The field of exoplanet research has advanced significantly with the development of high-resolution spectrograph instruments on 10m-class telescopes. These cutting-edge instruments are enabling scientists to explore new realms of knowledge and uncover the secrets of worlds beyond our solar system. However, to fully leverage the capabilities of these instruments, precise calibration methods are crucial.
In this regard, the High-resolution Infrared SPectrograph for Exoplanet Characterization (HISPEC) Calibration Unit (CAL) is a game-changer. Designed to support challenging science cases, such as Doppler imaging of exoplanet atmospheres, precision radial velocity, and high-contrast high-resolution spectroscopy of nearby exoplanets, CAL takes advantage of innovative technologies and design principles.
CAL incorporates four near-infrared (NIR) light sources encoded with wavelength information, which are coupled into single-mode fibers. This allows for synchronous use during science observations or asynchronous use during daytime calibrations. To ensure accurate absolute calibration throughout the NIR range (0.98 μm to 2.5 μm), CAL utilizes a hollow cathode lamp (HCL) and a series of gas absorption cells. Additionally, a laser frequency comb (LFC) provides stable and time-independent wavelength information during observation, with a backup option of a lower finesse astro-etalon.
The experience gained from developing instruments like HISPEC will prove invaluable for future endeavors, particularly for the Extremely Large Telescopes (ELTs). The lessons learned will inform the requirements and specifications of similar instruments that will push the boundaries of exoplanet characterization.
With the implementation of HISPEC and CAL, scientists have the tools they need to delve deeper into the mysteries of exoplanets. These advancements pave the way for groundbreaking discoveries and bring us closer to understanding the diversity and potential for life beyond Earth.
Q: How do high-resolution spectrograph instruments advance exoplanet research?
A: High-resolution spectrograph instruments allow scientists to study exoplanets in greater detail, enabling the exploration of their atmospheres, radial velocity, and spectroscopic characteristics.
Q: What is the purpose of the HISPEC Calibration Unit (CAL)?
A: The CAL unit is designed to provide precise calibration for the HISPEC spectrograph instrument, enabling accurate measurements and supporting various scientific investigations related to exoplanet characterization.
Q: What technologies are used in CAL?
A: CAL incorporates four near-infrared light sources, a hollow cathode lamp, gas absorption cells, a laser frequency comb, and an astro-etalon backup.
Q: How will the lessons learned from HISPEC inform future instruments?
A: The experience gained from developing HISPEC and CAL will help define the requirements and specifications for future instruments, including the Extremely Large Telescopes (ELTs), enhancing our capabilities to study exoplanets and uncover new insights.
 Original article: arXiv:2311.10239 [astro-ph.IM]
 Image source: astro-ph.EP