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The Square Kilometre Array will push extragalactic masers, recombination lines, molecular gas, and light-isotope lines into new environments and redshifts, including a possible first detection of HeH+.

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2026-07-12 03:37 UTC pith:YBMSAABN

load-bearing objection Solid SKAO Science Book overview that cleanly ranks AA*/AA4/Band-6 returns for non-HI extragalactic lines; synthesis, not new results. the 2 major comments →

arxiv 2607.03271 v1 pith:YBMSAABN submitted 2026-07-03 astro-ph.GA astro-ph.COastro-ph.IMastro-ph.SR

Advancing extragalactic spectral line studies with the Square Kilometre Array Observatory

Jacco Th. van Loon , Viviana Casasola , Manuela Bischetti , Sandra Etoka , Hans-Rainer Kl\"ockner , Mamta Pandey-Pommier , Mark Sargent , Nick Seymour
show 1 more author
Andrea Tarchi
This is my paper
classification astro-ph.GA astro-ph.COastro-ph.IMastro-ph.SR
keywords Square Kilometre Arrayextragalactic spectral linesmasersmegamasersradio recombination linesmolecular absorptionHeH+deuterium hyperfine
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 overview argues that the Square Kilometre Array Observatory can transform studies of extragalactic spectral lines other than the classic 21-cm hydrogen line. With high sensitivity, arcsecond resolution, and useful fields of view, SKA-Mid and SKA-Low will let astronomers detect and map masers and megamasers, radio recombination lines, molecular emission and absorption, and hyperfine lines of deuterium and helium-3 from nearby galaxies out to high redshift. The planned mid-2030s array (AA*) is expected to deliver major first detections and samples, while the full AA4 design and a possible extension up to about 24 GHz would unlock water-maser and ammonia surveys nearby and systematic cold-gas inventories near redshift 5. A reader should care because these lines jointly trace star formation, black-hole environments, gas inflows and outflows, magnetic fields, Big Bang nucleosynthesis, and the first molecule, HeH+. The paper's claim is that multi-phase gas physics across cosmic time becomes newly accessible at scale once those capabilities exist.

Core claim

The paper claims that SKAO will push masers, kilomasers, megamasers, molecular and radio-recombination-line emission and absorption, and light-isotope hyperfine transitions into a far wider range of galactic environments and redshifts—including possible detection of the first cosmic molecule HeH+—and that while the baseline AA* array will forge major progress, only AA4 plus a high-frequency extension to ~24 GHz will fully transform the landscape.

What carries the argument

The mapping of SKA-Mid and SKA-Low sensitivity, angular resolution, and frequency coverage (AA* versus AA4, bands 2 and 5, and a proposed band 6 to ~24 GHz) onto concrete spectral-line cases. Indicative noise and beam sizes from the sensitivity calculator, RRL stacking, and VLBI follow-up of megamasers carry the quantitative forecasts.

Load-bearing premise

The predicted detections rest on calculator-based sensitivities and pathfinder yields that assume real observations will not be badly limited by calibration, radio-frequency interference, or source confusion.

What would settle it

If deep AA* or AA4 surveys of the LMC/SMC and of lensed high-redshift continuum sources fail to recover the claimed populations of OH/methanol masers, carbon RRLs, or molecular absorption lines at the forecast rates after known systematics are accounted for, the transformative-yield claims would be falsified.

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

If this is right

  • AA* will enable first statistically useful samples of extragalactic OH and methanol masers in metal-poor Local Group galaxies and push OH megamasers toward z~1.
  • AA4 will provide the sensitivity and resolution for kinematic maps of cold molecular gas, black-hole mass work with water megamasers, and large absorption surveys of inflows and outflows.
  • A band-6 extension would open water-maser and ammonia surveys in nearby galaxies and low-J CO/HCO+/methanol inventories near the peak of galaxy assembly.
  • Carbon RRLs and Di/3He+ hyperfine lines become practical probes of cold gas, star-forming conditions, and primordial light-element abundances.
  • HeH+ may become detectable from the recombination era into reionization if suitable cosmological search strategies are designed.

Where Pith is reading between the lines

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

  • Commensal redshifted OH and RRL detections inside large HI surveys could become a major discovery channel without dedicated spectral-line time.
  • Skipping a band-6 extension would leave a lasting redshift gap between ALMA's millimetre window and SKA-Mid for bulk cold molecular gas at z~3–6.
  • Secure Di detections in the LMC and SMC would recalibrate spin temperatures and molecular fractions used in high-redshift intensity mapping.
  • Synergy with infrared and large optical telescopes, not radio sensitivity alone, will likely set the pace for interpreting the new spectral-line samples.

