The impact of X-rays on molecular cloud fragmentation and the IMF

TL;DR

This study investigates how strong X-ray feedback from a nearby massive black hole influences molecular cloud fragmentation and the resulting initial mass function, revealing larger clumps and a flatter IMF.

Contribution

It introduces a simulation incorporating X-ray feedback effects on star-forming clouds, showing significant impact on fragmentation and the IMF shape.

Findings

Cloud fragments into larger, fewer cores under strong X-ray feedback

The initial mass function becomes flatter, deviating from the Salpeter form

Competitive accretion influences the mass distribution of protostars

Abstract

Star formation is regulated through a variety of feedback processes. In this study, we treat feedback by X-rays and discuss its implications. Our aim is to investigate whether star formation is significantly affected when a star forming cloud resides in the vicinity of a strong X-ray source. We perform an Eulerian grid simulation with embedded Lagrangian sink particles of a collapsing molecular cloud near a massive, 10^7 M_o black hole. The chemical and thermal changes caused by radiation are incorporated into the FLASH code. When there is strong X-ray feedback the star forming cloud fragments into larger clumps whereby fewer but more massive protostellar cores are formed. Competitive accretion has a strong impact on the mass function and a near-flat, non-Salpeter IMF results.