HIGH-RESOLUTION SPECTROSCOPY OF THE B[e] STAR MWC 645

Optical high-resolution spectroscopic observations of the emission-line star MWC645 are presented. The spectrum exhibits strong variable double-peaked Balmer emission lines as well as low-excitation emission lines of FeII, [FeII], and [OI] which are signatures of the B[e] phenomenon, while lines of helium have not been found. In addition to the emission lines, for the first time we identified absorption lines of neutral metals (e.g., LiI 6708 A, CaI 6717 A, and a number of FeI and TiI lines) that indicate the presence of a cool component in the system. The heliocentric radial velocity measured in our best spectrum was found to be −65.1±1.0 kms −1 for the emission lines and −23.2±0.4 kms −1 for the absorption lines. Using a combination of photometric and spectroscopic data as well as the Gaia EDR3 distance (D=6.5±0.9 kpc), we disentangled the component contributions and estimated their temperatures and luminosities (∼15000 K and ∼4000 K, log L/L ? = 3.8±0.2 and 2.8±0.2 for the hot and cool component, respectively).

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The Structure of the HH39 Region

Symposium - International Astronomical Union ◽

10.1017/s0074180900095759 ◽

1987 ◽

Vol 115 ◽

pp. 340-341

Author(s):

J. R. Walsh

Keyword(s):

High Resolution ◽

Radial Velocity ◽

Proper Motion ◽

High Velocity ◽

Velocity Structure ◽

The Other ◽

Emission Lines ◽

High Resolution Spectroscopy ◽

Bow Shocks ◽

Hh Objects

HH39 is the group of Herbig-Haro (HH) objects associated with the young semi-stellar object R Monocerotis (R Mon) and the variable reflection nebula NGC 2261. An R CCD frame and a B prime focus plate of the region show a filament connecting NGC 2261 with HH39, confirming the association between R Mon and the HH objects. This filament is probably composed of emission material. The southern knot in HH39 has brightened over the last 20 years; its proper motion has been determined and is similar to that of the other knots. A total of 8 knots can be distinguished in HH39 surrounded by diffuse nebulosity. High resolution spectroscopy of the Hα and [N II] emission lines shows the spatial variation of the radial velocity structure over the largest knots (HH39 A and C). Distinct differences in excitation and velocity structure between the knots are apparent. The observations are compatible with the knots being high velocity ejecta from R Mon, decelerated by interaction with ambient material and with bow shocks on their front surfaces.

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Long Term UV Continuum and Line Variability in NGC 1275

Mapana Journal of Sciences ◽

10.12723/mjs.56.4 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Bryan Rithesh Miranda ◽

Vijayakumar H Doddamani ◽

Vedavathi P

Keyword(s):

Emission Line ◽

Spectroscopic Data ◽

Wavelength Region ◽

Emission Lines ◽

Observational Period ◽

Flux Variability Analysis ◽

Variability Analysis ◽

Ngc 1275 ◽

First Time

In this paper, we present our results for the first time on long term emission-line and continuum variability studies using the International Ultraviolet Explorer’s final archive of UV spectroscopic data obtained in the wavelength region from 1150 Å to 3200 Å for NGC 1275, a dust dominated BL Lac characterized by the Rmax and F-variance parameter. The UV continuum flux variability analysis presented in this paper covers more number of emission-line free continuum windows in the UV region centred at 1710 Å, 1800 Å, 2625 Å, 2875 Å & 3025 Å. We have obtained a higher value of Fvar ~ 45 % at 1710 Å and a lower value of ~ 30 % at 1800 Å for the IUE's observational period of 1978 - 1989. The Lyα, C IV, C III] and Mg II emission lines have been observed as weaker line features on fewer occasions intermittently.

