OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY
Subject and Purpose. Since decameter carbon radio recombination lines (RRLs) were detected for the first time more than forty years ago, they have significantly extended our knowledge of the physics, kinematics and chemistry of the cold rarefied interstellar medium (ISM). A large number of these lin...
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cold rarefied gas; digital correlator interstellar carbon; interstellar medium; radio recombination lines; radio telescope Vasylkivskyi, Y. V. Konovalenko, O. O. Stepkin, S. V. OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY |
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cold rarefied gas; digital correlator interstellar carbon; interstellar medium; radio recombination lines; radio telescope |
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Article |
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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 1. EXPERIMENTAL STUDY |
| title_short |
OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY |
| title_full |
OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY |
| title_fullStr |
OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY |
| title_full_unstemmed |
OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY |
| title_sort |
observations of decameter carbon radio recombination lines in several galactic directions. part 1. experimental study |
| title_alt |
СПОСТЕРЕЖЕННЯ ДЕКАМЕТРОВИХ РЕКОМБІНАЦІЙНИХ РАДІОЛІНІЙ ВУГЛЕЦЮ В ДЕЯКИХ НАПРЯМКАХ ГАЛАКТИКИ. Частина 1. ЕКСПЕРИМЕНТАЛЬНІ ДОСЛІДЖЕННЯ |
| description |
Subject and Purpose. Since decameter carbon radio recombination lines (RRLs) were detected for the first time more than forty years ago, they have significantly extended our knowledge of the physics, kinematics and chemistry of the cold rarefied interstellar medium (ISM). A large number of these lines have been observed towards various Galactic radio sources. The present paper describes our studies of decameter carbon RRLs in such Galactic directions as the sight-lines to the S140 emission nebula and to the large volume of cold neutral hydrogen known as the GSH 139-03-69 super shell.Methods and Methodology. Observations within a 1-MHz frequency band centered at 26 MHz were performed using the UTR-2 radio telescope and a multi-channel digital correlator. The UTR-2 is still the world largest and the most sensitive low-frequency radio telescope.Results. We report the detection of decameter carbon RRL series C627α – C637α from the medium lying towards the S140 nebula. The extents of RRL forming regions have been estimated. It is suggested that RRLs in the S140 direction are formed in the local ISM lying along the line of sight. The RRL-forming region is probably associated with omnipresent diffuse neutral HI gas in the Galactic plane rather than with S140 nebula itself. Toward the GSH 139-03-69 super shell, decameter RRLs have been detected as well. Likewise, they apparently originate from the local medium lying along the sight-line. Yet, the spectrum contains a RRL component corresponding to the absorption of the cold gas of the GSH 139-03-69 itself in the ISM.Conclusions. The obtained results indicate great possibilities of decameter carbon RRLs not only for cold ISM probing but also for making a good auxiliary tool for studying large complexes of extremely cold hydrogen HI in the Galaxy.Keywords: cold rarefied gas, digital correlator, interstellar carbon, interstellar medium, radio recombination lines, radio telescopeManuscript submitted 03.03.2023Radio phys. radio astron. 2023, 28(3): 201-211REFERENCES 1. McKee, C.F., Ostriker, J.P., 1977. A theory of the interstellar medium: three components regulated by supernova explosions in an inhomogeneous substrate. Astrophys. J., 218, pp. 148—169. DOI: https://doi.org/10.1086/155667 2. 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/10.1007/978-0-387-09691-9 3. 