OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS

 Subject and Purpose. In Part 2 of the current paper, we seek to analyze the observational results of decameter carbon radio recombination lines (RRLs) detected near the frequency 26 MHz through the UTR-2 radio telescope towards the S140 emission nebula and the GSH 139-03-69 super shell. These lines...

Full description

Saved in:
Bibliographic Details
Date:2023
Main Authors: Vasylkivskyi, Y. V., Konovalenko, O. O., Stepkin, S. V.
Format: Article
Language:English
Published: Видавничий дім «Академперіодика» 2023
Subjects:
Online Access:http://rpra-journal.org.ua/index.php/ra/article/view/1425
Tags: Add Tag
No Tags, Be the first to tag this record!
Journal Title:Radio physics and radio astronomy

Institution

Radio physics and radio astronomy
id rpra-journalorgua-article-1425
record_format ojs
institution Radio physics and radio astronomy
baseUrl_str
datestamp_date 2023-12-13T19:23:30Z
collection OJS
language English
topic electron density
electron temperature
interstellar medium
ionized carbon
medium model
radio recombination lines
CII region
spellingShingle electron density
electron temperature
interstellar medium
ionized carbon
medium model
radio recombination lines
CII region
Vasylkivskyi, Y. V.
Konovalenko, O. O.
Stepkin, S. V.
OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS
topic_facet electron density
electron temperature
interstellar medium
ionized carbon
medium model
radio recombination lines
CII region
електронна густина
електронна температура
іонізований вуглець
міжзоряне середовище
модель середовища
рекомбінаційні радіолінії
СІІ-область
format Article
author Vasylkivskyi, Y. V.
Konovalenko, O. O.
Stepkin, S. V.
author_facet Vasylkivskyi, Y. V.
Konovalenko, O. O.
Stepkin, S. V.
author_sort Vasylkivskyi, Y. V.
title OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS
title_short OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS
title_full OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS
title_fullStr OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS
title_full_unstemmed OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS
title_sort observations of decameter carbon radio recombination lines in several galactic directions part 2. analysis of physical conditions in diffuse cii regions
title_alt СПОСТЕРЕЖЕННЯ ДЕКАМЕТРОВИХ РЕКОМБІНАЦІЙНИХ РАДІОЛІНІЙ ВУГЛЕЦЮ В ДЕЯКИХ НАПРЯМКАХ ГАЛАКТИКИ Частина 2. АНАЛІЗ ФІЗИЧНИХ УМОВ У ДИФУЗНИХ CII-ОБЛАСТЯХ
description  Subject and Purpose. In Part 2 of the current paper, we seek to analyze the observational results of decameter carbon radio recombination lines (RRLs) detected near the frequency 26 MHz through the UTR-2 radio telescope towards the S140 emission nebula and the GSH 139-03-69 super shell. These lines have proven themselves as a highly effective tool for cold, rarefied interstellar medium (ISM) diagnostics. The aim is to determine an association of line-forming regions (CII regions) with other ISM components and study physical conditions (electron temperature Te and electron density Ne) in these regions.Methods and Methodology. By iterative comparison of detected and modeled integral intensities of decameter carbon RRLs, we determine physical state ranges where recorded experimental data best fit the model values for various combinations of Te,Ne, and path lengths s.Results.It has been found that the characteristics of the detected decameter carbon