3D CMZ. I. Central Molecular Zone overview

Cara Battersby; Daniel L. Walker; Ashley Barnes; Adam Ginsburg; Dani Lipman; Danya Alboslani; H. Perry Hatchfield; John Bally; Simon C. O. Glover; Jonathan D. Henshaw; Katharina Immer; Ralf S. Klessen; Steven N. Longmore; Elisabeth A. C. Mills; Sergio Molinari; Rowan Smith; Mattia C. Sormani; Robin G. Tress; Qizhou Zhang

doi:10.3847/1538-4357/adb5f0

3D CMZ. I. Central Molecular Zone overview

Cara Battersby, Daniel L. Walker, Ashley Barnes, Adam Ginsburg, Dani Lipman, Danya Alboslani, H. Perry Hatchfield, John Bally, Simon C. O. Glover, Jonathan D. Henshaw, Katharina Immer, Ralf S. Klessen, Steven N. Longmore, Elisabeth A. C. Mills, Sergio Molinari, Rowan Smith, Mattia C. Sormani, Robin G. Tress, Qizhou Zhang

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract

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° (∣l∣ < 20°) of the Milky Way with a particular focus on the CMZ. We report a total dense gas (N(H₂) > 10²³ cm⁻²) CMZ mass of ∼ 2₋₁⁺² × 10⁷ M_⊙ 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° (∣l∣ < 20°) of the Galaxy. We find that the CMZ clearly stands out as a distinct structure, with an average mass per longitude that is at least 3× higher than the rest of the inner Galaxy contiguously from 1.°8 > ℓ > −1.°3. 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 × 10²⁴ cm⁻², and typical CMZ molecular clouds are about N(H₂) ∼ 10²³ cm⁻². Typical CMZ dust temperatures range from ∼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.

Original language	English
Article number	156
Number of pages	16
Journal	Astrophysical Journal
Volume	984
Issue number	2
Early online date	8 May 2025
DOIs	https://doi.org/10.3847/1538-4357/adb5f0
Publication status	Published - 10 May 2025

Keywords

Galactic center
Star formation
Dust continuum emission
Far infrared astronomy

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Battersby_2025_ApJ_3D-CMZ-I-Central-Molecular-Zone-overview_CC
© 2025. The Author(s). Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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Battersby, C., Walker, D. L., Barnes, A., Ginsburg, A., Lipman, D., Alboslani, D., Hatchfield, H. P., Bally, J., Glover, S. C. O., Henshaw, J. D., Immer, K., Klessen, R. S., Longmore, S. N., Mills, E. A. C., Molinari, S., Smith, R., Sormani, M. C., Tress, R. G., & Zhang, Q. (2025). 3D CMZ. I. Central Molecular Zone overview. Astrophysical Journal, 984(2), Article 156. https://doi.org/10.3847/1538-4357/adb5f0

@article{5f001f5ece57499da196780435eb8228,

title = "3D CMZ. I. Central Molecular Zone overview",

abstract = "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° (∣l∣ < 20°) of the Milky Way with a particular focus on the CMZ. We report a total dense gas (N(H2) > 1023 cm−2) CMZ mass of ∼ 2−1+2 × 107 M⊙ 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° (∣l∣ < 20°) of the Galaxy. We find that the CMZ clearly stands out as a distinct structure, with an average mass per longitude that is at least 3× higher than the rest of the inner Galaxy contiguously from 1.°8 > ℓ > −1.°3. This CMZ extent is larger than previously assumed, but is consistent with constraints from velocity information. The inner Galaxy{\textquoteright}s column density peaks towards the SgrB2 complex with a value of about 2 × 1024 cm−2, and typical CMZ molecular clouds are about N(H2) ∼ 1023 cm−2. Typical CMZ dust temperatures range from ∼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.",

keywords = "Galactic center, Star formation, Dust continuum emission, Far infrared astronomy",

