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REVIEW 4 major objections 5 minor 67 references

The Milky Way's central black hole is currently driving a hot wind that has cleared a parsec-long conical cavity in the cold molecular gas around it.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review

2026-08-04 17:44 UTC pith:IUDTNU3B

load-bearing objection A genuinely deeper CO map reveals a striking conical deficit near Sgr A*, but the wind interpretation currently rests on a visual identification that needs an independent cold-gas tracer before it can carry the paper. the 4 major comments →

arxiv 2509.10615 v3 pith:IUDTNU3B submitted 2025-09-12 astro-ph.GA

The Discovery of an Active Wind from the Milky Way's Black Hole

classification astro-ph.GA
keywords Sagittarius A*galactic centerblack hole windaccretion and feedbackcircumnuclear diskmolecular gasALMA observationsCO line emission
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper is trying to establish that Sagittarius A*, the Milky Way's central black hole, is not dormant: it is currently blowing a hot wind that is actively carving the cold gas in the Galactic Center. The authors combine several years of ALMA observations of the 12CO(J=2→1) line into a map about 100 times more sensitive and 80 times higher resolution than previous maps of the region, and in it they find a cone-shaped region nearly devoid of cold molecular gas, about 1 pc long with a 45-degree opening angle. They argue that the morphology and the energy needed to keep the cone clear—about 10^38 erg per second—are consistent with an active black-hole wind and exceed what stellar winds can supply. If correct, this resolves the five-decade puzzle of the missing wind from Sgr A* and gives the nearest laboratory for studying how black holes feed and push back on their surroundings.

Core claim

The paper's central claim is that Sgr A* is currently driving a hot, mildly collimated wind, and that this wind has carved a conical clearing into the cold molecular gas of the Galactic Center. Using combined ALMA observations of the 12CO(J=2→1) line, the authors produce a map roughly 100 times deeper and 80 times sharper than previous maps, revealing a cone-shaped region devoid of cold gas, about 1 pc long with a ~45 degree opening angle, extending south-southwest from Sgr A*. The cavity has sharp edges, molecular gas is otherwise present and rotating around the black hole, and X-ray emitting hot gas fills the region where CO is absent. The power required to heat or evacuate the gas crossin

What carries the argument

The central object is the conical clearing in the 12CO(J=2→1) emission map around Sgr A*: a region nearly devoid of cold molecular gas, roughly 1 pc long with a 45-degree opening angle, interpreted as the imprint of a hot wind. The argument is carried by comparing its morphology and the estimated power needed to keep the cone clear against plausible alternatives—stellar winds and a recent supernova—and by agreement with independent tracers: anti-correlation with hot X-ray gas, the ordered rotational velocity field of the surrounding gas, known structures such as the OH streamer, and the Western Arc of the minispiral lying along the cone's extrapolated path.

Load-bearing premise

The whole case rests on the assumption that the CO-free sector is a genuine continuous cone-shaped cavity in cold gas along the line of sight to Sgr A*, rather than an artifact of projection, foreground absorption, or cold gas being heated or dissociated so that its CO emission disappears.

What would settle it

A clean test is to map the same inner parsec in a cold-gas tracer that does not depend on CO excitation, such as dust continuum emission or an absorption line against a background continuum source behind the proposed SSW cone; if the same conical deficit is absent, the region is not empty and the wind interpretation collapses. A second test would be a direct detection of hot outflowing gas with the expected ~45 degree opening angle and SSW-oriented velocity gradient.

Watch this falsifier. Get emailed when new claim-graph text bears on it.