RRLs are consistent with the higher-frequency data for both the S140 line of sight and other Galactic plane directions, including the GSH 139-03-69 direction. Ranges of physical conditions where recorded data and model values are in the best agreement have been determined, being Te = 50÷ 100 K, Ne = 0.01 cm–3, and s= 10 pc — for the S140 nebula direction and its vicinity and, also, Te = 50÷ 100 K, Ne =0.01 cm–3, and s = 5÷ 7 pc — for the GSH 139-03-69 super shell direction.Conclusions. The obtained results indicate that the detected decameter carbon RRLs originate from CII regions associated with clouds of diffuse neutral hydrogen HI in the Galactic plane. The lines are seen against a background Galactic radio emission whose brightness temperature increases as frequency decreases. Keywords: electron density; electron temperature; interstellar medium; ionized carbon; medium model; radio recombination lines; CII region Manuscript submitted  03.03.2023Radio phys. radio astron. 2023, 28(4): 275-286REFERENCES1. Vasylkivskyi, Y.V., Konovalenko, O.O., Stepkin, S.V., 2023. Observations of decameter carbon radio recombination lines toward several Galactic directions. Part 1. Experimental study. Radio Phys. Radio Astron., 28(3), pp. 201—211. DOI: https://doi.org/10.15407/rpra28.03.2012. Konovalenko, A.A., and Sodin, L.G., 1981. The 26.13 MHz absorption line in the direction of Cassiopeia A. Nature, 294, pp. 135—136. DOI: https://doi.org/10.1038/294135a03. Gordon, M.A., and Sorochenko, R.L., 2009. Radio Recombination Lines. Their Physics and Astronomical Applications. Ser. Astrophysics and Space Science Library. Vol. 282. New York: Springer Science + Business Media. DOI: https://doi.org/10.1007/978-94-010-0261-54. Konovalenko, A.A., and Stepkin, S.V., 2005. Radio Recombination Lines. In: L.I. Gurvits, S. Frey, and S. Rawlings, eds., Radio Astronomy from Karl Jansky to Microjansky. Budapest, Hungary: EAS Publ., 15, pp. 271—295. DOI: https://doi.org/10.1051/eas:20051585. Stepkin, S.V., Konovalenko, O.O., Vasylkivskyi, Y.V., Mukha, D.V., 2021. Interstellar medium and decameter radio spectroscopy. Radio Phys. Radio Astron., 26(4), pp. 314—325. DOI: https://doi.org/10.15407/rpra26.04.3146. Walmsley, C.M., and Watson, W.D., 1982. The influence of dielectronic-like recombination at low temperatures on the interpretation of interstellar, radio recombination lines of carbon. Astrophys. J., 260, pp. 317—325. DOI: https://doi.org/10.1086/1602567. Knapp, G.R., Brown, R.L., Kuiper, T.B.H., Kaakr, R.K., 1976. Carbon recombination line observations of the sharpless 140 region. Astrophys. J., 204(1), pp. 781—783. DOI: https://doi.org/10.1086/1542258. Smirnov, G.T., Sorochenko, R.L., Walmsley, C.M., 1995. The S 140/L 1204 complex: radio recombination lines of hydrogen, carbon and sulphur. Astron. Astrophys., 300, pp. 923—932.9. Golynkin, A.A., Konovalenko, A.A., 1991. Radio recombination lines of highly excited carbon near DR21 and S140. Sov. Astron. Lett., 16(1), pp. 7—10.10. Smirnov, G.T., Sorochenko, R.L., Kitaev, V.V., 1992. Search for 42 MHz recombination lines toward S140. Sov. Astron. Lett., 18, pp. 192—194.11. Vasylkivskyi, Y.V., Stepkin, S.V., Konovalenko, O.O., 2023. Studies of low-frequency carbon radio recombination lines in medium toward S140 nebula. Contr. Astr. Obs. Skalnate Pleso, 53(1), pp. 17—27. DOI: https://doi.org/10.31577/caosp.2023.53.1.1712. Kalberla, P.M.W., Burton, W.B., Hartman, Dap, Arnal, E.M., Bajaja, E., Morras, R., Pöppel, W.G.L., 