Parque Astron\'omico de Atacama: An ideal site for millimeter, submillimeter, and mid-infrared astronomy

TL;DR

The Atacama Astronomical Park in Chile offers an exceptionally dry and high-altitude site ideal for millimeter, submillimeter, and mid-infrared astronomy, supported by favorable atmospheric conditions and institutional backing.

Contribution

This paper highlights the unique atmospheric conditions of the Chajnantor area and the establishment of the Atacama Astronomical Park as a premier site for astronomical observations.

Findings

Chajnantor has an annual median PWV of 1.1 mm, indicating extreme dryness.

Cerro Chajnantor is significantly drier than the plateau, especially during temperature inversions.

The Parque provides a secure legal and operational framework for astronomical projects.

Abstract

The area of Chajnantor, at more than 5000 meters altitude in northern Chile, offers unique atmospheric and operational conditions which arguably make it the best site in the world for millimeter, submillimeter, and mid-infrared observatories. Long-term monitoring of the precipitable water vapor (PWV) column on the Chajnantor plateau has shown its extreme dryness with annual median values of 1.1 mm. Simultaneous measurements of PWV on the Chajnantor plateau (5050 m) and on Cerro Chajnantor (5612 m) show that the latter is around 36% lower under normal atmospheric conditions and up to 80% lower than the plateau in the presence of temperature inversion layers. Recently, the Government of Chile has consolidated the creation of the Parque Astron\'omico de Atacama (Atacama Astronomical Park), an initiative of the Chilean Commission for Science and Technology (CONICYT). This new Parque offers an opportunity for national and international projects to settle within its boundaries, gain access to an extremely dry site that is suitable for observations over a broad spectral range, especially in the millimeter to mid-infrared wavelengths, and benefit from operational and logistical support within a secure legal framework.