Zoran Simić - Academia.edu (original) (raw)

Papers by Zoran Simić

Research paper thumbnail of Serbian virtual observatory

Proceedings of the 13th International Conference on Computer Systems and Technologies - CompSysTech '12, 2012

We review the newly established project of Serbian Virtual Observatory. In the last few years Vir... more We review the newly established project of Serbian Virtual Observatory. In the last few years Virtual Observatories are becoming a new concept in the world of astronomy. The main aim of Virtual Observatories is to make accessible astronomical data to astronomers regardless of their geographical location as well as provide them with tools for analysis.

Research paper thumbnail of The project of Serbian Virtual Observatory and data for stellar atmosphere modeling

New Astronomy Reviews, 2009

We review recent developments in Serbian Virtual Observatory (SerVO) as well as developments surr... more We review recent developments in Serbian Virtual Observatory (SerVO) as well as developments surrounding Virtual Atomic and Molecular Data Center. Main components of SerVO are going to be the archive of photographic plates, database of Stark broadening parameters and stellar evolution database. Photographic plates were obtained at Belgrade Observatory from 1936 to 1996. Data for Stark broadening were obtained using semiclassical perturbation and modified semiempirical theories. Stellar evolution database is a mirror of Darthmouth evolution database with improvement and VO compatible outputs.

Research paper thumbnail of Stark broadening of spectral lines in chemically peculiar stars: Te I lines and recent calculations for trace elements

With the development of astronomical observations from space, spectral lines of trace elements ca... more With the development of astronomical observations from space, spectral lines of trace elements can now be observed in stellar spectra with good resolution, and atomic data for such atoms and ions have an increasing significance. We review here work in Belgrade on the influence of Stark broadening of trace elements on stellar spectra and present new determinations of Stark broadening parameters of neutral tellurium. Also the corresponding Stark and Doppler widths are compared in atmospheres of A type stars.

Research paper thumbnail of On the Stark broadening of Cd I lines

We have calculated within the semiclassical perturbation theory Stark broadening parameters (widt... more We have calculated within the semiclassical perturbation theory Stark broadening parameters (width and shift) for 13 Cd I multiplets in UV and V, and for 24 multiplets in infrared spectral ranges, for temperatures between 2500 K and 50000 K, of interest for stellar plasma investigations.

Research paper thumbnail of Stark broadening of Cd III lines

Using a modified semiempirical approach, we have calculated Stark line widths for 10 Cd III trans... more Using a modified semiempirical approach, we have calculated Stark line widths for 10 Cd III transitions for an electron density of 1023m-3 and temperatures from 10000K to 300000K.

Research paper thumbnail of Stark broadening of Cd I spectral lines (Simic+, 2005)

Stark broadening parameters, widths, and shifts for 33 CdI singlets and 37 triplets were calculat... more Stark broadening parameters, widths, and shifts for 33 CdI singlets and 37 triplets were calculated using the semiclassical perturbation method. The results were compared with available experimental and theoretical data. Also, regularity in the spectral series 5s2 1S-np 1Po was investigated. The influence of Stark broadening was analyzed in A-type stellar atmospheres. (2 data files).

Research paper thumbnail of On the Stark Broadening of Ar XV Spectral Lines

In order to provide Stark broadening data in X-ray and far UV wavelength region, of interest for ... more In order to provide Stark broadening data in X-ray and far UV wavelength region, of interest for modelling and analysis of astrophysical plasmas in extreme conditions, we performed calculations of Stark broadened line widths and shifts for Ar XV using the semiclassical perturbation theory.

Research paper thumbnail of Stark-B Database Virtual Atomic and Molecular Data Center (VAMDC) and Data for White Dwarf Atmospheres Analysis

In a number of papers we have demonstrated the importance of Stark broadening mechanism for the m... more In a number of papers we have demonstrated the importance of Stark broadening mechanism for the modeling and synthesizing of lines observed in spectra of white dwarf atmo- spheres. We also determined a number of Stark broadening parameters of interest in particular for DB and DO white dwarf plasmas investigations. Now, work on their inclusion in STARK- B database and in Virtual Atomic and Molecular Data Center, an FP7 european project, as well as in Serbian Virtual Observatory is in progress. We review here the part of this work of interest for white dwarf atmospheres analysis.

