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REVIEW 4 major objections 5 minor 74 references

Two starless hydrogen clouds near M51 are promising dark-matter halo candidates.

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 →

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2026-08-01 08:38 UTC pith:VUV2CZD2

load-bearing objection Two new HI clouds plausibly placed in the RELHIC framework, with honest caveats; the unresolved beam and selection circularity keep this at 'candidate' level, but the discovery is solid. the 4 major comments →

arxiv 2607.21034 v1 pith:VUV2CZD2 submitted 2026-07-23 astro-ph.GA

A RELHIC twin candidate near the galaxy M51

Qingze Chen , Jie Wang , Yingjie Jing , Chen Xu , Tiantian Liang , Zerui Liu , Zhipeng Hou , Yiwei Xu
show 2 more authors
Cheng Cheng Wei Du
This is my paper
classification astro-ph.GA
keywords H I cloudsdark galaxiesRELHICM51low-mass dark matter halosstarless halosgalaxy formation threshold21-centimetre observations
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 reports the discovery of two starless hydrogen clouds, Cloud S and Cloud N, in the outskirts of the interacting galaxy M51. The authors argue that the clouds' gas masses, line widths, and lack of starlight match predictions for reionization-limited H I clouds: gas trapped in low-mass dark-matter halos, heated by the ultraviolet background, and unable to cool into stars. If this interpretation holds, each cloud sits in a dark-matter halo of roughly 3.7 billion solar masses, and the pair would be direct evidence that some halos near the galaxy-formation threshold remain dark. The paper is careful to say the clouds are promising but not definitive, because the radio beam does not resolve their internal structure and a tidal origin remains possible.

Core claim

Using deep 21-centimetre observations from a large single-dish radio telescope, the authors identified two compact hydrogen clouds at projected distances of 70-90 kpc from M51. Each cloud has an H I mass of about 10^6.5 solar masses and a velocity dispersion near 20 km/s. Cross-matching against deep optical imaging finds no stellar counterpart down to a g-band surface brightness of roughly 27.5 mag arcsec^-2, implying a stellar luminosity below about 10^5 solar luminosities. Modelling the clouds as hydrostatic gas embedded in Navarro-Frenk-White dark-matter halos, with heating by the ultraviolet background and self-shielding, gives best-fit halo masses of about 3.7 ± 0.4 × 10^9 solar masses

What carries the argument

The central object is the RELHIC model: reionization-limited H I clouds, defined as gas in low-mass dark-matter halos that remains gravitationally bound after reionization, settles into hydrostatic equilibrium with the ultraviolet background, and never cools enough to form stars. The argument uses the hydrostatic equilibrium equation for gas in an NFW dark-matter halo, a temperature-density relation set by photoionisation from the ultraviolet background, and a self-shielding prescription to compute the neutral hydrogen fraction and column density profile. The predicted profiles are convolved with the telescope beam and matched to the observed clouds; the inferred halo masses fall in the narr

Load-bearing premise

The interpretation depends on each cloud being a single gravitationally bound object; the observations do not resolve their internal structure, so several tidal gas clumps blended together could mimic one cloud.

What would settle it

Arcsecond-resolution 21-centimetre mapping of Cloud S and Cloud N: if they resolve into compact, roughly spherical cores with quiet, thermally broadened velocity fields, the RELHIC reading is supported; if they break into filaments or show velocity gradients linking them to M51's tidal debris, the dark-halo interpretation fails.

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

If this is right

  • If Cloud S and Cloud N are confirmed as RELHICs, they would almost double the number of credible starless dark-matter halo candidates and strengthen the case that galaxy formation shuts off near 10^9 solar masses.
  • Their inferred halo masses sit in the predicted sweet spot: massive enough for the ultraviolet background to leave a detectable neutral core, yet light enough that cooling and star formation have not switched on.
  • The model predicts intrinsic neutral-hydrogen column densities two to three orders of magnitude above the blurred values seen by the current telescope, so higher-resolution observations should detect the compact cores if the halos are real.
  • The clouds are kinematically consistent with the M51 system at a distance of 8 Mpc, so if they are gravitationally bound they could serve as dynamical tracers of M51's dark-matter distribution.
  • If follow-up observations instead resolve them as tidal debris, the same data will constrain how much neutral gas was stripped from M51 during its interaction and where that gas now sits.

Where Pith is reading between the lines

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

  • If the RELHIC interpretation is right, similar searches around other massive, gas-rich spirals should find such clouds routinely; the M51 pair may be the first of a population rather than a rare accident.
  • The two clouds have nearly identical gas masses and line widths but different apparent velocity gradients, so high-resolution kinematics could separate pressure-supported dark halos from rotating or shearing tidal debris more cleanly than mass alone.
  • The quoted halo mass depends on the assumed ultraviolet-background model and the adopted mass-concentration relation; independent dynamical masses from resolved kinematics would test whether the 3.7×10^9 solar-mass estimate is robust.
  • Deep optical imaging that resolves individual stars could push the stellar-mass limit below 10^5 solar masses and reveal whether any star formation has ever occurred, deciding between a truly dark halo and a failed galaxy with an extremely faint stellar component.