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New Spectroscopic Observations of Dwarf Nova BZ Ursae Majoris with Extremely Unusual Emission Lines Profiles

International Astronomical Union Colloquium ◽

10.1017/s0252921100153138 ◽

2004 ◽

Vol 194 ◽

pp. 269-269 ◽

Cited By ~ 1

Author(s):

V. V. Neustroev ◽

S. V. Zharikov ◽

A. Medvedev ◽

A. Shearer

Keyword(s):

Radial Velocity ◽

Emission Line ◽

Velocity Curve ◽

Emission Lines ◽

Radial Velocity Curve ◽

Dwarf Nova ◽

Preliminary Results ◽

Spectroscopic Observations ◽

Medium Resolution ◽

Hα Emission

We present preliminary results of new spectroscopic observations of dwarf nova BZ UMa in quiescence. Fifty medium resolution spectra allow us to reproduce the radial velocity curve from the Hα emission line. We confirm that BZ UMa shows extremely unusual emission lines profiles, Unlike the classical single or the double-peaked profiles usually observed in spectra of dwarf novae, emission lines of BZ UMa consist of at least five peaks.

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High-resolution spectroscopy of the high-velocity hot post-AGB star IRAS 18379–1707 (LS 5112)

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3355 ◽

2019 ◽

Vol 491 (4) ◽

pp. 4829-4842 ◽

Cited By ~ 1

Author(s):

N P Ikonnikova ◽

M Parthasarathy ◽

A V Dodin ◽

S Hubrig ◽

G Sarkar

Keyword(s):

High Resolution ◽

Model Atmosphere ◽

Emission Lines ◽

High Resolution Spectroscopy ◽

Atmospheric Parameters ◽

Optical Counterpart ◽

Chemical Abundances ◽

Balmer Lines ◽

Cno Abundances ◽

First Time

ABSTRACT The high-resolution ($R\sim 48\, 000$) optical spectrum of the B-type supergiant LS 5112, identified as the optical counterpart of the post-AGB candidate IRAS 18379–1707 is analysed. We report the detailed identifications of the observed absorption and emission features in the wavelength range 3700–9200 Å for the first time. The absorption line spectrum has been analysed using non-LTE model atmosphere techniques to determine stellar atmospheric parameters and chemical composition. We estimate Teff = 18 000 ± 1000 K, log g = 2.25 ± 0.08, ξt = 10 ± 4 km s−1, and vsin i = 37 ± 6 km s−1, and the derived abundances indicate a metal-deficient ([M/H] ≈ −0.6) post-AGB star. Chemical abundances of eight different elements were obtained. The estimates of the CNO abundances in IRAS 18379–1707 indicate that these elements are overabundant with [(C + N + O)/S] = + 0.5 ± 0.2 suggesting that the products of helium burning have been brought to the surface as a result of third dredge-up on the AGB. From the absorption lines, we derived heliocentric radial velocity of Vr = −124.0 ± 0.4 km s−1. We have identified permitted emission lines of O i, N i, Na i, S ii, Si ii, C ii, Mg ii, and Fe iii. The nebula forbidden lines of [N i], [O i], [Fe ii], [N ii], [S ii], [Ni ii], and [Cr ii] have also been identified. The Balmer lines H α, H β, and H γ show P-Cygni behaviour clearly indicating post-AGB mass-loss process in the object with the wind velocity up to 170 km s−1.

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The Kepler field of view covered with the LAMOST spectroscopic observations

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316006013 ◽

2015 ◽

Vol 11 (A29B) ◽

pp. 514-516

Author(s):

Joanna Molenda-Żakowicz ◽

Peter De Cat ◽

Jian-Ning Fu ◽

An-Bing Ren ◽

Antonio Frasca ◽

...

Keyword(s):

High Resolution ◽

Emission Line ◽

Effective Temperature ◽

Field Of View ◽

Surface Gravity ◽

High Resolution Spectroscopy ◽

Optical Fibres ◽

Low Resolution ◽

Spectroscopic Observations ◽

The Mean

AbstractThe Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) at the Xinglong observatory in China is a 4-m telescope equipped with 4,000 optical fibres. In 2010, we initiated the LAMOST-Kepler project which aimed at collecting low-resolution spectra of stars from the Kepler Input Catalog covering uniformly the Kepler field of view. The first round of the LAMOST-Kepler project has been completed in September 2014 resulting in more than 100,000 low-resolution spectra. We used those data to derive the effective temperature, the surface gravity, and the mean metallicity of our targets, as well as to detect fast rotators, and to identify emission-line stars. Our results are consistent with those reported in the literature and derived from high-resolution spectroscopy. The second round of the LAMOST-Kepler project will allow to improve the coverage of the Kepler field and to repeat observations of selected targets.