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/10.1038/294135a0 4. Oonk, J.B.R., Alexander, E.L., Broderick, J.W., Sokolowski, M., Wayth, R., 2019. Spectroscopy with the Engineering Development Array: cold H+ at 63 MHz towards the Galactic Centre. Mon. Not. R. Astron. Soc., 487(4), pp. 4737—4750. DOI:https://doi.org/10.1093/mnras/stz950 5. 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/rpra26.04.314 6. 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:2005158 7. Stepkin, S.V., Konovalenko, A.A., Kantharia, N.G., and Udaya Shankar N., 2007. Radio recombination lines from the largest bound atoms in space. Mon. Not. R. Astron. Soc., 374(3), pp. 852—856. DOI: https://doi.org/10.1111/j.1365-2966.2006.11190.x 8. 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/stx239 9. 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/10.1086/176471 10. Kantharia, N.G., Anantharamaiah, K.R., 2001. Carbon recombination lines from the Galactic plane at 34.5 & 328 MHz. J. Astro- phys. Astron., 22, pp. 51—80. DOI: https://doi.org/10.1007/BF02933590 11. 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, pt. 1, pp. 781—783. DOI: https://doi.org/10.1086/154225 12. 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. 13. 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. 14. 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. 15. Vasylkivskyi, Y.V., Stepkin, S.V., Konovalenko, O.O., 2023. Studies of low-frequency carbon radio recombination lines in medium toward S140 nebula. Contrib. Astron. Obs. Skaln. Pleso, 53(1), pp. 17—27. DOI: https://doi.org/10.31577/caosp.2023.53.1.17 16. 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/10.1038/35085519 17. Konovalenko, A., Sodin, L., Zakharenko, V., Zarka, P., Ulyanov, O., Sidorchuk, M., Stepkin, S., Tokarsky, P., Melnik, V., Kalinichen- ko, N., Stanislavsky, A., Koliadin, V., Shepelev, V., Dorovskyy, V., Ryabov, V., Koval, A., Bubnov, I., Yerin, S., Gridin, A., Kulishen- ko, V., Reznichenko, A., Bortsov, V., Lisachenko, V., Reznik, A., Kvasov, G., Mukha, D., Litvinenko, G., Khristenko, A., Shevchen- ko, V. V., Shevchenko, V. A., Belov, A., Rudavin, E., Vasylieva, I., Miroshnichenko, A., Vasilenko, N., Olyak, M., Mylostna, K., Skoryk, A., Shevtsova, A., Plakhov, M., Kravtsov, I., Volvach, Y., Lytvinenko, O., Shevchuk, N., Zhouk, I., Bovkun, V., Antonov, A., Vavriv, D., Vinogradov, V., Kozhin, R., Kravtsov, A., Bulakh, E., Kuzin, A., Vasilyev, A., Brazhenko, A., Vashchishin, R., Pylaev, O., Koshovyy, V., Lozinsky, A., Ivantyshin, O., Rucker, H. O., Panchenko, M., Fischer, G., Lecacheux, A., Denis, L., Coffre, A., Grieß- meier, J.-M., Tagger, M., Girard, J., Charrier, D., Briand, C., and Mann, G., 2016. The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT. Exp. Astron., 42(1), pp. 11—48. DOI: https://doi.org/10.1007/s10686-016-9498-x 18. 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 correc- tions. Astron. Astrophys., 440(2), pp. 775—782. DOI: https://doi.org/10.1051/0004-6361:20041864 |
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Видавничий дім «Академперіодика» |
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2023 |
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http://rpra-journal.org.ua/index.php/ra/article/view/1418 |
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oai:ri.kharkov.ua:article-14182023-12-08T07:43:14Z OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY СПОСТЕРЕЖЕННЯ ДЕКАМЕТРОВИХ РЕКОМБІНАЦІЙНИХ РАДІОЛІНІЙ ВУГЛЕЦЮ В ДЕЯКИХ НАПРЯМКАХ ГАЛАКТИКИ. Частина 1. ЕКСПЕРИМЕНТАЛЬНІ ДОСЛІДЖЕННЯ Vasylkivskyi, Y. V. Konovalenko, O. O. Stepkin, S. V. cold rarefied gas; digital correlator, interstellar carbon; interstellar medium; radio recombination lines; radio telescope Subject and Purpose. Since decameter carbon radio recombination lines (RRLs) were detected for the first time more than forty years ago, they have significantly extended our knowledge of the physics, kinematics and chemistry of the cold rarefied interstellar medium (ISM). A