Pith. sign in

REVIEW 3 major objections 5 minor 85 references

An e-MERLIN & EVN radio counterpart to the ultraluminous X-ray source M82 X-1

T0 review · 3 major / 5 minor · reviewed 2026-08-16 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read A new radio source is identified as the counterpart of the ultraluminous X-ray source M82 X-1.

desk verdict First credible radio counterpart to M82 X-1, with a robust detection and a plausible but not airtight astrometric association. read the letter →

arxiv 2504.18217 v1 pith:E6M2YKPM submitted 2025-04-25 astro-ph.HE astro-ph.GA

D. Williams-Baldwin (1) , T. W. B. Muxlow (1) , G. Lucatelli (1) , R. J. Beswick (1) ((1) Jodrell Bank Centre for Astrophysics , School of Physics , Astronomy , The University of Manchester , Manchester
show 2 more authors
M13 9PL UK)
This is my paper · ORCID
classification astro-ph.HEastro-ph.GA
keywords ultraluminousX-raysourcesM82X-1radiocounterparte-MERLINEVNintermediate-massblackholecontinuumvariablesgalaxies:individual:
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

This paper reports the first radio detections of M82 X-1, the brightest ultraluminous X-ray source in the nearby galaxy M82 and one of the best intermediate-mass black hole candidates. With deep wide-band e-MERLIN images from 2015 at 5–6 GHz, the authors discovered a compact source, 41.37+60.2, with an integrated flux of $S_{\nu=4.88\,{\rm GHz}}=174\pm15\,\mu$Jy, lying within 100 milliarcseconds of the Chandra position of M82 X-1. The source was also detected at $4.99\,{\rm GHz}$ with EVN+e-MERLIN in 2021 at $53\pm10\,\mu$Jy and is unresolved on milliarcsecond scales, implying a physical size below about $0.16\times0.13$ pc. It is absent from archival MERLIN surveys and from later e-MERLIN epochs, so it is variable on year timescales. These radio properties match other radio-detected ULXs and X-ray binaries, placing M82 X-1 on the radio–X-ray plane as an accreting black hole of stellar or intermediate mass.

What carries the argument

The central objects are the newly discovered radio source 41.37+60.2 and the astrometric frame tie that places it against the Chandra position of M82 X-1. The argument is carried by three linked mechanisms: (i) a rigid shift of all positions derived from an updated phase-reference calibrator position, which reduces the radio-to-X-ray offset to 100 mas; (ii) the milliarcsecond-scale EVN image, which shows the source is unresolved and hence compact; and (iii) the `fundamental plane of black hole activity', an empirical scaling law connecting radio luminosity, X-ray luminosity, and black hole mass, which turns the measured fluxes into a mass estimate of roughly 2650 $M_\odot$.

What would settle it

A full astrometric registration of multiple compact sources detected in both Chandra and e-MERLIN images of M82, solving for a transformation between the frames, would settle the identification: if after the fit 41.37+60.2 no longer falls within the 3-sigma X-ray error circle of M82 X-1, the association is refuted. A quasi-simultaneous radio and X-ray observation catching M82 X-1 in a bright state and detecting the radio source at high significance within the X-ray localization would confirm it.

Watch

Extended reading notes

Core claim

The central claim is that the compact, variable radio source 41.37+60.2 is the radio counterpart of M82 X-1. The source sits at ICRF J2000 RA $09^{h}55^{m}50.1172^{s}$, Dec $+69^{\circ}40'46.606''$ ($\pm1.5$ mas), within 100 mas of the most accurate Chandra position of M82 X-1. In 2015 May it was detected at $>20\sigma$ with integrated fluxes of $S_{\nu=4.88\,{\rm GHz}}=174\pm15\,\mu$Jy and $S_{\nu=6.20\,{\rm GHz}}=122\pm11\,\mu$Jy; in 2021 March it was detected at $S_{\nu=4.99\,{\rm GHz}}=53\pm10\,\mu$Jy with the EVN+e-MERLIN array and is unresolved at $10.8\times8.4$ mas. It is not detected in archival MERLIN data from 1992–2009 at comparable sensitivity, nor in later e-MERLIN data from 2016 and 2021, indicating variability on timescales of years. The compactness ($<0.16\times0.13$ pc), brightness temperature $T_B\ge2.8\times10^{4}$ K, steep optically-thin spectral index ($\alpha=-1.48$), and variability exclude a steady H II region or supernova remnant and are consistent with emission from an accreting compact object. On the radio:X-ray plane, 41.37+60.2 falls among other radio-bright ULXs and black hole X-ray binaries, and the `fundamental plane of black hole activity' yields a black hole mass of roughly 2650 $M_\odot$, a value the authors stress is highly uncertain.

Load-bearing premise

The identification rests on the assumption that applying a single rigid offset (from an updated calibrator position) to all radio, VLA, and Chandra positions yields a common astrometric frame accurate to roughly 100 mas; if the frame tie is off by more than that, the radio source would fall outside the Chandra error region and the association would be in doubt.

