3-D CMZ I: Central Molecular Zone Overview

• Published in: arXiv.org 2024-10
• Main Authors: Battersby, Cara, Walker, Daniel L, Barnes, Ashley, Ginsburg, Adam, Lipman, Dani, Alboslani, Danya, H Perry Hatchfield, Bally, John, Glover, Simon C O, Henshaw, Jonathan D, Immer, Katharina, Klessen, Ralf S, Longmore, Steven N, Mills, Elisabeth A C, Molinari, Sergio, Smith, Rowan, Sormani, Mattia C, Tress, Robin G, Zhang, Qizhou
• Format: Article
• Language: English
• Subjects: Columnar structure; Cosmic dust; Density; Galaxy distribution; Molecular clouds; Molecular gases; Skewed distributions
• ISSN: 2331-8422

The Central Molecular Zone (CMZ) is the largest reservoir of dense molecular gas in the Galaxy and is heavily obscured in the optical and near-IR. We present an overview of the far-IR dust continuum, where the molecular clouds are revealed, provided by Herschel in the inner 40\deg(\(|l| 10^{23}\) cm\(^{-2}\)) CMZ mass of M=\(2\substack{+2 \\ -1} \times 10^7\) M\(_{\odot}\) and confirm that there is a highly asymmetric distribution of dense gas, with about 70-75% at positive longitudes. We create and publicly release complete fore/background-subtracted column density and dust temperature maps in the inner 40\deg (\(|l| \ell >\) -1.3\deg. This CMZ extent is larger than previously assumed, but is consistent with constraints from velocity information. The inner Galaxy's column density peaks towards the SgrB2 complex with a value of about 2 \(\times\) 10\(^{24}\) cm\(^{-2}\), and typical CMZ molecular clouds are about N(H\(_2\))=10\(^{23}\) cm\(^{-2}\). Typical CMZ dust temperatures range from about \(12-35\) K with relatively little variation. We identify a ridge of warm dust in the inner CMZ that potentially traces the base of the northern Galactic outflow seen with MEERKAT.