 0-130 km
altitudes with 1 km step with the
isotropic particle flux penetrating
the Earth's atmosphere.
•
The yield function of a nuclide is
defined as its integrated
production in all channels
induced by the primary
interacting particle of a given
energy.
775 AD, model calculations
Ultimate spectra of solar protons
Strumimsky, 2015
Propagation limits
for different values of the IMF
strength. (Freier&Webber, 1963)
.
Spectra of non – relativistic (
γ
=2.5)
and relativistic (
γ
=4) solar protons
(Syrovatsky, 1961) .
Red - - normalised to
j
(E=10 MeV,
B=100
γ
)
Green -- normalized to GCR intensity
at 20 GeV
Brown -- normalized to GCR intensity
at 100 GeV.
Blue line - the spectrum of GCR.
775AD, ultimate spectra
Lunar samples
•
AJT Jull, S Cloudt, DJ Donahue,
JM Sisterson, RC Reedy, and J
Masarik.
14
C depth profiles in
Apollo 15 and 17 cores and
lunar rock 68815. Geochimica
et Cosmochimica Acta,
2(17):3025–3036, 1998.
•
K Nishiizumi, JR Arnold, CP
Kohl, MW Caffee, J Masarik,
and RC Reedy. Solar cosmic ray
records in lunar rock 64455.
Geochimica et Cosmochimica
Acta, 73
(7):2163–2176, 2009
In this work
Model for lunar
samples (Pavlov,
Ostryakov, Vasiliev,
Frolov)
14
C
26
Al
Spectra
of GCR,
solar
protons
INPUT
OUTPUT
Number of
possible
events
METHOD Lunar
•
Equilibrium densities of
long living isotopes
14
С
,
26
Al,
(origin by CR interaction =
decay
)
for different models
(
BIC and BERT) of internal
nuclear cascade
within
GEANT
•
14
С
and
36
Cl are better
described by BIC, but
26
Al
and
10
Be
by BERT
•
There is an excess of
radionuclei density within
first cm’s of lunar kerns in
comparison with their
production by GCR, it’s of
solar origin (SCR)
•
An estimate of event
frequency for events similar
to the
775
AD event
.
An
impact is less than excess
.
•
14
С –
scale
10-20
thousands
years
,
26
Al
–
scale
1-2
billion
years
Lunar samples, 775AD
•
14
С
– less than one event per
3000
years on a scale of <
20000
years
,
26
Al -
the same but on
a scale of
1-2
million
years.
•
14
С
- less than one event per
10000
years on a scale of
<
20000
years
,
26
Al –
less than one event per
60000
years
on a scale of
1-2
million years.
•
Like
19
56
•
Like
19
72
Lunar samples Ultimate spectra
775AD
•
14
С
- less than one event per
3000
years on a scale of
<
20000
years
,
26
Al
the same but on a scale of
1-2
million
years.
•
14
С
- less than one event per
1800
years
on a scale of
<
20000
years
,
26
Al –
less than one event per
10000
years on
a scale of
1-2
million years.
•
14
С
– less than one event per
330
years
on a scale of
<
20000
years
,
26
Al
- less
than one event per 1
000
years on a
scale
1-2
million years.
•
soft
•
Medium
•
hard
Conclusions
•
The ultimate spectra (Struminsky, 2015) do not contradict to
radionuclide production in the Earth atmosphere and Lunar rocks.
•
Modeling of global radionuclide production in the Earth
atmosphere during the
775
AD event with different spectra of solar
protons showed an excess by several times of
10
Be and
36
Cl
isotopes in comparison with observation for production of
14
С
equal to observations.
•
An agreement of measured and calculated values is possible under
an assumption that majority of
10
Be and
36
Cl have been produced
in the polar troposphere. Additional investigations are necessary.
•
A comparison of calculated and measured densities of radionuclide
in the upper layer of lunar soil gives a frequency of superflares on a
scale of
20000
years
is
1
event per 330 years for “hard” events and
per
10000
years for “soft”.
On a scale of
1-2
million years – one
“hard” event per 1000 years for events and one ‘soft” event
60000
years.
Researchers investigate isotopic imprints in lunar and terrestrial samples to understand extreme solar events and their impact on atmospheric radiocarbon concentrations. Using 10Be and 36Cl data, they analyze the solar proton spectra and energy fluxes associated with these events, shedding light on past cosmic phenomena and their effects on Earth.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
Analysis of Superflare Isotopic Imprints in Lunar and Terrestrial Samples Primary authors : Dr. PAVLOV, Anatoly (Ioffe Institute) Co-authors : Mr. FROLOV, Dminry (Peter the Great Saint-Petersburg Polytechnic University) ; Prof. OSTRYAKOV, Valery (Peter the Great Saint-Petersburg Polytechnic University) ; Dr. VASILYEV, Gennady (Ioffe Institute) ; Dr. STRUMINSKY, Alexei (Space Research Institute) Presenter : Dr. STRUMINSKY, Alexei (Space Research Institute) 8 September 2016 Torino, ECRS 2016
Mekhaldi et al, 2015 The origin of two large peaks in the atmospheric radiocarbon (14C) concentration at AD 774/5 and 993/4 is still debated. There is consensus that these features can only be explained by an increase in the atmospheric 14C production rate due to an extraterrestrial event. The authors provided evidence that these peaks were most likely produced by extreme solar events, based on several new annually resolved 10Be measurements from both Arctic and Antarctic ice cores. Using ice core 36Cl data in pair with 10Be, they showed that these solar events were characterized by a very hard energy spectrum with high fluxes of solar protons with energy above 100MeV. Experimental results 14C 10Be 36CL Enhancement relative background 4 3.4 6.3
In this work OUTPUT INPUT 14C Spectra of GCR, solar protons Model for the Earth atmosphere (Pavlov, Ostryakov, Vasiliev, Frolov) 10Be 36Cl COMPARE 775 AD
METHOD Terrestrial samples We used the standard GEANT4.10.0 code for simulations of atmospheric interactions of high-energy charged particles and gamma-rays. Production rates for 14 , 10 and 36Cl were calculated for 0-130 km altitudes with 1 km step with the isotropic particle flux penetrating the Earth's atmosphere. The yield function of a nuclide is defined as its integrated production in all channels induced by the primary interacting particle of a given energy.