2005. The Leiden/Argentine/Bonn (LAB) survey of Galactic HI: final data release of the combined LDS and IAR surveys with improved stray-radiation corrections. Astron. Astrophys., 440(2), pp. 775—782. DOI: https://doi.org/10.1051/0004-6361:2004186413. Knee, L.B.G., Brunt, C.M., 2001. A massive cloud of cold atomic hydrogen in the outer Galaxy. Nature, 412, pp. 308—310. DOI: https://doi.org/10.1038/3508551914. Ershov, A.A., Ilyashov, Y.P., Lekht, E.E., Smirnov, G.T., Solodkov, V.T., Sorochenko, R.L., 1984. Low-frequency (42, 57, 84 MHz) excited-carbon lines toward Cassiopeia A. Sov. Astron. Lett., 10, pp. 348—353.15. Konovalenko, A.A., 1984. Observations of carbon recombination lines at decametric wavelengths in the direction Cassiopeia A. Sov. Astron. Lett., 10, pp. 353—356.16. Ershov, A.A., Lekht, E.E., Smirnov, G.T., Sorochenko, R.L., 1987. Highly excited-carbon level population and nature of the low-frequency radio line forming regions toward Cassiopeia A. Sov. Astron. Lett., 13, pp. 8—11.17. Payne, H.E., Anantharamaiah, K.R., Erickson, W.C., 1989. Stimulated emission of carbon recombination lines from cold clouds in the direction of Cassiopeia A. Astrophys. J., 341, pp. 890—900. DOI: https://doi.org/10.1086/16754718. Payne, H.E., Anantharamaiah, K.R., Erickson, W.C., 1994. High Rydberg state carbon recombination lines toward Cassiopeia A: Physical conditions and a new class of models. Astrophys. J., 430, pp. 690—705. DOI: https://doi.org/10.1086/17444119. Sorochenko, R.L., 1996. Radio recombination lines as a tool for investigation of molecular clouds. Astron. Astrophys. Trans., 11(3), pp. 199—214. DOI: https://doi.org/10.1080/1055679960820546720. Kantharia, N.G., Anantharamaiah, K.R., and Payne, H.E., 1998. Carbon Recombination Lines between 34.5 and 770 MHz toward Cassiopeia A. Astrophys. J., 506(2), pp. 758—772. DOI: https://doi.org/10.1086/30626621. Oonk, J.B.R., van Weeren, R.J., Salas, P., Salgado, F., Morabito, L.K., Toribio, M.C., Tielens, A.G.G.M., Röttgering, H.J.A., 2016. Carbon and hydrogen radio recombination lines from the cold clouds towards Cassiopeia A. Mon. Not. R. Astron. Soc., 465(1), pp. 1066—1088. DOI: https://doi.org/10.1093/mnras/stw281822. Salas, P., Oonk, J.B.R., van Weeren, R.J., Salgado, F., Morabito, L.K., Toribio, M.C., Emig, K., Röttgering, H.J.A., and Tielens, A.G.G.M., 2017. LOFAR observations of decameter carbon radio recombination lines towards Cassiopeia A. Mon. Not. R. Astron. Soc., 467(2), pp. 2274—2287. DOI: https://doi.org/10.1093/mnras/stx23923. Erickson, W.C., McConnell, D., Anantharamaiah, K.R., 1995. Low-frequency carbon recombination lines in the central regions of the Galaxy. Astrophys. J., 454, pp. 125—133. DOI: https://doi.org/10.1086/17647124. Kantharia, N.G., Anantharamaiah, K.R., 2001. Carbon recombination lines from the Galactic plane at 34.5 & 328 MHz. J. Astrophys. Astron., 22, pp. 51—80. DOI: https://doi.org/10.1007/BF0293359025. Salgado, F., Morabito, L.K., Oonk, J.B.R., Salas, P., Toribio, M.C., Röttgering, H.J.A., and Tielens, A.G.G.M., 2017. Low-frequency carbon radio recombination lines. I. Calculation of departure coefficients. Astrophys. J., 837(2), id. 141. DOI: https://doi.org/10.3847/1538-4357/aa5d9e 
publisher Видавничий дім «Академперіодика»
publishDate 2023
url http://rpra-journal.org.ua/index.php/ra/article/view/1425
