Vasylkivskyi Y. Large-scale distribution of ionized carbon in Galaxy

Українська версія

Thesis for the degree of Candidate of Sciences (CSc)

State registration number

0424U000005

Applicant for

Specialization

  • 01.03.02 - Астрофізика, радіоастрономія

19-12-2023

Specialized Academic Board

Д 26.208.01

Main Astronomical Observatory of the National Academy of Sciences of Ukraine

Essay

This thesis is devoted to studies of low-frequency carbon radio recombination lines (RRLs) at UTR-2 radio telescope in order to determine the spatial distribution of C II regions in Galaxy. The long-term surveyed observations were carried out in spatial volumes that are ten times greater than the volumes of all previous studies of low-frequency carbon RRLs. DSP-Z digital spectral analyzers with wide analysis bandwidth were used as recorders. Low-frequency carbon RRLs were detected both near the Galactic plane (|b| = 0° – 5°) and far beyond it (|b| = 5° – 30°). Detected lines had relative intensities of the order of 10–4 – 10–5 against continuum level, the line widths were 4 – 7 kHz (50 – 100 km/s). As part of determining the spatial association of the C II regions responsible for observed RRLs, the observational characteristics of detected lines were compared with characteristics and spatial distribution of neutral hydrogen H I clouds in Galaxy. Good agreement was obtained for the intensities, line widths, and radial velocities for both types of lines. It was determined that the temperature of such clouds lying in the range of 50 – 100 K, the electron density is ≤ 0.01 cm–3, the hydrogen volume density is ≤ 35 cm–3, the clouds sizes along the line of sight are 5 – 10 pc.

Research papers

Konovalenko, A. A., Stepkin, S. V., Mukha, D. V., and Vasilkovskiy, E. V., “Tools and Methods of Low-Frequency Radio Recombination Lines Investigations”, Odessa Astronomical Publications, vol. 29, p. 187, 2016. doi:10.18524/1810-4215.2016.29.85213.

Zakharenko, V., Konovalenko, A., Zarka, P., Ulyanov, O., Sidorchuk, M., Stepkin, S., Koliadin, V., Kalinichenko, N., Stanislavsky, A., Dorovskyy, V., Shepelev, V., Bobnov, I., Yerin, S., Melnik, V., Koval, A., Shevchuk, N., Vasylieva, I., Mylostna, K., Shevtsova, A., Skoryk, A., Kravtsov, I., Volvach, Y., Plakhov, M., Vasilenko, N., Vasylkivskyi, Y., Vavriv, D., Vinogradov, V., Kozhin, R., Kravtsov, A., Bulakh, E., Kuzin, A., Vasilyev, A., Ryabov, V., Reznichenko, A., Bortsov, V., Lisachenko, V., Kvasov, G., Mukha, D., Litvinenko, G., Brazhenko, A., Vashchishin, R., Pylaev, O., Koshovyy, V., Lozinsky, A., Ivantyshyn, O., Rucker, H. O., Panchenko, M., Fisher, G., Lecacheux, A., Denis, L., Coffre, A., Grieβmeier, J.-M., “Digital Receivers for Low-Frequency Radio Telescopes UTR-2, URAN, GURT”, Journal of Astronomical Instrumentation, vol. 5, no. 4, 2016. doi:10.1142/S2251171716410105.

Konovalenko, A., Zarka, P., Rucker, H. O., Zakharenko, V., Ulyanov, O., Sidorchuk, M., Stepkin, S., Melnik, V., Kalinichenko, N., Stanislavsky, A., Tokarsky, P., Koliadin, V., Shepelev, V., Dorovskyy, V., Bubnov, I., Yerin, S., Reznichenko, A., Litvinenko, G., Shevchuk, N., Koval, A., Vasylieva, I., Mylostna, K., Skoryk, A., Shevtsova, A., Volvach, Y., Vasylkovsky, E., Ryabov, V., Lecacheux, A., Denis, L., Panchenko, M., Fisher, G., Imai, M., Grieβmeier, J.-M., Mann, G., Litvinenko, O., Brazhenko, A., Vashchishin, R., Frantsuzenko, A., Koshovy, V., Lozinsky, A., Ivantyshyn, O., “Multi-antenna observations in the low-frequency radio astronomy of solar system objects and related topics studies”, Austrian Academy of Sciences Press, 2017, Vienna, p. 467 – 478, DOI: 10.1553/PRE8s467.

