pith. sign in

arxiv: 1906.08263 · v1 · pith:YN4KQDLUnew · submitted 2019-06-19 · 🌌 astro-ph.CO · astro-ph.IM

Unified lensing and kinematic analysis for any elliptical mass profile

Pith reviewed 2026-05-25 20:06 UTC · model grok-4.3

classification 🌌 astro-ph.CO astro-ph.IM
keywords elliptical mass profilegravitational lensingGaussian decompositionintegral transformdeflection anglemagnificationkinematic analysissurface density
0
0 comments X

The pith

Any elliptical surface-density profile can be decomposed into Gaussians for analytic computation of lensing deflection and magnification.

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

The paper establishes a general method that decomposes an arbitrary elliptical mass profile into a sum of Gaussian components, then adds the known analytic lensing quantities of each Gaussian. An integral transform supplies the decomposition coefficients quickly and accurately. This approach removes the need for profile-by-profile analytic derivations that had blocked progress for decades and produces a self-consistent kinematic model from the same components. Readers would care because realistic galaxy lenses can now be modelled without custom mathematics or added computational cost.

Core claim

We demonstrate an efficient method to compute the strong-gravitational-lensing deflection angle and magnification for any elliptical surface-density profile. This method solves a numerical hurdle in lens modelling that has lacked a general solution for nearly three decades. The hurdle emerges because it is prohibitive to derive analytic expressions of the lensing quantities for most elliptical mass profiles. In our method, we first decompose an elliptical mass profile into Gaussian components. We introduce an integral transform that provides us with a fast and accurate algorithm for the Gaussian decomposition. We derive analytic expressions of the lensing quantities for a Gaussian component.

What carries the argument

An integral transform that decomposes any elliptical surface-density profile into a finite sum of Gaussian components whose individual lensing quantities are analytic.

If this is right

  • Lensing quantities for any elliptical profile are obtained by simple addition of the Gaussian contributions.
  • The same Gaussian decomposition supplies both lensing and kinematic quantities without additional machinery.
  • No profile-specific analytic derivations or extra computational overhead are required.
  • Modelling of previously intractable elliptical mass distributions becomes feasible.

Where Pith is reading between the lines

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

  • The same decomposition approach may extend to other non-elliptical density shapes if analogous transforms exist.
  • Faster and more flexible lens fitting could tighten constraints on the inner density slopes of galaxies.
  • Survey-scale analyses of strong lenses may adopt the method to handle diverse mass models uniformly.

Load-bearing premise

Any elliptical surface-density profile can be approximated to sufficient accuracy by a finite sum of Gaussians so that the summed deflection and magnification match the true profile within acceptable error.

What would settle it

Direct numerical integration of the deflection angle for a chosen elliptical profile that lacks a known analytic solution, compared against the summed Gaussian result, to check whether the difference stays below the claimed error threshold.

Figures

Figures reproduced from arXiv: 1906.08263 by Anowar J. Shajib.