work_keys_str_mv AT vasylkivskyiyv observationsofdecametercarbonradiorecombinationlinesinseveralgalacticdirectionspart2analysisofphysicalconditionsindiffuseciiregions
AT konovalenkooo observationsofdecametercarbonradiorecombinationlinesinseveralgalacticdirectionspart2analysisofphysicalconditionsindiffuseciiregions
AT stepkinsv observationsofdecametercarbonradiorecombinationlinesinseveralgalacticdirectionspart2analysisofphysicalconditionsindiffuseciiregions
AT vasylkivskyiyv sposterežennâdekametrovihrekombínacíjnihradíolíníjvuglecûvdeâkihnaprâmkahgalaktikičastina2analízfízičnihumovudifuznihciioblastâh
AT konovalenkooo sposterežennâdekametrovihrekombínacíjnihradíolíníjvuglecûvdeâkihnaprâmkahgalaktikičastina2analízfízičnihumovudifuznihciioblastâh
AT stepkinsv sposterežennâdekametrovihrekombínacíjnihradíolíníjvuglecûvdeâkihnaprâmkahgalaktikičastina2analízfízičnihumovudifuznihciioblastâh
first_indexed 2025-12-02T15:26:34Z
last_indexed 2025-12-02T15:26:34Z
_version_ 1851757477313380352
spelling rpra-journalorgua-article-14252023-12-13T19:23:30Z OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS Part 2. ANALYSIS OF PHYSICAL CONDITIONS IN DIFFUSE CII REGIONS СПОСТЕРЕЖЕННЯ ДЕКАМЕТРОВИХ РЕКОМБІНАЦІЙНИХ РАДІОЛІНІЙ ВУГЛЕЦЮ В ДЕЯКИХ НАПРЯМКАХ ГАЛАКТИКИ Частина 2. АНАЛІЗ ФІЗИЧНИХ УМОВ У ДИФУЗНИХ CII-ОБЛАСТЯХ Vasylkivskyi, Y. V. Konovalenko, O. O. Stepkin, S. V. electron density; electron temperature; interstellar medium; ionized carbon; medium model; radio recombination lines; CII region електронна густина; електронна температура; іонізований вуглець; міжзоряне середовище; модель середовища; рекомбінаційні радіолінії; СІІ-область  Subject and Purpose. In Part 2 of the current paper, we seek to analyze the observational results of decameter carbon radio recombination lines (RRLs) detected near the frequency 26 MHz through the UTR-2 radio telescope towards the S140 emission nebula and the GSH 139-03-69 super shell. These lines have proven themselves as a highly effective tool for cold, rarefied interstellar medium (ISM) diagnostics. The aim is to determine an association of line-forming regions (CII regions) with other ISM components and study physical conditions (electron temperature Te and electron density Ne) in these regions.Methods and Methodology. By iterative comparison of detected and modeled integral intensities of decameter carbon RRLs, we determine physical state ranges where recorded experimental data best fit the model values for various combinations of Te,Ne, and path lengths s.Results.It has been found that the characteristics of the detected decameter carbon RRLs are consistent with the higher-frequency data for both the S140 line of sight and other Galactic plane directions, including the GSH 139-03-69 direction. Ranges of physical conditions where recorded data and model values are in the best agreement have been determined, being Te = 50÷ 100 K, Ne = 0.01 cm–3, and s= 10 pc — for the S140 nebula direction and its vicinity and, also, Te = 50÷ 100 K, Ne =0.01 cm–3, and s = 5÷ 7 pc — for the GSH 139-03-69 super shell direction.Conclusions. The obtained results indicate that the detected decameter carbon RRLs originate from CII regions associated with clouds of diffuse neutral hydrogen HI in the Galactic plane. The lines are seen against a background Galactic radio emission whose brightness temperature increases as frequency decreases. Keywords: electron density; electron temperature; interstellar medium; ionized carbon; medium model; radio recombination lines; CII region Manuscript submitted  03.03.2023Radio phys. radio astron. 