large number of these lines have been observed towards various Galactic radio sources. The present paper describes our studies of decameter carbon RRLs in such Galactic directions as the sight-lines to the S140 emission nebula and to the large volume of cold neutral hydrogen known as the GSH 139-03-69 super shell.Methods and Methodology. Observations within a 1-MHz frequency band centered at 26 MHz were performed using the UTR-2 radio telescope and a multi-channel digital correlator. The UTR-2 is still the world largest and the most sensitive low-frequency radio telescope.Results. We report the detection of decameter carbon RRL series C627α – C637α from the medium lying towards the S140 nebula. The extents of RRL forming regions have been estimated. It is suggested that RRLs in the S140 direction are formed in the local ISM lying along the line of sight. The RRL-forming region is probably associated with omnipresent diffuse neutral HI gas in the Galactic plane rather than with S140 nebula itself. Toward the GSH 139-03-69 super shell, decameter RRLs have been detected as well. Likewise, they apparently originate from the local medium lying along the sight-line. Yet, the spectrum contains a RRL component corresponding to the absorption of the cold gas of the GSH 139-03-69 itself in the ISM.Conclusions. The obtained results indicate great possibilities of decameter carbon RRLs not only for cold ISM probing but also for making a good auxiliary tool for studying large complexes of extremely cold hydrogen HI in the Galaxy.Keywords: cold rarefied gas, digital correlator, interstellar carbon, interstellar medium, radio recombination lines, radio telescopeManuscript submitted 03.03.2023Radio phys. radio astron. 2023, 28(3): 201-211REFERENCES 1. McKee, C.F., Ostriker, J.P., 1977. A theory of the interstellar medium: three components regulated by supernova explosions in an inhomogeneous substrate. Astrophys. J., 218, pp. 148—169. DOI: https://doi.org/10.1086/155667 2. 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/10.1007/978-0-387-09691-9 3. 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/10.1038/294135a0 4. Oonk, J.B.R., Alexander, E.L., Broderick, J.W., Sokolowski, M., Wayth, R., 2019. Spectroscopy with the Engineering Development Array: cold H+ at 63 MHz towards the Galactic Centre. Mon. Not. R. Astron. Soc., 487(4), pp. 4737—4750. DOI:https://doi.org/10.1093/mnras/stz950 5. 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/rpra26.04.314 6. 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:2005158 7. Stepkin, S.V., Konovalenko, A.A., Kantharia, N.G., and Udaya Shankar N., 2007. Radio recombination lines from the largest bound atoms in space. Mon. Not. R. Astron. Soc., 374(3), pp. 852—856. DOI: https://doi.org/10.1111/j.1365-2966.2006.11190.x 8. 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/stx239 9. 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/10.1086/176471 10. Kantharia, N.G., Anantharamaiah, K.R., 2001. Carbon recombination lines from the Galactic plane at 34.5 & 328 MHz. J. Astro- phys. Astron., 22, pp. 51—80. DOI: https://doi.org/10.1007/BF02933590 11. 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, pt. 1, pp. 781—783. DOI: https://doi.org/10.1086/154225 12. 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. 13. 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. 14. 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. 15. Vasylkivskyi, Y.V., Stepkin, S.V., Konovalenko, O.O., 2023. Studies of low-frequency carbon radio recombination lines in medium toward S140 nebula. Contrib. Astron. Obs. Skaln. Pleso, 53(1), pp. 17—27. DOI: https://doi.org/10.31577/caosp.2023.53.1.17 16. 