DEFPOS Hα observations of Hii regions

Aksaker, Nazım; Şahan, Muhittin; Yeğingil, I.; Emrahoğlu, Nuri

doi:10.1016/j.newast.2011.04.005

Cited by 4 publications

(6 citation statements)

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“…Since FP spectrometers are capable of simultaneously achieving high throughput and high spectral resolution, they are particularly well suited for detailed studies of faint diffuse emission lines such as galactic Hα from PNe and H II regions within the ISM (Roesler 1974). In order to investigate the kinematic properties of diffuse, ionized gas, a 75 mm dual etalon Fabry-Pérot spectrometer called DEFPOS has been redesigned to be used at the coudé exit of RTT150 telescope and has initiated a program of Hα observations from H II regions and PNe sources (Aksaker et al , 2011Ş ahan et al 2009; Ş ahan 2011). Hα observations from over 100 sources were carried out between 2007 and 2010.…”

Section: Resultsmentioning

confidence: 99%

“…Horizontal axes was plotted according to the LSR velocities. Since the line center of the geocoronal Hα emission line is shifted by -2.33 km s −1 from the rest wavelength of the recombination line at 6562.82Å (Haffner et al 2003), the LSR velocity was corrected as V LSR = −V LSR − 2.33 km s −1 (Aksaker et al 2011). The vertical dashed line (near +18 km s −1 ) for the data represents the differences between center of the spectrum and its fit position of the LSR.…”

Section: Resultsmentioning

confidence: 99%

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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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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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

2012

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“…The big differences appear only in the DEFPOS observations (Aksaker 2013). Aksaker et al (2011) have statistically analyzed the spectra of 10 nebulae with DEFPOS, and stated that the FWHMs in DEFPOS are 10 km s −1 wider than those in other literature, and the radial velocity of DEFPOS has a deviation of 3 km s −1 .…”

Section: Emission Line Measurements In the W80 Regionmentioning

confidence: 96%

LAMOST MRS-N Observations of the W80 Region

Li,

Wu,

Yao

et al. 2022

Preprint

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The spectral observations and analysis for the W80 Region are presented by using the data of Medium-Resolution Spectroscopic Survey of Nebulae (MRS-N) with the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST). A total of 2982 high-quality nebular spectra have been obtained in the 20 square degree field of view (FoV) which covers the W80 complex, and the largest sample of spectral data have been established for the first time. The relative intensities, radial velocities (RVs), and Full Widths at Half Maximum (FWHMs) are measured with the high spectral resolution of LAMOST MRS, for Hα λ 6563 Å, [N II] λλ 6548 Å, 6584 Å , and [S II] λλ 6716 Å, 6731 Å emission lines. In the field of view of whole W80 Region, the strongest line emissions are found to be consistent with the bright nebulae, NGC 7000, IC 5070, and LBN 391, and weak line emissions also truly exist in the Middle Region, where no bright nebulae are detected by the wide-band optical observations. The large-scale spectral observations to the W80 Region reveal the systematic spatial variations of RVs and FWHMs, and several unique structural features. A 'curved feature' to the east of the NGC 7000, and a 'jet feature' to the west of the LBN 391 are detected to be showing with larger radial velocities. A 'wider FWHM region' is identified in the eastern part of the NGC 7000. The variations of [S II] / Hα ratios display a gradient from southwest to northeast in the NGC 7000 region, and manifest a ring shape around the 'W80 bubble' ionized by an O-type star in the L935. Further spectral and multi-band observations are guaranteed to investigate in detail the structural features.

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“…of such structures. Studying H II regions helps us to determine their sources of ionization (Aksaker et al 2011) and to understand how these regions are related to the general structure of the ISM (Reynolds et al 1998;Hausen et al 2002). Therefore, observing H II regions in a visual band using an Hα emission line gives valuable information (Aksaker et al 2011;Fich et al 1989).…”

Section: Introductionmentioning

confidence: 99%

“…Studying H II regions helps us to determine their sources of ionization (Aksaker et al 2011) and to understand how these regions are related to the general structure of the ISM (Reynolds et al 1998;Hausen et al 2002). Therefore, observing H II regions in a visual band using an Hα emission line gives valuable information (Aksaker et al 2011;Fich et al 1989). However, it is difficult to make accurate measurements of line fluxes by using traditional long-slit spectroscopic techniques, because of the low surface brightness and spatially extended emissions from large H II regions.…”

Section: Introductionmentioning

confidence: 99%

DEFPOS Hα observations of the W80 Complex

Aksaker

2013

Res. Astron. Astrophys.

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We present Hα emission line measurements of the W80 nebula complex. A total of 26 regions have been observed inside the nebula with the Dual Etalon Fabry-Perot Optical Spectrometer system at the f/48 Coudé focus of the 150 cm RTT150 telescope located at TUBITAK National Observatory in Antalya, Turkey. The intensities, local standard of rest velocities, heliocentric radial velocities and linewidths for full width at half maximum of the Hα emission lines have been determined from these observations. They lie in the range of 259 to 1159 Rayleigh (R; 1R = 106/4π photons cm−2 sr−1 s−1 = 2.41 × 10−7 erg cm−2 sr−1 s−1 at Hα), 4 to 12 km s−1, −3 to −11 km s−1 and 44 to 55 km s−1, respectively. The radial velocity measurements show that there are several maxima and minima inside W80. The new results confirm findings in the literature that the complex seems to be rather uniform in terms of radial velocity and no turbulent motion is seen inside the complex. The average value of the calculated emission measure for the region is 3.1 pc cm−6.

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DEFPOS Hα observations of Hii regions

Cited by 4 publications

References 25 publications

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

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

LAMOST MRS-N Observations of the W80 Region

DEFPOS Hα observations of the W80 Complex

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