Research paper thumbnail of STARK BROADENING OF SEVERAL Ne II, Ne III AND O III SPECTRAL LINES FOR THE STARK-B DATABASE

Baltic astronomy an international journal

In order to complete Stark broadening data for Ne II, and O III lines, needed for analysis of ste... more In order to complete Stark broadening data for Ne II, and O III lines, needed for analysis of stellar atmospheres, we determined, within the semiclassical perturbation method, the missing Stark broadening parameters for the broadening by collisions with protons and ionized helium, for 15 Ne II and 5 O III multiplets. Also, electron, proton and ionized helium impact broadening parameters for an important Ne II multiplet in the visible part of the spectrum and for three Ne III multiplets were calculated. The obtained data will be included in the STARK-B database, which is a part of the Virtual Atomic and Molecular Data Center.

Research paper thumbnail of Stark Broadening and White Dwarfs

White dwarf and pre-white dwarf atmospheres are one of the best examples for the application of S... more White dwarf and pre-white dwarf atmospheres are one of the best examples for the application of Stark broadening research results in astrophysics, due to plasma conditions very favorable for this line broadening mechanism. For example in hot hydrogen-deficient (pre-) white dwarf stars Teff = 75 000 K - 180 000 K and log g = 5.5-8 [cgs]. Even for much cooler DA and DB white dwarfs with typical effective temperatures of 10 000 K - 20 000 K, Stark broadening is usually the dominant broadening mechanism. In this review, Stark broadening in white dwarf spectra is considered and the attention is drawn to the STARK-B database (http://stark-b.obspm.fr/), containing Stark broadening parameters needed for white dwarf spectra analysis and synthesis, as well as to the new search facilities which will provide the collective effort to develop Virtual Atomic and Molecular Data Center (VAMDC - http://vamdc.org/).

Research paper thumbnail of Electron-impact broadening of ionized chromium lines for Ap star atmospheres analysis

The influence of Stark broadening on the shapes of Cr II spectral lines observed in stellar atmos... more The influence of Stark broadening on the shapes of Cr II spectral lines observed in stellar atmospheres is considered.

Research paper thumbnail of Stark broadening of O V 1371 A˚ line in stellar atmospheres

AIP Conference Proceedings

The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmospheres of ... more The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmospheres of hot stars, determined within the semiclassical perturbation method, are used for the analysis of the importance of this broadening mechanism in white dwarf atmospheres. We found that Stark broadening mechanism is very important in such plasma conditions and should be taken into account.

Research paper thumbnail of STARK BROADENING OF In III LINES IN ASTROPHYSICAL AND LABORATORY PLASMA

Baltic astronomy an international journal

Besides the need of Stark broadening parameters for a number of problems in physics and plasma te... more Besides the need of Stark broadening parameters for a number of problems in physics and plasma technology, in hot star atmospheres the condi-tions exist where Stark widths are comparable and even larger than the thermal Doppler widths. Using the semiclassical perturbation method we investigated here the influence of collisions with charged particles for In III spectral lines. We determined a number of Stark broadening parameters important for the investigation of plasmas in the atmospheres of A-type stars and white dwarfs. Also, we have compared the obtained results with existing experimental data. The results will be included in the STARK-B database, the Virtual Atomic and Molecular Data Center and the Serbian Virtual Observatory.

Research paper thumbnail of Stark broadening of Sn III lines in a type stellar atmospheres

Here we present Stark broadening parameters for Sn III 6s ^1S_0-6p ^1P^o_1 spectral line obtained... more Here we present Stark broadening parameters for Sn III 6s ^1S_0-6p ^1P^o_1 spectral line obtained by using semiclassical perturbation approach and Stark widths for this transition obtained by using modified semiempirical approach. Results obtained have been compared with available experimental data and used for the consideration of the influence of the Stark broadening effect in A type stellar atmospheres.

Research paper thumbnail of On Stark broadening of MnII lines in Ap-star conditions

Stark broadening parameters for six MnII lines are determined semi-classically and used to analys... more Stark broadening parameters for six MnII lines are determined semi-classically and used to analyse the influence of this broadening mechanism on A-type star spectral line profiles. Results for the MnII line at 2950.1Å are presented here as an example of the data obtained.

