Temperature, brightness and spectral index of the Cygnus radio loop

The estimated brightness of the Cygnus loop supernova remnant (SNR) at 2720, 1420, 820, 408 and 34.5 MHz are 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 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 Cygnus loop is also obtained. Also, from our results can be concluded that Cygnus loop evolves in the low density environment and the initial energy of supernova explosion was relatively low. The obtained results confirm non-thermal origin of the Cygnus radio loop and show that our method is applicable to almost all remnants.Comment: 12 pages, 5 tables, 11 figures. Accepted for publication in RevMexA

The Monoceros radio loop: temperature, brightness, spectral index and distance

In this paper we estimated the temperatures and brightnesses of the Monoceros radio loop at 1420, 820 and 408 MHz. 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.Comment: 9 pages, 7 tables, 5 figures. Accepted for publication in Astron. Nach

The brightness temperatures of the main Galactic radio-loops at 22 MHz

The average brightness temperatures and surface brightnesses at 22 MHz are derived for the four main Galactic radio-continuum loops (Loops I, II, III and IV, hereafter radio-loops). Also the radio-continuum spectra for the radio-loops are presented. Adding the average brightness temperatures at 22 MHz derived here with the average brightness temperatures derived from spectra published previously at 408, 820 and 1420 MHz we obtained clearly non-thermal spectral indices for all radio-loops. Our derived spectral indices are slightly shallower than those measured by previous works.Comment: 11 pages, 2 tables, 9 figures. Accepted for publication in Open Astronomy Journa

A search for candidate radio supernova remnants in the nearby irregular starburst galaxies NGC 4214 and NGC 4395

We present the results of a search for new candidate radio su­pernova remnants (SNRs) in the nearby starburst irregular galaxies NGC 4214 and NGC 4395 using archived radio observations made with the Very Large Array (VLA) at the wavelengths of 3.5 cm, 6 cm and 20 cm for NGC 4214 and 6 cm and 20 cm for NGC 4395. These observations were analyzed as part of our ongoing search for candidate radio SNRs in nearby galaxies: the goal of this search is to prepare a large sample of candidate radio SNRs for the purpose of a robust statistical study of the properties of these sources. Based on our analysis, we have confirmed the nonthermal nature of the discrete radio sources α and β in NGC 4214 and classify these sources as candidate radio SNRs based on their positional coincidences with HII regions in that galaxy. We have measured the flux densities of the two candidate radio SNRs at each wavelength and calculated corresponding spectral indices: we have also measured flux densities of two other discrete radio sources in these galaxies - ρ in NGC 4214 and #3 in NGC 4395 which we suspect to be additional candidate radio SNRs based on their positional coincidences with other HII regions in these galaxies. However, the radio data presently available for these sources can­not confirm such a classification and additional observations are needed. We have also calculated the radio luminosities Lradio at the wavelength of 20 cm for these two candidate radio SNRs as well as the corresponding values for the minimum total energy Emin required to power these radio sources via synchrotron emission and the corresponding magnetic field strength Bmin. We have compared our mean calculated values for these properties with the mean values for populations of candidate radio SNRs in other starburst galaxies: while the values for Lradio and Bmin are roughly comparable to the values seen in other starburst galaxies, the mean value for Emin is higher than the mean value of any other starburst galaxy. Finally, we include these two candidate radio SNRs in a discussion of the Σ − D relation for extragalactic candidate radio SNRs and find that these sources are located on the shallower end of the master Σ − D relation for all extragalactic SNRs as derived by Urošević et al.(2005).published_or_final_versio

Revealing the nature of central emission nebulae in the dwarf galaxy NGC 185

In this paper we present new optical observations of the galaxy NGC 185 intended to reveal the status of supernova remnants (SNRs) in this dwarf companion of the Andromeda galaxy. Previously, it was reported that this galaxy hosts one SNR. Our deep photometric study with the 2m telescope at Rozhen National Astronomical Observatory using narrow-band H$\alpha$ and [SII] filters revealed complex structure of the interstellar medium in the center of the galaxy. To confirm the classification and to study the kinematics of the detected nebulae, we carried out spectroscopic observations using the SCORPIO multi-mode spectrograph at the 6m telescope at the Special Astrophysical Observatory of the Russian Academy of Science, both in low- and high-resolution modes. We also searched the archival X-ray and radio data for counterparts of the candidate SNRs identified by our optical observations. Our observations imply the presence of one more SNR, one possible HII region previously cataloged as part of an SNR, and the presence of an additional source of shock ionization in one low-brightness PN. We detected enhanced [SII]/H_alpha and [NII]/H_alpha line ratios, as well as relatively high (up to 90 km s$^{-1}$) expansion velocities of the two observed nebulae, motivating their classification as SNRs (with diameters of 45 pc and 50 pc), confirmed by both photometric and spectral observations. The estimated electron density of emission nebulae is 30 - 200 cm$^{-3}$. Archival XMM-Newton observations indicate the presence of an extended, low-brightness, soft source in projection of one of the optical SNRs, whereas the archival VLA radio image shows weak, unresolved emission in the center of NGC 185.Comment: 15 pages, 14 figures, accepted for publication in A&