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

2 major / 6 minor

Summary. This chapter overviews SKAO science potential for extragalactic spectral lines other than 21-cm HI, synthesizing AASKAII topic chapters and adding prospects for RRLs, OH/H2O megamasers and kilomasers, circumstellar masers in nearby galaxies, molecular emission and absorption, non-21-cm hyperfine lines of D and 3He+, and high-z HeH+. Using pathfinder detections and the public SKA-Mid sensitivity calculator (Table 1), it ranks expected return for the planned AA* array, the fuller AA4 configuration, and a possible Band-6 extension to ~24 GHz, arguing that AA* will enable major progress while AA4 and Band 6 would be transformative for water masers, ammonia, and molecular inventories near z~5.

Significance. As a planning overview for the SKAO Science Book, the paper is significant if its capability ranking is accepted: it consolidates a multi-tracer case (masers, RRLs, molecular lines, light-isotope hyperfine transitions) that is otherwise scattered across working groups, and it makes a concrete, falsifiable facility argument for AA4 and Band 6. Strengths include transparent use of the public sensitivity calculator (Table 1), clear AA*/AA4/Band-6 hierarchy, and inclusion of under-discussed topics (D, 3He+, HeH+) not covered elsewhere in the volume. The work is prospective rather than a new data or simulation result, but that is appropriate for this genre and useful for observatory prioritization.

major comments (2)
  1. §3.7 and the abstract: the abstract states that SKAO “may detect the first molecule (HeH+)” at very high redshift, but §3.7 only notes that the 149.14 μm line enters SKA-Mid for z>130 (and ~1.8 GHz near recombination) and “encourages” cosmologists to consider detection strategies, without even an order-of-magnitude brightness, optical-depth, or stacking estimate. Either add a minimal detectability argument (or a clear statement that none yet exists) or soften the abstract so the claim matches the body.
  2. §3.2 (megamasers) and §2.2/Table 1: the central ranking of AA* vs AA4 rests partly on “quantitative analysis of the expected number of new extragalactic water masers” deferred to Tarchi et al. (2026) and on calculator rms values that omit RFI, calibration, and confusion. For a standalone overview chapter, please summarize the key yield numbers (or scaling with AA*→AA4) in the text and state explicitly that Table 1 figures are thermal-noise only, so that the AA4 “transformational” claim can be assessed without the companion chapter.
minor comments (6)
  1. Table 1 footnotes: superscripts 4–7 on frequencies and the “7.5 hr” entry are easy to misread; renumber footnotes sequentially and clarify which rows are “geared for” the low-luminosity OH stellar population.
  2. §1 footnote on LMC/SMC naming: the political note is understandable but abrupt in a technical preamble; consider a shorter wording or a single sentence in acknowledgments so the science scope remains the focus.
  3. Figure 1: axis labels “log(M_birth)” and “log(Z)” lack units/definition of the birth-mass scale; a one-line caption clarification would help non-specialists.
  4. §3.5: “OH is haled as a potential tracer” → “hailed”; also check spacing in “Hisurveys”, “Hifalls”, “Hiabsorbers” throughout (missing space after HI).
  5. §3.6: deuterium hyperfine frequency is given as 327.384 MHz and 3He+ as 8.666 GHz; a brief note on rest-frame vs redshifted band placement for the LMC/SMC Di case would aid readers planning SKA-Low vs Mid.
  6. References: several AASKAII chapters are cited as “2026” arXiv-search report numbers; ensure final volume citation keys are consistent before publication.

Circularity Check

0 steps flagged

No significant circularity; prospective science-case overview with no derivation chain that reduces to its own inputs.

full rationale

This is an overview chapter for the SKAO Science Book summarizing expected capabilities (AA*, AA4, possible Band 6) for extragalactic spectral lines other than 21-cm HI. It contains no first-principles derivation, no fitted parameters re-labeled as predictions, no uniqueness theorems, and no ansatz smuggled via citation. Indicative sensitivities in Table 1 are taken directly from the public external SKAO Mid sensitivity calculator; science prospects rest on independent pathfinder detections (MeerKAT, ASKAP, ALMA, etc.) and standard atomic/molecular physics. Cross-references to other AASKAII chapters (Emig et al. 2026, Tarchi et al. 2026, etc.) are ordinary volume-internal pointers, not load-bearing self-citations that force the ranking of AA*/AA4/Band-6 return. There is therefore no circular step to quote.