Editorial extensions

If this is right

  • M82 X-1 becomes one of only a handful of ULXs with a detected radio counterpart, enabling joint radio/X-ray studies of a leading intermediate-mass black hole candidate.
  • The compact, variable radio emission points to a jet or accretion-driven outflow from a black hole, ruling out a neutron star power source and steady compact sources such as H II regions.
  • The non-detections in archival and later epochs imply the source is transient or strongly variable on timescales of years; repeated monitoring can map the coupling between X-ray accretion state and radio ejection.
  • The fundamental-plane mass estimate, while uncertain and based on non-simultaneous data, is consistent with the intermediate-mass black hole hypothesis for M82 X-1.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the radio emission appears only in X-ray-bright states, as the 2015 detection versus 2016 non-detection hints, then snapshot surveys may systematically miss ULX radio counterparts; wide-field, multi-epoch monitoring of nearby galaxies could reveal many more.
  • The paper's chance-alignment calculation could be applied to other ULXs with deep radio maps, giving a simple statistical estimate of how many ULXs host black holes rather than neutron stars.
  • The steep spectral index suggests that higher-frequency observations (e.g., 8–15 GHz) during a bright state, together with simultaneous low-frequency coverage, could separate intrinsic variability from free-free absorption and sharpen the inferred jet properties.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. The paper presents deep e-MERLIN and EVN+e-MERLIN observations of the nearby galaxy M82 and reports a new radio source, 41.37+60.2, detected at >20σ in 2015 May at 5–6 GHz with an integrated flux of 151±10 μJy and at >6σ in 2021 March at 4.99 GHz with a flux of 53±10 μJy. The source is unresolved at 10 mas scales, is not detected in archival MERLIN/e-MERLIN data, and is argued to be variable on year timescales. Based on a 100 mas separation from the Chandra position of M82 X-1 after an approximate astrometric correction, the authors conclude that 41.37+60.2 is the radio counterpart of M82 X-1. They further place the source on the radio–X-ray plane and use the fundamental plane of black hole activity to estimate a black hole mass of ~2650 M⊙, which they flag as highly uncertain.

Significance. If confirmed, this would be the first radio detection of M82 X-1, a leading intermediate-mass black hole candidate, and would add an important data point to the sparse sample of radio-detected ULXs. The observational evidence is strong: two independent radio arrays detect a compact source at a consistent position, the detection significances are high, and the chance-alignment probability is small. The authors are appropriately cautious in their interpretation of the fundamental-plane mass estimate, which they present with explicit caveats. The use of standard reduction pipelines and the conservative detection thresholds strengthen the reproducibility of the result. The main weakness is the astrometric association, which rests on an approximate frame tie between radio and X-ray data.

major comments (3)
  1. [Section 3.3] The claimed positional coincidence of 100 mas is stated to be 'well within the 3σ error circle' without quoting the actual Chandra positional uncertainty for the Xu et al. (2015) position or its source. Since this offset is the sole direct basis for associating 41.37+60.2 with M82 X−1, the authors must provide the relevant 1σ and 3σ uncertainties (or recompute them) and explicitly demonstrate that a 100 mas offset is within the stated confidence region.
  2. [Section 3.3] The astrometric transfer to the Chandra frame is an approximate single-offset correction: a shift derived from an updated phase-reference calibrator position is applied to the e-MERLIN data, and the same shift is then applied to Chandra and VLA positions, with an additional comparison of only one source (41.95+57.5) between e-MERLIN and VLA. The paper itself states that a full astrometric analysis 'is not necessary for the analysis described below and is beyond the scope of this work.' Because the identification is the central claim, this leaves an unquantified systematic error that could be comparable to the 100 mas offset. A proper tie using multiple compact sources common to radio and X-ray (as in Körding et al. 2005), or a quantitative demonstration that the association is robust to plausible frame shifts of order 100 mas in declination, is needed.
  3. [Section 3.3] The chance-alignment probability of 2×10⁻⁵ (or 6×10⁻⁹ with the EVN size) is computed using an X-ray error region of ~0.5 arcsec², but the paper does not explain how this area is defined or which confidence level it corresponds to. Because the probability scales linearly with the area, the authors should state the origin of this value and recalculate the probability for a range of plausible Chandra 3σ error radii, especially in light of the 100 mas measured offset.
minor comments (5)
  1. [Section 3.3] The position of the radio transient 41.5+59.7 is given as 'RA: 09h51m50.s19' in the text, but the J2000 RA of M82 sources is around 09h55m; this appears to be a typo for 09h55m50.s19 and should be corrected.
  2. [Sections 1 and 3.3] The distance between 41.5+59.7 and M82 X−1 is quoted as 0.8 arcsec in the introduction and 0.56 arcsec in Section 3.3; these values should be reconciled or clarified.
  3. [Section 3.2] The phrase 'the source cannot be cataclysmic in nature' is ambiguous; it should be rephrased to 'cannot be a cataclysmic explosion such as a supernova' for clarity.
  4. [Section 3.4] There is a minor grammar issue: 'The 2015 June data was obtained ... at a time when Swift/XRT monitoring shows consistent X-ray flux' should use 'showed' instead of 'shows'.
  5. [Section 3.5] In the discussion of the fundamental plane, the sentence 'our data are not simultaneous' would be clearer as 'our radio and X-ray data are not quasi-simultaneous'.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: radio detection, X-ray association, and fundamental-plane mass estimate are independent of the conclusions by construction.

