Dispersion Spectrograph Research Articles

THE DOUBLE-LINED SPECTROSCOPIC BINARY HR 104

ABSTRACT Lines belonging to the companion of the primary star HR 104 have been found on high dispersion spectrograms. Both componenets are extremely sharp-lined. By combining data from two quite different observing programs a new orbit has been determined.

Visual Extinction and Physical Conditions in the Bipolar Nebula M2-9

A detailed analysis of the visual extinction and physical conditions of the extreme bipolar nebula M2-9 has been made from optical spectra acquired with the Intermediate Dispersion Spectrograph of the 2.5m Isaac Newton Telescope (Observatorio del Roque de los Muchachos, La Palma) in combination with a 235mm camera and the IPCS detector covering the spectral range 3500-7500 Å with spectral resolution of 4 Å.

「すばる」ＨＤＳによる天文学

We explain examples of the scientific studies which are planned to be undertaken with the SUBARU High Dispersion Spectrograph (HDS). The current specifications of the HDS are briefly described.

The media at war: The press and the Persian Gulf conflict

A high dispersion spectroscopic observation of Comet 116P/Wild 4 was performed on June 10, 2003, using the High Dispersion Spectrograph (HDS) on Subaru Telescope, when the comet was at 2.4 AU from the Sun. Three forbidden oxygen emission lines in optical region, the green line at 557.7330 nm (from 1S to 1D meta-stable state) and the red doublet lines at 630.0304 and 636.3776 nm (from 1D meta-stable state to 3P state) were observed. The oxygen atoms in meta-stable state are considered to be generated by the photo-dissociation of parent molecules such as H2O, CO, CO2, etc. H2O molecule is usually thought as the most dominant source of these oxygens in meta-stable state when a comet is at around 1 AU from the Sun. However, since the Comet 116P/Wild 4 was located at 2.4 AU far from the Sun at the observation, CO and/or CO2 could be a possible main source(s) of meta-stable oxygen atoms rather than H2O. The ratio between red doublet lines (630.0304 nm relative to 636.3776 nm) derived from our result is 2.94 ± 0.07, and the ratio of green line to the red doublet lines is 0.155 ± 0.007. The ratio of green to red doublet lines, which indicates the ratio of O(1S) to O(1D), give us a clue to distinguish the source of meta-stable oxygen atoms from different parent molecules. Considering the abundance of CO is comparable to or smaller than CO2, CO2 could be thought as the parent molecules of the meta-stable oxygen atoms as well as H2O. The number ratio of CO2/H2O within our observational aperture is discussed in this paper.

Pentagon rules on media access to the Persian Gulf War

A high dispersion spectroscopic observation of Comet 116P/Wild 4 was performed on June 10, 2003, using the High Dispersion Spectrograph (HDS) on Subaru Telescope, when the comet was at 2.4 AU from the Sun. Three forbidden oxygen emission lines in optical region, the green line at 557.7330 nm (from 1S to 1D meta-stable state) and the red doublet lines at 630.0304 and 636.3776 nm (from 1D meta-stable state to 3P state) were observed. The oxygen atoms in meta-stable state are considered to be generated by the photo-dissociation of parent molecules such as H2O, CO, CO2, etc. H2O molecule is usually thought as the most dominant source of these oxygens in meta-stable state when a comet is at around 1 AU from the Sun. However, since the Comet 116P/Wild 4 was located at 2.4 AU far from the Sun at the observation, CO and/or CO2 could be a possible main source(s) of meta-stable oxygen atoms rather than H2O. The ratio between red doublet lines (630.0304 nm relative to 636.3776 nm) derived from our result is 2.94 ± 0.07, and the ratio of green line to the red doublet lines is 0.155 ± 0.007. The ratio of green to red doublet lines, which indicates the ratio of O(1S) to O(1D), give us a clue to distinguish the source of meta-stable oxygen atoms from different parent molecules. Considering the abundance of CO is comparable to or smaller than CO2, CO2 could be thought as the parent molecules of the meta-stable oxygen atoms as well as H2O. The number ratio of CO2/H2O within our observational aperture is discussed in this paper.

Instrumentation for the ESO Very Large Telescope

The instrumentation plan for the ESO VLT has been approved in March 1990: it includes 10 instruments, two of which are to be replicated, distributed among the Nasmyth, Cassegrain and coude focii of the four unit telescopes of the VLT and the incoherently combined focus. The instruments will be used for a variety of observations in the wavelength range from the UV atmospheric cutoff to around 20 mu m. Conceptual designs are presented for a medium resolution IR spectrometer/imager, Ia focal reducer/low dispersion spectrograph, an echelle spectrograph, a multi-fibre spectrograph and an 8-14 mu m imager/spectrometer. Design requirements and expected capabilities are given for an high resolution infrared camera and for a speckle camera, planned to operate in combination with the telescope adaptive optics systems. These first seven instruments are expected to come into operation within a period of around 2 years beginning in 1996. The current design options for the high spectral resolution spectrometers for the UV-visual and the infrared region are also presented.

