FOCES - a fibre optics Cassegrain échelle spectrograph

Pfeiffer, M.; Frank, Christoph; Baumüller, D.; Fuhrmann, K.; Gehren, T.

doi:10.1051/aas:1998231

Cited by 151 publications

(125 citation statements)

References 6 publications

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“…Modes providing resolutions, R = 30 000 or 45 000, were employed (Table 2). Finally, a spectrum was taken in service mode at the Calar Alto observatory with the FOCES spectrograph (R = 40 000, Pfeiffer et al 1998). For these additional runs, ζ Per was not observed; we are nevertheless confident that these data are homogeneous with respect to the other spectra obtained.…”

Section: Description Of Optical Observationsmentioning

confidence: 98%

CO emission and variable CH and CH⁺absorption towards HD 34078: evidence for a nascent bow shock?

Boissé¹,

Rollinde

Hily-Blant

et al. 2009

A&A

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Context. The runaway star HD 34078, initially selected to investigate small scale structure in a foreground diffuse cloud, has been shown to be surrounded by highly excited H 2 , the origin of which is unclear. Aims. We first search for an association between the foreground cloud and HD 34078. Second, we extend previous investigations of temporal absorption line variations (CH, CH + , H 2 ) in order to better characterize them and understand their relation to small-scale structure in the molecular gas. Methods. We have mapped the 12 CO(2-1) emission at 12 resolution around HD 34078's position, using the 30 m IRAM antenna. The follow-up of CH and CH + absorption lines has been extended over 5 more years: 26 visible spectra have been acquired since 2003 at high or intermediate resolution. In parallel, CH absorption towards the reddened star ζ Per has been monitored to check the instrumental stability and homogeneity of our measurements. Three more FUSE spectra have been obtained to search for N(H 2 ) variations. Results. CO observations show a pronounced maximum near HD 34078's position, clearly indicating that the star and diffuse cloud are associated. The optical spectra confirm the reality of strong, rapid and correlated CH and CH + fluctuations (up to 26% for N(CH + ) between 2007 and 2008). On the other hand, N(H 2 , J = 0) has varied by less than 5% over 4 years, indicating the absence of marked density structure at scales below 100 AU. We also discard N(CH) variations towards ζ Per at scales less than 20 AU. Conclusions. Observational constraints from this work and from 24 μm dust emission appear to be consistent with H 2 excitation but inconsistent with steady-state bow shock models and rather suggest that the shell of compressed gas surrounding HD 34078 or lying at the boundary of a small foreground clump is seen at an early stage of the interaction. The CH and CH + time variations as well as their high abundances are likely due to chemical structure in the shocked gas layer located at the stellar wind/ambient cloud interface. Finally, the lack of variation in both N(H 2 , J = 0) towards HD 34078 and N(CH) towards ζ Per suggests that quiescent molecular gas is not subject to pronounced small-scale structure.

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Section: Description Of Optical Observationsmentioning

confidence: 98%

CO emission and variable CH and CH⁺absorption towards HD 34078: evidence for a nascent bow shock?

Boissé¹,

Rollinde

Hily-Blant

et al. 2009

A&A

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“…The spectra were obtained in 2002-2004 with the high resolution Échelle spectrograph FOCES at the 2.2 m-telescope of the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto (Pfeiffer et al 1998;Grupp 2003Grupp , 2004, and the Coudé-Échelle spectrograph at the 2 m-Alfred-Jensch telescope of the Thüringer Landessternwarte at Tautenburg (Hatzes et al 2005;König 2003). Since the analysis works differentially with respect to the Sun, we also obtained solar spectra by observing the illuminated disk of the Moon during each observing campaign 4 .…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Spectroscopic properties of cool Ursa Major group members