Research paper thumbnail of On the Stark broadening of TeI spectral lines for CP star plasma analysis

By using the semiclassical perturbation method, Stark widths and shifts have been calculated for ... more By using the semiclassical perturbation method, Stark widths and shifts have been calculated for the TeI 6s 5S° - 7p 5P (5125.2 Å) multiplet, of interest for CP star plasma studies. Results were applied to the investigation of the influence of Stark broadening on CP star spectra. It was found that layers exist in the stellar atmospheres considered where the

Research paper thumbnail of Stark Broadening of F III Lines in Laboratory and Stellar Plasma

Journal of Applied Spectroscopy, 2005

∨ ic ′ a UDC 533.9.082.5

Research paper thumbnail of Experimental and Theoretical Stark Widths for Au II

In the present work, we have reviewed and compared our experimental and theoretical Au II Stark w... more In the present work, we have reviewed and compared our experimental and theoretical Au II Stark widths. The interest in Au II resides not only on the knowledge of its atomic structure, or to check the adequacy of theoretical models, but also on its astrophysical importance because its lines are present in spectra of chemically peculiar stars. The plasma source

Research paper thumbnail of Stark broadening of O V 1371 A˚ line in stellar atmospheres

The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmosphere... more The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmospheres of hot stars, determined within the semiclassical perturbation method, are used for the analysis of the importance of this broadening mechanism in white dwarf atmospheres. We found that Stark broadening mechanism is very important in such plasma conditions and should be taken into account.

Research paper thumbnail of On the Stark broadening in hot stars

In hot star atmospheres exist conditions where Stark widths are comparable and even larger than t... more In hot star atmospheres exist conditions where Stark widths are comparable and even larger than the thermal Doppler widths, so that the corresponding line broadening parameters are of importance for the hot star plasma investigation. Here, we investigated theoretically the influence of collisions with charged particles on heavy element spectral line profiles for Te I, Cr II and Sn III in spectra of A stars and white dwarfs. We applied semiclassical perturbation theory. When it can not be applied in an adequate way, due to the lack of reliable atomic data, we used modified semiempirical theory.

Research paper thumbnail of Serbian virtual observatory

Proceedings of the 13th International Conference on Computer Systems and Technologies - CompSysTech '12, 2012

We review the newly established project of Serbian Virtual Observatory. In the last few years Vir... more We review the newly established project of Serbian Virtual Observatory. In the last few years Virtual Observatories are becoming a new concept in the world of astronomy. The main aim of Virtual Observatories is to make accessible astronomical data to astronomers regardless of their geographical location as well as provide them with tools for analysis.

Research paper thumbnail of The project of Serbian Virtual Observatory and data for stellar atmosphere modeling

New Astronomy Reviews, 2009

We review recent developments in Serbian Virtual Observatory (SerVO) as well as developments surr... more We review recent developments in Serbian Virtual Observatory (SerVO) as well as developments surrounding Virtual Atomic and Molecular Data Center. Main components of SerVO are going to be the archive of photographic plates, database of Stark broadening parameters and stellar evolution database. Photographic plates were obtained at Belgrade Observatory from 1936 to 1996. Data for Stark broadening were obtained using semiclassical perturbation and modified semiempirical theories. Stellar evolution database is a mirror of Darthmouth evolution database with improvement and VO compatible outputs.

Research paper thumbnail of Stark broadening of spectral lines in chemically peculiar stars: Te I lines and recent calculations for trace elements

With the development of astronomical observations from space, spectral lines of trace elements ca... more With the development of astronomical observations from space, spectral lines of trace elements can now be observed in stellar spectra with good resolution, and atomic data for such atoms and ions have an increasing significance. We review here work in Belgrade on the influence of Stark broadening of trace elements on stellar spectra and present new determinations of Stark broadening parameters of neutral tellurium. Also the corresponding Stark and Doppler widths are compared in atmospheres of A type stars.

Research paper thumbnail of On the Stark broadening of Cd I lines

We have calculated within the semiclassical perturbation theory Stark broadening parameters (widt... more We have calculated within the semiclassical perturbation theory Stark broadening parameters (width and shift) for 13 Cd I multiplets in UV and V, and for 24 multiplets in infrared spectral ranges, for temperatures between 2500 K and 50000 K, of interest for stellar plasma investigations.