full rationale

The paper's load-bearing claim is that a newly detected e-MERLIN/EVN radio source, 41.37+60.2, is the radio counterpart of M82 X-1. The radio position is measured directly from the 2015 e-MERLIN and 2021 EVN+e-MERLIN data, and the Chandra position is taken from the external Xu et al. (2015) sub-pixeling analysis. The astrometric correction applied in Section 3.3 is derived from an updated phase-reference calibrator position (Petrov & Kovalev 2025), not from fitting the radio source to the X-ray position; the resulting 100 mas offset is then compared with the quoted Chandra 3-sigma region. The paper explicitly defers a full astrometric tie ('A full astrometric analysis aligning the Chandra sources to the e-MERLIN data is required to give a better positional accuracy, but this is not necessary for the analysis described below and is beyond the scope of this work'), which is an accuracy caveat rather than a circular step. The chance-alignment estimate uses the source density from the same image, but as a null-hypothesis calculation, not as an input that forces the association. The fundamental-plane mass in Section 3.5 is obtained by substituting measured radio and X-ray luminosities into the externally published Merloni et al. (2003) relation; no parameter is fitted to make the mass come out. Self-citations to earlier M82 radio catalogues (e.g., Muxlow et al. 1994; Fenech et al. 2008; Gendre et al. 2013) are used only for archival upper limits and do not define or predict the new source. The derivation is therefore self-contained, with only conventional caveats about astrometric accuracy and non-simultaneity.

Assumptions & free parameters 0 free parameters · 4 assumptions · 0 invented entities

The central claim rests on the radio detection itself and the positional association. The paper introduces no new free parameters or entities; it relies on a distance assumption, an empirical fundamental plane, an X-ray flux conversion, and an astrometric frame tie. These are all stated, but the frame tie and flux conversion are the least externally anchored.

assumptions (4)
  • domain assumption Distance to M82 is 3.2 Mpc
    Assumed throughout for luminosity calculations (Section 1 and Section 3.1).
  • domain assumption Fundamental plane of black hole activity applies to M82 X-1
    Used in Section 3.5 to infer M_BH; assumes similar accretion and outflow coupling across mass scales; authors cite caveats (Gültekin et al. 2019).
  • domain assumption X-ray flux conversion from 0.5-30 keV to 2-10 keV using a power law of 3 and nH=1.3e22 cm^-2
    Section 3.5; used to estimate L_X-ray(2-10 keV) for the fundamental plane; authors note the actual spectral models are more complex.
  • ad hoc to paper Astrometric frame tie between e-MERLIN, VLA, and Chandra positions via updated calibrator position
    Section 3.3; offsets from Petrov & Kovalev 2025 are applied to all positions; no full astrometric solution is performed, yet the 100 mas match with the X-ray position is central to the identification.

how reviews work

0 comments
Cite this review

Pith. "Pith review of An e-MERLIN & EVN radio counterpart to the ultraluminous X-ray source M82 X-1." pith.science (2026). https://pith.science/paper/E6M2YKPM

@misc{pith2026250418217,
  author       = {Pith},
  title        = {Pith review of: An e-MERLIN & EVN radio counterpart to the ultraluminous X-ray source M82 X-1},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/E6M2YKPM}},
  note         = {Machine review of arXiv:2504.18217}
}
abstract

Ultra-luminous X-ray sources (ULXs) are X-ray bright (L$_{\rm X-ray} >$3$\times$10$^{39}$erg s$^{-1}$) extra-galactic objects that are powered by either neutron stars, or stellar or intermediate-mass black holes (IMBHs) but few have been detected in the radio waveband. In the nearby galaxy M82, the brightest ULX - M82 X$-$1, is thought to be associated with an IMBH but to date does not have a radio counterpart. We present deep wide-band reprocessed e-MERLIN images observed in 2015 May with an r.m.s. sensitivity of 7$\mu$Jy beam$^{-1}$ and report the discovery of a new radio source with an integrated flux of S$_{\rm \nu=4.88\,GHz}$ = 174$\pm$15$\mu$Jy, which is spatially co-incident with the Chandra X-ray position of M82 X$-$1. This source is not detected in archival MERLIN/e-MERLIN observations in the last three decades. A search for intra-observation variability in the 2015 e-MERLIN data was inconclusive, but a comparison with 1.5 GHz e-MERLIN observations taken a week prior yielded no detection. We also detect the source at the same position with milliarcsecond angular resolution in EVN+e-MERLIN data from 2021 March at 53$\pm$10$\mu$Jy. The radio source position is ICRF J2000 RA: 09$^{h}$55$^{m}$50.1172$^{s}$, Dec: +69$^{\circ}$40'46.606" ($\pm$1.5 mas). These radio fluxes are consistent with other radio-detected ULXs on the radio:X-ray plane and points towards a stellar/intermediate-mass black hole. The black hole mass inferred by the `fundamental plane of black hole activity' is 2650 M$_{\odot}$, but this value remains highly uncertain.

Figures

Figures reproduced from arXiv: 2504.18217 by the authors.

