Fiber Scrambling for High-Resolution Spectrographs. I. Lick Observatory

Spronck, Jo W.; Fischer, Debra A.; Kaplan, Zachary; Schwab, Christian; Szymkowiak, Andrew E.

doi:10.1086/670814

Cited by 14 publications

(18 citation statements)

References 24 publications

(19 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a series of tests performed with the slit-fed Hamilton spectrograph (Spronck et al 2013), we have shown a strong correlation between SLSF variations and changes in star position in the sky, most likely due to changes of spectrograph illumination with varying telescope positioning (Figure 8; Spronck et al 2013). In addition, we have also documented correlations between SLSF variations and guiding, focusing and seeing changes.…”

Section: Tests With Fiber Scramblersmentioning

confidence: 90%

The Twenty-Five Year Lick Planet Search

Fischer

Marcy

Spronck

2013

ApJS

Self Cite

131

126

View full text Add to dashboard Cite

The Lick planet search program began in 1987 when the first spectrum of τ Ceti was taken with an iodine cell and the Hamilton Spectrograph. Upgrades to the instrument improved the Doppler precision from about 10 m s −1 in 1992 to about 3 m s −1 in 1995. The project detected dozens of exoplanets with orbital periods ranging from a few days to several years. The Lick survey identified the first planet in an eccentric orbit (70 Virginis) and the first multi-planet system around a normal main sequence star (Upsilon Andromedae). These discoveries advanced our understanding of planet formation and orbital migration. Data from this project helped to quantify a correlation between host star metallicity and the occurrence rate of gas giant planets. The program also served as a test bed for innovation with testing of a tip-tilt system at the coudé focus and fiber scrambler designs to stabilize illumination of the spectrometer optics. The Lick planet search with the Hamilton spectrograph effectively ended when a heater malfunction compromised the integrity of the iodine cell. Here, we present more than 14,000 velocities for 386 stars that were surveyed between 1987 and 2011.

show abstract

Section: Tests With Fiber Scramblersmentioning

confidence: 90%

The Twenty-Five Year Lick Planet Search

Fischer

Marcy

Spronck

2013

ApJS

Self Cite

131

126

View full text Add to dashboard Cite

show abstract

“…These variations may be responsible for changes in the shape of the spectral lines, introducing systematic uncertainties in velocity estimates along the slit (e.g. Campbell 1915;Spronck et al 2013).…”

Section: Slit Illumination Effectsmentioning

confidence: 99%

LBT/ARGOS adaptive optics observations of z ∼ 2 lensed galaxies

Perna¹,

Curti²,

Cresci³

et al. 2018

A&A

View full text Add to dashboard Cite

Aims. Gravitationally lensed systems allow a detailed view of galaxies at high redshift. High spatial-and spectral-resolution measurements of arc-like structures can offer unique constraints on the physical and dynamical properties of high-z systems. Methods. We present near-infrared spectra centred on the gravitational arcs of six known z ∼ 2 lensed star-forming galaxies of stellar masses of 10 9−11 M and star formation rate (SFR) in the range between 10 and 400 M /yr. Ground layer adaptive optics (AO)assisted observations are obtained at the Large Binocular Telescope (LBT) with the LUCI spectrographs during the commissioning of the ARGOS facility. We used MOS masks with curved slits to follow the extended arched structures and study the diagnostic emission lines. LBT observations are used to demonstrate the spectroscopic capabilities of ARGOS. Results. Combining spatially resolved kinematic properties across the arc-like morphologies, emission line diagnostics and archival information, we distinguish between merging and rotationally supported systems, and reveal the possible presence of ejected gas. For galaxies that have evidence for outflows, we derive outflow energetics and mass-loading factors compatible with those observed for stellar winds in local and high-z galaxies. We also use flux ratio diagnostics to derive gas-phase metallicities. The low signal-to-noise ratio in the faint Hβ and nitrogen lines allows us to derive an upper limit of ≈ 0.15 dex for the spatial variations in metallicity along the slit for the lensed galaxy J1038. Conclusions. Analysed near-infrared spectra presented here represent the first scientific demonstration of performing AO-assisted multi-object spectroscopy with narrow curved-shape slits. The increased angular and spectral resolution, combined with the binocular operation mode with the 8.4-m-wide eyes of LBT, will allow the characterisation of kinematic and chemical properties of a large sample of galaxies at high-z in the near future.

show abstract

“…10 Octagonal fibers, especially, have shown promising results both in laboratory experiments and on sky. 5,7,9,11,12 Figure 4 is a sample image from our scrambling tests, and illustrates the dramatic improvement introduced by the use of octagonal fibers. Splicing an octagonal section fiber into the fiber link before the double scrambler (only near-field scrambling) has been shown to provide SG∼3,500 in the laboratory, and ∼1,500 on sky.…”

Section: Achieving High-level Scramblingmentioning

confidence: 99%

Scrambling and modal noise mitigation in the Habitable Zone Planet Finder fiber feed

et al. 2014

View full text Add to dashboard Cite

We present the baseline fiber feed design for the Habitable-zone Planet Finder (HPF), a precision radial velocity (RV) spectrograph designed to detect Earth analogs around M-dwarfs. HPF is a stabilized, fiber-fed, R∼50,000 spectrograph operating in the near-infrared (NIR) from 0.82 to 1.3 µm, and will be deployed on the HobbyEberly Telescope (HET) in Texas. While the essential function of the optical fibers is to deliver high throughput, this mode of light transport also provides the opportunity to introduce radial and azimuthal scrambling, which boosts instrument stability and thereby RV precision. Based on the unique requirements of HPF on the HET, we present initial tests showing very high scrambling gains via a compact scrambler in conjunction with octagonal fibers. Conversely, the propagation of light through the fibers injects modal noise, which can limit achievable RV precision. Laboratory tests of a custom-built mechanical agitator show significant gains over a static fiber feed. Overall, the fiber feed is designed to provide high relative throughput, excellent scrambling, and reliable modal noise suppression. We will also attempt to minimize focal ratio degradation (FRD) to the extent possible with the chosen configuration. HPF inculcates several other new technologies developed by the Penn State Optical-Infrared instrumentation group, including a rigorous calibration system, which are discussed separately in these proceedings.

show abstract

Fiber Scrambling for High-Resolution Spectrographs. I. Lick Observatory

Cited by 14 publications

References 24 publications

The Twenty-Five Year Lick Planet Search

The Twenty-Five Year Lick Planet Search

LBT/ARGOS adaptive optics observations of z ∼ 2 lensed galaxies

Scrambling and modal noise mitigation in the Habitable Zone Planet Finder fiber feed

Contact Info

Product

Resources

About