2023, 28(4): 275-286REFERENCES1. Vasylkivskyi, Y.V., Konovalenko, O.O., Stepkin, S.V., 2023. Observations of decameter carbon radio recombination lines toward several Galactic directions. Part 1. Experimental study. Radio Phys. Radio Astron., 28(3), pp. 201—211. DOI: https://doi.org/10.15407/rpra28.03.2012. Konovalenko, A.A., and Sodin, L.G., 1981. The 26.13 MHz absorption line in the direction of Cassiopeia A. Nature, 294, pp. 135—136. DOI: https://doi.org/10.1038/294135a03. Gordon, M.A., and Sorochenko, R.L., 2009. Radio Recombination Lines. Their Physics and Astronomical Applications. Ser. Astrophysics and Space Science Library. Vol. 282. New York: Springer Science + Business Media. DOI: https://doi.org/10.1007/978-94-010-0261-54. Konovalenko, A.A., and Stepkin, S.V., 2005. Radio Recombination Lines. In: L.I. Gurvits, S. Frey, and S. Rawlings, eds., Radio Astronomy from Karl Jansky to Microjansky. Budapest, Hungary: EAS Publ., 15, pp. 271—295. DOI: https://doi.org/10.1051/eas:20051585. Stepkin, S.V., Konovalenko, O.O., Vasylkivskyi, Y.V., Mukha, D.V., 2021. Interstellar medium and decameter radio spectroscopy. Radio Phys. Radio Astron., 26(4), pp. 314—325. DOI: https://doi.org/10.15407/rpra26.04.3146. Walmsley, C.M., and Watson, W.D., 1982. The influence of dielectronic-like recombination at low temperatures on the interpretation of interstellar, radio recombination lines of carbon. Astrophys. J., 260, pp. 317—325. DOI: https://doi.org/10.1086/1602567. Knapp, G.R., Brown, R.L., Kuiper, T.B.H., Kaakr, R.K., 1976. Carbon recombination line observations of the sharpless 140 region. Astrophys. J., 204(1), pp. 781—783. DOI: https://doi.org/10.1086/1542258. Smirnov, G.T., Sorochenko, R.L., Walmsley, C.M., 1995. The S 140/L 1204 complex: radio recombination lines of hydrogen, carbon and sulphur. Astron. Astrophys., 300, pp. 923—932.9. Golynkin, A.A., Konovalenko, A.A., 1991. Radio recombination lines of highly excited carbon near DR21 and S140. Sov. Astron. Lett., 16(1), pp. 7—10.10. Smirnov, G.T., Sorochenko, R.L., Kitaev, V.V., 1992. Search for 42 MHz recombination lines toward S140. Sov. Astron. Lett., 18, pp. 192—194.11. Vasylkivskyi, Y.V., Stepkin, S.V., Konovalenko, O.O., 2023. Studies of low-frequency carbon radio recombination lines in medium toward S140 nebula. Contr. Astr. Obs. Skalnate Pleso, 53(1), pp. 17—27. DOI: https://doi.org/10.31577/caosp.2023.53.1.1712. Kalberla, P.M.W., Burton, W.B., Hartman, Dap, Arnal, E.M., Bajaja, E., Morras, R., Pöppel, W.G.L., 2005. The Leiden/Argentine/Bonn (LAB) survey of Galactic HI: final data release of the combined LDS and IAR surveys with improved stray-radiation corrections. Astron. Astrophys., 440(2), pp. 775—782. DOI: https://doi.org/10.1051/0004-6361:2004186413. Knee, L.B.G., Brunt, C.M., 2001. A massive cloud of cold atomic hydrogen in the outer Galaxy. Nature, 412, pp. 308—310. DOI: https://doi.org/10.1038/3508551914. Ershov, A.A., Ilyashov, Y.P., Lekht, E.E., Smirnov, G.T., Solodkov, V.T., Sorochenko, R.L., 1984. Low-frequency (42, 57, 84 MHz) excited-carbon lines toward Cassiopeia A. Sov. Astron. Lett., 10, pp. 348—353.15. Konovalenko, A.A., 1984. Observations of carbon recombination lines at decametric wavelengths in the direction Cassiopeia A. Sov. Astron. Lett., 10, pp. 353—356.16. Ershov, A.A., Lekht, E.E., Smirnov, G.T., Sorochenko, R.L., 