Figure 1
Figure 1. Image of the region surrounding the new source 41.37+60.2 (marked by a black ‘+’ symbol) from the 5−6 GHz 2015 e-MERLIN dataset. The image size is 1.8′′×1.8′′ and shows both 41.37+60.2 and the nearby SNR 41.30+59.6 to the south-west, labelled with a yellow plus-symbol and yellow circle showing the VLA synthesized beam size from Körding et al. 2005. The black contour levels are the image r.m.s. sensitivity 7𝜇Jy beam−… view at source ↗
Figure 3
Figure 3. Inter-observation variability across the archival and new datasets presented in this work. Upper limits are denoted with downward facing arrows and the error bars in the x-axis refer to the total observing time of that observation. We only include the 5 GHz datasets in the archive from MERLIN observations in this plot as ‘Archival MERLIN 4.99 GHz’ points for the following publications: Muxlow et al. 1994; McDonald e… view at source ↗
Figure 4
Figure 4. Radio:X-ray plane of X-ray binaries and other compact objects ob￾tained from the online repository maintained by Arash Bahramian (Bahramian & Rushton 2022), with the source types and symbols shown in the legend and the dark green dashed line representing the radio:X-ray correlation for black hole X-ray binaries of the form 𝐿radio ∝ 𝐿 0.61 X−ray . We have included a sample of radio detections of intermediate-mass bla… view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

85 extracted references · 18 canonical work pages

  1. [1]

    write newline

    " write newline "" before.all 'output.state := FUNCTION fin.entry write newline FUNCTION new.block output.state before.all = 'skip after.block 'output.state := if FUNCTION new.sentence output.state after.block = 'skip output.state before.all = 'skip after.sentence 'output.state := if if FUNCTION not #0 #1 if FUNCTION and 'skip pop #0 if FUNCTION or pop #1...

  2. [2]

    write newline

    " write newline "" before.all 'output.state := FUNCTION fin.entry write newline FUNCTION new.block output.state before.all = 'skip after.block 'output.state := if FUNCTION new.sentence output.state after.block = 'skip output.state before.all = 'skip after.sentence 'output.state := if if FUNCTION not #0 #1 if FUNCTION and 'skip pop #0 if FUNCTION or pop #1...

  3. [3]

    N., 2013, Journal of Improbable Astronomy, 1, 1

    Author A. N., 2013, Journal of Improbable Astronomy, 1, 1

    2013

  4. [4]

    D., 2015, Journal of Interesting Stuff, 17, 198

    Jones C. D., 2015, Journal of Interesting Stuff, 17, 198

    2015

  5. [5]

    B., 2014, The Example Journal, 12, 345 (Paper I)

    Smith A. B., 2014, The Example Journal, 12, 345 (Paper I)

    2014

  6. [6]

    K., Pedlar A., Beswick R

    Argo M. K., Pedlar A., Beswick R. J., Muxlow T. W. B., 2007, @doi [ ] 10.1111/j.1365-2966.2007.12088.x , https://ui.adsabs.harvard.edu/abs/2007MNRAS.380..596A 380, 596

    arXiv 2007

  7. [7]

    Atri P., et al., 2025, @doi [ ] 10.1051/0004-6361/202452837 , 696, A223

    doi:10.1051/0004-6361/202452837 2025

  8. [8]

    Bachetti M., 2016, @doi [Astronomische Nachrichten] 10.1002/asna.201612312 , https://ui.adsabs.harvard.edu/abs/2016AN....337..349B 337, 349

    doi:10.1002/asna.201612312 2016

Show all 85 references
  1. [9]

    Bachetti M., et al., 2014, @doi [ ] 10.1038/nature13791 , https://ui.adsabs.harvard.edu/abs/2014Natur.514..202B 514, 202

    2014 doi

  2. [10]

    Bahramian A., Rushton A., 2022, bersavosh/XRB-LrLx\_pub: update 20220908, @doi 10.5281/zenodo.7059313 , https://doi.org/10.5281/zenodo.7059313

    2022 doi

  3. [11]

    T., Johnson M

    Berghea C. T., Johnson M. C., Secrest N. J., Dudik R. P., Hennessy G. S., El-khatib A., 2020, @doi [ ] 10.3847/1538-4357/ab9108 , https://ui.adsabs.harvard.edu/abs/2020ApJ...896..117B 896, 117

    2020 doi

  4. [12]

    J., et al., 2006, @doi [ ] 10.1111/j.1365-2966.2006.10363.x , https://ui.adsabs.harvard.edu/abs/2006MNRAS.369.1221B 369, 1221

    Beswick R. J., et al., 2006, @doi [ ] 10.1111/j.1365-2966.2006.10363.x , https://ui.adsabs.harvard.edu/abs/2006MNRAS.369.1221B 369, 1221

    2006

  5. [13]

    J., Soria R., Miller-Jones J

    Beuchert T., Middleton M. J., Soria R., Miller-Jones J. C. A., Dauser T., Roberts T. P., Sathyaprakash R., Markoff S., 2024, @doi [ ] 10.1093/mnras/stae1975 , https://ui.adsabs.harvard.edu/abs/2024MNRAS.534..645B 534, 645

    2024 doi

  6. [14]