author = "Cara Battersby and Walker, \{Daniel L.\} and Ashley Barnes and Adam Ginsburg and Dani Lipman and Danya Alboslani and Hatchfield, \{H. Perry\} and John Bally and Glover, \{Simon C. O.\} and Henshaw, \{Jonathan D.\} and Katharina Immer and Klessen, \{Ralf S.\} and Longmore, \{Steven N.\} and Mills, \{Elisabeth A. C.\} and Sergio Molinari and Rowan Smith and Sormani, \{Mattia C.\} and Tress, \{Robin G.\} and Qizhou Zhang",

note = "Funding: C.B. gratefully acknowledges funding from National Science Foundation (NSF) under award Nos. 1816715, 2108938, 2206510, and CAREER 2145689, as well as from the National Aeronautics and Space Administration through the Astrophysics Data Analysis Program under award “3D MC: Mapping Circumnuclear Molecular Clouds from X-ray to Radio,” grant No. 80NSSC22K1125. D.W. and D.L. gratefully acknowledge funding from the NSF under award No. 1816715, and D.L. also acknowledges funding from the National Science Foundation under award Nos. 2108938 and CAREER 2145689, as well as from the NASA Connecticut Space Grant Consortium under PTE Federal award No. 80NSSC20M0129. A.G. acknowledges funding from NSF awards AST 2008101 and 2206511 and CAREER 2142300. J.D.H. gratefully acknowledges financial support from the Royal Society (University Research Fellowship; URF/R1/221620). R.S.K. and S.C.O.G. acknowledge financial support from the European Research Council via the ERC Synergy Grant “ECOGAL” (project ID 855130), from the German Excellence Strategy via the Heidelberg Cluster of Excellence (EXC 2181—390900948) “STRUCTURES,” and from the German Ministry for Economic Affairs and Climate Action in project “MAINN” (funding ID 50OO2206). E.A.C. Mills gratefully acknowledges funding from the National Science Foundation under award Nos. 1813765, 2115428, 2206509, and CAREER 2339670. M.C.S. acknowledges financial support from the European Research Council under the ERC Starting Grant “GalFlow” (grant 101116226). Q.Z. acknowledges the support from the National Science Foundation under award No. 2206512.",

year = "2025",

month = may,

day = "10",

doi = "10.3847/1538-4357/adb5f0",

language = "English",

volume = "984",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "2",

}

Battersby, C, Walker, DL, Barnes, A, Ginsburg, A, Lipman, D, Alboslani, D, Hatchfield, HP, Bally, J, Glover, SCO, Henshaw, JD, Immer, K, Klessen, RS, Longmore, SN, Mills, EAC, Molinari, S, Smith, R, Sormani, MC, Tress, RG & Zhang, Q 2025, '3D CMZ. I. Central Molecular Zone overview', Astrophysical Journal, vol. 984, no. 2, 156. https://doi.org/10.3847/1538-4357/adb5f0

TY - JOUR

T1 - 3D CMZ. I. Central Molecular Zone overview

AU - Battersby, Cara

AU - Walker, Daniel L.

AU - Barnes, Ashley

AU - Ginsburg, Adam

AU - Lipman, Dani

AU - Alboslani, Danya

AU - Hatchfield, H. Perry

AU - Bally, John

AU - Glover, Simon C. O.

AU - Henshaw, Jonathan D.

AU - Immer, Katharina

AU - Klessen, Ralf S.

AU - Longmore, Steven N.

AU - Mills, Elisabeth A. C.

AU - Molinari, Sergio

AU - Smith, Rowan

AU - Sormani, Mattia C.

AU - Tress, Robin G.