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 manuscript reports the detection of two compact H I clouds, Cloud S and Cloud N, in FEASTS FAST observations of the M51 system. After removing sources with optical counterparts in DESI Legacy Surveys and applying morphological and line-width criteria, the authors identify these two clouds as candidate reionisation-limited H I clouds (RELHICs). They model each cloud as hydrostatic H I embedded in an NFW dark-matter halo within the Benítez-Llambay et al. (2017) framework and infer host halo masses M200 ~ 3.7 ± 0.4 × 10^9 M⊙. They validate the mass-inference method against starless TNG50 subhalos and compare mock beam-convolved gas kinematics with the observations. They conclude that the clouds are promising but not definitive RELHIC candidates, explicitly leaving open a tidal origin in the interacting M51 system.

Significance. If the two clouds are genuinely single, gravitationally bound, dark-matter-dominated systems with no stars, they would add two objects to the sparse catalogue of dark galaxy candidates and would support the predicted suppression of star formation in low-mass ΛCDM halos. The paper's strengths are its honest hedging, the use of TNG50 to sanity-check the mass estimator, and the explicit statement of the tidal alternative. Its central limitation is that FAST does not resolve the clouds: the 3.24′ beam corresponds to ~7.5 kpc at 8 Mpc, so the fundamental assumption that each detection is one coherent structure is untested. The claimed consistency with RELHIC predictions is also partly built into the source selection and into the mass-fitting procedure that uses the observed H I mass as input.

major comments (4)
  1. [Section 2, criterion (iii), and Table 1] Criterion (iii) requires velocity dispersions 'of order ~20 km/s, as expected for thermally broadened neutral gas in RELHICs.' The later statement that the measured W50 values are compatible with RELHIC predictions is therefore not an independent test. In particular, Cloud N has W50 = 29.3 km/s, above the fiducial thermal value. Please report how many optical-dark, morphologically round H I sources in the full FEASTS sample were rejected only by this criterion, and show the observed spectra with single-Gaussian fits. Without this, the reader cannot assess how strongly the candidate selection has pre-biased the sample toward RELHIC-like line widths.
  2. [Section 3.1 and Appendix A] The hydrostatic RELHIC model assumes each cloud is a single spherical gas core in one NFW halo, but the data do not resolve the clouds; Section 3.1 explicitly states that 'the intrinsic cloud shapes remained unresolved by FAST.' If a 'cloud' is a blend of unresolved tidal filaments, the integrated M_HI and W50 are not meaningful inputs to Eq. (A.1), and the inferred M200 is meaningless. The paper acknowledges this in the Conclusions, but the quoted uncertainty (3.7 ± 0.4 × 10^9 M⊙) reflects only concentration scatter, not the blending systematic. This systematic should be stated as the dominant uncertainty. Please add any available diagnostics for blending: spectral Gaussianity/asymmetry, whether the P-V diagrams in Fig. C.2 can be described by two overlapping components, and a quantitative statement of how beam dilution affects the inferred central column density.
  3. [Appendix A, Fig. A.1 and Section 3.1] The halo mass is essentially derived by requiring the model M_HI to match the observed M_HI at the adopted concentration (or within the Ludlow+16 scatter). The radial-profile comparison in Fig. 2 is weak because the intrinsic RELHIC size is much smaller than the FAST beam, so the beam-convolved profiles differ mainly in normalization, not in shape. Thus the claimed 'consistency' is a one-parameter reproduction of the observed H I mass, not a multi-property prediction. The TNG50 check in Appendix B shows that the mass estimator recovers M200 within a factor of two for simulated starless halos, but only under the assumption that each real cloud is a single such halo; it does not test the tidal-blend scenario. A stronger test would be to compare the model-predicted W50 and line profile with the observed values, rather than only the total H I mass.
  4. [Appendix B, Fig. B.1] The comparison with TNG50 starless halos shows that Cloud S and Cloud N lie inside a broad range of simulated v_rot–σ_z values. As stated, this is a very weak consistency test: a wide simulated distribution will contain almost any observed point. Please report the fraction of simulated halos that are as extreme as Cloud N in v_rot and σ_z, and, ideally, compare against mock observations of tidal debris from an M51-like interaction simulation. Without such a control sample, Fig. B.1 does not provide evidence that a tidal origin is excluded, and this should be stated explicitly.
minor comments (5)
  1. [Throughout] There are numerous formatting issues: 'Himass' should be 'H I mass'; 'V olume' appears in the Introduction; and the H I / Hi spacing is inconsistent. Please run a careful copyedit.
  2. [Table 1] The table lists W50 without uncertainties or a statement of whether the values are corrected for the 1.61 km/s channel width. Barycentric velocities are given without formal errors. Please add this information.
  3. [Section 3.2] The effective-radius assumption for the luminosity limit is important: L_lim ~ 10^5 L⊙ depends on adopting r_e ~ 500 pc, and the text notes that a more extended stellar component would raise the limit. The notation '10′′×10′′' and '10 ′′ scale' is inconsistent. Please clarify the exact scale and explicitly state that the quoted M_HI/L limit is conditional on the assumed effective radius.
  4. [Appendix A] The boundary condition 'gas pressure at large radii matches the IGM pressure at the mean density of the Universe' is not fully defined. For reproducibility, specify how the IGM pressure, mean density, and temperature are computed (e.g., from the chosen UVB model and redshift).
  5. [Figure C.1] The rightmost column is described as the velocity dispersion map (moment 2), but the axis label reads 'v [km/s]' and the color bar spans 0–24. Please relabel this panel as σ or σ_v to avoid confusion with the moment-1 map.

