The enigmatic core L1451-mm: a first hydrostatic core? or a hidden VeLLO?

TL;DR

This study investigates the L1451-mm dense core, presenting evidence that it may host either a first hydrostatic core or a very low luminosity object, based on multi-wavelength observations and modeling of its emission and outflow characteristics.

Contribution

The paper provides the first detailed observational analysis of L1451-mm, highlighting its potential as a candidate for a first hydrostatic core and comparing models to interpret its nature.

Findings

Detection of dust continuum at 3-mm and 1.3-mm wavelengths.

Presence of a slow, poorly collimated outflow consistent with FHSC predictions.

The core's properties can be explained by models with either a YSO or a FHSC.

Abstract

We present the detection of a dust continuum source at 3-mm (CARMA) and 1.3-mm (SMA), and 12CO(2-1) emission (SMA) towards the L1451-mm dense core. These detections suggest a compact object and an outflow where no point source at mid-infrared wavelengths is detected using Spitzer. An upper limit for the dense core bolometric luminosity of 0.05 Lsun is obtained. By modeling the broadband SED and the continuum interferometric visibilities simultaneously, we confirm that a central source of heating is needed to explain the observations. This modeling also shows that the data can be well fitted by a dense core with a YSO and disk, or by a dense core with a central First Hydrostatic Core (FHSC). Unfortunately, we are not able to decide between these two models, which produce similar fits. We also detect 12CO(2-1) emission with red- and blue-shifted emission suggesting the presence of a slow and poorly collimated outflow, in opposition to what is usually found towards young stellar objects but in agreement with prediction from simulations of a FHSC. This presents the best candidate, so far, for a FHSC, an object that has been identified in simulations of collapsing dense cores. Whatever the true nature of the central object in L1451-mm, this core presents an excellent laboratory to study the earliest phases of low-mass star formation.