    J., Xu Y., Earnshaw H

    Brightman M., Walton D. J., Xu Y., Earnshaw H. P., Harrison F. A., Stern D., Barret D., 2020, @doi [ ] 10.3847/1538-4357/ab629a , https://ui.adsabs.harvard.edu/abs/2020ApJ...889...71B 889, 71

    2020 doi

  7. [15]

    M., Reid M

    Brunthaler A., Menten K. M., Reid M. J., Henkel C., Bower G. C., Falcke H., 2009, @doi [ ] 10.1051/0004-6361/200912327 , https://ui.adsabs.harvard.edu/abs/2009A&A...499L..17B 499, L17

    2009 doi

  8. [17]

    M., Burbidge G

    Burbidge E. M., Burbidge G. R., Rubin V. C., 1964, @doi [ ] 10.1086/147997 , https://ui.adsabs.harvard.edu/abs/1964ApJ...140..942B 140, 942

    1964 doi

  9. [19]

    J., Cotton W

    Condon J. J., Cotton W. D., Greisen E. W., Yin Q. F., Perley R. A., Taylor G. B., Broderick J. J., 1998, @doi [ ] 10.1086/300337 , https://ui.adsabs.harvard.edu/abs/1998AJ....115.1693C 115, 1693

    1998 doi

  10. [20]

    P., Tzioumis A

    Corbel S., Fender R. P., Tzioumis A. K., Nowak M., McIntyre V., Durouchoux P., Sood R., 2000, , http://adsabs.harvard.edu/abs/2000A

    2000

  11. [21]

    A., Fender R

    Corbel S., Nowak M. A., Fender R. P., Tzioumis A. K., Markoff S., 2003, @doi [ ] 10.1051/0004-6361:20030090 , http://adsabs.harvard.edu/abs/2003A

    2003 doi

  12. [22]

    K., Fender R

    Corbel S., Coriat M., Brocksopp C., Tzioumis A. K., Fender R. P., Tomsick J. A., Buxton M. M., Bailyn C. D., 2013, @doi [ ] 10.1093/mnras/sts215 , https://ui.adsabs.harvard.edu/abs/2013MNRAS.428.2500C 428, 2500

    2013 doi

  13. [23]

    Coriat M., et al., 2011, @doi [ ] 10.1111/j.1365-2966.2011.18433.x , http://adsabs.harvard.edu/abs/2011MNRAS.414..677C 414, 677

    2011

  14. [24]

    Cseh D., et al., 2012, @doi [ ] 10.1088/0004-637X/749/1/17 , https://ui.adsabs.harvard.edu/abs/2012ApJ...749...17C 749, 17

    2012 doi

  15. [25]

    Cseh D., et al., 2014, @doi [ ] 10.1093/mnrasl/slt166 , https://ui.adsabs.harvard.edu/abs/2014MNRAS.439L...1C 439, L1

    2014 doi

  16. [26]

    Cseh D., et al., 2015a, @doi [ ] 10.1093/mnras/stu2363 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.446.3268C 446, 3268

    doi

  17. [27]

    Cseh D., et al., 2015b, @doi [ ] 10.1093/mnras/stv1308 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.452...24C 452, 24

    doi

  18. [28]

    Falcke H., K \"o rding E., Markoff S., 2004, @doi [ ] 10.1051/0004-6361:20031683 , https://ui.adsabs.harvard.edu/abs/2004A&A...414..895F 414, 895

    2004 doi

  19. [29]

    Fender R., Belloni T., 2004, @doi [ ] 10.1146/annurev.astro.42.053102.134031 , http://adsabs.harvard.edu/abs/2004ARA

    2004

  20. [30]

    P., Belloni T

    Fender R. P., Belloni T. M., Gallo E., 2004, @doi [ ] 10.1111/j.1365-2966.2004.08384.x , https://ui.adsabs.harvard.edu/abs/2004MNRAS.355.1105F 355, 1105

    2004

  21. [31]

    M., Muxlow T

    Fenech D. M., Muxlow T. W. B., Beswick R. J., Pedlar A., Argo M. K., 2008, @doi [ ] 10.1111/j.1365-2966.2008.13986.x , https://ui.adsabs.harvard.edu/abs/2008MNRAS.391.1384F 391, 1384

    2008

  22. [32]

    Fenech D., Beswick R., Muxlow T. W. B., Pedlar A., Argo M. K., 2010, @doi [ ] 10.1111/j.1365-2966.2010.17144.x , https://ui.adsabs.harvard.edu/abs/2010MNRAS.408..607F 408, 607

    2010

  23. [33]

    Feng H., Kaaret P., 2010, @doi [ ] 10.1088/2041-8205/712/2/L169 , https://ui.adsabs.harvard.edu/abs/2010ApJ...712L.169F 712, L169

    2010 doi

  24. [34]

    Feng H., Soria R., 2011, @doi [ ] 10.1016/j.newar.2011.08.002 , https://ui.adsabs.harvard.edu/abs/2011NewAR..55..166F 55, 166

    2011 doi

  25. [35]

    P., Pooley G

    Gallo E., Fender R. P., Pooley G. G., 2003, @doi [ ] 10.1046/j.1365-8711.2003.06791.x , http://adsabs.harvard.edu/abs/2003MNRAS.344...60G 344, 60

    2003

  26. [36]