Circularity Check

2 steps flagged

The main quantitative 'consistency with RELHIC predictions' is partly built in: candidates were preselected to have ~20 km/s velocity dispersions, and the halo masses are obtained by matching the observed HI mass, then the same values are quoted as support.

specific steps
  1. fitted input called prediction [Sec. 2 selection criterion (iii); Sec. 4 point 1]
    "(iii) velocity dispersions of order ∼20 km s−1, as expected for thermally broadened neutral gas in RELHICs. ... The observed HI masses (∼10^6.5 M⊙) and velocity dispersions (∼20 km s−1) are compatible with the theoretical predictions of the RELHIC model."

    The velocity dispersion was a pre-selection filter: only sources with ~20 km/s dispersions survived criterion (iii). The same measured property is then cited in Sec. 4 as evidence of compatibility with RELHIC predictions. For that property the 'test' is tautological because the sample was constructed to satisfy it. The HI mass and the lack of an optical counterpart were not selection criteria, so the circularity is only partial, but the line-width compatibility claim is not an independent confirmation.

  2. fitted input called prediction [Abstract; Appendix A and Fig. A.1 caption; Sec. 3.1]
    "The red contour marks models with M_HI = 10^6.5 M⊙, corresponding to the observed HI mass of Cloud N and Cloud S. ... The intersection between the observed-HI contour and the allowed concentration range constrains the halo mass to M200 ≃ 3.7±0.4×10^9 M⊙. ... Their H I properties are consistent with RELHIC predictions, corresponding to host halo masses of 3.7 ± 0.4 × 10^9 M⊙."

    The halo mass M200 is not independently predicted; it is the parameter adjusted so that the model's HI mass equals the measured 10^6.5 M⊙. Saying that the clouds 'correspond to' M200 ≈ 3.7×10^9 M⊙ is simply inverting the model's M_HI(M200, c) relation. The abstract then presents this same match as consistency with RELHIC predictions. Because FAST leaves the clouds unresolved ('the intrinsic cloud shapes remained unresolved by FAST', Sec. 3.1), the beam-convolved radial-profile comparison in Fig. 2 is essentially a point-source/flux match and adds no independent shape constraint. Thus the central quantitative consistency reduces to the observed HI mass used as input.

full rationale

The paper is honest about its limitations and is not built on a load-bearing self-citation chain: the RELHIC framework is taken from external work (Benítez-Llambay et al. 2017, Rahmati et al. 2013, Haardt & Madau 2001, Ludlow et al. 2016), and the TNG50 comparison is an external, parameter-free benchmark that lies within a factor of two. The no-optical-counterpart constraint, the isolation of the clouds, and the absence of a stellar counterpart are also independent of the RELHIC model. Nevertheless, the paper's positive case contains two places where the evidence is partly circular by construction: the ~20 km/s velocity dispersion was a source-selection criterion and is then reported as model agreement, and the ~3.7×10^9 M⊙ halo masses are fitted to reproduce the observed HI masses and then counted as consistency. These two quantities carry much of the abstract's and Sec. 4's claim that the clouds are 'consistent with RELHIC predictions.' The paper does not overclaim—it explicitly labels the clouds as 'promising, but not definitive' and acknowledges that a tidal origin remains a serious alternative—so the circularity is partial rather than total, warranting a score of 6 rather than higher.

Axiom & Free-Parameter Ledger

3 free parameters · 6 axioms · 0 invented entities

The inference chain rests on the RELHIC model (external theory), the assumed distance and association with M51, and the assumption that unresolved FAST sources are single objects. The halo mass is a fitted parameter matched to the observed H I mass, not a prediction. No new entities are introduced.

free parameters (3)
  • Host halo mass M200 (per cloud) = ~3.7 ± 0.4 × 10^9 M⊙
    Chosen so the beam-convolved RELHIC model reproduces the observed M_HI ~ 10^6.5 M⊙; not predicted independently (Appendix A).
  • NFW concentration c = c = 12.8 median (Ludlow+16)
    Adopted fiducial; M200 estimate depends on assumed mass-concentration relation and scatter.
  • Assumed effective radius for optical luminosity limit = ~500 pc
    Taken from typical ELVES dwarfs; directly converts the g-band surface brightness limit into L_lim < 10^5 L⊙ (Section 3.2).
axioms (6)
  • standard math NFW halo profile and hydrostatic equilibrium equation (Eq. A.1) describe RELHIC gas.
    Used to infer halo mass from H I content; standard but unverified for these systems.
  • domain assumption Gas is in thermal and ionization equilibrium with the Haardt & Madau (2001) UV background, with ionization from Rahmati et al. (2013).
    Underpins the M_HI–M200 mapping in Appendix A.
  • domain assumption Cloud S and Cloud N are at the M51 distance (8 Mpc) and physically associated with M51.
    P-V diagrams show kinematic continuity, but a foreground/background coincidence would change all physical scales.
  • ad hoc to paper Each FAST detection is a single bound object, not unresolved tidal debris.
    Required for the RELHIC interpretation; explicitly unverifiable at FAST resolution (Section 3.1).
  • standard math Mass-concentration relation of Ludlow et al. (2016) applies to the candidate host halos.
    Used to fix c=12.8 and its scatter; if the relation fails at these masses, M200 shifts.
  • domain assumption TNG50 starless Hi subhalos are representative of real RELHICs for validating the mass estimator.
    Appendix B compares derived vs true M200 but only within simulation, not against observed halo masses.