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/10.1038/35085519 17. Konovalenko, A., Sodin, L., Zakharenko, V., Zarka, P., Ulyanov, O., Sidorchuk, M., Stepkin, S., Tokarsky, P., Melnik, V., Kalinichen- ko, N., Stanislavsky, A., Koliadin, V., Shepelev, V., Dorovskyy, V., Ryabov, V., Koval, A., Bubnov, I., Yerin, S., Gridin, A., Kulishen- ko, V., Reznichenko, A., Bortsov, V., Lisachenko, V., Reznik, A., Kvasov, G., Mukha, D., Litvinenko, G., Khristenko, A., Shevchen- ko, V. V., Shevchenko, V. A., Belov, A., Rudavin, E., Vasylieva, I., Miroshnichenko, A., Vasilenko, N., Olyak, M., Mylostna, K., Skoryk, A., Shevtsova, A., Plakhov, M., Kravtsov, I., Volvach, Y., Lytvinenko, O., Shevchuk, N., Zhouk, I., Bovkun, V., Antonov, A., Vavriv, D., Vinogradov, V., Kozhin, R., Kravtsov, A., Bulakh, E., Kuzin, A., Vasilyev, A., Brazhenko, A., Vashchishin, R., Pylaev, O., Koshovyy, V., Lozinsky, A., Ivantyshin, O., Rucker, H. O., Panchenko, M., Fischer, G., Lecacheux, A., Denis, L., Coffre, A., Grieß- meier, J.-M., Tagger, M., Girard, J., Charrier, D., Briand, C., and Mann, G., 2016. The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT. Exp. Astron., 42(1), pp. 11—48. DOI: https://doi.org/10.1007/s10686-016-9498-x 18. 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 correc- tions. Astron. Astrophys., 440(2), pp. 775—782. DOI: https://doi.org/10.1051/0004-6361:20041864 Предмет і мета роботи. Декаметрові рекомбінаційні радіолінії (РРЛ) вуглецю було вперше виявлено більше сорока років тому. За цей час дослідження РРЛ значно розширили наші знання відносно фізики, кінематики і хімічних властивостей холодного розрідженого міжзоряного середовища (МЗС). Велика кількість цих ліній спостерігалась у напрямках різних галактичних радіоджерел. У цій статті описано наші дослідження декаметрових РРЛ вуглецю в напрямках емісійної туман- ності S140 і гігантської оболонки холодного нейтрального водню GSH 139-03-69.Методи і методологія. Спостереження було проведено на радіотелескопі УТР-2 за допомогою багатоканального цифро- вого корелометра в смузі аналізу 1 МГц відносно центральної частоти 26 МГц. УТР-2 є найбільшим у світі та найчутливішим низькочастотним радіотелескопом.Результати. Серії декаметрових РРЛ вуглецю C627α – C637α було виявлено в середовищі, що лежить у напрямку S140. Було оцінено розміри областей формування ліній. Передбачається, що лінії в напрямку S140 утворюються в місцевому МЗС, який лежить на промені зору. Область формування ліній, ймовірно, пов’язана із широко розповсюдженим дифузним газом HI, що лежить в Галактичній площині, і не пов’язана із самою туманністю S140. Декаметрові лінії також було виявлено й у напрямку гігантської оболонки GSH 139-03-69. Вони, судячи з усього, також утворилися в місцевому середовищі, що лежить увздовж променя зору. Однак у спектрі присутній також і компонент лінії, який відповідає поглинанню холодного газу самої GSH 139-03-69 у МЗС.Висновки. Отримані результати свідчать про високі можливості декаметрових РРЛ вуглецю не тільки для зондуван- ня холодного МЗС, а й як допоміжного інструменту при вивченні великих комплексів надзвичайно холодного водню HI в Галактиці.Ключові слова: міжзоряний вуглець, міжзоряне середовище, радіотелескоп, рекомбінаційні радіолінії, холодний розріджений газ, цифровий корелометрСтаття надійшла до редакції 03.03.2023Radio phys. radio astron. 2023, 28(3): 201-211БІБЛІОГРАФІЧНИЙ СПИСОК1. McKee, C.F., Ostriker, J.P., 1977. A theory of the interstellar medium: three components regulated by supernova explosions in an inhomogeneous substrate. Astrophys. J., 218, pp. 148—169. DOI: 10.1086/155667 2. 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- 0261-5 3. Konovalenko, A.A., and Sodin, L.G., 1981. 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DOI: 10.1051/0004-6361:20041864 Видавничий дім «Академперіодика» 2023-09-12 Article Article application/pdf http://rpra-journal.org.ua/index.php/ra/article/view/1418 10.15407/rpra28.03.201 РАДИОФИЗИКА И РАДИОАСТРОНОМИЯ; Vol 28, No 3 (2023); 201 RADIO PHYSICS AND RADIO ASTRONOMY; Vol 28, No 3 (2023); 201 РАДІОФІЗИКА І РАДІОАСТРОНОМІЯ; Vol 28, No 3 (2023); 201 2415-7007 1027-9636 10.15407/rpra28.03 en http://rpra-journal.org.ua/index.php/ra/article/view/1418/pdf Copyright (c) 2023 RADIO PHYSICS AND RADIO ASTRONOMY |