    Gallo E., Fender R., Kaiser C., Russell D., Morganti R., Oosterloo T., Heinz S., 2005, @doi [ ] 10.1038/nature03879 , https://ui.adsabs.harvard.edu/abs/2005Natur.436..819G 436, 819

    2005 doi

  27. [37]

    Garrington S., Beswick R., 2016, @doi [Astronomy and Geophysics] 10.1093/astrogeo/atw101 , https://ui.adsabs.harvard.edu/abs/2016A&G....57c3.28G 57, 3.28

    2016 doi

  28. [38]

    A., Fenech D

    Gendre M. A., Fenech D. M., Beswick R. J., Muxlow T. W. B., Argo M. K., 2013, @doi [ ] 10.1093/mnras/stt231 , https://ui.adsabs.harvard.edu/abs/2013MNRAS.431.1107G 431, 1107

    2013 doi

  29. [39]

    Gong H., Urquhart R., Vinokurov A., Bai Y., Cabrera-Lavers A., Fabrika S., Wang L., Liu J., 2023, @doi [ ] 10.3847/1538-4357/acf8c3 , https://ui.adsabs.harvard.edu/abs/2023ApJ...958...24G 958, 24

    2023 doi

  30. [40]

    L., Cackett E

    G \"u ltekin K., King A. L., Cackett E. M., Nyland K., Miller J. M., Di Matteo T., Markoff S., Rupen M. P., 2019, @doi [ ] 10.3847/1538-4357/aaf6b9 , https://ui.adsabs.harvard.edu/abs/2019ApJ...871...80G 871, 80

    2019 doi

  31. [41]

    Iwasawa K., 2021, @doi [ ] 10.1051/0004-6361/202040209 , https://ui.adsabs.harvard.edu/abs/2021A&A...652A..18I 652, A18

    2021 doi

  32. [42]

    D., Maccarone T

    Joseph T. D., Maccarone T. J., Fender R. P., 2011, @doi [ ] 10.1111/j.1745-3933.2011.01078.x , https://ui.adsabs.harvard.edu/abs/2011MNRAS.415L..59J 415, L59

    2011

  33. [44]

    H., Zezas A., 2003, @doi [Science] 10.1126/science.1079610 , https://ui.adsabs.harvard.edu/abs/2003Sci...299..365K 299, 365

    Kaaret P., Corbel S., Prestwich A. H., Zezas A., 2003, @doi [Science] 10.1126/science.1079610 , https://ui.adsabs.harvard.edu/abs/2003Sci...299..365K 299, 365

    2003 doi

  34. [45]

    Kaaret P., Feng H., Gorski M., 2009, @doi [ ] 10.1088/0004-637X/692/1/653 , https://ui.adsabs.harvard.edu/abs/2009ApJ...692..653K 692, 653

    2009 doi

  35. [46]

    P., 2017, @doi [ ] 10.1146/annurev-astro-091916-055259 , https://ui.adsabs.harvard.edu/abs/2017ARA&A..55..303K 55, 303

    Kaaret P., Feng H., Roberts T. P., 2017, @doi [ ] 10.1146/annurev-astro-091916-055259 , https://ui.adsabs.harvard.edu/abs/2017ARA&A..55..303K 55, 303

    2017 doi

  36. [47]

    Kimani N., et al., 2016, @doi [ ] 10.1051/0004-6361/201628800 , https://ui.adsabs.harvard.edu/abs/2016A&A...593A..18K 593, A18

    2016 doi

  37. [48]

    King A., Lasota J.-P., 2016, @doi [ ] 10.1093/mnrasl/slw011 , https://ui.adsabs.harvard.edu/abs/2016MNRAS.458L..10K 458, L10

    2016 doi

  38. [49]

    Kong A. K. H., Yang Y. J., Hsieh P. Y., Mak D. S. Y., Pun C. S. J., 2007, @doi [ ] 10.1086/522291 , https://ui.adsabs.harvard.edu/abs/2007ApJ...671..349K 671, 349

    2007 doi

  39. [50]

    K \"o rding E., Colbert E., Falcke H., 2005, @doi [ ] 10.1051/0004-6361:20042452 , https://ui.adsabs.harvard.edu/abs/2005A&A...436..427K 436, 427

    2005 doi

  40. [51]

    P., Sramek R

    Kronberg P. P., Sramek R. A., 1985, @doi [Science] 10.1126/science.227.4682.28 , https://ui.adsabs.harvard.edu/abs/1985Sci...227...28K 227, 28

    1985 doi

  41. [52]

    R., Muxlow T

    McDonald A. R., Muxlow T. W. B., Pedlar A., Garrett M. A., Wills K. A., Garrington S. T., Diamond P. J., Wilkinson P. N., 2001, @doi [ ] 10.1046/j.1365-8711.2001.04109.x , https://ui.adsabs.harvard.edu/abs/2001MNRAS.322..100M 322, 100

    2001

  42. [53]

    R., Muxlow T

    McDonald A. R., Muxlow T. W. B., Wills K. A., Pedlar A., Beswick R. J., 2002, @doi [ ] 10.1046/j.1365-8711.2002.05580.x , https://ui.adsabs.harvard.edu/abs/2002MNRAS.334..912M 334, 912