1987. Highly excited-carbon level population and nature of the low-frequency radio line forming regions toward Cassiopeia A. Sov. Astron. Lett., 13, pp. 8—11.17. Payne, H.E., Anantharamaiah, K.R., Erickson, W.C., 1989. Stimulated emission of carbon recombination lines from cold clouds in the direction of Cassiopeia A. Astrophys. J., 341, pp. 890—900. DOI: https://doi.org/10.1086/16754718. Payne, H.E., Anantharamaiah, K.R., Erickson, W.C., 1994. High Rydberg state carbon recombination lines toward Cassiopeia A: Physical conditions and a new class of models. Astrophys. J., 430, pp. 690—705. DOI: https://doi.org/10.1086/17444119. Sorochenko, R.L., 1996. Radio recombination lines as a tool for investigation of molecular clouds. Astron. Astrophys. Trans., 11(3), pp. 199—214. DOI: https://doi.org/10.1080/1055679960820546720. Kantharia, N.G., Anantharamaiah, K.R., and Payne, H.E., 1998. Carbon Recombination Lines between 34.5 and 770 MHz toward Cassiopeia A. Astrophys. J., 506(2), pp. 758—772. DOI: https://doi.org/10.1086/30626621. Oonk, J.B.R., van Weeren, R.J., Salas, P., Salgado, F., Morabito, L.K., Toribio, M.C., Tielens, A.G.G.M., Röttgering, H.J.A., 2016. Carbon and hydrogen radio recombination lines from the cold clouds towards Cassiopeia A. Mon. Not. R. Astron. Soc., 465(1), pp. 1066—1088. DOI: https://doi.org/10.1093/mnras/stw281822. Salas, P., Oonk, J.B.R., van Weeren, R.J., Salgado, F., Morabito, L.K., Toribio, M.C., Emig, K., Röttgering, H.J.A., and Tielens, A.G.G.M., 2017. LOFAR observations of decameter carbon radio recombination lines towards Cassiopeia A. Mon. Not. R. Astron. Soc., 467(2), pp. 2274—2287. DOI: https://doi.org/10.1093/mnras/stx23923. Erickson, W.C., McConnell, D., Anantharamaiah, K.R., 1995. Low-frequency carbon recombination lines in the central regions of the Galaxy. Astrophys. J., 454, pp. 125—133. DOI: https://doi.org/10.1086/17647124. Kantharia, N.G., Anantharamaiah, K.R., 2001. Carbon recombination lines from the Galactic plane at 34.5 & 328 MHz. J. Astrophys. Astron., 22, pp. 51—80. DOI: https://doi.org/10.1007/BF0293359025. Salgado, F., Morabito, L.K., Oonk, J.B.R., Salas, P., Toribio, M.C., Röttgering, H.J.A., and Tielens, A.G.G.M., 2017. Low-frequency carbon radio recombination lines. I. Calculation of departure coefficients. Astrophys. J., 837(2), id. 141. DOI: https://doi.org/10.3847/1538-4357/aa5d9e  Предмет і мета роботи. У цій статті описано аналіз результатів спостережень декаметрових рекомбінаційних радіоліній (РРЛ) вуглецю, виконаних у напрямках емісійної туманності S140 і гігантської оболонки GSH 139-03-69 на радіотелескопіУТР-2 поблизу частоти 26 МГц. Такі лінії є високоефективним засобом діагностики холодного розрідженого міжзоряного середовища (МЗС). Метою даної роботи є визначення зв’язку областей формування цих декаметрових ліній (CII-областей) з іншими компонентами МЗС, а також дослідження фізичних умов у цих областях (електронна температура Te, електронна густина Ne ).Методи та методологія. Шляхом ітераційного порівняння експериментально отриманих інтегральних інтенсивностей декаметрових РРЛ вуглецю з їхніми модельними значеннями для різних комбінацій Te,  Ne, а також розміру області крізь промінь зору s, було визначено діапазони фізичних умов, для яких спостерігається найкраще узгодження.Результати. Характеристики зареєстрованих декаметрових РРЛ вуглецю узгоджуються з більш високочастотними даними як для напрямку S140, так і для інших напрямків Галактичної площини, в тому числі й поблизу GSH 139-03-69.