pith-pipeline@v1.3.0-alltime-deepseek · 10482 in / 13083 out tokens · 133327 ms · 2026-08-01T08:38:15.399249+00:00 · methodology

0 comments
read the original abstract

We report the discovery of a pair of H I clouds near M51 (NGC 5194) using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These clouds have no optical counterparts and are potential candidates for Reionization-Limited H I Clouds (RELHICs). We search for compact H I sources in deep FEASTS observations using SoFiA and remove objects with optical counterparts through cross-matching with the DESI Legacy Imaging Surveys. The remaining candidates are modelled as hydrostatic H I structures embedded in Navarro-Frenk-White dark matter haloes and compared with RELHIC predictions and TNG50 simulations. We identify two H I clouds, Cloud S and Cloud N, at projected distances of 70--90 kpc from M51. Each cloud has an H I mass of approximately 10^6.5 solar masses, a velocity dispersion of about 20 km/s, and no detectable optical counterpart down to a g-band surface brightness limit of approximately 27.5 mag arcsec^-2. Their stellar luminosities are constrained to be below 10^5 solar luminosities. Their H I properties are consistent with RELHIC predictions, corresponding to host halo masses of 3.7 +- 0.4 * 10^9 solar masses. Cloud S and Cloud N are promising but not definitive RELHIC candidates. A tidal origin remains possible in the interacting M51 system, especially because the clouds are unresolved by FAST and Cloud N may show a velocity gradient. Future high-resolution interferometric observations will be crucial for distinguishing between starless dark matter haloes and tidal debris.

Figures

Figures reproduced from arXiv: 2607.21034 by Cheng cheng, Chen Xu, Jie Wang, Qingze Chen, Tiantian Liang, Wei Du, Yingjie Jing, Yiwei Xu, Zerui Liu, Zhipeng Hou.

Figure 1
Figure 1. Figure 1: H i distribution in the vicinity of M51 overlaid on a Pan￾STARRS1 DR1 optical image. The yellow circles indicate the locations of the two RELHIC candidates: Cloud N and Cloud S. The colour shows the H i column density (moment 0) map. The green circles indicate other H i components identified by SoFiA. The blue dot in the bottom-left cor￾ner represents the 3.24′ FAST beam (FWHM) at 1.42 GHz. A physical scal… view at source ↗
Figure 2
Figure 2. Figure 2: Radial H i column density profiles for the two RELHIC candi￾dates. Blue circles with error bars represent the observed profiles mea￾sured from the FAST data. The solid curves denote a series of theo￾retical RELHIC models calculated for the distance of M51 (8 Mpc) and convolved with the FAST Gaussian beam. The different curves correspond to varying halo masses, with the best-fit model suggesting M200 ≈ 3.7 … view at source ↗
Figure 3
Figure 3. Figure 3: Constraints on the stellar luminosity and structural properties of the RELHIC candidates. Blue dots represent the dwarf satellites from the ELVES survey (Carlsten et al. 2022) for comparison. The grey shaded region indicates the parameter space excluded by our 3σ surface brightness limit of µg ≈ 27.5 mag arcsec−2 . The green shaded area de￾fines the region occupied by ultra-diffuse galaxies (UDGs). The thr… view at source ↗

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Reference graph

Works this paper leans on

74 extracted references · 1 canonical work pages

  1. [1]

    ApJ , fjournal=

    Fournier, Paul , title=. ApJ , fjournal=

  2. [2]

    An important paper , journal=

  3. [3]

    The Journal of Open Source Software , keywords =

    MARTINI: Mock Array Radio Telescope Interferometry of the Neutral ISM. The Journal of Open Source Software , keywords =. doi:10.21105/joss.06860 , adsurl =

    doi:10.21105/joss.06860

  4. [4]

    , keywords =

    The mass-concentration-redshift relation of cold and warm dark matter haloes. , keywords =. doi:10.1093/mnras/stw1046 , archivePrefix =. 1601.02624 , primaryClass =

    Pith/arXiv arXiv

  5. [5]

    Another Unreal Paper , journal=

  6. [6]

    A Last Unreal Paper , journal=

  7. [7]

    , keywords =

    FEASTS: Radial Distribution of H I Surface Densities Down to 0.01 M _ pc ^ - 2 of 35 Nearby Galaxies. , keywords =. doi:10.3847/1538-4357/ada95a , archivePrefix =. 2501.01289 , primaryClass =

    Pith/arXiv arXiv

  8. [8]

    High-sensitivity H i image of diffuse gas and new tidal features in M51 observed by FAST , volume =

    Haiyang Yu and Ming Zhu and Jin Long Xu and Mei Ai and Peng Jiang and Yanbin Yang , issn =. High-sensitivity H i image of diffuse gas and new tidal features in M51 observed by FAST , volume =. Monthly Notices of the Royal Astronomical Society , keywords =