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If this is right

  • Sgr A* is not dormant: it is actively clearing cold gas within ~1 pc, so the long-standing search for a wind from the Milky Way's central black hole has a concrete candidate.
  • The estimated wind power of ~10^38 erg per second exceeds the energy that stellar winds in the Galactic Center can supply, ruling out stellar winds as the origin of the cavity.
  • The wind has likely been active for at least ~2×10^4 years, as set by the Keplerian travel time from the wind cone to the far end of the Western Arc.
  • The wind is probably the ionization source for the Western Arc of the minispiral, linking black hole activity to the observed morphology of ionized gas.
  • Cold molecular gas fills the inner ~0.5 pc and flows inward toward the black hole, so feeding and feedback are happening simultaneously at the Galactic Center.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: the conical deficit should also appear in other cold-gas tracers and in dust continuum emission; a targeted survey with, for example, CS or HCN lines, plus absorption measurements against a background source, would independently confirm that the cavity is truly empty rather than merely CO-dark.
  • Editorial inference: if the wind is steady, the counter-cone toward the north-northeast may be hidden by projection and by the Sgr A East supernova remnant; deeper observations at wavelengths less affected by foreground confusion could reveal a symmetric pair and constrain the full three-dimensional opening angle.
  • Editorial inference: brightness variations along the Western Arc could encode past episodes of elevated Sgr A* activity, potentially allowing a reconstruction of the black hole's accretion and outflow history over roughly 10^4 to 10^5 years.
  • Editorial inference: if this wind persists over longer timescales, it may connect to the kiloparsec-scale bubbles and chimneys seen above and below the Galactic plane, implying that the local parsec-scale clearing is one part of a longer feedback cycle.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The paper presents new ALMA 12CO(2-1) observations of the inner ~1 pc around Sgr A*, with unprecedented depth and resolution, and identifies a conical region largely devoid of CO emission extending south-southwest from the black hole. The authors interpret this as a cavity cleared by a currently active hot wind from Sgr A*, with an opening angle of ~45 degrees and length of at least 1 pc. They also point to an X-ray/CO anti-correlation, a possible NNE counterpart, and an association with the Western Arc of the minispiral. They estimate the required wind power at ~10^38 erg/s and, assuming wind ionization of the Western Arc, a lifetime of at least ~2x10^4 years. The central claim is that the morphology and energetics are consistent with an active Sgr A* wind clearing the cold gas.

Significance. If the interpretation is correct, this would be the first direct detection of Sgr A*'s currently active wind, with implications for black hole feeding and feedback at the Galactic Center and by extension for SMBH physics. The observation itself is a substantial technical achievement: combining multiple ALMA epochs with time-variable Sgr A* subtraction yields a CO map 100 times deeper and 80 times sharper than previous maps, and the recovery of known structures (CND, triop, SEW, OH streamer) validates the data quality. However, the paper's main claim rests on a single morphological interpretation of a CO deficit, without a quantitative significance test or an independent cold-gas tracer. Because CO(2-1) emission is suppressed by heating to ~1000 K or by dissociation, the 'clearing' could equally be a CO-dark region rather than a true cavity. The energetics estimate is a consistency check, not an independent measurement, and the lifetime argument assumes the very wind that is claimed. These weaknesses mean the paper currently offers a promising hypothesis rather than a demonstrated discovery.