Було визначено діапазони фізичних умов, для яких найкращим чином узгоджуються експериментальні та модельні дані. Для напрямку на туманність S140 та її околиці найкраще узгодження спостерігається для Te = 50...100 К, Ne= 0.01 см–3 та s = 10 пк. Для напрямку на оболонку GSH 139-03-69 найкраще узгодження відповідає Te = 50...100 K, Ne =0.01 cm–3, та s = 5...7 пк.Висновок. Отримані результати свідчать про те, що зареєстровані декаметрові РРЛ вуглецю утворились у CII-областях, асоційованих із хмарами дифузного нейтрального водню HI в Галактичній площині. Лінії утворилися на тлі фоновогоГалактичного радіовипромінювання, яскравісна температура якого зростає зі зменшенням частоти.Ключові слова: електронна густина; електронна температура; іонізований вуглець; міжзоряне середовище; модель середовища; рекомбінаційні радіолінії; СІІ-областьСтаття надійшла до редакції  03.03.2023Radio phys. radio astron. 2023, 28(4): 275-286БІБЛІОГРАФІЧНИЙ СПИСОК1. Vasylkivskyi, Y.V., Konovalenko, O.O., Stepkin, S.V., 2023. Observations of decameter carbon radio recombination lines toward several Galactic directions. Part 1. Experimental study. Radio Phys. Radio Astron., 28(3), pp. 201—211. DOI: 10.15407/rpra28.03.2012. Konovalenko, A.A., and Sodin, L.G., 1981. The 26.13 MHz absorption line in the direction of Cassiopeia A. Nature, 294, pp. 135—136. DOI: 10.1038/294135a03. Gordon, M.A., and Sorochenko, R.L., 2009. Radio Recombination Lines. Their Physics and Astronomical Applications. Ser. Astrophysics and Space Science Library. Vol. 282. New York: Springer Science + Business Media. DOI: 10.1007/978-94-010-0261-54. Konovalenko, A.A., and Stepkin, S.V., 2005. Radio Recombination Lines. In: L.I. Gurvits, S. Frey, and S. Rawlings, eds., Radio Astronomy from Karl Jansky to Microjansky. Budapest, Hungary: EAS Publ., 15, pp. 271—295. DOI: 10.1051/eas:20051585. Stepkin, S.V., Konovalenko, O.O., Vasylkivskyi, Y.V., Mukha, D.V., 2021. Interstellar medium and decameter radio spectroscopy. Radio Phys. Radio Astron., 26(4), pp. 314—325. DOI: 10.15407/rpra26.04.3146. Walmsley, C.M., and Watson, W.D., 1982. The influence of dielectronic-like recombination at low temperatures on the interpretation of interstellar, radio recombination lines of carbon. Astrophys. J., 260, pp. 317—325. DOI: 10.1086/1602567. Knapp, G.R., Brown, R.L., Kuiper, T.B.H., Kaakr, R.K., 1976. Carbon recombination line observations of the sharpless 140 region.Astrophys. J., 204(1), pp. 781—783. DOI: 10.1086/1542258. Smirnov, G.T., Sorochenko, R.L., Walmsley, C.M., 1995. The S 140/L 1204 complex: radio recombination lines of hydrogen, carbon and sulphur. Astron. Astrophys., 300, pp. 923—932.9. Golynkin, A.A., Konovalenko, A.A., 1991. Radio recombination lines of highly excited carbon near DR21 and S140. Sov. Astron. Lett., 16(1), pp. 7—10.10. Smirnov, G.T., Sorochenko, R.L., Kitaev, V.V., 1992. Search for 42 MHz recombination lines toward S140. Sov. Astron. Lett., 18, pp. 192—194.11. Vasylkivskyi, Y.V., Stepkin, S.V., Konovalenko, O.O., 2023. Studies of low-frequency carbon radio recombination lines in medium toward S140 nebula. Contr. Astr. Obs. Skalnate Pleso, 53(1), pp. 17—27. DOI: 10.31577/caosp.2023.53.1.1712. Kalberla, P.M.W., Burton, W.B., Hartman, Dap, Arnal, E.M., Bajaja, E., Morras, R., Pöppel, W.G.L., 2005. The Leiden/Argentine/Bonn (LAB) survey of Galactic HI: final data release of the