  9. [9]

    Nature Astronomy , keywords =

    Baryonic solutions and challenges for cosmological models of dwarf galaxies. Nature Astronomy , keywords =. doi:10.1038/s41550-022-01689-w , archivePrefix =. 2206.05295 , primaryClass =

    Pith/arXiv arXiv

  10. [10]

    Science China: Physics, Mechanics and Astronomy , title =

    Chuan Peng Zhang and Ming Zhu and Peng Jiang and Cheng Cheng and Jing Wang and Jie Wang and Jin Long Xu and Xiao Lan Liu and Nai Ping Yu and Lei Qian and Haiyang Yu and Mei Ai and Yingjie Jing and Chen Xu and Ziming Liu and Xin Guan and Chun Sun and Qingliang Yang and Menglin Huang and Qiaoli Hao , doi =. Science China: Physics, Mechanics and Astronomy , title =

  11. [11]

    H. A. Flewelling and E. A. Magnier and K. C. Chambers and J. N. Heasley and C. Holmberg and M. E. Huber and W. Sweeney and C. Z. Waters and A. Calamida and S. Casertano and X. Chen and D. Farrow and G. Hasinger and R. Henderson and K. S. Long and N. Metcalfe and G. Narayan and M. A. Nieto-Santisteban and P. Norberg and A. Rest and R. P. Saglia and A. Szal...

  12. [12]

    Carlsten and Jenny E

    Scott G. Carlsten and Jenny E. Greene and Rachael L. Beaton and Shany Danieli and Johnny P. Greco , title =. The Astrophysical Journal , abstract =. 2022 , month =. doi:10.3847/1538-4357/ac6fd7 , url =

    doi:10.3847/1538-4357/ac6fd7 2022

  13. [13]

    Navarro and Carlos S

    Alejandro Benítez-Llambay and Julio F. Navarro and Carlos S. Frenk and Till Sawala and Kyle Oman and Azadeh Fattahi and Matthieu Schaller and Joop Schaye and Robert A. Crain and Tom Theuns , doi =. The properties of 'dark' CDM haloes in the Local Group , volume =. Monthly Notices of the Royal Astronomical Society , keywords =

  14. [14]

    Pawlik and Milan Raicevic and Joop Schaye , doi =

    Alireza Rahmati and Andreas H. Pawlik and Milan Raicevic and Joop Schaye , doi =. On the evolution of the Hi column density distribution in cosmological simulations , volume =. Monthly Notices of the Royal Astronomical Society , month =

  15. [15]

    and Staveley-Smith, Lister and Courtois, Hélène , year=

    Serra, Paolo and Westmeier, Tobias and Giese, Nadine and Jurek, Russell and Flöer, Lars and Popping, Attila and Winkel, Benjamin and van der Hulst, Thijs and Meyer, Martin and Koribalski, Bärbel S. and Staveley-Smith, Lister and Courtois, Hélène , year=. SoFiA: a flexible source finder for 3D spectral line data , volume=. Monthly Notices of the Royal Astr...

    doi:10.1093/mnras/stv079

  16. [16]

    , keywords =

    New lessons from the H I size-mass relation of galaxies. , keywords =. doi:10.1093/mnras/stw1099 , archivePrefix =. 1605.01489 , primaryClass =

    Pith/arXiv arXiv

  17. [17]

    Schlegel and Dustin Lang and Robert Blum and Kaylan Burleigh and Xiaohui Fan and Joseph R

    Arjun Dey and David J. Schlegel and Dustin Lang and Robert Blum and Kaylan Burleigh and Xiaohui Fan and Joseph R. Findlay and Doug Finkbeiner and David Herrera and Stéphanie Juneau and Martin Landriau and Michael Levi and Ian McGreer and Aaron Meisner and Adam D. Myers and John Moustakas and Peter Nugent and Anna Patej and Edward F. Schlafly and Alistair ...

  18. [18]

    The detailed structure and the onset of galaxy formation in low-mass gaseous dark matter haloes , volume =

    Benitez-Llambay, Alejandro and Frenk, Carlos , urldate =. The detailed structure and the onset of galaxy formation in low-mass gaseous dark matter haloes , volume =. Monthly Notices of the Royal Astronomical Society , shortjournal =. doi:10.1093/mnras/staa2698 , abstract =

    doi:10.1093/mnras/staa2698

  19. [19]

    , keywords =

    Discovery of an Isolated Dark Dwarf Galaxy in the Nearby Universe. , keywords =. doi:10.3847/2041-8213/acb932 , archivePrefix =. 2302.02646 , primaryClass =

    Pith/arXiv arXiv 2041

  20. [20]

    , keywords =

    Is a Recently Discovered H I Cloud near M94 a Starless Dark Matter Halo?. , keywords =. doi:10.3847/1538-4357/acf767 , archivePrefix =. 2309.03253 , primaryClass =

    Pith/arXiv arXiv

  21. [21]

    , keywords =

    Universal structure of dark matter haloes over a mass range of 20 orders of magnitude. , keywords =. doi:10.1038/s41586-020-2642-9 , archivePrefix =. 1911.09720 , primaryClass =

    arXiv 1911

  22. [22]