Research paper thumbnail of Stark broadening of Cd III lines

Using a modified semiempirical approach, we have calculated Stark line widths for 10 Cd III trans... more Using a modified semiempirical approach, we have calculated Stark line widths for 10 Cd III transitions for an electron density of 1023m-3 and temperatures from 10000K to 300000K.

Research paper thumbnail of Stark broadening of Cd I spectral lines (Simic+, 2005)

Stark broadening parameters, widths, and shifts for 33 CdI singlets and 37 triplets were calculat... more Stark broadening parameters, widths, and shifts for 33 CdI singlets and 37 triplets were calculated using the semiclassical perturbation method. The results were compared with available experimental and theoretical data. Also, regularity in the spectral series 5s2 1S-np 1Po was investigated. The influence of Stark broadening was analyzed in A-type stellar atmospheres. (2 data files).

Research paper thumbnail of On the Stark Broadening of Ar XV Spectral Lines

In order to provide Stark broadening data in X-ray and far UV wavelength region, of interest for ... more In order to provide Stark broadening data in X-ray and far UV wavelength region, of interest for modelling and analysis of astrophysical plasmas in extreme conditions, we performed calculations of Stark broadened line widths and shifts for Ar XV using the semiclassical perturbation theory.

Research paper thumbnail of Stark-B Database Virtual Atomic and Molecular Data Center (VAMDC) and Data for White Dwarf Atmospheres Analysis

In a number of papers we have demonstrated the importance of Stark broadening mechanism for the m... more In a number of papers we have demonstrated the importance of Stark broadening mechanism for the modeling and synthesizing of lines observed in spectra of white dwarf atmo- spheres. We also determined a number of Stark broadening parameters of interest in particular for DB and DO white dwarf plasmas investigations. Now, work on their inclusion in STARK- B database and in Virtual Atomic and Molecular Data Center, an FP7 european project, as well as in Serbian Virtual Observatory is in progress. We review here the part of this work of interest for white dwarf atmospheres analysis.

Research paper thumbnail of STARK BROADENING OF SEVERAL Ne II, Ne III AND O III SPECTRAL LINES FOR THE STARK-B DATABASE

Baltic astronomy an international journal

In order to complete Stark broadening data for Ne II, and O III lines, needed for analysis of ste... more In order to complete Stark broadening data for Ne II, and O III lines, needed for analysis of stellar atmospheres, we determined, within the semiclassical perturbation method, the missing Stark broadening parameters for the broadening by collisions with protons and ionized helium, for 15 Ne II and 5 O III multiplets. Also, electron, proton and ionized helium impact broadening parameters for an important Ne II multiplet in the visible part of the spectrum and for three Ne III multiplets were calculated. The obtained data will be included in the STARK-B database, which is a part of the Virtual Atomic and Molecular Data Center.

Research paper thumbnail of Stark Broadening and White Dwarfs

White dwarf and pre-white dwarf atmospheres are one of the best examples for the application of S... more White dwarf and pre-white dwarf atmospheres are one of the best examples for the application of Stark broadening research results in astrophysics, due to plasma conditions very favorable for this line broadening mechanism. For example in hot hydrogen-deficient (pre-) white dwarf stars Teff = 75 000 K - 180 000 K and log g = 5.5-8 [cgs]. Even for much cooler DA and DB white dwarfs with typical effective temperatures of 10 000 K - 20 000 K, Stark broadening is usually the dominant broadening mechanism. In this review, Stark broadening in white dwarf spectra is considered and the attention is drawn to the STARK-B database (http://stark-b.obspm.fr/), containing Stark broadening parameters needed for white dwarf spectra analysis and synthesis, as well as to the new search facilities which will provide the collective effort to develop Virtual Atomic and Molecular Data Center (VAMDC - http://vamdc.org/).

Research paper thumbnail of Electron-impact broadening of ionized chromium lines for Ap star atmospheres analysis

The influence of Stark broadening on the shapes of Cr II spectral lines observed in stellar atmos... more The influence of Stark broadening on the shapes of Cr II spectral lines observed in stellar atmospheres is considered.