AU - Zhang, Qizhou

N1 - Funding: C.B. gratefully acknowledges funding from National Science Foundation (NSF) under award Nos. 1816715, 2108938, 2206510, and CAREER 2145689, as well as from the National Aeronautics and Space Administration through the Astrophysics Data Analysis Program under award “3D MC: Mapping Circumnuclear Molecular Clouds from X-ray to Radio,” grant No. 80NSSC22K1125. D.W. and D.L. gratefully acknowledge funding from the NSF under award No. 1816715, and D.L. also acknowledges funding from the National Science Foundation under award Nos. 2108938 and CAREER 2145689, as well as from the NASA Connecticut Space Grant Consortium under PTE Federal award No. 80NSSC20M0129. A.G. acknowledges funding from NSF awards AST 2008101 and 2206511 and CAREER 2142300. J.D.H. gratefully acknowledges financial support from the Royal Society (University Research Fellowship; URF/R1/221620). R.S.K. and S.C.O.G. acknowledge financial support from the European Research Council via the ERC Synergy Grant “ECOGAL” (project ID 855130), from the German Excellence Strategy via the Heidelberg Cluster of Excellence (EXC 2181—390900948) “STRUCTURES,” and from the German Ministry for Economic Affairs and Climate Action in project “MAINN” (funding ID 50OO2206). E.A.C. Mills gratefully acknowledges funding from the National Science Foundation under award Nos. 1813765, 2115428, 2206509, and CAREER 2339670. M.C.S. acknowledges financial support from the European Research Council under the ERC Starting Grant “GalFlow” (grant 101116226). Q.Z. acknowledges the support from the National Science Foundation under award No. 2206512.

PY - 2025/5/10

Y1 - 2025/5/10

N2 - 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° (∣l∣ < 20°) of the Milky Way with a particular focus on the CMZ. We report a total dense gas (N(H2) > 1023 cm−2) CMZ mass of ∼ 2−1+2 × 107 M⊙ 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° (∣l∣ < 20°) of the Galaxy. We find that the CMZ clearly stands out as a distinct structure, with an average mass per longitude that is at least 3× higher than the rest of the inner Galaxy contiguously from 1.°8 > ℓ > −1.°3. 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 × 1024 cm−2, and typical CMZ molecular clouds are about N(H2) ∼ 1023 cm−2. Typical CMZ dust temperatures range from ∼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.

AB - 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° (∣l∣ < 20°) of the Milky Way with a particular focus on the CMZ. We report a total dense gas (N(H2) > 1023 cm−2) CMZ mass of ∼ 2−1+2 × 107 M⊙ 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° (∣l∣ < 20°) of the Galaxy. We find that the CMZ clearly stands out as a distinct structure, with an average mass per longitude that is at least 3× higher than the rest of the inner Galaxy contiguously from 1.°8 > ℓ > −1.°3. 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 × 1024 cm−2, and typical CMZ molecular clouds are about N(H2) ∼ 1023 cm−2. Typical CMZ dust temperatures range from ∼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.

KW - Galactic center

KW - Star formation

KW - Dust continuum emission

KW - Far infrared astronomy

UR - https://www.scopus.com/pages/publications/105004686594

U2 - 10.3847/1538-4357/adb5f0

DO - 10.3847/1538-4357/adb5f0

M3 - Article

AN - SCOPUS:105004686594

SN - 0004-637X

VL - 984

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

M1 - 156

ER -

3D CMZ. I. Central Molecular Zone overview

Abstract

Keywords

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Other files and links

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Papers I & II (Battersby et al. 2024a,b)

3D CMZ. II. Hierarchical structure analysis of the Central Molecular Zone

3D CMZ. III. Constraining the 3D structure of the Central Molecular Zone via molecular line emission and absorption

3D CMZ. IV. Distinguishing near versus far distances in the galactic center using Spitzer and Herschel

Cite this

3D CMZ. I. Central Molecular Zone overview

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Datasets

Papers I & II (Battersby et al. 2024a,b)

Research output

3D CMZ. II. Hierarchical structure analysis of the Central Molecular Zone

3D CMZ. III. Constraining the 3D structure of the Central Molecular Zone via molecular line emission and absorption

3D CMZ. IV. Distinguishing near versus far distances in the galactic center using Spitzer and Herschel

Cite this