major comments (4)
  1. [Main text, 'Finally, and crucially, we find a large conical clearing...' and Figures 1-2] The conical clearing is identified visually; no quantitative significance test, edge detection, or comparison with symmetric control regions is provided. More importantly, the CO deficit itself is degenerate with heating or dissociation: the Supplementary Information explicitly states that heating to ≳1,000 K suppresses 12CO(2→1) and that CO would fully dissociate at 10^4 K. Thus the 'cone devoid of cold gas' may simply be a region where CO is not emitting, while the molecular gas remains present. No independent cold-gas tracer (e.g., HCN, CS, NH3, or dust continuum) or absorption measurement inside the cone is presented to establish that the gas is actually absent. This is the load-bearing assumption of the entire wind claim and needs to be tested before the cavity can be attributed to a wind.
  2. [Supplementary Information, 'Estimate of the Wind Energetics'] The jet-power estimate of ~10^38 erg/s is derived from the assumption that the wind cone must be kept clear by ejecting ~250 Msun of gas every ~2200 years. But the heating cost alone is only ~8e35 erg/s (to 10^3 K) or ~1e37 erg/s (to 10^4 K), and the data do not distinguish between heating and clearing because CO emission is suppressed in both cases. The order-of-magnitude estimate is a consistency check, not a detection of the wind power. The paper should either present a direct observable that ties the CO deficit to physical clearing, or clearly frame 10^38 erg/s as an upper limit under a specific ejection scenario.
  3. [Main text, 'Evidence of the Wind' and 'Energetics and Lifetime of the Wind'] Two inferential steps are circular. First, the NNE counterpart is inferred post hoc from a lack of CO and an X-ray excess, which is the same signature as the SSW cone; this does not independently corroborate the wind. Second, the lifetime estimate assumes that 'the Sgr A* wind is the primary ionization source for the Western Arc' (stated in the main text) and then uses that assumption to derive a 2x10^4-year lifetime. The Western Arc could be ionized by other mechanisms, and the argument is only as strong as the wind-assumption it is meant to validate. The paper should present independent tests, such as spectral diagnostics of the ionized gas or a kinematic model that does not presuppose the wind geometry.
  4. [Main text, 'Evidence of the Wind', paragraph citing ref. 42] The claim that 'for the edges of the conical clearing to be as pronounced as they are, a presently active wind must be present' relies on the authors' own simulation (ref. 42) to argue that infalling gas would erase past cavities. This is a consistency argument, not independent evidence. The simulation itself is not shown to reproduce the observed clumpy morphology with the same clearing, and the statement does not rule out other mechanisms (e.g., recent stochastic accretion, photodissociation, or geometrical projection). The paper needs a dedicated comparison between the simulation with and without a wind, or an observational proxy that can distinguish wind-clearing from other ways to produce a CO deficit.
minor comments (5)
  1. [Figure 1 caption] The caption states 'The active black hole wind manifests as a large cavity...' before the interpretation is established. Please use 'candidate cavity' or 'region devoid of CO' to avoid prejudging the result.
  2. [Supplementary Information, 'Observations and Image Quality'] The terms 'recoverable scale' and 'maximum recoverable scale' are used inconsistently; a single definition (e.g., from the shortest baseline) should be used throughout.
  3. [Supplementary Information, 'Estimate of the Wind Energetics'] The sentence 'Below,' is incomplete and appears to be a leftover fragment. Also, 'Jupiter' should be 'Jupyter' and 'far' should be 'for' in the Data and materials availability section.
  4. [Main text, 'Cold Molecular Gas Around Sgr A*'] The statement that the interior of the CND 'is in fact filled with cold molecular gas' is supported by the new map, but the density estimate in the SI relies on a 1 pc cylindrical height and a 10% overlap assumption. Please state the systematic uncertainties more prominently.
  5. [Figure 2 and Figure 6] The surface-density profile plots are presented in arbitrary units; converting to physically meaningful column density with an assumed abundance would help the reader assess the significance of the radial decline and the contrast of the putative cavity.

Circularity Check

0 steps flagged

No significant circularity; the wind inference is an interpretation of the observed CO deficit, not a derivation from fitted inputs.

full rationale

The paper's central claim is based on an observed conical deficit in CO(2-1) emission. The interpretation as a wind is supported by X-ray anti-correlation, comparison with known structures, and an energy budget calculation that is computed from the observed gas distribution. The wind power is an order-of-magnitude consistency estimate, not a fitted parameter. The only self-citation (ref 42) is used to argue that the CND erases past signatures, justifying the need for a current wind; however, this simulation contains independent content and does not assume the target result, so it is not circular. No equation-level reduction or parameter-prediction equivalence was found.

Axiom & Free-Parameter Ledger

0 free parameters · 4 axioms · 0 invented entities

The central inference rests on interpreting a CO deficit as a wind-blown cone. This requires a tracer-to-density mapping, a mass and inflow scaling, and a simulation-based argument for present activity. No new physical entities are introduced.

axioms (4)
  • domain assumption The 12CO(J=2-1) emission traces cold molecular gas column density in the inner parsec; deficits trace evacuated or heated cavities.
    Central to the cavity detection; alternative CO excitation or opacity effects are not excluded. The supplementary mass estimate section acknowledges density uncertainties.
  • domain assumption The gas mass in the inner 0.5 pc and the inflow rate through the wind cone are estimated by scaling the CND's HCN-based mass and Keplerian velocities; the cone clearing rate is roughly 250 Msun per 2200 yr.
    Used in the energetics estimate to conclude stellar winds are insufficient; the scaling is order-of-magnitude and depends on clumpy gas with large density fluctuations.
  • domain assumption Simulations of the CND (Solanki et al. 2023, ref 42) correctly describe the refill and erasure timescale, so a sharp cavity implies a presently active wind.
    Used to argue the wind is active rather than a fossil. Ref 42 has author overlap with the present paper, so this is a self-cited interpretive anchor.
  • ad hoc to paper The Western Arc of the minispiral is ionized by the Sgr A* wind, providing the 20,000 year lifetime estimate.
    Standard models attribute minispiral ionization to the central stellar cluster; the wind-as-ionizing-source assumption is introduced here specifically to estimate the lifetime.

