What can the SEDs of first hydrostatic core candidates reveal about their nature?

TL;DR

This study uses synthetic spectral energy distributions from simulations to analyze and identify first hydrostatic core candidates, providing insights into their properties and evolutionary stage.

Contribution

It introduces a method to fit observed SEDs of FHSC candidates with simulated models, aiding in constraining their physical properties and evolutionary status.

Findings

Certain candidates fit well with models, suggesting they are in the FHSC phase.

Some candidates are likely more evolved, not in the FHSC stage.

SED fitting can help estimate age and rotation rate of pre-stellar cores.

Abstract

The first hydrostatic core (FHSC) is the first stable object to form in simulations of star formation. This stage has yet to be observed definitively, although several candidate FHSCs have been reported. We have produced synthetic spectral energy distributions (SEDs) from 3D hydrodynamical simulations of pre-stellar cores undergoing gravitational collapse for a variety of initial conditions. Variations in the initial rotation rate, radius and mass lead to differences in the location of the SED peak and far-infrared flux. Secondly, we attempt to fit the SEDs of five FHSC candidates from the literature and five newly identified FHSC candidates located in the Serpens South molecular cloud with simulated SEDs. The most promising FHSC candidates are fitted by a limited number of model SEDs with consistent properties, which suggests the SED can be useful for placing constraints on the age and rotation rate of the source. The sources we consider most likely to be in FHSC phase are B1-bN, CB17-MMS, Aqu-MM1 and Serpens South candidate K242. We were unable to fit SerpS-MM22, Per-Bolo 58 and Chamaeleon-MMS1 with reasonable parameters, which indicates that they are likely to be more evolved.