Axiom & Free-Parameter Ledger

0 free parameters · 3 axioms · 0 invented entities

The paper is a science-case review; its load-bearing content rests on standard atomic/molecular physics, published pathfinder detections, and the official SKAO array configurations and sensitivity calculator. No free parameters are fitted, no new physical entities are postulated, and the axioms are ordinary domain assumptions of radio astronomy.

axioms (3)
  • domain assumption SKAO AA* and AA4 dish counts, diameters and frequency bands will deliver the continuum and spectral-line sensitivities given by the public Mid sensitivity calculator.
    Invoked throughout §2 and Table 1; all quantitative claims scale with these numbers.
  • domain assumption Known rest frequencies and excitation conditions of OH, H2O, CH3OH, RRLs, Di, 3He+ and HeH+ remain valid at the redshifts and metallicities discussed.
    Standard atomic/molecular physics used in every science subsection (§3.1–3.7).
  • domain assumption Pathfinder detections (LMC OH masers, MeerKAT OH megamasers, carbon RRLs in M82/Cas A/Cyg A, etc.) correctly indicate the luminosity functions and environments that SKAO will sample more deeply.
    Cited throughout §3 as the empirical basis for yield estimates.

pith-pipeline@v1.1.0-grok45 · 20930 in / 2459 out tokens · 23130 ms · 2026-07-12T03:37:35.442852+00:00 · methodology

0 comments
read the original abstract

We present an overview of the Square Kilometre Array Observatory (SKAO) science potential in the area of extragalactic spectral lines besides 21-cm neutral hydrogen. It highlights the main points from the SKAO Science Book chapters on individual topics, but is augmented by additional prospects. The SKAO will push studies and use of masers, kilomasers, megamasers, molecular and radio-recombination-line emission and absorption to a wider variety of environments, including to very high redshift where it may detect the first molecule (HeH$^+$). It will open the door to measurements of hydrogen and helium isotopes, probing the conditions for star formation and Big Bang nucleosynthesis. While the planned SKAO of the 2030s (AA*) is destined to forge major progress, an SKAO as initially envisaged (AA4) will truly transform the landscape, and an extension towards higher frequencies (up to 24 GHz) would enable water maser and ammonia surveys in nearby galaxies and systematic molecular gas inventories at redshift 5.

Figures

Figures reproduced from arXiv: 2607.03271 by Andrea Tarchi, Hans-Rainer Kl\"ockner, Jacco Th. van Loon, Mamta Pandey-Pommier, Manuela Bischetti, Mark Sargent, Nick Seymour, Sandra Etoka, Viviana Casasola.

Figure 1
Figure 1. Figure 1: Schematic overview of the birth masses and metallicities represented in the main stellar populations of the nearby galaxies LMC, SMC and NGC 6822 compared to those in the Galactic Centre (GC) and the rest of the Milky Way. Figure courtesy J. van Loon. Luminous, cool evolved stars are frequent hosts of OH masers (at 1612, 1665 and 1667 MHz in SKA-Mid band 2) that trace their slow, dense winds and directly m… view at source ↗
Figure 2
Figure 2. Figure 2: Schematic diagram showing different regions and spatial scales over which AGN feedback operates. Multi-phase gas dynamics including molecular, atomic and ionised phases leads to formation of complex molecules. Adapted from Pandey-Pommier et al. (2026). transitions that more reliably trace the bulk of cold CO move into the SKA-Mid regime. CO emission has been detected out to 𝑧 ∼ 6 with ALMA and the Northern… view at source ↗

discussion (0)

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Works this paper leans on

68 extracted references · 35 canonical work pages · 3 internal anchors

  1. [1]

    doi: 10.1038/179370a0. E. Araya, W. A. Baan, and P. Hofner.ApJSS, 154(2):541–552, Oct

    work page doi:10.1038/179370a0

  2. [2]

    The hyperfine transition of 3He+ as a probe of the intergalactic medium

    doi: 10.1086/423246. W.A.Baan,J.N.H.S.Aditya,T.An,andH.-R.Klöckner.MNRAS,523(4):5487–5501,Aug.2023. doi: 10.1093/mnras/stad1770. J. S. Bagla and A. Loeb.arXiv e-prints, art. arXiv:0905.1698, May