Supplementary material for the article: Milićević, T.; Aničić Urošević, M.; Vuković, G.; Škrivanj, S.; Relić, D.; Frontasyeva, M. V.; Popović, A. Assessment of Species-Specific and Temporal Variations of Major, Trace and Rare Earth Elements in Vineyard Ambient Using Moss Bags. Ecotoxicology and Environmental Safety 2017, 144, 208–215. https://doi.org/10.1016/j.ecoenv.2017.06.028

Supplementary material for: [. https://doi.org/10.1016/j.ecoenv.2017.06.028 ]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2513

Supplementary material for the article: Milićević, T.; Aničić Urošević, M.; Vuković, G.; Škrivanj, S.; Relić, D.; Frontasyeva, M. V.; Popović, A. Assessment of Species-Specific and Temporal Variations of Major, Trace and Rare Earth Elements in Vineyard Ambient Using Moss Bags. Ecotoxicology and Environmental Safety 2017, 144, 208–215. https://doi.org/10.1016/j.ecoenv.2017.06.028

Supplementary material for: [. https://doi.org/10.1016/j.ecoenv.2017.06.028 ]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2513

Reptiles in Serbia: Distribution and diversity patterns

In this paper we present confirmed and potential distribution ranges of all native Serbian reptile species. The information provided herein presents the combination of the newly collected faunistic data and previously published records. The centres of reptilian diversity in Serbia were evaluated, in order to focus future conservation efforts on the regions of particular importance for the protection of this understudied group of animals. We found four main centres of species richness: three in Metohija and one in Šumadija, with 17-21 species per 50 × 50 km square. Analysis of the similarity of species composition in different regions of Serbia showed that South-eastern Serbia is the most distinct from other regions of Serbia, due to high number of Mediterranean species, with two being found exclusively in that region (E. quatuorlineata and P. najadum). Metohija is also very distinct, due to the highest number of species and significant number of specific (Mediterranean) faunal elements. The remaining geographic regions are grouped into three clusters, with Kosovo-Southern Serbia cluster being especially distinct in the terms of species richness and the presence of Mediterranean species. We also compared Serbian herpetofauna with those in other Balkan countries, considering species' numbers and zoogeographic herpetofaunistic elements. Serbian herpetofauna is closest to the Romanian. Zoogeographic analysis showed that reptilian fauna of Serbia consists of eight chorotypes, with the Eastern-Mediterranean (nine species) and Southern-European (five species) as the most dominant ones.U ovom radu predstavljeni su potvrđeni i potencijalni areali svih autohtonih gmizavaca Srbije. Korišćeni su do sada neobjavljeni podaci terenskih istraživanja, kao i informacije objavljene u literaturi. Ocenjeni su pretpostavljeni centri diverziteta gmizavaca u Srbiji, sa ciljem da se skrene pažnja na konzervacione mere neophodne za zaštitu pojedinih regiona od značaja za diverzitet gmizavaca u našoj zemlji. Utvrđeno je postojanje četiri centra diverziteta: tri u Metohiji i jednog u Šumadiji, sa prisustvom od 17 do 21 vrste na površini od 50 × 50 km. Analiza regiona Srbije po pitanju sličnosti sastava faune gmizavaca pokazala je da se region jugoistočne Srbije najviše odvaja od svih ostalih zbog ekskluzivnog prisustva dve mediteranske vrste gmizavaca (Elaphe quatuorlineata i Platyceps najadum). Metohija se odvaja po najvećem diverzitetu kao i prisustvu velikog broja mediteranskih vrsta gmizavaca. Ostali regioni formiraju tri grupe, pri čemu se klaster koga čine Kosovo i južna Srbija odvaja po prisustvu mediteranskih vrsta gmizavaca. Kada su na sličan način upoređene faune gmizavaca svih država Balkanskog poluostrva ispostavilo se da je fauna gmizavaca Srbije najsličnija onoj u Rumuniji. Zoogeografska analiza je pokazala da gmizavci Srbije spadaju u osam horotipova, pri čemu su po broju vrsta najzastupljeniji istočnomediteranski (sa devet vrsta) i južnoevropski (sa pet vrsta) horotipovi.nul