reviewed 2026-08-04 · how reviews work

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Cite this review

Pith. "Pith review of The Discovery of an Active Wind from the Milky Way's Black Hole." pith.science (2026). https://pith.science/paper/IUDTNU3B

@misc{pith2026250910615,
  author       = {Pith},
  title        = {Pith review of: The Discovery of an Active Wind from the Milky Way's Black Hole},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/IUDTNU3B}},
  note         = {Machine review of arXiv:2509.10615}
}
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read the original abstract

Every large galaxy has a black hole in its center. The interaction between the black hole and its host profoundly shapes galactic evolution and the Universe as a whole. The key features of this interaction are black hole jets -- or more generally, winds -- which every black hole must have. Despite the proximity and importance of our Galaxy's central black hole, Sagittarius A* (Sgr A*), the active wind from it has eluded scientists for over half a century. Here we report the discovery of a large active wind from Sgr A* using unprecedentedly deep (T$_b \sim30$ mK) and high angular resolution (<0.25") observations with the Atacama Large Millimeter/Submillimeter Array (ALMA). We detect a large conical clearing in the cold molecular gas surrounding Sgr A* that is at least 1~parsec long and has a ~45 degree opening angle. The morphology and energetics of this structure are consistent with active clearing of gas by a hot wind from Sgr A*.

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Works this paper leans on

67 extracted references · 9 canonical work pages

  1. [1]

    Kormendy, L

    J. Kormendy, L. C. Ho, Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies.Ann. Rev. Astron. Astrophys.51(1), 511–653 (2013), doi:10.1146/ annurev-astro-082708-101811

  2. [2]

    Weinberger,et al., Supermassive black holes and their feedback effects in the IllustrisTNG simulation.Mon

    R. Weinberger,et al., Supermassive black holes and their feedback effects in the IllustrisTNG simulation.Mon. Not. R. Astron. Soc.479(3), 4056–4072 (2018), doi:10.1093/mnras/sty1733

  3. [3]

    Blandford, D

    R. Blandford, D. Meier, A. Readhead, Relativistic Jets from Active Galactic Nuclei.Ann. Rev. Astron. Astrophys.57, 467–509 (2019), doi:10.1146/annurev-astro-081817-051948

  4. [4]

    A. H. Bridle, R. A. Perley, Extragalactic Radio Jets.Ann. Rev. Astron. Astrophys.22, 319–358 (1984), doi:10.1146/annurev.aa.22.090184.001535

  5. [5]

    Frank, A

    J. Frank, A. King, D. J. Raine,Accretion Power in Astrophysics: Third Edition(2002)

  6. [6]

    Lynden-Bell, M

    D. Lynden-Bell, M. J. Rees, On quasars, dust and the galactic centre.Mon. Not. R. Astron. Soc. 152, 461 (1971), doi:10.1093/mnras/152.4.461

  7. [7]

    J. Silk, M. J. Rees, Quasars and galaxy formation.Astron. Astrophys.331, L1–L4 (1998), doi:10.48550/arXiv.astro-ph/9801013

  8. [8]

    S. W. Davis, A. Tchekhovskoy, Magnetohydrodynamics Simulations of Active Galactic Nucleus Disks and Jets.Ann. Rev. Astron. Astrophys.58, 407–439 (2020), doi:10.1146/ annurev-astro-081817-051905

  9. [9]

    I. D. Novikov, K. S. Thorne, Astrophysics of black holes., inBlack Holes (Les Astres Occlus), C. Dewitt, B. S. Dewitt, Eds. (1973), pp. 343–450

  10. [10]

    F. Yuan, R. Narayan, Hot Accretion Flows Around Black Holes.Ann. Rev. Astron. Astrophys. 52, 529–588 (2014), doi:10.1146/annurev-astro-082812-141003

  11. [11]

    R. D. Blandford, R. L. Znajek, Electromagnetic extraction of energy from Kerr black holes. Mon. Not. R. Astron. Soc.179, 433–456 (1977), doi:10.1093/mnras/179.3.433

  12. [12]

    Blandford, N

    R. Blandford, N. Globus, Ergomagnetosphere, ejection disc, magnetopause in M87 - I. Global flow of mass, angular momentum, energy, and current.Mon. Not. R. Astron. Soc.514(4), 5141–5158 (2022), doi:10.1093/mnras/stac1682

