The Near-Infrared Sky Surveyor

TL;DR

NIRSS is a proposed space-based near-infrared surveyor designed to map the entire sky at unprecedented sensitivities, enabling discoveries from exoplanets to early universe quasars, and complementing existing surveys.

Contribution

This paper introduces the NIRSS mission concept, a space telescope capable of conducting a deep, full-sky near-infrared survey surpassing previous surveys in sensitivity and coverage.

Findings

NIRSS will reach 0.2 μJy sensitivity in four passbands from 1 to 4 microns.

It will be 3000 times more sensitive than 2MASS and 500 times more sensitive than WISE.

NIRSS will enable new discoveries in cosmic origins and exoplanet identification.

Abstract

[NIRSS is one of three concepts that contributed to the Wide-Field Infrared Survey Telescope (WFIRST) mission advocated by the Decadal Survey.] Operating beyond the reaches of the Earth's atmosphere, free of its limiting absorption and thermal background, the Near-Infrared Sky Surveyor (NIRSS) will deeply map the entire sky at near-infrared wavelengths, thereby enabling new and fundamental discoveries ranging from the identification of extrasolar planets to probing the reionization epoch by identifying thousands of quasars at z>10. NIRSS will directly address the NASA scientific objective of studying cosmic origins by using a 1.5-meter telescope to reach full-sky 0.2 uJy (25.6 mag AB) sensitivities in four passbands from 1 to 4 microns in a 4-yr mission. At the three shorter passbands (1 - 2.5 microns), the proposed depth is comparable to the deepest pencil-beam surveys done to date and is 3000 times more sensitive than the only previous all-sky near-infrared survey, 2MASS. At the longest passband (3.5 micron), which is not feasible from the ground, NIRSS will be 500 times more sensitive than WISE. NIRSS fills a pivotal gap in our knowledge of the celestial sphere, is a natural complement to WISE, and is well matched to the next generation of deep (0.1 uJy), wide-area (>2 pi ster), ground-based optical surveys (LSST and Pan-Starrs). With the high thermal backgrounds of ground-based infrared observations, a near-infrared full sky survey at sub-uJy sensitivity is only feasible from space.