    , keywords =

    The dark matter haloes of dwarf galaxies: a challenge for the cold dark matter paradigm?. , keywords =. doi:10.1111/j.1365-2966.2012.21623.x , archivePrefix =. 1111.6609 , primaryClass =

    arXiv 2012

  23. [23]

    , keywords =

    The Structure of Cold Dark Matter Halos. , keywords =. doi:10.1086/177173 , archivePrefix =. astro-ph/9508025 , primaryClass =

    Pith/arXiv arXiv

  24. [24]

    Nature , author =

    Formation of dwarf galaxies in tidal tails , volume =. Nature , author =. 1992 , langid =. doi:10.1038/360715a0 , abstract =

    doi:10.1038/360715a0 1992

  25. [25]

    and Schaller, Matthieu and Barber, Christopher , urldate =

    Ploeckinger, Sylvia and Sharma, Kuldeep and Schaye, Joop and Crain, Robert A. and Schaller, Matthieu and Barber, Christopher , urldate =. Tidal dwarf galaxies in cosmological simulations , volume =. Monthly Notices of the Royal Astronomical Society , shortjournal =. 2018 , file =. doi:10.1093/mnras/stx2787 , abstract =

    doi:10.1093/mnras/stx2787 2018

  26. [26]

    , year =

    Kormendy, John and Ho, Luis C. , year =. Coevolution (. Annual Review of Astronomy and Astrophysics , volume =. doi:10.1146/annurev-astro-082708-101811 , urldate =

    doi:10.1146/annurev-astro-082708-101811

  27. [27]

    , keywords =

    FAST Reveals New Evidence for M94 as a Merger. , keywords =. doi:10.3847/1538-4357/acdcf5 , archivePrefix =. 2306.05080 , primaryClass =

    arXiv

  28. [28]

    , title =

    Benítez-Llambay, Alejandro and Dutta, Rajeshwari and Fumagalli, Michele and Navarro, Julio F. , title =. The Astrophysical Journal , abstract =. 2024 , month =. doi:10.3847/1538-4357/ad65d9 , url =

    doi:10.3847/1538-4357/ad65d9 2024

  29. [29]

    , year =

    Fabian, A.C. , year =. Observational. Annual Review of Astronomy and Astrophysics , volume =. doi:10.1146/annurev-astro-081811-125521 , urldate =

    doi:10.1146/annurev-astro-081811-125521

  30. [30]

    Harrison, C. M. and Costa, T. and Tadhunter, C. N. and Fl. 2018 , month = mar, journal =. doi:10.1038/s41550-018-0403-6 , urldate =

    doi:10.1038/s41550-018-0403-6 2018

  31. [31]

    , keywords =

    Cold Gas in Massive Galaxies as a Critical Test of Black Hole Feedback Models. , keywords =. doi:10.3847/1538-4357/ac51d5 , archivePrefix =. 2202.01376 , primaryClass =

    Pith/arXiv arXiv

  32. [32]

    The Astrophysical Journal , volume=

    The effect of AGNs on the global H i content of isolated low-mass galaxies , author=. The Astrophysical Journal , volume=. 2018 , publisher=

    2018

  33. [33]

    The Astronomical Journal , volume=

    Atomic hydrogen properties of active galactic nuclei host galaxies: H i in 16 NUclei of GAlaxies (NUGA) sources , author=. The Astronomical Journal , volume=. 2007 , publisher=

    2007

  34. [34]

    The Astronomical Journal , volume=

    SPARC: Mass models for 175 disk galaxies with Spitzer photometry and accurate rotation curves , author=. The Astronomical Journal , volume=. 2016 , publisher=

    2016

  35. [35]

    H I content of the host galaxies of active galactic nuclei

    Arecibo Legacy Fast ALFA H I data stacking - II. H I content of the host galaxies of active galactic nuclei. , keywords =. doi:10.1111/j.1365-2966.2011.18825.x , archivePrefix =. 1104.0414 , primaryClass =

    arXiv 2011

  36. [36]

    The Astrophysical Journal , volume=

    Properties of active galaxies deduced from HI observations , author=. The Astrophysical Journal , volume=. 2008 , publisher=

    2008

  37. [37]

    The Astrophysical Journal , volume=

    xGASS: H i Fueling of Star Formation in Disk-dominated Galaxies , author=. The Astrophysical Journal , volume=. 2020 , publisher=

    2020

  38. [38]

    Monthly Notices of the Royal Astronomical Society , volume=

    New lessons from the H i size--mass relation of galaxies , author=. Monthly Notices of the Royal Astronomical Society , volume=. 2016 , publisher=

    2016

  39. [39]

    Monthly Notices of the Royal Astronomical Society , volume=

    An observational and theoretical view of the radial distribution of H i gas in galaxies , author=. Monthly Notices of the Royal Astronomical Society , volume=. 2014 , publisher=

    2014

  40. [40]

    Monthly Notices of the Royal Astronomical Society , volume=

    Atomic gas fractions in active galactic nucleus host galaxies , author=. Monthly Notices of the Royal Astronomical Society , volume=. 2019 , publisher=

    2019

  41. [41]

    The Astrophysical Journal Letters , volume=

    Cold Gas Reservoirs of Low-and High-mass Central Galaxies Differ in Response to Active Galactic Nucleus Feedback , author=. The Astrophysical Journal Letters , volume=. 2022 , publisher=