775 AD, model calculations Enhancement relative observations 14C F(1956)*75.6 = F(775) F(1972)*283= F(775 ) F(2005)*620= F(775) 10Be 2 36Cl 1.35 1.5 9 2 2.2
Ultimate spectra of solar protons Strumimsky, 2015 Propagation limits for different values of the IMF strength. (Freier&Webber, 1963). Spectra of non relativistic ( =2.5) and relativistic ( =4) solar protons (Syrovatsky, 1961) . Red - - normalised to j (E=10 MeV, B=100 ) Green -- normalized to GCR intensity at 20 GeV Brown -- normalized to GCR intensity at 100 GeV. Blue line - the spectrum of GCR. 100 nTl soft mean hard J(>30 ) F(>30 ) J(>200 ) F(>200 ) 934 4.2 109 244 9.2 107 4.9 105 1.8 1011 13981 5.3 109 4.9 105 1.8 1011 1.7 105 6.4 1010
775AD, ultimate spectra Enhancement relative observations 14C Soft*149 medium *1.2 hard* 0.074 10Be 1.8 2 2 36Cl 7 2.4 1
Lunar samples AJT Jull, S Cloudt, DJ Donahue, JM Sisterson, RC Reedy, and J Masarik. 14C depth profiles in Apollo 15 and 17 cores and lunar rock 68815. Geochimica et Cosmochimica Acta, 2(17):3025 3036, 1998. K Nishiizumi, JR Arnold, CP Kohl, MW Caffee, J Masarik, and RC Reedy. Solar cosmic ray records in lunar rock 64455. Geochimica et Cosmochimica Acta, 73 (7):2163 2176, 2009
In this work OUTPUT INPUT Spectra of GCR, solar protons Model for lunar samples (Pavlov, Ostryakov, Vasiliev, Frolov) 14C 26Al Number of possible events
METHOD Lunar Equilibrium densities of long living isotopes 14 , 26Al, (origin by CR interaction = decay) for different models (BIC and BERT) of internal nuclear cascade within GEANT described by BIC, but 26Al and 10Be by BERT There is an excess of radionuclei density within first cm s of lunar kerns in comparison with their production by GCR, it s of solar origin (SCR) An estimate of event frequency for events similar to the 775AD event. An impact is less than excess. years, 26Al scale 1-2 billion years 14 and 36Cl are better 14 scale 10-20 thousands
Lunar samples, 775AD 14 less than one event per 3000 years on a scale of <20000 years, 26Al - the same but on a scale of 1-2 million years. Like 1956 14 - less than one event per 10000 years on a scale of <20000 years, 26Al less than one event per 60000 years on a scale of 1-2 million years. Like 1972 14 C (BIC) at/cm^3 at 1 g/cm*2 8 7 1.4 5 8.7 5 26 Al (BERT) at/cm^3 at 1 g/cm*2 10 10 1.3 5 9,5 5 observations 1956 1972
Lunar samples Ultimate spectra 775AD observations 1.17 8 Model, soft spectrum 7,1 4 Model, medium spectrum 5,9 6 Model, hard spectrum 1.8 7 14C (BIC) at/cm^3 at 1 g/cm*2 26Al(BERT) at/cm^3 at 1 g/cm*2 1.8 10 7 5 2.9 7 4.9 7 14 - less than one event per 3000 years on a scale of <20000 years, 26Al the same but on a scale of 1-2 million years. 14 - less than one event per 1800 years on a scale of <20000 years, 26Al less than one event per 10000 years on a scale of 1-2 million years. 14 less than one event per 330 years on a scale of <20000 years, 26Al - less than one event per 1000 years on a scale 1-2 million years. soft Medium hard
Conclusions The ultimate spectra (Struminsky, 2015) do not contradict to radionuclide production in the Earth atmosphere and Lunar rocks. Modeling of global radionuclide production in the Earth atmosphere during the 775AD event with different spectra of solar protons showed an excess by several times of 10 Be and 36Cl isotopes in comparison with observation for production of 14 equal to observations. An agreement of measured and calculated values is possible under an assumption that majority of 10 Be and 36Cl have been produced in the polar troposphere. Additional investigations are necessary. A comparison of calculated and measured densities of radionuclide in the upper layer of lunar soil gives a frequency of superflares on a scale of 20000 years is 1 event per 330 years for hard events and per 10000 years for soft . On a scale of 1-2 million years one hard event per 1000 years for events and one soft event 60000 years.