Chromospheric variability of M giant semiregular variables

view Abstract Citations (7) References (41) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Chromospheric Variability of M Giant Semiregular Variables Eaton, Joel A. ; Johnson, Hollis R. ; Cadmus, Robert R., Jr. Abstract The results of monitoring the chromospheric emission from three M giant semiregular variables, W Cyg, NU Pav, and Theta Aps at low dispersion with the IUE satellite are reported along with high-dispersion IUE spectra for R Lyr and Delta(2) Lyr. The chromospheric emission is variable in all of the first three stars, and the Mg II strength generally follows changes in the continuum. However, the changes are not directly proportional, and there is a phase lag between the emission in the continuum and that in the Mg II lines, at least in W Cyg and probably in NU Pav. R Lyr showed changes in Mg II lines strengths and profiles uncorrelated with Al II 2669 A strength or with the strengths of fluorescent Fe I lines. The chromospheres of all these stars are clearly modified by stellar pulsation. The position and extent of the emitting layers of the chromospheres of the stars are estimated. Publication: The Astrophysical Journal Pub Date: November 1990 DOI: 10.1086/169409 Bibcode: 1990ApJ...364..259E Keywords: Chromosphere; Giant Stars; M Stars; Semiregular Variable Stars; High Dispersion Spectrographs; Iue; Stellar Atmospheres; Stellar Luminosity; Stellar Oscillations; Astrophysics; STARS: CHROMOSPHERES; STARS: LATE-TYPE; STARS: SEMIREGULAR VARIABLES; ULTRAVIOLET: SPECTRA full text sources ADS | data products SIMBAD (6) MAST (1) INES (1)

High Velocity Outflows in Post-Main Sequence Nebulae

We have observed a broad range of post-main-sequence, type I and irregular nebulae using the intermediate dispersion spectrograph of the Isaac Newton Telescope (La Palma, Spain). Many of these show evidence for high velocity mass outflow, and in particular we find: (i) High velocity (∼ 500 km s−1), and appreciable mass loss outflows within ≅ 10 arcsecs of M2-9 and SH 2-71; (ii) Substantial shell expansion velocities in NGC 7026 (∼ 102 km s−1) with evidence for an appreciable driving wind at the central star, velocity ≅ 103 km s−1; (iii) Jet outflows extending over a range 260 km s−1 in Hb 5, with a distinctly tilted line structure suggestive of shock compression at the edges of an outflow cavity; and finally (iv) similarly strong winds (2 × 10 km s−1) from each member of a WC binary in the nucleus of NGC 6905. The binary separation is approximately 3.6 arcseconds, and the core is further enveloped by two, apparently co-spatial shells, expansion velocity 90 km s−1, and separation ΔV ≅ 130 km s−1. The [N II] emission for the shells is extraordinarily weak, although ansae located outside of the shells, and perpendicular to the binary major axis, possess I([N II]λ6584) > I(HIλ6563). We propose that the two shells were ejected at differing phases of binary evolution.

9Be abundances in dwarfs of intermediate metal deficiency: Impications for galactic evolution

We present observations of the λ3130 A Beii resonance doublet in stars of intermediate metal deficiency, −0.6≥[Fe/H]≥−1.1 obtained with the Intermediate Dispersion Spectrograph and IPCS detector at the 2.5 m Isaac Newton Telescope on La Palma. The derived beryllium abundances range from 5.6×10−12 (one hafl solar) to 2×10−12 (one sixth solar). These values, interpolated between the sets of previous beryllium measurements at higher and at lower metallicities, serve to confirm the monotonic variation of the Be abundance with Fe during the evolution of the galactic disc. We find that there was no extreme burst of Be production in the halo. To circumvent the effects of depletion, a statistical set of data is needed, for which the upper envelope can be used to trace galactic Be evolution. We note that no observations with sufficient sensitivity to detect Be in the extremely metal deficient stars of the halo have been reported to date.