    2022

  42. [42]

    Monthly Notices of the Royal Astronomical Society , volume=

    Automated kinematic modelling of warped galaxy discs in large H i surveys: 3D tilted-ring fitting of H i emission cubes , author=. Monthly Notices of the Royal Astronomical Society , volume=. 2015 , publisher=

    2015

  43. [43]

    2003 , month = dec, journal =

    The Host Galaxies of Active Galactic Nuclei , author =. 2003 , month = dec, journal =. doi:10.1111/j.1365-2966.2003.07154.x , urldate =

    arXiv 2003

  44. [44]

    2006 , month = nov, journal =

    The Host Galaxies and Classification of Active Galactic Nuclei , author =. 2006 , month = nov, journal =. doi:10.1111/j.1365-2966.2006.10859.x , urldate =

    arXiv 2006

  45. [45]

    , keywords =

    Radio observations of the circumnuclear ring in NGC 6951. , keywords =. doi:10.1051/0004-6361:20011710 , archivePrefix =. astro-ph/0201079 , primaryClass =

    Pith/arXiv arXiv

  46. [46]

    , keywords =

    Dynamical Evolution of AGN Host Galaxies Gas In/Out-Flow Rates in Seven NUGA Galaxies. , keywords =. doi:10.1088/0004-637X/692/2/1623 , archivePrefix =. 0811.1988 , primaryClass =

    Pith/arXiv arXiv 1988

  47. [47]

    2014 , month = may, journal =

    Properties of Galaxies Reproduced by a Hydrodynamic Simulation , author =. 2014 , month = may, journal =. doi:10.1038/nature13316 , urldate =

    doi:10.1038/nature13316 2014

  48. [48]

    , keywords =

    Completely dark galaxies: their existence, properties and strategies for finding them. , keywords =. doi:10.1046/j.1365-8711.2001.04158.x , archivePrefix =. astro-ph/0010545 , primaryClass =

    arXiv 2001

  49. [49]

    , keywords =

    Dark galaxies, spin bias and gravitational lenses. , keywords =. doi:10.1093/mnras/292.1.L5 , archivePrefix =. astro-ph/9709050 , primaryClass =

    Pith/arXiv arXiv

  50. [50]

    First results from the TNG50 simulation: galactic outflows driven by supernovae and black hole feedback , volume=

    Nelson, Dylan and Pillepich, Annalisa and Springel, Volker and Pakmor, Rüdiger and Weinberger, Rainer and Genel, Shy and Torrey, Paul and Vogelsberger, Mark and Marinacci, Federico and Hernquist, Lars , year=. First results from the TNG50 simulation: galactic outflows driven by supernovae and black hole feedback , volume=. Monthly Notices of the Royal Ast...

    doi:10.1093/mnras/stz2306

  51. [51]

    First results from the TNG50 simulation: the evolution of stellar and gaseous discs across cosmic time , volume=

    Pillepich, Annalisa and Nelson, Dylan and Springel, Volker and Pakmor, Rüdiger and Torrey, Paul and Weinberger, Rainer and Vogelsberger, Mark and Marinacci, Federico and Genel, Shy and van der Wel, Arjen and Hernquist, Lars , year=. First results from the TNG50 simulation: the evolution of stellar and gaseous discs across cosmic time , volume=. Monthly No...

    doi:10.1093/mnras/stz2338

  52. [52]

    , keywords =

    Tiny galaxies and dark substructures: exploring the 'dark' subhaloes in TNG50. , keywords =. doi:10.1093/mnras/stag385 , archivePrefix =. 2506.09122 , primaryClass =

    arXiv

  53. [53]

    Clusters of Galaxies and the High Redshift Universe Observed in X-rays , year = 2001, editor =

    Modelling the UV/X-ray cosmic background with CUBA. Clusters of Galaxies and the High Redshift Universe Observed in X-rays , year = 2001, editor =. doi:10.48550/arXiv.astro-ph/0106018 , archivePrefix =. astro-ph/0106018 , primaryClass =

    Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/0106018 2001

  54. [54]

    DISTANCE DETERMINATION TO EIGHT GALAXIES USING EXPANDING PHOTOSPHERE METHOD , volume=

    Bose, Subhash and Kumar, Brijesh , year=. DISTANCE DETERMINATION TO EIGHT GALAXIES USING EXPANDING PHOTOSPHERE METHOD , volume=. The Astrophysical Journal , publisher=. doi:10.1088/0004-637x/782/2/98 , number=

    doi:10.1088/0004-637x/782/2/98

  55. [55]

    and Bower, Richard G

    Schaye, Joop and Crain, Robert A. and Bower, Richard G. and Furlong, Michelle and Schaller, Matthieu and Theuns, Tom and Dalla Vecchia, Claudio and Frenk, Carlos S. and McCarthy, I. G. and Helly, John C. and Jenkins, Adrian and. The. 2015 , month = jan, journal =. doi:10.1093/mnras/stu2058 , urldate =

    doi:10.1093/mnras/stu2058 2015

  56. [56]

    Dav. Simba:. 2019 , month = jun, journal =. doi:10.1093/mnras/stz937 , urldate =

    doi:10.1093/mnras/stz937 2019

  57. [57]