  13. [13]

    M. Su, T. R. Slatyer, D. P. Finkbeiner, Giant Gamma-ray Bubbles from Fermi-LAT: Active Galactic Nucleus Activity or Bipolar Galactic Wind?Astrophys. J.724(2), 1044–1082 (2010), doi:10.1088/0004-637X/724/2/1044

  14. [14]

    Predehl,et al., Detection of large-scale X-ray bubbles in the Milky Way halo.Nature 588(7837), 227–231 (2020), doi:10.1038/s41586-020-2979-0

    P. Predehl,et al., Detection of large-scale X-ray bubbles in the Milky Way halo.Nature 588(7837), 227–231 (2020), doi:10.1038/s41586-020-2979-0

  15. [15]

    Ponti,et al., An X-ray chimney extending hundreds of parsecs above and below the Galactic Centre.Nature567(7748), 347–350 (2019), doi:10.1038/s41586-019-1009-6

    G. Ponti,et al., An X-ray chimney extending hundreds of parsecs above and below the Galactic Centre.Nature567(7748), 347–350 (2019), doi:10.1038/s41586-019-1009-6. 8

  16. [16]

    M. R. Morris, M. P. Muno, F. K. Baganoff, Bipolar x-ray lobes around the Galactic Center. X-ray Astronomy 2009; Present Status, Multi-Wavelength Approach and Future Perspectives: Proceedings of the International Conference, inX-ray Astronomy 2009; Present Status, Multi- Wavelength Approach and Future Perspectives, A. Comastri, L. Angelini, M. Cappi, Eds. ...

  17. [17]

    Yusef-Zadeh,et al., Evidence for a jet and outflow from Sgr A*: a continuum and spectral line study.Mon

    F. Yusef-Zadeh,et al., Evidence for a jet and outflow from Sgr A*: a continuum and spectral line study.Mon. Not. R. Astron. Soc.499(3), 3909–3931 (2020), doi:10.1093/mnras/staa2399

  18. [18]

    Peißker,et al., Monitoring dusty sources in the vicinity of Sagittarius A*.Astron

    F. Peißker,et al., Monitoring dusty sources in the vicinity of Sagittarius A*.Astron. Astrophys. 634, A35 (2020), doi:10.1051/0004-6361/201935953

  19. [19]

    Z. Li, M. R. Morris, F. K. Baganoff, Evidence for a Parsec-scale Jet from the Galactic Center Black Hole: Interaction with Local Gas.Astrophys. J.779(2), 154 (2013), doi:10.1088/ 0004-637X/779/2/154

  20. [20]

    Cecil, A

    G. Cecil, A. Y. Wagner, J. Bland-Hawthorn, G. V. Bicknell, D. Mukherjee, Tracing the Milky Way’s Vestigial Nuclear Jet.Astrophys. J.922(2), 254 (2021), doi:10.3847/1538-4357/ac224f

  21. [21]

    F. K. Baganoff,et al., Chandra X-Ray Spectroscopic Imaging of Sagittarius A* and the Central Parsec of the Galaxy.Astrophys. J.591(2), 891–915 (2003), doi:10.1086/375145

  22. [22]

    Event Horizon Telescope Collaboration,et al., First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole.Astrophys. J. Lett. 930(2), L16 (2022), doi:10.3847/2041-8213/ac6672

  23. [23]

    Astrophys.618, L10 (2018), doi:10.1051/0004-6361/ 201834294

    GRA VITY Collaboration,et al., Detection of orbital motions near the last stable circular orbit of the massive black hole SgrA*.Astron. Astrophys.618, L10 (2018), doi:10.1051/0004-6361/ 201834294

  24. [24]

    Genzel, F

    R. Genzel, F. Eisenhauer, S. Gillessen, The Galactic Center massive black hole and nuclear star cluster.Reviews of Modern Physics82(4), 3121–3195 (2010), doi:10.1103/RevModPhys. 82.3121

  25. [25]

    Harada,et al., Chemical features in the circumnuclear disk of the Galactic center.Astron

    N. Harada,et al., Chemical features in the circumnuclear disk of the Galactic center.Astron. Astrophys.584, A102 (2015), doi:10.1051/0004-6361/201526994

  26. [26]

