TY  - 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 .

TY  - JOUR
AU  - Borka Jovanović, Vesna
AU  - Urosevic, D.
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4264
AB  - The estimated brightness of the Cygnus loop supernova remnant; (SNR) at 2720, 1420, 820, 408 and 34.5 MHz is presented. The observations of the continuum radio emission are used to calculate the mean brightness temperatures and surface brightnesses of this loop at the five frequencies in a wide spectral range, using the method we have previously developed for large radio loops. The spectrum for mean temperatures versus frequency between the five frequencies is estimated and the spectral index of the Cygnus loop is obtained. Also, from our results it; can be concluded that the Cygnus loop evolves in a low density environment and that the initial energy of the supernova explosion was relatively low. The results obtained confirm the non-thermal origin of the Cygnus radio loop and show that our method is applicable to almost all remnants.
T2  - Revista Mexicana de Astronomia y Astrofisica
T1  - Temperature, Brightness and Spectral Index of the Cygnus Radio Loop
VL  - 47
IS  - 1
SP  - 159
EP  - 171
UR  - https://hdl.handle.net/21.15107/rcub_vinar_4264
ER  - 

@article{
author = "Borka Jovanović, Vesna and Urosevic, D.",
year = "2011",
abstract = "The estimated brightness of the Cygnus loop supernova remnant; (SNR) at 2720, 1420, 820, 408 and 34.5 MHz is presented. The observations of the continuum radio emission are used to calculate the mean brightness temperatures and surface brightnesses of this loop at the five frequencies in a wide spectral range, using the method we have previously developed for large radio loops. The spectrum for mean temperatures versus frequency between the five frequencies is estimated and the spectral index of the Cygnus loop is obtained. Also, from our results it; can be concluded that the Cygnus loop evolves in a low density environment and that the initial energy of the supernova explosion was relatively low. The results obtained confirm the non-thermal origin of the Cygnus radio loop and show that our method is applicable to almost all remnants.",
journal = "Revista Mexicana de Astronomia y Astrofisica",
title = "Temperature, Brightness and Spectral Index of the Cygnus Radio Loop",
volume = "47",
number = "1",
pages = "159-171",
url = "https://hdl.handle.net/21.15107/rcub_vinar_4264"
}

Borka Jovanović, V.,& Urosevic, D.. (2011). Temperature, Brightness and Spectral Index of the Cygnus Radio Loop. in Revista Mexicana de Astronomia y Astrofisica, 47(1), 159-171.
https://hdl.handle.net/21.15107/rcub_vinar_4264

Borka Jovanović V, Urosevic D. Temperature, Brightness and Spectral Index of the Cygnus Radio Loop. in Revista Mexicana de Astronomia y Astrofisica. 2011;47(1):159-171.
https://hdl.handle.net/21.15107/rcub_vinar_4264 .

Borka Jovanović, Vesna, Urosevic, D., "Temperature, Brightness and Spectral Index of the Cygnus Radio Loop" in Revista Mexicana de Astronomia y Astrofisica, 47, no. 1 (2011):159-171,
https://hdl.handle.net/21.15107/rcub_vinar_4264 .

TY  - CONF
AU  - Borka Jovanović, Vesna
AU  - Urosevic, D.
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6909
AB  - Observations of the continuum radio emission at 1420, 820 and 408 MHz enabled estimations of the brightness of the radio loops. We calculated the mean brightness temperatures and surface brightnesses of the six main Galactic radio-continuum loops I-VI at the three frequencies. We have demonstrated the reality of Loops V and VI and presented diagrams of their spectra for the first time. We derived the radio spectral indices of Galactic radio loops from radio surveys at three frequencies. The method we have developed for large radio loops, was also used for smaller ones. In this paper we also estimated the temperatures and brightnesses of the Monoceros radio loop at 1420, 820 and 408 MHz and of Cygnus loop. The spectra (mean temperature versus frequency) between the three frequencies, as well as the T - T graphs, are estimated and the spectral indices are also obtained. Using the supernova remnant (SNR) hypothesis for the origin of radio loops, distances are calculated from the surface brightnesses and the angular diameters. The obtained results confirm non-thermal origin of all radio loops and we show that our method is applicable to almost all SNRs.
C3  - Journal of Physics: Conference Series
T1  - Spectral indices of radio loops
VL  - 257
DO  - 10.1088/1742-6596/257/1/012030
ER  - 

