DEFPOS and Its First Results

Şahan, Muhittin; Yeğingil, I.; Aksaker, Nazım; Kızıloğlu, Ü.; Akyilmaz, M.

doi:10.1088/1009-9271/5/2/013

Cited by 12 publications

(22 citation statements)

References 10 publications

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“…Since Fabry-Pérot spectrometers offer the advantage of simultaneously achieving high throughput and high spectral resolution, they are used to obtain high-resolution spectra of very faint, extended diffuse emission line objects of the ISM such as H II regions and PNe (Roesler 1974;Tufte 1997;Mierkiewicz et al 2006 spectral resolution (Sahan et al 2005(Sahan et al , 2007. After completing test observations in the zenith direction, the spectrometer was supported by TUBITAK (The Scientific and Technical Research Council of Turkey) with grant number 104T252 to explore ionized gas in ISM with a spatial resolution of 4 .…”

Section: Defpos Spectrometermentioning

confidence: 99%

Hα observations with DEFPOS

Şahan

2011

Astron Nachr

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A 7.5 cm, dual étalon Fabry‐Pérot spectrometer called DEFPOS has been set up at Coudé focus of 150 cm RTT150 telescope at TUBITAK National Observatory (TUG, Antalya, Turkey) to investigate the physical properties of Diffuse Ionized Gas (DIG) in our Galaxy. The spectrometer, having a 4 arcmin circular field of view over a 200 km s–1 (4.4 Å) spectral window near Hα, has been used to observe H II regions and Planetary Nebulae (PNe) since May 2007 (Sahan et al. 2009). Early observations have been analyzed and physical and kinematic properties such as the intensity, the line width, and the LSR velocity are presented here. These values are compared with earlier results from different studies. In this study, I discuss some results obtained by DEFPOS, including two H II regions (Sh2‐156, Sh2‐157), and two PNe (NGC 1360, and NGC 6826). The Intensities, the radial velocities and the line widths of the Hα emission line vary from 101.4R to 149.97R (1 Rayleigh =106/4π photons cm–2 sr–1 s–1 = 2.41 × 10–7 erg cm–2 s–1 sr–1 at Hα), –41.19 km s–1 to +8.34 km s–1, and 39.55 km s–1 to 58.23 km s–1, respectively (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Defpos Spectrometermentioning

confidence: 99%

Hα observations with DEFPOS

Şahan

2011

Astron Nachr

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“…When they die, they return some of their matter and energy back into the ISM. The life time of stars range from a few million years for the most massive to trillions of years for the least massive [1][2][3].The amount of H and He elements in the universe are approximately 73% and 25% of the mass, respectively. After H and He, C, N and O elements are the most abundant elements in the Universe.…”

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“…1, in the protonproton fusion reaction inside stars like the sun, the first step in ppI process is the collision of two protons (p or 1 H) to make an atom of heavy hydrogen ( 2 H). The second step containing the weak interaction involves the collision of a 2 H nuclei with a proton to make a nucleus of 3 He, and then gamma ray is emitted having very high energy. In the final third step, a normal 4 He nucleus are created with combining two 3 He nuclei and two extra protons (2 1 H) are released to start the whole process again.…”

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“…The second step containing the weak interaction involves the collision of a 2 H nuclei with a proton to make a nucleus of 3 He, and then gamma ray is emitted having very high energy. In the final third step, a normal 4 He nucleus are created with combining two 3 He nuclei and two extra protons (2 1 H) are released to start the whole process again. Inside the Sun, about 655×10 6 tons of H are converted into 650×10 6 tons of 4 He every second.…”

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Calculation of (p,γ) and (p,α) nuclear reaction cross sections in stars up to 10 MeV

et al. 2016

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Abstract. In Knowledge of the proton-proton (p-p) chain and CNO cycle are required for the evolution of main sequence stars during the early formation of the universe. In this study, we summarized the excitation functions of (p,γ) and (p,α) reactions for 7 Be(p,γ) 8 B, 12 C(p,γ) 13 N, 13 C(p,γ) 14 N, 14 N(p,γ) 15 O and 15 N(p,α) 15 O in p-p chain and CNO cycle using EMPIRE and TALYS computer up to 10 MeV. The calculated data on nuclear fusion cross sections in hydrogen-burning stars were compared with theoretical TENDL-2014 and ENDF/B-VII data from EXFOR. The calculation results show closed agreement between the calculations and the data from literature.Animals, plants, soil, air, planets, stars like everything formed by the basic blocks of matter called atoms. After the big bang, approximately 13.7 billion years ago, a large part of atoms formed in the early formation of the universe and came unchanged until the present day. Since the universe includes everything from subatomic particles to galaxies, from planets to stars, it is needed to be explored in detailed.All stars are born from collapsing clouds of gas and dust the interstellar medium (ISM). During their lives, they deposit energy into the ISM in the form of electromagnetic radiation and stellar winds. When they die, they return some of their matter and energy back into the ISM. The life time of stars range from a few million years for the most massive to trillions of years for the least massive [1][2][3].The amount of H and He elements in the universe are approximately 73% and 25% of the mass, respectively. After H and He, C, N and O elements are the most abundant elements in the Universe. Energy production in massive stars is governed by the CNO cycles throughout most of their lifetimes [4]. Hydrogen and helium elements having low-mass were produced in the hot and dense conditions of the birth of the universe itself. The life of stars is described in terms of nuclear reactions.The Hydrogen burning mechanism is essentially the nuclear fusion of four protons into one 4 He nucleus. There are two reaction chains that can convert hydrogen to helium, namely the proton-proton (or pp chain) chain, also called pp reaction, and the CNO cycle. The pp chain is more important in stars the mass of the Sun or less and stars of similar mass The CNO cycle by which stars convert hydrogen to helium is the dominant source of energy in more massive stars [5].The p-p fusion is the nuclear fusion process which fuels the Sun and other stars which have core temperatures less than 15×10 6 K and a reaction cycle at energy of 25 MeV. The p-p chains occur under lower temperature than the carbon-nitrogen-oxygen cycle. The pp chain in stars like our Sun divides into three main branches, called as the ppI, ppII and ppIII chains. These are given Eq. 1-3. According to Eq. 1, in the protonproton fusion reaction inside stars like the sun, the first step in ppI process is the collision of two protons (p or 1 H) to make an atom of heavy hydrogen ( 2 H). The second step contain...

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The Hα observations of the California Nebula (NGC 1499) with DEFPOS

2012

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A dual étalon Fabry‐Pérot spectrometer called DEFPOS has been used for observing physical properties of HII regions and planetary nebulae since May 2007 (Aksaker et al. 2009, 2011; Şahan et al. 2009; Şahan 2011). In this study, the Hα measurements of the HII region NGC 1499 (California Nebula) have been investigated with a 4′ circular field of view over a 200 km s–1 (4.4 Å) spectral window. These measurements provide information about the densities, line widths, and radial velocities of the surrounding NGC 1499 nebula. The intensities, the radial velocities and the line widths of the Hα emission line vary from 397.75 R to 1044.14 R, –4.88 km s–1 to –1.02 km s–1, and 36.72 km s–1 to 42.81 km s–1, respectively (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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DEFPOS and Its First Results

Cited by 12 publications

References 10 publications

Hα observations with DEFPOS

Hα observations with DEFPOS

Calculation of (p,γ) and (p,α) nuclear reaction cross sections in stars up to 10 MeV

The Hα observations of the California Nebula (NGC 1499) with DEFPOS

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