    T. A. James, S. Viti, F. Yusef-Zadeh, M. Royster, M. Wardle, Revealing the Physical Conditions around Sgr A* Using Bayesian Inference. I. Observations and Radiative Transfer.Astrophys. J.916(2), 69 (2021), doi:10.3847/1538-4357/abfd99

  27. [27]

    A. D. Bolatto, M. Wolfire, A. K. Leroy, The CO-to-H 2 Conversion Factor.Ann. Rev. Astron. Astrophys.51(1), 207–268 (2013), doi:10.1146/annurev-astro-082812-140944

  28. [28]

    J. R. Goicoechea,et al., High-speed molecular cloudlets around the Galactic center’s super- massive black hole.Astron. Astrophys.618, A35 (2018), doi:10.1051/0004-6361/201833558

  29. [29]

    Marshall, A

    J. Marshall, A. N. Lasenby, CO observations of high negative gas towards the Galactic Centre. Mon. Not. R. Astron. Soc.269, 619–625 (1994), doi:10.1093/mnras/269.3.619. 9

  30. [30]

    Mart ´ı-Vidal, W

    I. Mart ´ı-Vidal, W. H. T. Vlemmings, S. Muller, S. Casey, UVMULTIFIT: A versatile tool for fitting astronomical radio interferometric data.Astron. Astrophys.563, A136 (2014), doi: 10.1051/0004-6361/201322633

  31. [31]

    Ciurlo, T

    A. Ciurlo, T. Paumard, D. Rouan, Y. Cl ´enet, Hot molecular hydrogen in the central parsec of the Galaxy through near-infrared 3D fitting.Astron. Astrophys.594, A113 (2016), doi: 10.1051/0004-6361/201527173

  32. [32]

    Genzel, F

    R. Genzel, F. Eisenhauer, S. Gillessen, The Galactic Center massive black hole and nuclear star cluster.Reviews of Modern Physics82, 3121–3195 (2010), doi:10.1103/RevModPhys.82.3121

  33. [33]

    P. R. Maloney, D. J. Hollenbach, A. G. G. M. Tielens, X-Ray–irradiated Molecular Gas. I. Physical Processes and General Results.Astrophys. J.466, 561 (1996), doi:10.1086/177532

  34. [34]

    K. Y. Lo, M. J. Claussen, High-resolution observations of ionized gas in central 3 parsecs of the Galaxy: possible evidence for infall.Nature306(5944), 647–651 (1983), doi:10.1038/ 306647a0

  35. [35]

    J.-H. Zhao, M. R. Morris, W. M. Goss, T. An, Dynamics of Ionized Gas at the Galactic Center: Very Large Array Observations of the Three-dimensional Velocity Field and Location of the Ionized Streams in Sagittarius A West.Astrophys. J.699(1), 186–214 (2009), doi: 10.1088/0004-637X/699/1/186

  36. [36]

    Hsieh,et al., The Circumnuclear Disk Revealed by ALMA

    P.-Y. Hsieh,et al., The Circumnuclear Disk Revealed by ALMA. I. Dense Clouds and Tides in the Galactic Center.The Astrophysical Journal913(2), 94 (2021), doi:10.3847/1538-4357/ abf4cd,https://doi.org/10.3847%2F1538-4357%2Fabf4cd

  37. [37]

    J.-H. Zhao, M. R. Morris, W. M. Goss, A New Perspective of the Radio Bright Zone at The Galactic Center: Feedback from Nuclear Activities.Astrophys. J.817(2), 171 (2016), doi:10.3847/0004-637X/817/2/171

  38. [38]

    Q. D. Wang,et al., Dissecting X-ray-Emitting Gas Around the Center of Our Galaxy.Science 341(6149), 981–983 (2013), doi:10.1126/science.1240755

  39. [39]

    T. M. Kwan, L. Dai, A. Tchekhovskoy, The Effects of Gas Angular Momentum on the Formation of Magnetically Arrested Disks and the Launching of Powerful Jets.Astrophys. J. Lett.946(2), L42 (2023), doi:10.3847/2041-8213/acc334

  40. [40]

    Liska,et al., A phase lag between disc and corona in GRMHD simulations of precessing tilted accretion discs.New Astronomy101, 102012 (2023), doi:10.1016/j.newast.2023.102012