    2002

  43. [54]

    P., Waters B., Schiebel D., Young W., Golap K., 2007, in Shaw R

    McMullin J. P., Waters B., Schiebel D., Young W., Golap K., 2007, in Shaw R. A., Hill F., Bell D. J., eds, Astronomical Society of the Pacific Conference Series Vol. 376, Astronomical Data Analysis Software and Systems XVI. p. 127

    2007

  44. [55]

    Merloni A., Heinz S., di Matteo T., 2003, @doi [ ] 10.1046/j.1365-2966.2003.07017.x , https://ui.adsabs.harvard.edu/abs/2003MNRAS.345.1057M 345, 1057

    2003

  45. [56]

    Mezcua M., 2017, @doi [International Journal of Modern Physics D] 10.1142/S021827181730021X , https://ui.adsabs.harvard.edu/abs/2017IJMPD..2630021M 26, 1730021

    2017 doi

  46. [57]

    A., Gladstone J

    Mezcua M., Farrell S. A., Gladstone J. C., Lobanov A. P., 2013, @doi [ ] 10.1093/mnras/stt1674 , https://ui.adsabs.harvard.edu/abs/2013MNRAS.436.1546M 436, 1546

    2013 doi

  47. [58]

    J., et al., 2013, @doi [ ] 10.1038/nature11697 , https://ui.adsabs.harvard.edu/abs/2013Natur.493..187M 493, 187

    Middleton M. J., et al., 2013, @doi [ ] 10.1038/nature11697 , https://ui.adsabs.harvard.edu/abs/2013Natur.493..187M 493, 187

    2013 doi

  48. [59]

    Moldon J., 2018, in 14th European VLBI Network Symposium & Users Meeting (EVN 2018). p. 152

    2018

  49. [60]

    K., 2022, @doi [Journal of Astrophysics and Astronomy] 10.1007/s12036-022-09881-0 , https://ui.adsabs.harvard.edu/abs/2022JApA...43...90M 43, 90

    Mondal S., Palit B., Chakrabarti S. K., 2022, @doi [Journal of Astrophysics and Astronomy] 10.1007/s12036-022-09881-0 , https://ui.adsabs.harvard.edu/abs/2022JApA...43...90M 43, 90

    2022 doi

  50. [61]

    E., Belloni T

    Motta S. E., Belloni T. M., Stella L., Mu \ n oz-Darias T., Fender R., 2014, @doi [ ] 10.1093/mnras/stt2068 , https://ui.adsabs.harvard.edu/abs/2014MNRAS.437.2554M 437, 2554

    2014 doi

  51. [62]

    E., et al., 2020, @doi [ ] 10.3847/1538-4357/ab9b81 , https://ui.adsabs.harvard.edu/abs/2020ApJ...898..174M 898, 174

    Motta S. E., et al., 2020, @doi [ ] 10.3847/1538-4357/ab9b81 , https://ui.adsabs.harvard.edu/abs/2020ApJ...898..174M 898, 174

    2020 doi

  52. [63]

    E., Atri P., Matthews J

    Motta S. E., Atri P., Matthews J. H., van den Eijnden J., Fender R., Miller-Jones J. C. A., Heywood I., Woudt P., 2025, @doi [ ] 10.48550/arXiv.2504.17425 , 696, A222

    2025 doi arXiv

  53. [64]

    Mukai K., 1993, Legacy, https://ui.adsabs.harvard.edu/abs/1993Legac...3...21M 3, 21

    1993

  54. [65]

    Muxlow T. W. B., Pedlar A., Wilkinson P. N., Axon D. J., Sanders E. M., de Bruyn A. G., 1994, @doi [ ] 10.1093/mnras/266.2.455 , https://ui.adsabs.harvard.edu/abs/1994MNRAS.266..455M 266, 455

    1994 doi

  55. [66]

    Muxlow T. W. B., Pedlar A., Beswick R. J., Argo M. K., O'Brien T. J., Fenech D., Trotman W., 2005, , https://ui.adsabs.harvard.edu/abs/2005MmSAI..76..586M 76, 586

    2005

  56. [67]

    Muxlow T. W. B., Beswick R. J., Pedlar A., Fenech D., Argo M. K., Ward M. J., Zezas A., 2009, The Astronomer's Telegram, https://ui.adsabs.harvard.edu/abs/2009ATel.2073....1M 2073, 1

    2009

  57. [68]

    Muxlow T. W. B., et al., 2010, @doi [ ] 10.1111/j.1745-3933.2010.00845.x , https://ui.adsabs.harvard.edu/abs/2010MNRAS.404L.109M 404, L109

    2010

  58. [69]

    G., Ulvestad J

    Neff S. G., Ulvestad J. S., Campion S. D., 2003, @doi [ ] 10.1086/379596 , https://ui.adsabs.harvard.edu/abs/2003ApJ...599.1043N 599, 1043

    2003 doi

  59. [70]

    R., Smirnov O., 2017, @doi [MNRAS] 10.1093/mnras/stx1547 , 471, 301

    Offringa A. R., Smirnov O., 2017, @doi [MNRAS] 10.1093/mnras/stx1547 , 471, 301

    2017 doi

  60. [71]

