A Survey of Acetic Acid toward Hot Molecular Cores

Abstract

We have surveyed 12 Galactic hot molecular cores for interstellar acetic acid (CH3COOH). This is the most extensive search for acetic acid to date. We have detected a new source of acetic acid toward the high-mass hot molecular core source G34.3+0.2. Using a temperature range between 70 and 185 K, we find a CH3COOH column density range of (0.77-1.64) × 1015 cm-2 toward G34.3+0.2. This gives a relative CH3COOH/HCOOCH3 abundance ratio of ~3.3 × 10-2, which is comparable to the abundance ratio of (3-6) × 10-2 found toward Sgr B2(N-LMH) and W51e2 by Remijan and colleagues. All currently known acetic acid sources are within 7 kpc of the Galactic center. Furthermore, our survey suggests that hot molecular cores that have a mass range between 200 and 2000 M☉ and do not show a distinct differentiation between O and N chemistry may be the best places to search for acetic acid and the structurally similar biologically important molecule glycine.