@conference{
author = "Borka Jovanović, Vesna and Urosevic, D.",
year = "2010",
abstract = "Observations of the continuum radio emission at 1420, 820 and 408 MHz enabled estimations of the brightness of the radio loops. We calculated the mean brightness temperatures and surface brightnesses of the six main Galactic radio-continuum loops I-VI at the three frequencies. We have demonstrated the reality of Loops V and VI and presented diagrams of their spectra for the first time. We derived the radio spectral indices of Galactic radio loops from radio surveys at three frequencies. The method we have developed for large radio loops, was also used for smaller ones. In this paper we also estimated the temperatures and brightnesses of the Monoceros radio loop at 1420, 820 and 408 MHz and of Cygnus loop. The spectra (mean temperature versus frequency) between the three frequencies, as well as the T - T graphs, are estimated and the spectral indices are also obtained. Using the supernova remnant (SNR) hypothesis for the origin of radio loops, distances are calculated from the surface brightnesses and the angular diameters. The obtained results confirm non-thermal origin of all radio loops and we show that our method is applicable to almost all SNRs.",
journal = "Journal of Physics: Conference Series",
title = "Spectral indices of radio loops",
volume = "257",
doi = "10.1088/1742-6596/257/1/012030"
}

Borka Jovanović, V.,& Urosevic, D.. (2010). Spectral indices of radio loops. in Journal of Physics: Conference Series, 257.
https://doi.org/10.1088/1742-6596/257/1/012030

Borka Jovanović V, Urosevic D. Spectral indices of radio loops. in Journal of Physics: Conference Series. 2010;257.
doi:10.1088/1742-6596/257/1/012030 .

Borka Jovanović, Vesna, Urosevic, D., "Spectral indices of radio loops" in Journal of Physics: Conference Series, 257 (2010),
https://doi.org/10.1088/1742-6596/257/1/012030 . .

TY  - CONF
AU  - Borka Jovanović, Vesna
AU  - Urosevic, D.
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6910
AB  - Observations of the continuum radio emission at 1420, 820 and 408 MHz enabled estimations of the brightness of the Cygnus Loop supernova remnant (SNR). We calculated the mean brightness temperatures and surface brightnesses of this loop at the three frequencies.
T1  - The Cygnus Radio Loop: Temperature and Brightness
VL  - 86
SP  - 101
EP  - +
UR  - https://hdl.handle.net/21.15107/rcub_vinar_6910
ER  - 

@conference{
author = "Borka Jovanović, Vesna and Urosevic, D.",
year = "2009",
abstract = "Observations of the continuum radio emission at 1420, 820 and 408 MHz enabled estimations of the brightness of the Cygnus Loop supernova remnant (SNR). We calculated the mean brightness temperatures and surface brightnesses of this loop at the three frequencies.",
title = "The Cygnus Radio Loop: Temperature and Brightness",
volume = "86",
pages = "101-+",
url = "https://hdl.handle.net/21.15107/rcub_vinar_6910"
}

Borka Jovanović, V.,& Urosevic, D.. (2009). The Cygnus Radio Loop: Temperature and Brightness. , 86, 101-+.
https://hdl.handle.net/21.15107/rcub_vinar_6910

Borka Jovanović V, Urosevic D. The Cygnus Radio Loop: Temperature and Brightness. 2009;86:101-+.
https://hdl.handle.net/21.15107/rcub_vinar_6910 .

Borka Jovanović, Vesna, Urosevic, D., "The Cygnus Radio Loop: Temperature and Brightness", 86 (2009):101-+,
https://hdl.handle.net/21.15107/rcub_vinar_6910 .