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1086/423246 2023

  3. [3]

    0905.1698

    doi: 10.48550/arXiv. 0905.1698. T.M.Bania, R.T.Rood, andD.S.Balser. InC.Charbonnel, M.Tosi, F.Primas, andC.Chiappini, editors,LightElementsintheUniverse,volume268ofIAUSymposium,pages81–90,Apr.2010. doi: 10.1017/S174392131000390X. T. Bourke et al. Advancing astrophysics with the square kilometre array (aaska14),

    Pith/arXiv arXiv doi:10.48550/arxiv 2010

  4. [4]

    doi: 10.48550/arXiv.1912.12699

    R.Braunetal.arXive-prints,art.arXiv:1912.12699,Dec.2019. doi: 10.48550/arXiv.1912.12699. S. L. Breen et al.MNRAS, 432(2):1382–1395, June

    Pith/arXiv arXiv doi:10.48550/arxiv.1912.12699 1912

  5. [5]

    C.Brogan,K.Johnson,andJ.Darling.ApJL,716(1):L51–L56,June2010.doi: 10.1088/2041-8205/ 716/1/L51

    doi: 10.1093/mnras/stt558. C.Brogan,K.Johnson,andJ.Darling.ApJL,716(1):L51–L56,June2010.doi: 10.1088/2041-8205/ 716/1/L51. C. L. Brogan, W. M. Goss, J. S. Lazendic, and A. J. Green.AJ, 128(2):700–708, Aug

    work page doi:10.1093/mnras/stt558 2041

  6. [6]

    doi: 10.1086/422351. A. Brunthaler et al.A&A, 457(1):109–114, Oct

    work page doi:10.1086/422351

  7. [7]

    doi: 10.1051/0004-6361:20065650. S. Burles and D. Tytler.ApJ, 507(2):732–744, Nov

    work page doi:10.1051/0004-6361:20065650

  8. [8]

    D.A.Cesarsky,A.T.Moffet,andJ.M.Pasachoff.ApJL,180:L1,Feb.1973

    doi: 10.1086/306341. D.A.Cesarsky,A.T.Moffet,andJ.M.Pasachoff.ApJL,180:L1,Feb.1973. doi: 10.1086/181140. C. Cicone et al.A&A, 562:A21, Feb

    doi:10.1086/306341 1973

  9. [9]

    A.Coc,J.-P.Uzan,andE.Vangioni.JCAP,2014(10):050–050,Oct.2014.doi: 10.1088/1475-7516/ 2014/10/050

    doi: 10.1051/0004-6361/201322464. A.Coc,J.-P.Uzan,andE.Vangioni.JCAP,2014(10):050–050,Oct.2014.doi: 10.1088/1475-7516/ 2014/10/050. F. Combes and N. Gupta.A&A, 683:A20, Mar

    doi:10.1051/0004-6361/201322464 2014

  10. [10]

    doi: 10.1051/0004-6361/202348386. F. Combes et al.A&A, 648:A116, Apr

    doi:10.1051/0004-6361/202348386

  11. [11]

    doi: 10.1051/0004-6361/202040167. L. Cros et al.A&A, 701:A148, Sept

    doi:10.1051/0004-6361/202040167

  12. [12]

    doi: 10.1051/0004-6361/202555085. E. da Cunha et al.ApJ, 766(1):13, Mar

    doi:10.1051/0004-6361/202555085

  13. [13]

    doi: 10.1088/0004-637X/766/1/13. J. Darling.ApJL, 732(1):L2, May

    doi:10.1088/0004-637x/766/1/13

  14. [14]

    S.P.Ellingsenetal.MNRAS,404(2):779–791,May2010

    doi: 10.1088/2041-8205/732/1/L2. S.P.Ellingsenetal.MNRAS,404(2):779–791,May2010. doi: 10.1111/j.1365-2966.2010.16349.x. K. L. Emig et al.A&A, 622:A7, Feb

    work page doi:10.1088/2041-8205/732/1/l2 2041

  15. [15]

    doi: 10.1051/0004-6361/201834052. K. L. Emig et al.ApJ, 944(1):93, Feb

    doi:10.1051/0004-6361/201834052

  16. [16]

    doi: 10.3847/1538-4357/acb49d. K. L. Emig et al. InAdvancing Astrophysics with the SKA – II (AASKAII)

