iLocater: a diffraction-limited Doppler spectrometer for the Large Binocular Telescope

Abstract

We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named "iLocater." The instrument comprises three principal components: a cross-dispersed echelle spectrograph that operates in the YJ-bands (0.97-1.30 µm), a fiber-injection acquisition camera system, and a wavelength calibration unit. iLocater will deliver high spectral resolution (R~150,000-240,000) measurements that permit novel studies of stellar and substellar objects in the solar neighborhood including extrasolar planets. Unlike previous planet-finding instruments, which are seeing-limited, iLocater operates at the diffraction limit and uses single mode fibers to eliminate the effects of modal noise entirely. By receiving starlight from two 8.4m diameter telescopes that each use "extreme" adaptive optics (AO), iLocater shows promise to overcome the limitations that prevent existing instruments from generating sub-meter-per-second radial velocity (RV) precision. Although optimized for the characterization of low-mass planets using the Doppler technique, iLocater will also advance areas of research that involve crowded fields, line-blanketing, and weak absorption lines.

SOUL: the Single conjugated adaptive Optics Upgrade for LBT

“…The 2 of LBTI will have the first light in the fall 2017, being ready for the integration of the high contrast imager and coronograph SHARK-NIR and V-SHARK. The same AO system will also feed the LBT planet finder called iLocator [17]. In the fall 2018 is planned the first light of the upgrade for the 2 FLAO systems feeding the NIR spectro-imagers LUCI1 and LUCI2.…”

Assessing the suitability of H4RG near-infrared detectors for precise Doppler radial velocity measurements

“…[1][2][3] As such, a number of precise Doppler spectrographs are being developed to target this spectral region (λ = 0.9 − 2.5 µm), including systems that use adaptive optics to correct for atmospheric seeing. [4][5][6][7][8][9] At the same time, ever-increasing demands for wavelength coverage and spectral resolution require large format, two-dimensional arrays to offer sufficient pixels to sample dispersed starlight.…”

MAROON-X: a radial velocity spectrograph for the Gemini Observatory

“…In the coming years, more instruments at large telescopes will become available, such KPF on Keck 4 and iLocator on the LBT. 5 However, none of these instruments offers unrestricted access to the entire US community. Core spectrograph of MAROON-X installed in its environmental chamber in the lab at the University of Chicago.…”