TY  - JOUR
AU  - Borka Jovanović, Vesna
AU  - Urosevic, D.
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3769
AB  - In this paper we estimated the temperatures and brightnesses of the Monoceros radio loop at 1420, 820 and 408 MHz. The linear spectrum is estimated for mean temperatures versus frequency between 1420, 820 and 408 MHz. The spectral index of Monoceros loop is also obtained. The brightness temperatures and surface brightnesses of the loop are computed using data taken from radio-continuum surveys at the three frequencies. The spectral index of the loop is also obtained from T-T plots between 1420-820, 1420-408, and 820-408 MHz. The obtained results confirm non-thermal origin of the Monoceros radio loop. (C) 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim
T2  - Astronomische Nachrichten
T1  - The Monoceros radio loop: Temperature, brightness, spectral index, and distance
VL  - 330
IS  - 7
SP  - 741
EP  - 748
DO  - 10.1002/asna.200911205
ER  - 

@article{
author = "Borka Jovanović, Vesna and Urosevic, D.",
year = "2009",
abstract = "In this paper we estimated the temperatures and brightnesses of the Monoceros radio loop at 1420, 820 and 408 MHz. The linear spectrum is estimated for mean temperatures versus frequency between 1420, 820 and 408 MHz. The spectral index of Monoceros loop is also obtained. The brightness temperatures and surface brightnesses of the loop are computed using data taken from radio-continuum surveys at the three frequencies. The spectral index of the loop is also obtained from T-T plots between 1420-820, 1420-408, and 820-408 MHz. The obtained results confirm non-thermal origin of the Monoceros radio loop. (C) 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim",
journal = "Astronomische Nachrichten",
title = "The Monoceros radio loop: Temperature, brightness, spectral index, and distance",
volume = "330",
number = "7",
pages = "741-748",
doi = "10.1002/asna.200911205"
}

Borka Jovanović, V.,& Urosevic, D.. (2009). The Monoceros radio loop: Temperature, brightness, spectral index, and distance. in Astronomische Nachrichten, 330(7), 741-748.
https://doi.org/10.1002/asna.200911205

Borka Jovanović V, Urosevic D. The Monoceros radio loop: Temperature, brightness, spectral index, and distance. in Astronomische Nachrichten. 2009;330(7):741-748.
doi:10.1002/asna.200911205 .

Borka Jovanović, Vesna, Urosevic, D., "The Monoceros radio loop: Temperature, brightness, spectral index, and distance" in Astronomische Nachrichten, 330, no. 7 (2009):741-748,
https://doi.org/10.1002/asna.200911205 . .

TY  - CONF
AU  - Borka Jovanović, Vesna
AU  - Urosevic, D.
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6831
AB  - In this article we estimated the average brightness temperatures and surface brightnesses of Monoceros radio loop at 1420, 820 and 408 MHz. It is possible to make new estimation for distance to this loop using new derived brightnesses.
T1  - The Monoceros Radio Loop: Temperature and Brightness
IS  - 84
SP  - 459
EP  - +
UR  - https://hdl.handle.net/21.15107/rcub_vinar_6831
ER  - 

@conference{
author = "Borka Jovanović, Vesna and Urosevic, D.",
year = "2008",
abstract = "In this article we estimated the average brightness temperatures and surface brightnesses of Monoceros radio loop at 1420, 820 and 408 MHz. It is possible to make new estimation for distance to this loop using new derived brightnesses.",
title = "The Monoceros Radio Loop: Temperature and Brightness",
number = "84",
pages = "459-+",
url = "https://hdl.handle.net/21.15107/rcub_vinar_6831"
}

Borka Jovanović, V.,& Urosevic, D.. (2008). The Monoceros Radio Loop: Temperature and Brightness. (84), 459-+.
https://hdl.handle.net/21.15107/rcub_vinar_6831

Borka Jovanović V, Urosevic D. The Monoceros Radio Loop: Temperature and Brightness. 2008;(84):459-+.
https://hdl.handle.net/21.15107/rcub_vinar_6831 .

