INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI
Cosmic-ray induced γ-ray emission in active galactic nuclei (AGN) has been examined in this study for the first time. Cross-sections for the formation of γ-quanta in such cosmic-ray collisions were selected in the 1-150 MeV energy range. Synthetic γ-ray spectra were computed for both interstellar ga...
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| Format: | Article |
| Language: | English |
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Odessa I. I. Mechnykov National University
2020-11-01
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| Series: | Odessa Astronomical Publications |
| Subjects: | |
| Online Access: | http://oap.onu.edu.ua/article/view/216282 |
| _version_ | 1818700485061771264 |
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| author | D. N. Doikov |
| author_facet | D. N. Doikov |
| author_sort | D. N. Doikov |
| collection | DOAJ |
| description | Cosmic-ray induced γ-ray emission in
active galactic nuclei (AGN) has been examined in this
study for the first time. Cross-sections for the formation of
γ-quanta in such cosmic-ray collisions were selected in the
1-150 MeV energy range. Synthetic γ-ray spectra were
computed for both interstellar gas and dust. At the same
energies of particle collisions and induced emission of γ-
quanta, energy intervals of diagnostic interest were
determined. Specific characteristics of emission were
detected in the energy ranges of 5-15 MeV and 23-30 MeV
for most investigated elements. Diffuse continuous γ-ray
spectra for the other energy ranges were less informative
with regard to the determination of the chemical
composition of interstellar gas. It has been shown that
exploring cosmic-ray fluxes in the vicinity of galactic
centres by employing the examined γ-ray spectra yields a
pattern of their energy distribution. Diagrams of cross-
sections for γ-quanta formation were computed for the α-
process elements. Synthetic γ-ray spectra of interstellar gas
and dust were calculated individually and collectively. It
has been indicated that, under certain conditions in AGN,
cross-sections for ionisation of atoms due to energy losses
by cosmic-ray induced ionisation and γ-quanta emission
resulting from collisions with cosmic rays are similar. It has
been found that when the maximum of proton and α-
particle energy distribution function falls within the
investigated range of energies, it leads to the formation of
the peak flux of γ-rays. This is particularly important for
the interpretation of observations in the energy ranges of 5-
15 MeV and 23-30 MeV. Synthetic induced γ-ray spectra
of interstellar dust were computed, and methods of their
observations for silicate and carbon-containing dust, which
account for 80% and 20% of the interstellar-dust total mass,
respectively, were determined. It has been deduced that the
contribution of Compton processes to γ-quanta emission
can be neglected at the investigated energies. |
| first_indexed | 2024-12-17T15:05:41Z |
| format | Article |
| id | doaj.art-af5186ab30f846e38301d9a0203ce4cf |
| institution | Directory Open Access Journal |
| issn | 1810-4215 |
| language | English |
| last_indexed | 2024-12-17T15:05:41Z |
| publishDate | 2020-11-01 |
| publisher | Odessa I. I. Mechnykov National University |
| record_format | Article |
| series | Odessa Astronomical Publications |
| spelling | doaj.art-af5186ab30f846e38301d9a0203ce4cf2022-12-21T21:43:47ZengOdessa I. I. Mechnykov National UniversityOdessa Astronomical Publications1810-42152020-11-01330283310.18524/1810-4215.2020.33.216282216282INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEID. N. Doikov0Odessa National Maritime University. Department of Natural and Technical SciencesCosmic-ray induced γ-ray emission in active galactic nuclei (AGN) has been examined in this study for the first time. Cross-sections for the formation of γ-quanta in such cosmic-ray collisions were selected in the 1-150 MeV energy range. Synthetic γ-ray spectra were computed for both interstellar gas and dust. At the same energies of particle collisions and induced emission of γ- quanta, energy intervals of diagnostic interest were determined. Specific characteristics of emission were detected in the energy ranges of 5-15 MeV and 23-30 MeV for most investigated elements. Diffuse continuous γ-ray spectra for the other energy ranges were less informative with regard to the determination of the chemical composition of interstellar gas. It has been shown that exploring cosmic-ray fluxes in the vicinity of galactic centres by employing the examined γ-ray spectra yields a pattern of their energy distribution. Diagrams of cross- sections for γ-quanta formation were computed for the α- process elements. Synthetic γ-ray spectra of interstellar gas and dust were calculated individually and collectively. It has been indicated that, under certain conditions in AGN, cross-sections for ionisation of atoms due to energy losses by cosmic-ray induced ionisation and γ-quanta emission resulting from collisions with cosmic rays are similar. It has been found that when the maximum of proton and α- particle energy distribution function falls within the investigated range of energies, it leads to the formation of the peak flux of γ-rays. This is particularly important for the interpretation of observations in the energy ranges of 5- 15 MeV and 23-30 MeV. Synthetic induced γ-ray spectra of interstellar dust were computed, and methods of their observations for silicate and carbon-containing dust, which account for 80% and 20% of the interstellar-dust total mass, respectively, were determined. It has been deduced that the contribution of Compton processes to γ-quanta emission can be neglected at the investigated energies.http://oap.onu.edu.ua/article/view/216282active galactic nucleiγ-ray emission |
| spellingShingle | D. N. Doikov INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI Odessa Astronomical Publications active galactic nuclei γ-ray emission |
| title | INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI |
| title_full | INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI |
| title_fullStr | INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI |
| title_full_unstemmed | INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI |
| title_short | INDUCING INTRINSIC γ-RAY EMISSION OF THE INTERSTELLAR MEDIUM BY INTENSE FLUXES OF PROTONS AND α-PARTICLES IN ACTIVE GALACTIC NUCLEI |
| title_sort | inducing intrinsic γ ray emission of the interstellar medium by intense fluxes of protons and α particles in active galactic nuclei |
| topic | active galactic nuclei γ-ray emission |
| url | http://oap.onu.edu.ua/article/view/216282 |
| work_keys_str_mv | AT dndoikov inducingintrinsicgrayemissionoftheinterstellarmediumbyintensefluxesofprotonsandaparticlesinactivegalacticnuclei |