Spectra of the Hb 21 Supernova Remnant: Evidence of Spectrum Flattening At the Low Frequencies
Апстракт
We use observations of the continuum radio emission at 1420, 820, 408, 34.5 and 22 MHz to estimate the mean brightness temperatures of the HB 21 supernova remnant (SNR) at five frequencies. We also present mean spectral index of HB 21. The spectra of LIB 21 are estimated from mean temperatures versus frequency plots for 1420, 820, 408, 34.5 and 22 MHz. We also present T - T plots of three frequency pairs: between 1420-34.5, 1420-22, 34.5-22 MHz. We notice flatter spectral indices at; frequencies below 408 MHz. Probably this is due to the absorption by thermal plasma at low frequencies.
Кључне речи:
ISM: individual objects (HB 21) / radiation mechanisms: non-thermal / radiation mechanisms: thermal / radio continuum: general / surveysИзвор:
Revista Mexicana de Astronomia y Astrofisica, 2012, 48, 1, 53-60Финансирање / пројекти:
- Гравитација и структура космоса на великим скалама (RS-MESTD-Basic Research (BR or ON)-176003)
- Емисионе маглине: структура и еволуција (RS-MESTD-Basic Research (BR or ON)-176005)
Колекције
Институција/група
VinčaTY - JOUR AU - Borka, Duško AU - Borka Jovanović, Vesna AU - Urosevic, D. PY - 2012 UR - https://vinar.vin.bg.ac.rs/handle/123456789/4355 AB - We use observations of the continuum radio emission at 1420, 820, 408, 34.5 and 22 MHz to estimate the mean brightness temperatures of the HB 21 supernova remnant (SNR) at five frequencies. We also present mean spectral index of HB 21. The spectra of LIB 21 are estimated from mean temperatures versus frequency plots for 1420, 820, 408, 34.5 and 22 MHz. We also present T - T plots of three frequency pairs: between 1420-34.5, 1420-22, 34.5-22 MHz. We notice flatter spectral indices at; frequencies below 408 MHz. Probably this is due to the absorption by thermal plasma at low frequencies. T2 - Revista Mexicana de Astronomia y Astrofisica T1 - Spectra of the Hb 21 Supernova Remnant: Evidence of Spectrum Flattening At the Low Frequencies VL - 48 IS - 1 SP - 53 EP - 60 UR - https://hdl.handle.net/21.15107/rcub_vinar_4355 ER -
@article{ author = "Borka, Duško and Borka Jovanović, Vesna and Urosevic, D.", year = "2012", abstract = "We use observations of the continuum radio emission at 1420, 820, 408, 34.5 and 22 MHz to estimate the mean brightness temperatures of the HB 21 supernova remnant (SNR) at five frequencies. We also present mean spectral index of HB 21. The spectra of LIB 21 are estimated from mean temperatures versus frequency plots for 1420, 820, 408, 34.5 and 22 MHz. We also present T - T plots of three frequency pairs: between 1420-34.5, 1420-22, 34.5-22 MHz. We notice flatter spectral indices at; frequencies below 408 MHz. Probably this is due to the absorption by thermal plasma at low frequencies.", journal = "Revista Mexicana de Astronomia y Astrofisica", title = "Spectra of the Hb 21 Supernova Remnant: Evidence of Spectrum Flattening At the Low Frequencies", volume = "48", number = "1", pages = "53-60", url = "https://hdl.handle.net/21.15107/rcub_vinar_4355" }
Borka, D., Borka Jovanović, V.,& Urosevic, D.. (2012). Spectra of the Hb 21 Supernova Remnant: Evidence of Spectrum Flattening At the Low Frequencies. in Revista Mexicana de Astronomia y Astrofisica, 48(1), 53-60. https://hdl.handle.net/21.15107/rcub_vinar_4355
Borka D, Borka Jovanović V, Urosevic D. Spectra of the Hb 21 Supernova Remnant: Evidence of Spectrum Flattening At the Low Frequencies. in Revista Mexicana de Astronomia y Astrofisica. 2012;48(1):53-60. https://hdl.handle.net/21.15107/rcub_vinar_4355 .
Borka, Duško, Borka Jovanović, Vesna, Urosevic, D., "Spectra of the Hb 21 Supernova Remnant: Evidence of Spectrum Flattening At the Low Frequencies" in Revista Mexicana de Astronomia y Astrofisica, 48, no. 1 (2012):53-60, https://hdl.handle.net/21.15107/rcub_vinar_4355 .