    M. Liska,et al., A phase lag between disc and corona in GRMHD simulations of precessing tilted accretion discs.New Astronomy101, 102012 (2023), doi:10.1016/j.newast.2023.102012

  41. [41]

    Borodina,et al., You Shall Not Pass! The Propagation of Low-/Moderate-powered Jets Through a Turbulent Interstellar Medium.Astrophys

    O. Borodina,et al., You Shall Not Pass! The Propagation of Low-/Moderate-powered Jets Through a Turbulent Interstellar Medium.Astrophys. J.981(2), 149 (2025), doi:10.3847/ 1538-4357/adb016

  42. [42]

    Solanki, S

    S. Solanki, S. M. Ressler, L. Murchikova, J. M. Stone, M. R. Morris, The Inner 2 pc of Sagittarius A*: Simulations of the Circumnuclear Disk and Multiphase Gas Accretion in the Galactic Center.Astrophys. J.953(1), 22 (2023), doi:10.3847/1538-4357/acdb6f. 10

  43. [43]

    Ehlerov ´a,et al., How to create Sgr A East

    S. Ehlerov ´a,et al., How to create Sgr A East. Where did the supernova explode?Astron. Astrophys.668, A124 (2022), doi:10.1051/0004-6361/202244682

  44. [44]

    Maeda,et al., A Chandra Study of Sagittarius A East: A Supernova Remnant Regulating the Activity of Our Galactic Center?Astrophys

    Y. Maeda,et al., A Chandra Study of Sagittarius A East: A Supernova Remnant Regulating the Activity of Our Galactic Center?Astrophys. J.570(2), 671–687 (2002), doi:10.1086/339773

  45. [45]

    Calder ´on, J

    D. Calder ´on, J. Cuadra, M. Schartmann, A. Burkert, C. M. P. Russell, Stellar Winds Pump the Heart of the Milky Way.Astrophys. J. Lett.888(1), L2 (2020), doi:10.3847/2041-8213/ab5e81

  46. [46]

    S. M. Ressler, E. Quataert, J. M. Stone, The surprisingly small impact of magnetic fields on the inner accretion flow of Sagittarius A* fueled by stellar winds.Mon. Not. R. Astron. Soc. 492(3), 3272–3293 (2020), doi:10.1093/mnras/stz3605

  47. [47]

    Paumard,et al., The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics, and Formation.Astrophys

    T. Paumard,et al., The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics, and Formation.Astrophys. J.643(2), 1011–1035 (2006), doi:10.1086/503273

  48. [48]

    H. Mo, F. C. van den Bosch, S. White,Galaxy Formation and Evolution(2010), doi:10.1017/ CBO9780511807244

  49. [49]

    CASA Team,et al., CASA, the Common Astronomy Software Applications for Radio As- tronomy.Publications of the Astronomical Society of the Pacifc134(1041), 114501 (2022), doi:10.1088/1538-3873/ac9642

  50. [50]

    Binney, O

    J. Binney, O. E. Gerhard, A. A. Stark, J. Bally, K. I. Uchida, Understanding the kinematics of Galactic Centre gas.Mon. Not. R. Astron. Soc.252, 210 (1991), doi:10.1093/mnras/252.2.210

  51. [51]

    Mart ´ın, J

    S. Mart ´ın, J. Mart´ın-Pintado, M. Montero-Casta˜no, P. T. P. Ho, R. Blundell, Surviving the hole. I. Spatially resolved chemistry around Sagittarius A∗.Astron. Astrophys.539, A29 (2012), doi: 10.1051/0004-6361/201117268

  52. [52]

    Hsieh,et al., A Magnetic Field Connecting the Galactic Center Circumnuclear Disk with Streamers and Mini-spiral: Implications from 850𝜇m Polarization Data.Astrophys

    P.-Y. Hsieh,et al., A Magnetic Field Connecting the Galactic Center Circumnuclear Disk with Streamers and Mini-spiral: Implications from 850𝜇m Polarization Data.Astrophys. J.862(2), 150 (2018), doi:10.3847/1538-4357/aacb27

  53. [53]

    Moser,et al., Approaching hell’s kitchen: Molecular daredevil clouds in the vicinity of Sagittarius A*.Astron

    L. Moser,et al., Approaching hell’s kitchen: Molecular daredevil clouds in the vicinity of Sagittarius A*.Astron. Astrophys.603, A68 (2017), doi:10.1051/0004-6361/201628385

