Nebular and auroral emission lines of [Cl III] in the optical spectra of planetary nebulae

ABSTRACT We report the validation of a recently proposed infrared (IR) selection criterion for symbiotic stars (SySts). Spectroscopic data were obtained for seven candidates, selected from the SySt candidates of Akras et al. by employing the new supplementary IR selection criterion for SySts in the VST/OmegaCAM Photometric H-Alpha Survey. Five of them turned out to be genuine SySts after the detection of H α, He ii, and [O iii] emission lines as well as TiO molecular bands. The characteristic O vi Raman-scattered line is also detected in one of these SySts. According to their IR colours and optical spectra, all five newly discovered SySts are classified as S-type. The high rate of true SySts detections of this work demonstrates that the combination of the H α emission and the new IR criterion improves the selection of target lists for follow-up observations by minimizing the number of contaminants and optimizing the observing time.

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Cloud Cover and Aurora Contamination at Dome A in 2017 from KLCAM

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3824 ◽

2020 ◽

Author(s):

Xu Yang ◽

Zhaohui Shang ◽

Keliang Hu ◽

Yi Hu ◽

Bin Ma ◽

...

Keyword(s):

Cloud Cover ◽

Emission Lines ◽

Austral Winter ◽

Site Testing ◽

Dome A ◽

Astronomical Observations ◽

Auroral Emission ◽

Long Term Monitoring ◽

Term Monitoring

Abstract Dome A in Antarctica has many characteristics that make it an excellent site for astronomical observations, from the optical to the terahertz. Quantitative site testing is still needed to confirm the site’s properties. In this paper, we present a statistical analysis of cloud cover and aurora contamination from the Kunlun Cloud and Aurora Monitor (KLCAM). KLCAM is an automatic, unattended all-sky camera aiming for long-term monitoring of the usable observing time and optical sky background at Dome A. It was installed at Dome A in January 2017, worked through the austral winter, and collected over 47,000 images over 490 days. A semi-quantitative visual data analysis of cloud cover and auroral contamination was carried out by five individuals. The analysis shows that the night sky was free of clouds for 83 per cent of the time, which ranks Dome A highly in a comparison with other observatory sites. Although aurorae were detected somewhere on an image for nearly 45 per cent of the time, the chance of a point on the sky being affected by an aurora is small. The strongest auroral emission lines can be filtered out with customized filters.

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Observations of the Far-Infrared Emission Lines of OI and CII in Planetary Nebulae

Astrophysics and Space Science Library - Mass Loss from Red Giants ◽

10.1007/978-94-009-5428-1_46 ◽

1985 ◽

pp. 309-310 ◽

Cited By ~ 2

Author(s):

H. Benton Ellis ◽

Michael W. Werner

Keyword(s):

Planetary Nebulae ◽

Far Infrared ◽

Infrared Emission ◽

Emission Lines

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Ultraviolet Variability of the Symbiotic Star AG PEG

International Astronomical Union Colloquium ◽

10.1017/s0252921100103598 ◽

1988 ◽

Vol 103 ◽

pp. 263-264

Author(s):

D. Chochol ◽

Z. Komárek ◽

A. Vittone

Keyword(s):

Optical Spectra ◽

Radial Velocities ◽

Roche Lobe ◽

Emission Lines ◽

High Dispersion ◽

Symbiotic Star ◽

Observational Material

Symbiotic star AG Peg consists of a hot subdwarf with a WN6 spectrum and a cool M3 giant, which is not filling its Roche lobe (Boyarchuk 1967, 1985). A detailed study of profiles, equivalent widths and radial velocities of emission lines in optical spectra allowed Hutchings et al. (1975) to conclude that a hot subluminous star approximately 1 M⊙ rotates rapidly and ejects material which streams towards the cool M giant with the mass 3-4 M⊙. UV observations seems to support this model.UV observations provided from the databank of the IUE satellite were obtained in 1978–81 by different observers. The observational material consists of 12 high dispersion SWP spectra and covers the region 1200 – 2100 A. The spectra were reduced at Trieste observatory using standard IUESIPS package. The radial velocities of emission lines were measured on tracings and corrected for the motion of Earth and satellite.