    doi:10.3847/1538-4357/acb49d

  17. [17]

    doi: 10.22323/1.215.0125. X. Fernández et al.ApJL, 824(1):L1, June

    doi:10.22323/1.215.0125

  18. [18]

    doi: 10.3847/2041-8205/824/1/L1. S. R. Furlanetto and S. P. Oh.ApJ, 681(1):1–17, July

    doi:10.3847/2041-8205/824/1/l1 2041

  19. [19]

    doi: 10.1086/588546. D. Galli and F. Palla.ARA&A, 51(1):163–206, Aug

    work page doi:10.1086/588546

  20. [20]

    14 Extragalactic Spectral Line van Loon et al

    doi: 10.3847/2041-8213/ac63b0. 14 Extragalactic Spectral Line van Loon et al. S. R. Goldman et al.MNRAS, 465(1):403–433, Feb

    doi:10.3847/2041-8213/ac63b0 2041

  21. [21]

    doi: 10.1093/mnras/stw2708. S. R. Goldman et al.MNRAS, 473(3):3835–3853, Jan

    doi:10.1093/mnras/stw2708

  22. [22]

    doi: 10.1093/mnras/stx2601. P. F. Goldsmith, J. D. Pandian, and A. A. Deshpande.ApJ, 680(2):1132–1136, June

    doi:10.1093/mnras/stx2601

  23. [23]

    doi: 10.1086/524651. E. González-Alfonso et al.A&A, 561:A27, Jan

    work page doi:10.1086/524651

  24. [24]

    doi: 10.1051/0004-6361/201321709. E. González-Alfonso et al.ApJ, 836(1):11, Feb

    work page doi:10.1051/0004-6361/201321709

  25. [25]

    doi: 10.3847/1538-4357/836/1/11. J. A. Green et al.MNRAS, 385(2):948–956, Apr

    doi:10.3847/1538-4357/836/1/11

  26. [26]

    doi: 10.1111/j.1365-2966.2008.12888.x. R. Güsten et al.Nature, 568(7752):357–359, Apr

    doi:10.1111/j.1365-2966.2008.12888.x 2008

  27. [27]

    doi: 10.1038/s41586-019-1090-x. G. Hébrard et al.A&A, 364:L31–L35, Dec

    work page doi:10.1038/s41586-019-1090-x

  28. [28]

    doi: 10.48550/arXiv.astro-ph/0008420. H. Imai, Y. Katayama, S. P. Ellingsen, and Y. Hagiwara.MNRAS, 432:L16–L20, May

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.astro-ph/0008420

  29. [29]

    doi: 10.1093/mnrasl/slt027. M. Imanishi et al.arXiv e-prints, art. arXiv:2605.06842, May

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnrasl/slt027

  30. [30]

    doi: 10.1093/mnras/stad3821. N. Kanekar, J. N. Chengalur, and W. M. Lane.MNRAS, 375(4):1528–1536, Mar

    doi:10.1093/mnras/stad3821

  31. [31]

    doi: 10.1111/j.1365-2966.2007.11430.x. S. G. Karshenboim and V. G. Ivanov.European Physical Journal D, 19(1):13–23, Apr

    doi:10.1111/j.1365-2966.2007.11430.x 2007

  32. [32]

    doi: 10.1140/epjd/e20020050. H.-R. Klöckner, W. A. Baan, and M. A. Garrett.Nature, 421(6925):821–823, Feb

    work page doi:10.1140/epjd/e20020050

  33. [33]

    J.P.KnellerandG.Steigman.NewJournalofPhysics,6(1):117,sep2004.doi: 10.1088/1367-2630/ 6/1/117

    doi: 10.1038/nature01381. J.P.KnellerandG.Steigman.NewJournalofPhysics,6(1):117,sep2004.doi: 10.1088/1367-2630/ 6/1/117. URLhttps://doi.org/10.1088/1367-2630/6/1/117. B. S. Koribalski et al.AJ, 128(1):16–46, July

    work page doi:10.1038/nature01381

  34. [34]

    doi: 10.1086/421744. M.-Y. Lee et al.AJ, 138(4):1101–1115, Oct

    doi:10.1086/421744

  35. [35]

    doi: 10.1088/0004-6256/138/4/1101. J. L. Linsky et al.ApJ, 647(2):1106–1124, Aug

    work page doi:10.1088/0004-6256/138/4/1101

  36. [36]

    doi: 10.1086/505556. C. J. Lonsdale, C. J. Lonsdale, H. E. Smith, and P. J. Diamond.ApJ, 592(2):804–818, Aug

    doi:10.1086/505556

  37. [37]

