The Galactic Center Cloud G0.253+0.016: A Massive Dense Cloud with low Star Formation Potential

TL;DR

This study maps the dense, massive Galactic Center cloud G0.253+0.016, revealing its low star formation activity despite high mass, challenging existing star formation laws and suggesting it may evolve into a stellar cluster over time.

Contribution

First interferometric molecular line and dust emission maps of G0.253+0.016, showing its low star formation potential despite high mass, challenging current star formation models.

Findings

Lack of dense cores explains low star formation activity.

Presence of low-density cores with narrow line widths.

Potential evolution into a stellar cluster over several 10^5 years.

Abstract

We present the first interferometric molecular line and dust emission maps for the Galactic Center (GC) cloud G0.253+0.016, observed using the Combined Array for Research in Millimeter--wave Astronomy (CARMA) and the Submillimeter Array (SMA). This cloud is very dense, and concentrates a mass exceeding the Orion Molecular Cloud Complex (2x10^5 M_sun) into a radius of only 3pc, but it is essentially starless. G0.253+0.016 therefore violates "star formation laws" presently used to explain trends in galactic and extragalactic star formation by a factor ~45. Our observations show a lack of dense cores of significant mass and density, thus explaining the low star formation activity. Instead, cores with low densities and line widths 1km/s---probably the narrowest lines reported for the GC region to date---are found. Evolution over several 10^5 yr is needed before more massive cores, and possibly an Arches--like stellar cluster, could form. Given the disruptive dynamics of the GC region, and the potentially unbound nature of G0.253+0.016, it is not clear that this evolution will happen.