Cosmic-ray origin in OB associations and preferential acceleration of refractory elements: Evidence from abundances of elements 26Fe through 34Se

TL;DR

This study measures element abundances in cosmic rays to support the idea that cosmic-ray acceleration occurs mainly in OB associations and favors refractory elements from interstellar grains over gas.

Contribution

It provides new observational evidence for cosmic-ray acceleration in OB associations and preferential acceleration of refractory elements, advancing understanding of cosmic-ray origins.

Findings

Supports cosmic-ray acceleration in OB associations

Shows preferential acceleration of refractory elements

Provides elemental abundance data from Fe to Se

Abstract

We report abundances of elements from 26Fe to 34Se in the cosmic radiation measured during fifty days of exposure of the Trans-Iron Galactic Element Recorder (TIGER) balloon-borne instrument. These observations add support to the concept that the bulk of cosmic-ray acceleration takes place in OB associations, and they further support cosmic-ray acceleration models in which elements present in interstellar grains are accelerated preferentially compared with those found in interstellar gas.