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Probing the local bubble with diffuse interstellar bands
, Article Proceedings of the International Astronomical Union ; Vol. 9, issue. S297 , February , 2014 , pp. 84-88 ; ISSN: 17439213 ; Khosroshahi, H. G ; Javadi, A ; Van Loon, J ; Sharif University of Technology
Abstract
The Sun is located inside an enormous local cavity filled with a million degree, ionized hydrogen gas and surrounded by a wall of dense and cold gas, this cavity is known as the Local Bubble (LB). Since the tempreture of Local Bubble is high, the typical singly-ionized atoms or molecules can not survive at this high tempreture. To overcome this problem we should probe the Local Bubble using species which survive under this condition so we have done a whole sky survey in north hemisphere by observing absorptions in the Diffuse Interstellar Bands (DIBs) for sight-lines with distance >300 pc. We have done 30 nights observation and have observed 473 bright stars. We found that the correlations...
Probing the local bubble with diffuse interstellar bands. II. The dib properties in the northern hemisphere
, Article Astrophysical Journal ; Volume 800, Issue 1 , February , 2015 ; 0004637X (ISSN) ; Khosroshahi, H. G ; Javadi, A ; Van Loon, J. Th ; Bailey, M ; Molaeinezhad, A ; Tavasoli, S ; Habibi, F ; Kourkchi, E ; Rezaei, S ; Saberi, M ; Hardy, L ; Sharif University of Technology
Institute of Physics Publishing
2015
Abstract
We present a new high signal-to-noise ratio spectroscopic survey of the Northern hemisphere to probe the Local Bubble and its surroundings using the λ5780Å and λ5797Å diffuse interstellar bands (DIBs). We observed 432 sightlines to a distance of 200 pc over a duration of three years. In this study, we establish the λ5780 and λ5797 correlations with Na I, Ca II and EB-V, for both inside and outside the Local Bubble. The correlations show that among all neutral and ionized atoms, the correlation between Ca ii and λ5780 is stronger than its correlation with λ5797, suggesting that λ5780 is more associated with regions where Ca+ is more abundant. We study the λ5780 correlation with λ5797, which...
Probing the local bubble with diffuse interstellar bands. III. The northern hemisphere data and catalog
, Article Astrophysical Journal, Supplement Series ; Volume 216, Issue 2 , February , 2015 ; 00670049 (ISSN) ; Khosroshahi, H. G ; Javadi, A ; Van Loon, J. T ; Sharif University of Technology
Institute of Physics Publishing
2015
Abstract
We present new high signal-to-noise ratio (S/N) observations of the diffuse interstellar bands (DIBs) in the Local Bubble and its surroundings. We observed 432 sightlines and obtain the equivalent widths of the λ5780 and λ5797 Å DIBs up to a distance of ∼200 pc. All of the observations were carried out using the Intermediate Dispersion Spectrograph on the 2.5 m Isaac Newton Telescope, during three years, to reach a minimum S/N of ∼2000. All of the λ5780 and λ5797 absorptions are presented in this paper and we tabulate the observed values of the interstellar parameters, λ5780, λ5797, Na ID1, and Na ID2, including the uncertainties