    F.M.Maccagnietal

    doi: 10.1086/375778. F.M.Maccagnietal. InAdvancingAstrophysicswiththeSKA–II(AASKAII).2026. arXivsearch: Report number AASKAII/Maccagni01. E. K. Mahony et al. InAdvancing Astrophysics with the SKA – II (AASKAII)

    doi:10.1086/375778 2026

  38. [38]

    T.E.Manamelaetal.arXive-prints,art.arXiv:2602.13396,Feb.2026

    arXiv search: Report number AASKAII/Mahony01. T.E.Manamelaetal.arXive-prints,art.arXiv:2602.13396,Feb.2026. doi: 10.48550/arXiv.2602. 13396. M. A. Marshall et al.MNRAS, 466(2):2450–2457, Apr

    doi:10.48550/arxiv.2602 2026

  39. [39]

    V.Migenesetal.MNRAS,416(2):1267–1273,Sept.2011.doi: 10.1111/j.1365-2966.2011.19124.x

    doi: 10.1093/mnras/stw3295. V.Migenesetal.MNRAS,416(2):1267–1273,Sept.2011.doi: 10.1111/j.1365-2966.2011.19124.x. L. K. Morabito et al.ApJL, 795(2):L33, Nov

    work page doi:10.1093/mnras/stw3295 2011

  40. [40]

    doi: 10.1088/2041-8205/795/2/L33. J. E. Nafe and E. B. Nelson.Phys. Rev., 73:718–728, Apr

    work page doi:10.1088/2041-8205/795/2/l33 2041

  41. [41]

    URLhttps://link.aps.org/doi/10.1103/PhysRev.73.718

    doi: 10.1103/PhysRev.73.718. URLhttps://link.aps.org/doi/10.1103/PhysRev.73.718. P. Ogle et al.ApJ, 724(2):1193–1217, Dec

    work page doi:10.1103/physrev.73.718

  42. [42]

    doi: 10.1088/0004-637X/724/2/1193. K. A. Olive et al.ApJ, 444:680, May

    doi:10.1088/0004-637x/724/2/1193

  43. [43]

    doi: 10.1086/175640. J. M. Oliveira, J. T. van Loon, S. Stanimirović, and A. A. Zijlstra.MNRAS, 372(4):1509–1524, Nov

    work page doi:10.1086/175640

  44. [44]

    J.M.Oliveiraetal.MNRAS,411(1):L36–L40,Feb.2011

    doi: 10.1111/j.1365-2966.2006.11007.x. J.M.Oliveiraetal.MNRAS,411(1):L36–L40,Feb.2011. doi: 10.1111/j.1745-3933.2010.00990.x. J. M. Oliveira et al.MNRAS, 490(3):3909–3935, Dec

    doi:10.1111/j.1365-2966.2006.11007.x 2006

  45. [45]

    15 Extragalactic Spectral Line van Loon et al

    doi: 10.1093/mnras/stz2810. 15 Extragalactic Spectral Line van Loon et al. J.Ott,C.Henkel, L.Staveley-Smith, andA.Weiß.ApJ,710(1):105–111, Feb.2010. doi: 10.1088/ 0004-637X/710/1/105. M. Pandey-Pommier et al. InAdvancing Astrophysics with the SKA – II (AASKAII)

    work page doi:10.1093/mnras/stz2810 2010

  46. [46]

    doi: 10.1051/0004-6361/201833910. J. Radcliffe et al. InAdvancing Astrophysics with the SKA – II (AASKAII)

    doi:10.1051/0004-6361/201833910

  47. [47]

    doi: 10.3847/1538-4357/ab72f0. H. Roberts and J. Darling. In T. Hirota, H. Imai, K. Menten, and Y. Pihlström, editors,Cos- mic Masers: Proper Motion Toward the Next-Generation Large Projects, volume 380 ofIAU Symposium, pages 16–20, Jan

    work page doi:10.3847/1538-4357/ab72f0

  48. [48]

    doi: 10.1017/S1743921323002314. T. Robishaw et al. InAdvancing Astrophysics with the SKA – II (AASKAII)

    work page doi:10.1017/s1743921323002314

  49. [49]