combined LDS and IAR surveys with improved stray-radiation corrections. Astron. Astrophys., 440(2), pp. 775—782. DOI: 10.1051/0004-6361:2004186413. Knee, L.B.G., Brunt, C.M., 2001. A massive cloud of cold atomic hydrogen in the outer Galaxy. Nature, 412, pp. 308—310. DOI: 10.1038/3508551914. Ershov, A.A., Ilyashov, Y.P., Lekht, E.E., Smirnov, G.T., Solodkov, V.T., Sorochenko, R.L., 1984. Low-frequency (42, 57, 84 MHz) excited-carbon lines toward Cassiopeia A. Sov. Astron. Lett., 10, pp. 348—353.15. Konovalenko, A.A., 1984. Observations of carbon recombination lines at decametric wavelengths in the direction Cassiopeia A. Sov. Astron. Lett., 10, pp. 353—356.16. Ershov, A.A., Lekht, E.E., Smirnov, G.T., Sorochenko, R.L., 1987. Highly excited-carbon level population and nature of the low-frequency radio line forming regions toward Cassiopeia A. Sov. Astron. Lett., 13, pp. 8—11.17. Payne, H.E., Anantharamaiah, K.R., Erickson, W.C., 1989. Stimulated emission of carbon recombination lines from cold clouds in the direction of Cassiopeia A. Astrophys. J., 341, pp. 890—900. DOI: 10.1086/16754718. Payne, H.E., Anantharamaiah, K.R., Erickson, W.C., 1994. High Rydberg state carbon recombination lines toward Cassiopeia A: Physical conditions and a new class of models. Astrophys. J., 430, pp. 690—705. DOI: 10.1086/17444119. Sorochenko, R.L., 1996. Radio recombination lines as a tool for investigation of molecular clouds. Astron. Astrophys. Trans., 11(3), pp. 199—214. DOI: 10.1080/1055679960820546720. Kantharia, N.G., Anantharamaiah, K.R., and Payne, H.E., 1998. Carbon Recombination Lines between 34.5 and 770 MHz toward Cassiopeia A. Astrophys. J., 506(2), pp. 758—772. DOI: 10.1086/30626621. Oonk, J.B.R., van Weeren, R.J., Salas, P., Salgado, F., Morabito, L.K., Toribio, M.C., Tielens, A.G.G.M., Röttgering, H.J.A., 2016. Carbon and hydrogen radio recombination lines from the cold clouds towards Cassiopeia A. Mon. Not. R. Astron. Soc., 465(1), pp. 1066—1088. DOI: 10.1093/mnras/stw281822. Salas, P., Oonk, J.B.R., van Weeren, R.J., Salgado, F., Morabito, L.K., Toribio, M.C., Emig, K., Röttgering, H.J.A., and Tielens, A.G.G.M., 2017. LOFAR observations of decameter carbon radio recombination lines towards Cassiopeia A. Mon. Not. R. Astron. Soc., 467(2), pp. 2274—2287. DOI: 10.1093/mnras/stx23923. Erickson, W.C., McConnell, D., Anantharamaiah, K.R., 1995. Low-frequency carbon recombination lines in the central regions of the Galaxy. Astrophys. J., 454, pp. 125—133. DOI: 10.1086/17647124. Kantharia, N.G., Anantharamaiah, K.R., 2001. Carbon recombination lines from the Galactic plane at 34.5 & 328 MHz. J. Astrophys. Astron., 22, pp. 51—80. DOI: 10.1007/BF0293359025. Salgado, F., Morabito, L.K., Oonk, J.B.R., Salas, P., Toribio, M.C., Röttgering, H.J.A., and Tielens, A.G.G.M., 2017. Low-frequency carbon radio recombination lines. I. Calculation of departure coefficients. Astrophys. J., 837(2), id. 141. DOI: 10.3847/1538-4357/aa5d9e   Видавничий дім «Академперіодика» 2023-12-08 Article Article application/pdf http://rpra-journal.org.ua/index.php/ra/article/view/1425 10.15407/rpra28.04.275 РАДИОФИЗИКА И РАДИОАСТРОНОМИЯ; Vol 28, No 4 (2023); 275 RADIO PHYSICS AND RADIO ASTRONOMY; Vol 28, No 4 (2023); 275 РАДІОФІЗИКА І РАДІОАСТРОНОМІЯ; Vol 28, No 4 (2023); 275 2415-7007 1027-9636 10.15407/rpra28.04 en http://rpra-journal.org.ua/index.php/ra/article/view/1425/pdf Copyright (c) 2023 RADIO PHYSICS AND RADIO ASTRONOMY