    R., McKinley B., Hurley-Walker et al., 2014, @doi [MNRAS] 10.1093/mnras/stu1368 , 444, 606

    Offringa A. R., McKinley B., Hurley-Walker et al., 2014, @doi [MNRAS] 10.1093/mnras/stu1368 , 444, 606

    2014 doi

  61. [72]

    Panurach T., et al., 2024, @doi [ ] 10.3847/1538-4357/ad8b9c , https://ui.adsabs.harvard.edu/abs/2024ApJ...977..211P 977, 211

    2024 doi

  62. [73]

    R., Strohmayer T

    Pasham D. R., Strohmayer T. E., Mushotzky R. F., 2014, @doi [ ] 10.1038/nature13710 , https://ui.adsabs.harvard.edu/abs/2014Natur.513...74P 513, 74

    2014 doi

  63. [74]

    A., et al., 2014, @doi [ ] 10.1088/0004-637X/792/1/38 , https://ui.adsabs.harvard.edu/abs/2014ApJ...792...38P 792, 38

    P \'e rez-Torres M. A., et al., 2014, @doi [ ] 10.1088/0004-637X/792/1/38 , https://ui.adsabs.harvard.edu/abs/2014ApJ...792...38P 792, 38

    2014 doi

  64. [75]

    Y., Kovalev Y

    Petrov L. Y., Kovalev Y. Y., 2025, @doi [ ] 10.1051/0004-6361/201014133 , https://ui.adsabs.harvard.edu/abs/2010A&A...516A..27B 276, 1

    2025 doi

  65. [76]

    P., Keane E

    Pietka M., Fender R. P., Keane E. F., 2015, @doi [ ] 10.1093/mnras/stu2335 , https://ui.adsabs.harvard.edu/abs/2015MNRAS.446.3687P 446, 3687

    2015 doi

  66. [77]

    A., McClintock J

    Remillard R. A., McClintock J. E., 2006, @doi [ ] 10.1146/annurev.astro.44.051905.092532 , http://adsabs.harvard.edu/abs/2006ARA

    2006 arXiv

  67. [78]

    L., Magno M., Tripathi A., 2023, @doi [ ] 10.3847/1538-4357/acf4f8 , https://ui.adsabs.harvard.edu/abs/2023ApJ...956....3S 956, 3

    Smith K. L., Magno M., Tripathi A., 2023, @doi [ ] 10.3847/1538-4357/acf4f8 , https://ui.adsabs.harvard.edu/abs/2023ApJ...956....3S 956, 3

    2023 doi

  68. [79]

    P., Long K

    Soria R., Blair W. P., Long K. S., Russell T. D., Winkler P. F., 2020, @doi [ ] 10.3847/1538-4357/ab5b0c , https://ui.adsabs.harvard.edu/abs/2020ApJ...888..103S 888, 103

    2020 doi

  69. [80]

    A., Tennant A

    Swartz D. A., Tennant A. F., Soria R., 2009, @doi [ ] 10.1088/0004-637X/703/1/159 , https://ui.adsabs.harvard.edu/abs/2009ApJ...703..159S 703, 159

    2009 doi

  70. [81]

    S., 2003, @doi [ ] 10.1086/345339 , https://ui.adsabs.harvard.edu/abs/2003ApJ...583..145T 583, 145

    Terashima Y., Wilson A. S., 2003, @doi [ ] 10.1086/345339 , https://ui.adsabs.harvard.edu/abs/2003ApJ...583..145T 583, 145

    2003 doi

  71. [82]

    Urquhart R., Soria R., 2016, @doi [ ] 10.1093/mnras/stv2293 , https://ui.adsabs.harvard.edu/abs/2016MNRAS.456.1859U 456, 1859

    2016 doi

  72. [83]

    Varenius E., et al., 2015, @doi [ ] 10.1051/0004-6361/201425089 , https://ui.adsabs.harvard.edu/abs/2015A&A...574A.114V 574, A114

    2015 doi

  73. [84]

    Webb N., et al., 2012, @doi [Science] 10.1126/science.1222779 , https://ui.adsabs.harvard.edu/abs/2012Sci...337..554W 337, 554

    2012 doi

  74. [85]

    C., 1985, Data Analysis in Astronomy

    Wells D. C., 1985, Data Analysis in Astronomy. Springer US, Boston, MA

    1985

  75. [86]

    A., Pedlar A., Muxlow T

    Wills K. A., Pedlar A., Muxlow T. W. B., Wilkinson P. N., 1997, @doi [ ] 10.1093/mnras/291.3.517 , https://ui.adsabs.harvard.edu/abs/1997MNRAS.291..517W 291, 517

    1997 doi

  76. [87]

    Xu X.-j., Liu J., Liu J., 2015, @doi [ ] 10.1088/2041-8205/799/2/L28 , https://ui.adsabs.harvard.edu/abs/2015ApJ...799L..28X 799, L28

    2015 doi

  77. [88]

    Yang J., et al., 2023, @doi [ ] 10.1093/mnrasl/slad111 , https://ui.adsabs.harvard.edu/abs/2023MNRAS.526L...1Y 526, L1

    2023 doi

Pith tools

Reviewed August 16, 2026 · model on record in the stance chip above.