Borka Jovanović, Vesna, Urosevic, D., "The Monoceros Radio Loop: Temperature and Brightness", no. 84 (2008):459-+,
https://hdl.handle.net/21.15107/rcub_vinar_6831 .

TY  - JOUR
AU  - Borka Jovanović, Vesna
AU  - Milogradov-Turin, J.
AU  - Urosevic, D.
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3447
AB  - In this article we use 1420 MHz data to demonstrate the likely reality of Galactic radio Loops V and VI. We further estimate distances and spectral indices for both these and the four main radio loops. In the cases of Loops I-IV, radio spectral indices are calculated from the mean brightnesses at 1420 and 820/404 MHz. The spectral indices of Loops V and VI are obtained from T-T plots between 1420 and 408 MHz. Using the supernova remnant (SNR) hypothesis for the origin of radio loops, distances are calculated from the surface brightnesses and the angular diameters at 1420 MHz. We also study how results for brightnesses and distances of radio loops agree with current theories of SNR evolution. For this purpose, the ambient density and initial explosion energy of the loops are discussed. We also discuss applications of different Q-D relations. The results obtained confirm a non-thermal origin and nearby locations for the Galactic radio loops. Therefore, we have indications that they are very old SNRs that evolve in low ambient densities, with high initial explosion energies. (C) 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.
T2  - Astronomische Nachrichten
T1  - The brightness of the galactic radio loops at 1420 MHz: Some indications for the existence of Loops V and VI
VL  - 329
IS  - 4
SP  - 397
EP  - 402
DO  - 10.1002/asna.200610927
ER  - 

@article{
author = "Borka Jovanović, Vesna and Milogradov-Turin, J. and Urosevic, D.",
year = "2008",
abstract = "In this article we use 1420 MHz data to demonstrate the likely reality of Galactic radio Loops V and VI. We further estimate distances and spectral indices for both these and the four main radio loops. In the cases of Loops I-IV, radio spectral indices are calculated from the mean brightnesses at 1420 and 820/404 MHz. The spectral indices of Loops V and VI are obtained from T-T plots between 1420 and 408 MHz. Using the supernova remnant (SNR) hypothesis for the origin of radio loops, distances are calculated from the surface brightnesses and the angular diameters at 1420 MHz. We also study how results for brightnesses and distances of radio loops agree with current theories of SNR evolution. For this purpose, the ambient density and initial explosion energy of the loops are discussed. We also discuss applications of different Q-D relations. The results obtained confirm a non-thermal origin and nearby locations for the Galactic radio loops. Therefore, we have indications that they are very old SNRs that evolve in low ambient densities, with high initial explosion energies. (C) 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.",
journal = "Astronomische Nachrichten",
title = "The brightness of the galactic radio loops at 1420 MHz: Some indications for the existence of Loops V and VI",
volume = "329",
number = "4",
pages = "397-402",
doi = "10.1002/asna.200610927"
}

Borka Jovanović, V., Milogradov-Turin, J.,& Urosevic, D.. (2008). The brightness of the galactic radio loops at 1420 MHz: Some indications for the existence of Loops V and VI. in Astronomische Nachrichten, 329(4), 397-402.
https://doi.org/10.1002/asna.200610927

Borka Jovanović V, Milogradov-Turin J, Urosevic D. The brightness of the galactic radio loops at 1420 MHz: Some indications for the existence of Loops V and VI. in Astronomische Nachrichten. 2008;329(4):397-402.
doi:10.1002/asna.200610927 .

Borka Jovanović, Vesna, Milogradov-Turin, J., Urosevic, D., "The brightness of the galactic radio loops at 1420 MHz: Some indications for the existence of Loops V and VI" in Astronomische Nachrichten, 329, no. 4 (2008):397-402,
https://doi.org/10.1002/asna.200610927 . .