    R.T.Rood,T.L.Wilson,andG.Steigman.ApJL,227:L97–L101,Jan.1979

    doi: 10.1086/511978. R.T.Rood,T.L.Wilson,andG.Steigman.ApJL,227:L97–L101,Jan.1979. doi: 10.1086/182875. K. L. J. Rygl et al. InAdvancing Astrophysics with the SKA – II (AASKAII)

    work page doi:10.1086/511978 1979

  50. [50]

    doi: 10.1093/mnras/stx239. P. Salas et al.MNRAS, 475(2):2496–2511, Apr

    doi:10.1093/mnras/stx239

  51. [51]

    doi: 10.1093/mnras/stx3340. N. Seymour et al.PASA, 41:e114, Dec

    doi:10.1093/mnras/stx3340

  52. [52]

    Shklovsky, I

    doi: 10.1017/pasa.2024.101. Shklovsky, I. S.A.J. U.S.S.R., 29,

    work page doi:10.1017/pasa.2024.101 2024

  53. [53]

    doi: 10.1088/2041-8205/724/2/ L158. B. Spina et al.A&A, 707:A173, Mar

    work page doi:10.1088/2041-8205/724/2/ 2041

  54. [54]

    doi: 10.1051/0004-6361/202558216. G. J. Stanley.Nature, 177(4522):1221–1222, June

    work page doi:10.1051/0004-6361/202558216

  55. [55]

    doi: 10.1038/1771221a0. C. Tadhunter et al.Nature, 511(7510):440–443, July

    work page doi:10.1038/1771221a0

  56. [56]

    doi: 10.1038/nature13520. A. Tarchi et al.A&A, 525:A91, Jan

    doi:10.1038/nature13520

  57. [57]

    doi: 10.1051/0004-6361/201014714. A. Tarchi et al.MNRAS, 492(1):45–57, Feb

    doi:10.1051/0004-6361/201014714

  58. [58]

    A.Tarchietal

    doi: 10.1093/mnras/stz3445. A.Tarchietal. InAdvancingAstrophysicswiththeSKA–II(AASKAII).2026. arXivsearch: Report number AASKAII/Tarchi01. C. H. Townes. In H. C. van de Hulst, editor,Radio astronomy, volume 4 ofIAU Symposium, page 92, Jan

    work page doi:10.1093/mnras/stz3445 2026

  59. [59]

    doi: 10.3847/1538-4357/ad0ecf. J. T. van Loon.Galaxies, 13(4):72, June

    work page doi:10.3847/1538-4357/ad0ecf

  60. [60]

    doi: 10.3390/galaxies13040072. J. T. van Loon and A. A. Zijlstra.ApJL, 547(1):L61–L64, Jan

    work page doi:10.3390/galaxies13040072

  61. [61]

    doi: 10.1086/318892. J. T. van Loon, A. A. Zijlstra, V. Bujarrabal, and L.-Å. Nyman.A&A, 368:950–968, Mar

    work page doi:10.1086/318892

  62. [62]

    doi: 10.1051/0004-6361:20010052. J. T. van Loon et al.AJ, 139(4):1553–1565, Apr

    work page doi:10.1051/0004-6361:20010052

  63. [63]

    doi: 10.1088/0004-6256/139/4/1553. S. Veilleux, R. Maiolino, A. D. Bolatto, and S. Aalto.A&ARv, 28(1):2, Apr

    work page doi:10.1088/0004-6256/139/4/1553

  64. [64]

    doi: 10.1038/379139a0. R. W. Wilson, A. A. Penzias, K. B. Jefferts, and P. M. Solomon.ApJL, 179:L107, Feb

    doi:10.1038/379139a0

  65. [65]

    doi: 10.1086/181127. P. R. Wood et al.ApJ, 397:552, Oct

    work page doi:10.1086/181127

  66. [66]

    doi: 10.1086/171812. H. Wu et al.A&A, 661:A125, May

    doi:10.1086/171812

  67. [67]

    doi: 10.1051/0004-6361/202142854. I. Zinchenko, V. Dubrovich, and C. Henkel.MNRAS, 415(1):L78–L80, July

    work page doi:10.1051/0004-6361/202142854

  68. [68]

    1745-3933.2011.01083.x

    doi: 10.1111/j. 1745-3933.2011.01083.x. 17

    doi:10.1111/j 2011