  54. [54]

    Sandqvist, R

    A. Sandqvist, R. Karlsson, J. B. Whiteoak, OH in the Environment of SGR a, inThe Center of the Galaxy, M. Morris, Ed., vol. 136 ofIAU Symposium(1989), p. 421

  55. [55]

    Karlsson, L

    R. Karlsson, L. O. Sjouwerman, A. Sandqvist, J. B. Whiteoak, 18-cm VLA observations of OH towards the Galactic Centre. Absorption and emission in the four ground-state OH lines. Astron. Astrophys.403, 1011–1021 (2003), doi:10.1051/0004-6361:20030309

  56. [56]

    Karlsson, A

    R. Karlsson, A. Sandqvist, K. Fathi, S. Mart ´ın, The OH-streamer in Sagittarius A revisited: analysis of hydroxyl absorption within 10 pc from the Galactic centre.Astron. Astrophys.582, A118 (2015), doi:10.1051/0004-6361/201424426. 11

  57. [57]

    Z. Zhu, Z. Li, M. R. Morris, An Ultradeep Chandra Catalog of X-Ray Point Sources in the Galactic Center Star Cluster.Astrophys. J. Suppl. Ser.235(2), 26 (2018), doi:10.3847/ 1538-4365/aab14f

  58. [58]

    M. A. Requena-Torres,et al., GREAT confirms transient nature of the circum-nuclear disk. Astron. Astrophys.542, L21 (2012), doi:10.1051/0004-6361/201219068

  59. [59]

    Quataert, A Thermal Bremsstrahlung Model for the Quiescent X-Ray Emission from Sagit- tarius A*.Astrophys

    E. Quataert, A Thermal Bremsstrahlung Model for the Quiescent X-Ray Emission from Sagit- tarius A*.Astrophys. J.575(2), 855–859 (2002), doi:10.1086/341425

  60. [60]

    A. G. G. M. Tielens, D. Hollenbach, Photodissociation regions. I. Basic model.Astrophys. J. 291, 722–746 (1985), doi:10.1086/163111

  61. [61]

    K. M. Sandstrom,et al., The CO-to-H 2 Conversion Factor and Dust-to-gas Ratio on Kiloparsec Scales in Nearby Galaxies.Astrophys. J.777(1), 5 (2013), doi:10.1088/0004-637X/777/1/5

  62. [62]

    Kunneriath,et al., The Galactic centre mini-spiral in the mm-regime.Astron

    D. Kunneriath,et al., The Galactic centre mini-spiral in the mm-regime.Astron. Astrophys. 538, A127 (2012), doi:10.1051/0004-6361/201117676

  63. [63]

    S. M. Ressler, E. Quataert, J. M. Stone, Hydrodynamic simulations of the inner accretion flow of Sagittarius A* fuelled by stellar winds.Monthly Notices of the Royal Astronomical Soci- ety478(3), 3544–3563 (2018), doi:10.1093/mnras/sty1146,https://doi.org/10.1093/ mnras/sty1146

  64. [64]

    Chatzopoulos,et al., The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass.Mon

    S. Chatzopoulos,et al., The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass.Mon. Not. R. Astron. Soc.447(1), 948–968 (2015), doi:10.1093/mnras/stu2452

  65. [65]

    EHT MWL Science Working Group,et al., Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign.Astrophys. J. Lett.911(1), L11 (2021), doi:10.3847/2041-8213/abef71

  66. [66]

    M. A. Prieto, J. A. Fern ´andez-Ontiveros, S. Markoff, D. Espada, O. Gonz ´alez-Mart´ın, The central parsecs of M87: jet emission and an elusive accretion disc.Mon. Not. R. Astron. Soc. 457(4), 3801–3816 (2016), doi:10.1093/mnras/stw166. 12 Acknowledgments We are grateful to Claire J. Chandler for advice on data processing, and to Ivan Marti-Vidal, Anna C...

  67. [67]

    jet power

    that the molecular gas is not uniformly distributed in the region, but largely forms clumps and streamers, so the actual density fluctuates a few orders-of-magnitude about this value. This method for calculating gas mass relies on the integrated knowledge of the CND accumulated over decades of observations, and therefore, in our opinion, the most reliable...

This paper was first reviewed by deepseek-v4-flash on August 4, 2026.