Konovalenko, A. A., Stepkin, S. V., and Vasilkovskiy, E. V., “Low-frequency radio recombination lines: observations and data processing”, Kosmichna Nauka i Tekhnologiya, vol. 23, no. 1, pp. 50–53, 2017. doi:10.15407/knit2017.01.050.

Konovalenko, O. O., Zakharenko, V. V., Lytvynenko, L. M., Ulyanov, O. M., Sidorchuk, M. A., Stepkin, S. V., Shepelev, V. A., Zarka, P., Rucker, H. O., Lecacheux, A., Panchenko, M., Bruck, Yu. M., Tokarsky, P. L., Bubnov, I. M., Yerin, S. M., Koliadin, V. L., Melnik, V. M., Kalinichenko, M. M., Stanislavsky, O. O., Dorovskyy, V. V., Khristenko, O. D., Shevchenko, V. V., Belov, O. S., Gridin, A. O., Antonov, O. V., Bovkun, V. P., Reznichenko, O. M., Bortsov, V. M., Kvasov, G. V., Ostapchenko, L. M., Shevchuk, M. V., Shevchenko, V. A., Yatskiv, Ya. S., Vavilova, I. B., Braude, I. S., 19 Shkuratov, Y. G., Ryabov, V. B., Pidgorny, G. I., Tymoshevsky, A. G., Lytvynenko, O. O., Galanin, V. V., Ryabov, M. I., Brazhenko, A. I., Vashchishin, R. V., Frantsuzenko, A. V., Koshovyy, V. V., Ivantyshyn, C. L., Lozinsky, A. B., Kharchenko, B. S., Vasylieva, I. Y., Kravtsov, I. P., Vasylkivskyi, Y. V., Litvinenko, G. V., Mukha, D. V., Vasylenko, N. V., Shevtsova, A. I., Miroshnichenko, A. P., Kuhai, N. V., Sobolev, Ya. M., Tsvyk, N. C., “The Founder of the Decameter Radio Astronomy in Ukraine Academician of NAS of Ukraine Semen Yakovych Braude is 110 Years Old: History of Creation and Development of the National Experimental Base for the Last Half Century”, Radio Physics and Radio Astronomy, vol. 26, no. 1, pp. 5–73, 2021. doi:10.15407/rpra26.01.005.

Stepkin, S. V., Konovalenko, O. O., Vasylkivskyi, Y. V., and Mukha, D. V., “Interstellar Medium and Decameter Radio Spectroscopy”, Radio Physics and Radio Astronomy, vol. 26, no. 4, pp. 314–325, 2021. doi:10.15407/rpra26.04.314.

Vasylkivskyi, Y. V., Stepkin, S. V., and Konovalenko, O. O., “The low-frequency carbon radio recombination lines in medium toward S140 nebula”, Contributions of the Astronomical Observatory Skalnate Pleso, vol. 53, no. 1, pp. 17–27, 2023. doi:10.31577/caosp.2023.53.1.17.

Konovalenko, A. A., Stepkin, S. V., and Vasilkovskiy, E. V., “Low-frequency radio recombination lines investigations”, 2016 II International Young Scientists Forum on Applied Physics and Engineering (YSF), Kharkiv, Ukraine, 2016, pp. 218 – 221, doi: 10.1109/YSF.2016.7753841.

Vasylkivskyi, Y. V., Konovalenko, O. O., and Stepkin, S. V., “Broadband studies of decameter carbon radio recombination lines toward Cygnus A and Perseus A radio galaxies”, 2022 IEEE 2nd Ukrainian Microwave Week (UkrMW), Ukraine, 2022, p. 1 – 5, DOI: 10.1109/UkrMW58013.2022.10037153.

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