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UV Monochromatic Imaging of the Protoplanetary Nebula Hen 3-1475 Using HST STIS

Galaxies ◽

10.3390/galaxies6040141 ◽

2018 ◽

Vol 6 (4) ◽

pp. 141

Author(s):

Xuan Fang ◽

Martín Guerrero ◽

Ana Castro ◽

Jesús Toalá ◽

Bruce Balick ◽

...

Keyword(s):

Hubble Space Telescope ◽

Critical Role ◽

Planetary Nebulae ◽

Emission Lines ◽

Comparison Analysis ◽

Space Telescope ◽

Monochromatic Imaging ◽

Protoplanetary Nebula ◽

Low Dispersion ◽

Negative Gradient

Collimated outflows and jets play a critical role in shaping planetary nebulae (PNe), especially in the brief transition from a spherical AGB envelope to an aspherical PN, which is called the protoplanetary nebula (pPN) phase. We present UV observations of Hen 3-1475, a bipolar pPN with fast, highly collimated jets, obtained with STIS on board the Hubble Space Telescope (HST). The deep, low-dispersion spectroscopy enabled monochromatic imaging of Hen 3-1475 in different UV nebular emission lines; this is the first of such attempt ever conducted for a pPN. The northwest inner knot (NW1) is resolved into four components in Mg ii λ 2800. Through comparison analysis with the HST optical narrowband images obtained 6 yr earlier, we found that these components of NW1 hardly move, despite of a negative gradient of high radial velocities, from −1550 km s - 1 on the innermost component to ∼−300 km s - 1 on the outermost. These NW1 knot components might thus be quasi-stationary shocks near the tip of the conical outflow of Hen 3-1475.

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Late-time Spectral Observations of Type IIP Supernovae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316005895 ◽

2015 ◽

Vol 11 (A29B) ◽

pp. 472-472

Author(s):

Jeffrey M. Silverman ◽

Stephanie Pickett ◽

J. Craig Wheeler ◽

Alexei V. Filippenko

Keyword(s):

Temporal Evolution ◽

Optical Spectra ◽

Photometric Data ◽

Emission Lines ◽

Late Time ◽

Type Ii ◽

Insight Into

We are analysing late-time (older than about 150 d past explosion) optical spectra of Type II-Plateau (IIP) supernovae (SNe), which are H-rich SNe that come from red supergiant (RSG) progenitors. The dataset includes nearly 100 spectra of about 40 objects, making this the largest sample of SN IIP nebular spectra ever investigated. Quantitative criteria from within the spectra themselves are employed to determine if an observation is truly nebular, and thus should be included in the study. We present the temporal evolution of the fluxes, shapes, and velocities of various emission lines (see, for example, Fig. 1). These measured values are also compared to photometric data in order to search for correlations that can allow us to gain insight into the diversity of RSG progenitors and learn more about the details of the explosion itself.

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Ultraviolet emission line imaging of planetary nebulae with GALEX

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312011167 ◽

2011 ◽

Vol 7 (S283) ◽

pp. 308-309 ◽

Cited By ~ 2

Author(s):

Luciana Bianchi ◽

Arturo Manchado ◽

Karl Forster

Keyword(s):

Galaxy Evolution ◽

Broad Band ◽

Planetary Nebulae ◽

Emission Lines ◽

Continuum Emission ◽

Ultraviolet Emission ◽

The Galaxy ◽

Optical Domain ◽

Line Imaging ◽

Shock Fronts

AbstractGALEX (the Galaxy Evolution Explorer) has provided far-UV(1344-1786Å) and near-UV(1771-2831Å) imaging of several Planetary Nebulae (e.g., Bianchi et al. 2008, Bianchi 2012), with flux limits ~27.5 mag/sq.arcsec for objects in the Medium-deph Imaging Survey (MIS). PNe images in the GALEX broad-band UV filters include flux from both nebular line and continuum emission. We use the GALEX grism observing mode to obtain slitless spectral imaging of a sample of PNe with diameters >1′, in the near-UV. We show the first data from this program. The grism produces 2D images of the prominent UV nebular emission lines, when such lines dominate the flux. Combined with monochromatic images of diagnostic lines in the optical domain, such data help detect and interpret ionization and shock fronts, especially in faint nebular regions.

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