IUE observations of the interstellar medium toward Beta Geminorum

view Abstract Citations (6) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS IUE Observations of the Interstellar Medium toward beta Geminorum Murthy, J. ; Wofford, J. B. ; Henry, R. C. ; Moos, H. W. ; Vidal-Madjar, A. ; Linsky, J. L. ; Gry, C. Abstract A dispersion IUE spectrum of the hydrogen Ly-alpha emission line of the nearby late-type star Beta Gem is presented. Values are determined for the density, velocity, dispersion, and bulk velocity of the interstellar H I toward the star, showing agreement with previous IUE results for stars in the same general direction (Murthy et al., 1987). It is shown that the interstellar medium in the line of sight to Beta Gem has a total column density of about 2 x 10 to the 18th/sq cm and a velocity dispersion of 13-16 km/s. The flow vector is in agreement with the interstellar wind found by Crutcher (1982). Publication: The Astrophysical Journal Pub Date: January 1989 DOI: 10.1086/167064 Bibcode: 1989ApJ...336..949M Keywords: High Dispersion Spectrographs; Interstellar Matter; Late Stars; Lyman Alpha Radiation; Stellar Spectra; Ultraviolet Spectra; Absorption Spectra; Abundance; Iue; Astrophysics; INTERSTELLAR: ABUNDANCES; STARS: INDIVIDUAL CONSTELLATION NAME: BETA GEMINORUM; ULTRAVIOLET: SPECTRA full text sources ADS | data products SIMBAD (4) MAST (1) INES (1)

Calcium Features in the “Featureless” Continuum of Seyfert Nuclei: Evidence for a Young Stellar Population?

We have obtained intermediate resolution spectra for about 30 galaxies, normal and active, in the near infrared region covering the CaII triplet (λλ 7800–9300 Å). The data were obtained with the INT at the Roque de los Muchachos Observatory in La Palma, Spain using the Intermediate Dispersion Spectrograph and a GEC CCD detector. Details of these observations are given elsewhere (Terlevich et al. 1988). Our data show that active (Seyfert galaxies and LINERS) and normal galaxies have comparable nuclear CaII strengths and line widths.

Fourier transform Raman optical activity

Raman optical activity (ROA) is conventionally measured by modulating the incident laser polarization between right and left circular polarization states and detecting the difference in the scattered Raman intensities using a dispersive spectrograph attached to a multichannel detector. In this article, a Fourier transform technique using a Martin-Puplett interferometer is shown to be suitable for measuring both the ROA and ordinary Raman intensities in a single measurement. Novel features in this technique include: (a) incident laser radiation is plane polarized; (b) the scattered Raman light is collected without an analyzer.

The Lick Observatory Hamilton Echelle Spectrometer

The Hamilton Echelle Spectrometer, recently installed at the coudé focus of the Shane 3-m telescope, is a high dispersion spectrograph optimized for use with large format CCD's. It was designed primarily for high resolution (R=50,000) wide bandpass spectroscopy of point-like sources down to a limiting magnitude of about V=16.5, over the 0.34 μm to 1.1 μm spectral region. Its design features a relatively large collimated beam size, the use of prisms rather than gratings for cross dispersion, minimum order separation, the use of protected silver mirror coatings throughout the system, and a fast (f/1.67) folded Schmidt camera with a flat external focal plane. Together, these features yield a very powerful spectrometer for high resolution stellar spectroscopy. This paper gives a brief description of the Hamilton spectrometer and gives several examples of its performance on astronomical objects.

The Accuracy of High S/N Spectroscopic Measurements

A careful intercomparison is made of several sets of high S/N spectrsocopic observations made by different astronomers, using different telescopes and detectors, observing the same objects. Spectra of moderately weak (10-50 mÅ) Li lines, observed at S/N of one to several hundred using the CFHT Reticon, Lick Observatory Reticon, McDonald Observatory Digicon, and the Intermediate Dispersion Spectrograph plus CCD of the Isaac Newton Telescope agree within the claimed measurement accuracies of about 3-6 mÅ almost without exception. CFHT Reticon observations of Hyades dwarfs are compared with unpublished observations taken with a CCD at Lick Observatory; again, the agreement is very good. However, abundance determinations based on these measurements agree less well. The discrepancy arises from different temperatures used by different investigators for the same stars. The accuracy of various methods of temperature determination is examined, including B-V, R-I, and V-K colors, continuum scans, Hα line profile fitting, and temperatures derived from fine analyses. With careful work and good data, temperatures still limit the accuracy of some of the programs discussed.

Ultraviolet to Near Infrared Observations of BF Cyg

In this paper we provide preliminary results of multifrequency observations of BF Cyg carried out in July 1986. The ultraviolet spectra were obtained on July 26, 1986 using the IUE satellite. The optical observations were made at the Observatorio del Roque de los Muchachos (La Palma, Canary Islands) in July 1986 during the night 13/14 using the Isaac Newton 2.5m telescope with the Intermediate Dispersion Spectrograph (IDS, 500 mm camera) and the Image Photon Counting System (IPCS). The infrared observations were made during the night 13/14 of July, 1986, at the Observatorio del Teide (Tenerife, Canary Islands) using the Carlos Sanchez 1.5m telescope and an infrared single-channel photometer with an InSb detector.

