The Astrophysical Journal (Jan 2023)

The SPHEREx Target List of Ice Sources (SPLICES)

  • Matthew L. N. Ashby,
  • Joseph L. Hora,
  • Kiran Lakshmipathaiah,
  • Sarita Vig,
  • Rama Krishna Sai Subrahmanyam Gorthi,
  • Miju Kang,
  • Volker Tolls,
  • Gary J. Melnick,
  • Michael W. Werner,
  • Brendan P. Crill,
  • Daniel C. Masters,
  • Carlos Contreras Peña,
  • Jeong-Eun Lee,
  • Jaeyeong Kim,
  • Ho-Gyu Lee,
  • Sung-Yong Yoon,
  • Soung-Chul Yang,
  • Nicholas Flagey,
  • Bertrand Mennesson

DOI
https://doi.org/10.3847/1538-4357/acc86b
Journal volume & issue
Vol. 949, no. 2
p. 105

Abstract

Read online

One of the primary objectives of the SPHEREx mission is to understand the origin of molecules such as H _2 O, CO _2 , and other volatile compounds at the early stages of planetary system formation. Because the vast majority of these compounds—typically exceeding 95%—exist in the solid phase rather than the gaseous phase in the systems of concern here, the observing strategy planned to characterize them is slightly unusual. Specifically, SPHEREx will target highly obscured sources throughout the Milky Way, and observe the species of concern in absorption against background illumination. SPHEREx spectrophotometry will yield ice column density measurements for millions of obscured Milky Way sources of all ages and types. By correlating those column densities with source ages, the SPHEREx mission will shed light on whether those molecules were formed in situ along with their nascent stellar systems, or whether instead they formed elsewhere and were introduced into those systems after their formation. To that end, this work describes version 7.1 of the SPHEREx target List of ICE Sources (SPLICES) for the community. It contains 8.6 × 10 ^6 objects brighter than W 2 ∼ 12 Vega mag over much of the sky, principally within a broad strip running the length of the Milky Way midplane, but also within high-latitude molecular clouds and even the Magellanic Clouds.

Keywords