Research paper thumbnail of Stark broadening of O V 1371 A˚ line in stellar atmospheres

AIP Conference Proceedings

The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmospheres of ... more The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmospheres of hot stars, determined within the semiclassical perturbation method, are used for the analysis of the importance of this broadening mechanism in white dwarf atmospheres. We found that Stark broadening mechanism is very important in such plasma conditions and should be taken into account.

Research paper thumbnail of STARK BROADENING OF In III LINES IN ASTROPHYSICAL AND LABORATORY PLASMA

Baltic astronomy an international journal

Besides the need of Stark broadening parameters for a number of problems in physics and plasma te... more Besides the need of Stark broadening parameters for a number of problems in physics and plasma technology, in hot star atmospheres the condi-tions exist where Stark widths are comparable and even larger than the thermal Doppler widths. Using the semiclassical perturbation method we investigated here the influence of collisions with charged particles for In III spectral lines. We determined a number of Stark broadening parameters important for the investigation of plasmas in the atmospheres of A-type stars and white dwarfs. Also, we have compared the obtained results with existing experimental data. The results will be included in the STARK-B database, the Virtual Atomic and Molecular Data Center and the Serbian Virtual Observatory.

Research paper thumbnail of Stark broadening of Sn III lines in a type stellar atmospheres

Here we present Stark broadening parameters for Sn III 6s ^1S_0-6p ^1P^o_1 spectral line obtained... more Here we present Stark broadening parameters for Sn III 6s ^1S_0-6p ^1P^o_1 spectral line obtained by using semiclassical perturbation approach and Stark widths for this transition obtained by using modified semiempirical approach. Results obtained have been compared with available experimental data and used for the consideration of the influence of the Stark broadening effect in A type stellar atmospheres.

Research paper thumbnail of On Stark broadening of MnII lines in Ap-star conditions

Stark broadening parameters for six MnII lines are determined semi-classically and used to analys... more Stark broadening parameters for six MnII lines are determined semi-classically and used to analyse the influence of this broadening mechanism on A-type star spectral line profiles. Results for the MnII line at 2950.1Å are presented here as an example of the data obtained.

Research paper thumbnail of On the Stark broadening of TeI spectral lines for CP star plasma analysis

By using the semiclassical perturbation method, Stark widths and shifts have been calculated for ... more By using the semiclassical perturbation method, Stark widths and shifts have been calculated for the TeI 6s 5S° - 7p 5P (5125.2 Å) multiplet, of interest for CP star plasma studies. Results were applied to the investigation of the influence of Stark broadening on CP star spectra. It was found that layers exist in the stellar atmospheres considered where the

Research paper thumbnail of Stark Broadening of F III Lines in Laboratory and Stellar Plasma

Journal of Applied Spectroscopy, 2005

∨ ic ′ a UDC 533.9.082.5

Research paper thumbnail of Experimental and Theoretical Stark Widths for Au II

In the present work, we have reviewed and compared our experimental and theoretical Au II Stark w... more In the present work, we have reviewed and compared our experimental and theoretical Au II Stark widths. The interest in Au II resides not only on the knowledge of its atomic structure, or to check the adequacy of theoretical models, but also on its astrophysical importance because its lines are present in spectra of chemically peculiar stars. The plasma source

Research paper thumbnail of Stark broadening of O V 1371 A˚ line in stellar atmospheres

The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmosphere... more The Stark broadening parameters of O V 1371 A˚ spectral line, observed in stellar atmospheres of hot stars, determined within the semiclassical perturbation method, are used for the analysis of the importance of this broadening mechanism in white dwarf atmospheres. We found that Stark broadening mechanism is very important in such plasma conditions and should be taken into account.

Research paper thumbnail of On the Stark broadening in hot stars

In hot star atmospheres exist conditions where Stark widths are comparable and even larger than t... more In hot star atmospheres exist conditions where Stark widths are comparable and even larger than the thermal Doppler widths, so that the corresponding line broadening parameters are of importance for the hot star plasma investigation. Here, we investigated theoretically the influence of collisions with charged particles on heavy element spectral line profiles for Te I, Cr II and Sn III in spectra of A stars and white dwarfs. We applied semiclassical perturbation theory. When it can not be applied in an adequate way, due to the lack of reliable atomic data, we used modified semiempirical theory.