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High Resolution Spectroscopy As a Tool for Luminosity Calibration

Highlights of Astronomy ◽

10.1017/s1539299600014647 ◽

2002 ◽

Vol 12 ◽

pp. 676-679

Author(s):

Ruth C. Peterson

Keyword(s):

High Resolution ◽

Reasonable Agreement ◽

Empirical Relationship ◽

Model Atmosphere ◽

Stellar Mass ◽

Physical Basis ◽

Emission Lines ◽

High Resolution Spectroscopy ◽

Chromospheric Emission ◽

Advance Knowledge

AbstractRecent results are reviewed for two methods of luminosity calibration based on high-resolution spectroscopy. The first relies onTeff/loggdeterminations from model-atmosphere analyses based on high-resolution spectra. This method is physically well founded but operationally demanding, and requires advance knowledge of stellar mass. The second, W-B, stems from the empirical relationship between luminosity and the width of chromospheric emission lines first established by Wilson and Bappu. Its physical basis is only partially understood, however, and the calibration depends on stellar metallicity and on the choice of lines.BothTeff/loggand W-B easily distinguish cool dwarfs from cool giants. Generally reasonable agreement is found between distances derived from Hipparcos parallaxes and those inferred from the loggvalues derived for nearby dwarfs with relatively well-known Hipparcos parallaxes, σ(π)/π < 0.2. Constraining Hipparcos parallaxes star-by-star is not possible at present. Improvements are suggested for both approaches.

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Asteroids as radial velocity and resolving power standards for medium and high resolution spectroscopy

Astronomy and Astrophysics ◽

10.1051/0004-6361:20053717 ◽

2006 ◽

Vol 462 (2) ◽

pp. 795-799 ◽

Cited By ~ 8

Author(s):

T. Zwitter ◽

F. Mignard ◽

F. Crifo

Keyword(s):

High Resolution ◽

Radial Velocity ◽

Resolving Power ◽

High Resolution Spectroscopy

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Selecting lines for spectroscopic (re)measurements to improve the accuracy of absolute energies of rovibronic quantum states

Journal of Cheminformatics ◽

10.1186/s13321-021-00534-y ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Péter Árendás ◽

Tibor Furtenbacher ◽

Attila G. Császár

Keyword(s):

Graph Theory ◽

High Resolution ◽

Experimental Research ◽

Spectroscopic Data ◽

Quantum States ◽

High Resolution Spectroscopy ◽

Research Groups

AbstractImproving the accuracy of absolute energies associated with rovibronic quantum states of molecules requires accurate high-resolution spectroscopy measurements. Such experiments yield transition wavenumbers from which the energies can be deduced via inversion procedures. To address the problem that not all transitions contribute equally to the goal of improving the accuracy of the energies, the method of Connecting Spectroscopic Components (CSC) is introduced. Using spectroscopic networks and tools of graph theory, CSC helps to find the most useful target transitions and target wavenumber regions for (re)measurement. The sets of transitions suggested by CSC should be investigated by experimental research groups in order to select those target lines which they can actually measure based on the apparatus available to them. The worked-out examples, utilizing extensive experimental spectroscopic data on the molecules H$$_2^{~16}$$ 2 16 O, $$^{32}$$ 32 S$$^{16}$$ 16 O$$_2$$ 2 , H$$_2^{~12}$$ 2 12 C$$^{16}$$ 16 O, and $$^{14}$$ 14 NH$$_{3}$$ 3 , clearly prove the overall usefulness of the CSC method and provide suggestions how CSC can be used for various tasks and under different practical circumstances.

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