    2022 , month = mar, journal =

    Ionised Gas Kinematics in. 2022 , month = mar, journal =. doi:10.1051/0004-6361/202140613 , urldate =

    doi:10.1051/0004-6361/202140613 2022

  58. [58]

    , keywords =

    Outflows in Sodium Excess Objects. , keywords =. doi:10.1088/0004-637X/809/1/91 , archivePrefix =. 1507.03342 , primaryClass =

    Pith/arXiv arXiv

  59. [59]

    , keywords =

    The Pan-STARRS1 Database and Data Products. , keywords =. doi:10.3847/1538-4365/abb82d , archivePrefix =. 1612.05243 , primaryClass =

    Pith/arXiv arXiv

  60. [60]

    Keim, Michael A. and Dokkum, Pieter van and Danieli, Shany and Lokhorst, Deborah and Li , Jiaxuan and Shen, Zili and Abraham, Roberto and Chen, Seery and Gilhuly, Colleen and Liu , Qing and Merritt, Allison and Miller, Tim B. and Pasha, Imad and Polzin, Ava , year=. Tidal Distortions in NGC1052-DF2 and NGC1052-DF4: Independent Evidence for a Lack of Dark ...

    doi:10.3847/1538-4357/ac7dab

  61. [61]

    , keywords =

    FEASTS: IGM Cooling Triggered by Tidal Interactions through the Diffuse H I Phase around NGC 4631. , keywords =. doi:10.3847/1538-4357/acafe8 , archivePrefix =. 2301.00937 , primaryClass =

    Pith/arXiv arXiv

  62. [62]

    , keywords =

    Almost Optically Dark Galaxies in DECaLS (I): Detection, Optical Properties, and Possible Origins. , keywords =. doi:10.3847/1538-4357/ad234f , archivePrefix =. 2403.12130 , primaryClass =

    Pith/arXiv arXiv

  63. [63]

    HIDES. I. The Population and Diversity of H I-rich Faint Dwarf Galaxies in the HESTIA and Auriga Simulations. , keywords =. doi:10.3847/1538-4357/ae6b84 , archivePrefix =. 2511.16726 , primaryClass =

    arXiv

  64. [64]

    , keywords =

    Understanding the Formation and Evolution of Dark Galaxies in a Simulated Universe. , keywords =. doi:10.3847/1538-4357/ad1e5d , archivePrefix =. 2401.07007 , primaryClass =

    Pith/arXiv arXiv

  65. [65]

    , keywords =

    Searching for Dark Galaxies with H I Detection from the Arecibo Legacy Fast ALFA (ALFALFA) Survey. , keywords =. doi:10.3847/1538-4365/ade0b8 , archivePrefix =. 2506.03678 , primaryClass =

    Pith/arXiv arXiv

  66. [66]

    , keywords =

    FASHI: A Search for Extragalactic OH Megamasers with FAST. , keywords =. doi:10.3847/1538-4357/ad59a5 , archivePrefix =. 2401.15397 , primaryClass =

    Pith/arXiv arXiv

  67. [67]

    Monthly Notices of the Royal Astronomical Society , volume =

    Monaci, Marco and Forbes, Duncan A and Gannon, Jonah S and Koribalski, Bärbel S and Bekki, Kenji and Brodie, Jean P and Couch, Warrick J , title =. Monthly Notices of the Royal Astronomical Society , volume =. 2026 , month =. doi:10.1093/mnras/stag732 , url =

    work page doi:10.1093/mnras/stag732 2026

  68. [68]

    On the Nature of Sodium Excess Objects. I. Data and Observed Trends. , keywords =. doi:10.1088/0067-0049/208/1/7 , archivePrefix =. 1307.1472 , primaryClass =

    Pith/arXiv arXiv

  69. [69]

    Science Advances , keywords =

    Discovery of a high-velocity cloud of the Milky Way as a potential dark galaxy. Science Advances , keywords =. doi:10.1126/sciadv.ads4057 , archivePrefix =. 2504.09419 , primaryClass =

    Pith/arXiv arXiv

  70. [70]

    , keywords =

    Discovery of a galaxy associated with the HI cloud FAST J0139+4328. , keywords =. doi:10.1051/0004-6361/202558391 , archivePrefix =. 2512.24924 , primaryClass =

    arXiv

  71. [71]

    , keywords =

    Not so-dark: High resolution H I imaging of J0139+4328 and identification of an optical counterpart. , keywords =. doi:10.1051/0004-6361/202556900 , archivePrefix =. 2601.12513 , primaryClass =

    arXiv

  72. [72]

    , keywords =

    Simulations of the grand design galaxy M51: a case study for analysing tidally induced spiral structure. , keywords =. doi:10.1111/j.1365-2966.2009.16161.x , archivePrefix =. 0912.1201 , primaryClass =

    arXiv 2009

  73. [73]

    , keywords =

    High-sensitivity H I image of diffuse gas and new tidal features in M51 observed by FAST. , keywords =. doi:10.1093/mnras/stad436 , archivePrefix =. 2302.03270 , primaryClass =

    Pith/arXiv arXiv

  74. [74]

    , keywords =

    The First RELHIC? Cloud-9 is a Starless Gas Cloud. , keywords =. doi:10.3847/2041-8213/ae1584 , archivePrefix =. 2508.20157 , primaryClass =

    arXiv 2041