Eiff

Guenther

2009

A&A

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Context. Until now, most members of the Ursa Major (UMa) group of stars have been identified by means of kinematic criteria. However, in many cases kinematic criteria alone are insufficient to ascertain, whether an individual star is really a member of this group. Since photometric criteria are ineffective in the case of cool dwarf members, one must use spectroscopic criteria. Nevertheless, resulting membership criteria are inconclusive. Aims. We reanalyse spectroscopic properties of cool UMa group dwarfs. In particular, we study the distribution of iron abundance, the strength of the Li I absorption at 6708 Å and the Li abundance, and the infilling of the core of the Hα line. Methods. Twenty-five cool and northern bona-fide members are carefully selected from the literature. Homogeneously measured stellar parameters and iron abundances are given for all Sun-like stars selected, based on spectra of high resolution and high signalto-noise ratio. In addition, we measure the Li equivalent width and abundance as well as the relative intensity of the Hα core and the corresponding chromospheric flux. Results. The studied stars infer an average Ursa Major group iron abundance of −0.03 ± 0.05 dex, which is higher by about 0.06 dex than determined elsewhere. The Li abundance derived of Ursa Major group dwarf stars is higher than in the Hyades at effective temperatures cooler than the Sun, but lower than in the younger Pleiades, a result which is independent of the exact value of the effective temperature adopted. The Sun-like and cooler dwarfs also display chromospheric infilling of the Hα core. We present spectroscopic criteria that may be used to exclude non-members.

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“…The first element in the optical bench is the entrance slit used to recover the original resolution when the entrance diaphragm at the Cassegrain focus is widely open to let pass starlight in (Pfeiffer et al 1998). case of poor seeing. It is immediately next to the folding mirror, therefore the entrance slit and its spectral image are very nearby, as close as 0.9 mm.…”

Section: Optical Designmentioning

confidence: 99%

“…The Calar Alto Fiber-fed Échelle spectrograph (CAFE) is an instrument manufactured at the Centro Astronómico Hispano Alemán (CAHA) to replace FOCES (Pfeiffer 1992;Pfeiffer et al 1998), the high-resolution Échelle spectrograph at the 2.2 m telescope of the observatory that was being operated during the period 1997−2010. CAFE was designed following the common concept of this type of instrument (e.g.…”

Section: Introductionmentioning

confidence: 99%

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CAFE: Calar Alto Fiber-fed Échelle spectrograph

Aceituno

Sanchez

Grupp

et al. 2013

A&A

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We present here CAFE, the Calar Alto Fiber-fed Échelle spectrograph, a new instrument built at the Centro Astronomico Hispano Alemán (CAHA). CAFE is a single-fiber, high-resolution (R ∼ 70 000) spectrograph, covering the wavelength range between 3650−9800 Å. It was built on the basis of the common design for Échelle spectrographs. Its main aim is to measure radial velocities of stellar objects up to V ∼ 13−14 mag with a precision as good as a few tens of m s −1 . To achieve this goal the design was simplified at maximum, removing all possible movable components, the central wavelength is fixed, as is the wavelength coverage; there is no filter wheel, etc. Particular care was taken with the thermal and mechanical stability. The instrument is fully operational and publically accessible at the 2.2 m telescope of the Calar Alto Observatory. In this article we describe (i) the design, summarizing its manufacturing phase; (ii) characterize the main properties of the instrument; (iii) describe the reduction pipeline; and (iv) show the results from the first light and commissioning runs. The preliminar results indicate that the instrument fulfills the specifications and can achieve the planned goals. In particular, the results show that the instrument is more efficient than anticipated, reaching a signalto-noise of ∼20 for a stellar object as faint as V ∼ 14.5 mag in ∼2700 s integration time. The instrument is a wonderful machine for exoplanetary research (by studying large samples of possible systems cotaining massive planets), galactic dynamics (highly precise radial velocities in moving groups or stellar associations), or astrochemistry.

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FOCES - a fibre optics Cassegrain échelle spectrograph

Cited by 151 publications

References 6 publications

CO emission and variable CH and CH⁺absorption towards HD 34078: evidence for a nascent bow shock?

CO emission and variable CH and CH⁺absorption towards HD 34078: evidence for a nascent bow shock?

Spectroscopic properties of cool Ursa Major group members

CAFE: Calar Alto Fiber-fed Échelle spectrograph

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FOCES - a fibre optics Cassegrain échelle spectrograph

Cited by 151 publications

References 6 publications

CO emission and variable CH and CH+absorption towards HD 34078: evidence for a nascent bow shock?

CO emission and variable CH and CH+absorption towards HD 34078: evidence for a nascent bow shock?

Spectroscopic properties of cool Ursa Major group members

CAFE: Calar Alto Fiber-fed Échelle spectrograph

Contact Info

Product

Resources

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CO emission and variable CH and CH⁺absorption towards HD 34078: evidence for a nascent bow shock?

CO emission and variable CH and CH⁺absorption towards HD 34078: evidence for a nascent bow shock?