New Observational Results of Of/WN - Transition Types

Of/WN stars have been introduced by walborn (1977). These luminous stars are particularly characterized by the appearance of both the characteristic of emission lines of HeII and NIII and strong HeI and [NII] emissions. These objects have become particularly interesting due to the discovery of their link to the S Dor variables (Stahl et al. 1983, Stahl 1986, Wolf 1987). They are supposed to represent key objects in the evolution of massive stars being the immediate progenitors of WN stars. We observed the Of/WN transition type stars R127, R84, and S61 of the LMC with high dispersion spectroscopy in the optical and satellite-UV range. R127 is at present undergoing an S Dor-type outburst. In 1986 R127 became the visually brightest star of the LMC until it was surpassed by SN1987A in Feb. 1987. The spectrum in the optical range during the extraordinary bright outburst phase is distinguished by numerous P Cygni type lines of singly ionized metals. Since the beginning of the present outburst the spectral type has gradually become later and the equivalent spectral type as derived from our latest CASPE spectrum taken in 1986, August 22 was middle A. The IUE-spectrum of R127 during maximum is characterized by copious lines of singly ionized metals formed in the wind. A detailed disucssion of the optical and satellite UV high dispersion spectrograms of R127 taken during its present extraordinary bright outburst phase is forthcoming in Astronomy and Astrophysics (Wolf et al. 1987a).

64 ORI (= HR 2130L), a B-type tripple system

view Abstract Citations (8) References (26) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS 64 Ori (=HR 2130), a B-type triple system. Fekel, Francis C. ; Scarfe, C. D. Abstract 64 Ori is a close triple system consisting of three B stars which has recently been resolved by speckle interferometry. High-dispersion spectroscopic observations show that the probable visual primary is a double-lined spectroscopic binary with a period of 14.57221 days, which orbits a broad-lined (v sin i = 163 km s-1) third star with a period of 13.03 yr. From a consideration of magnitude differences and line-strength ratios the authors classify the components as B7 III, B8 III, and B5 V for the short-period primary, Aa, short-period secondary, Ab, and visual secondary, B, respectively. Components Aa and Ab both have v sin i ≤ 5 km s-1. Since it is shown that both are intrinsically slow rotators with no Hg-Mn abundance peculiarities, any mechanism which attempts to explain the presence of such peculiarities in late B stars must also explain their absence in these two stars. Publication: The Astronomical Journal Pub Date: November 1986 DOI: 10.1086/114248 Bibcode: 1986AJ.....92.1162F Keywords: B Stars; Binary Stars; Star Clusters; Stellar Spectra; High Dispersion Spectrographs; Line Spectra; Phase Deviation; Radial Velocity; Stellar Magnitude; Astrophysics full text sources ADS | data products SIMBAD (1)

Stellar spectrophotometry with a microcomputer based, intensified, silicon vidicon

We have developed several detector systems for use in observational astronomy. These include a rapid scanning spectrometer (Jeffers and Weller, 1973), a rapid chopping spectrophotometer (Stiff and Jeffers, 1978) and an intensified, silicon vidicon detector for use either for spectrophotometry (Jeffers, Stiff and Weller, 1983) or direct imaging (Jeffers, 1982). These detector systems have been used for rapid variability studies of emission line strengths and profiles in Wolf-Rayet and Of stars (Weller and Jeffers, 1979; Jeffers, Stiff and Weller, 1985) and for low dispersion spectrophotometry of these stars (Jeffers and Weller, 1985). Here we report on the spectrophotometric performance of the intensified, silicon vidicon detector (RCA 4804H) when used with a low dispersion spectrograph.

The 3p63d9-(3p53d10+3p63d84f) Transitions in Cobalt-like ions: As VII, Se VIII and Br IX

The spectra of As VII, Se VIII and Br IX have been studied in the 100 Å - 130 Å, 80 Å - 120 Å and 70 Å - 115 Å wavelength regions, respectively, using high dispersion spectrographs at various laboratories. A triggered vacuum spark was used as excitation source. It has been shown that substantial configuration interaction exists between the 3p5 3d10 and 3p63d84f configurations. In the 3p63d84f configuration, 34 levels have been established in As VII, 35 out of 37 levels reported earlier in Se VIII, have been confirmed, two have been revised and one additional level established, and 30 levels have been established in Br IX. Least-Squares-Fit calculations using a two-configuration model space support the analyses. Fifty-two (52), 5 and 40 newly classified lines are reported in As VII, Se VIII and Br IX, respectively.

Elemental Abundances of Normal Sharp-Lined B and A Stars from Optical Region Analyses

Optical-region elemental-abundance analyses were performed for ten sharp-lined main sequence B and A stars. The derived abundances are generally in good agreement with those of the Sun. Multiple high dispersion spectrograms, fully line-blanketed solar composition model atmospheres, optical spectrophotometry, and the most accurate gf values were employed. This study provides initial parameters for studies of these stars in the ultraviolet and a consistent set of values for comparison with abundances of more exotic stars.