Figure 1
Figure 1. Figure 1: Elliptical deflection potential (left column) producing dumbbell￾shaped surface-density (right column). The dashed contours in the left col￾umn are isopotential curves for Sérsic profile with nSérsic = 4, and the solid contours in the right column are corresponding isodensity curves. The axis ratios are q = 0.8 in the top row, and q = 0.6 in the bottom row. The dumb￾bell shape in surface density is unphysi… view at source ↗
Figure 2
Figure 2. Figure 2: “Divide and conquer” strategy to compute lensing quantities for elliptical surface-density profile. In this figure, we choose the deflection field as the quantity of interest to illustrate the method. However, this method works equally well for other quantities such as the lensing shear and the line-of-sight velocity dispersion. Each column demonstrates one step in the strategy and the arrows show the prog… view at source ↗
Figure 3
Figure 3. Figure 3: Decomposing the Sérsic profile and the projected NFW profile into Gaussian components using the integral transform with a Gaussian kernel. The blue lines correspond to the Sérsic profiles with: solid for Sérsic index nSérsic = 1 and dotted for nSérsic = 4. The red, dashed lines correspond to the two-dimensional projected NFW profile. Left: the inverse transform f (σ) of the Sérsic profiles and the projecte… view at source ↗
Figure 4
Figure 4. Figure 4: Comparison between our method and the multi-Gaussian expansion (MGE) method from Cappellari (2002) to decompose a one-dimensional function into Gaussian components. Here, we only show the case for a Sérsic function with nSérsic = 1, however the cases for higher Sérsic indices of for the projected NFW profile are qualitatively similar or better. Left: the Sérsic function (solid, blue line) approximated with… view at source ↗
Figure 5
Figure 5. Figure 5: Lensing quantities for an elliptical Gaussian convergence profile. Left: convergence (orange shade), deflection field (green arrows), isopo￾tential contours (blue, dashed contours). The arrow directions are for the negative of the deflection angles and the lengths are shrunk by a factor of 4 for nicer visualization. Right: Critical curves (black lines) and cor￾responding caustics (pink lines). The solid-co… view at source ↗
Figure 6
Figure 6. Figure 6: Fitting synthetic lensing data with Gaussian components of an elliptical Sérsic profile for the luminous component. We fit the dark component with an elliptical NFW profile. The Sérsic parameters for the lens light are joint with the luminous mass distribution except for the amplitudes letting the global mass-to-light ratio be a free parameter. We generated the synthetic data for a composite model with ell… view at source ↗
read the original abstract

We demonstrate an efficient method to compute the strong-gravitational-lensing deflection angle and magnification for any elliptical surface-density profile. This method solves a numerical hurdle in lens modelling that has lacked a general solution for nearly three decades. The hurdle emerges because it is prohibitive to derive analytic expressions of the lensing quantities for most elliptical mass profiles. In our method, we first decompose an elliptical mass profile into Gaussian components. We introduce an integral transform that provides us with a fast and accurate algorithm for the Gaussian decomposition. We derive analytic expressions of the lensing quantities for a Gaussian component. As a result, we can compute these quantities for the total mass profile by adding up the contributions from the individual components. This lensing analysis self-consistently completes the kinematic description in terms of Gaussian components presented by Cappellari (2008). Our method is general without extra computational burden unlike other methods currently in use.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper claims to demonstrate an efficient method to compute strong-gravitational-lensing deflection angle and magnification for any elliptical surface-density profile. The approach first decomposes the profile into a finite sum of Gaussian components via a new integral transform, derives analytic lensing expressions for individual Gaussians, and obtains the total by summation. This completes the MGE kinematic framework of Cappellari (2008) in a self-consistent manner without profile-specific derivations or extra computational burden.

Significance. If the decomposition accuracy and analytic expressions hold as described, the method removes a long-standing numerical limitation in strong-lens modeling, enabling general, efficient joint lensing+kinematic analyses of elliptical mass distributions. The integral transform for decomposition and the Gaussian lensing formulae constitute reusable technical contributions.

major comments (2)
  1. [Numerical validation / results] The central claim requires that the finite Gaussian decomposition reproduces the true lensing quantities (deflection angle and magnification) to acceptable accuracy. No quantitative error metrics, convergence tests, or comparisons against direct numerical integration of the deflection integral are presented for the lensing observables themselves (only surface-density approximation is referenced).
  2. [Integral transform derivation] The integral transform is asserted to enable a fast, accurate decomposition for arbitrary elliptical profiles, yet the manuscript provides no explicit demonstration that the summed analytic lensing expressions converge to the exact deflection/magnification of the original profile (as opposed to merely approximating the surface density).
minor comments (2)
  1. A brief reference to the specific prior work that established the 'nearly three decades' hurdle would help contextualize the contribution.
  2. Notation for the general elliptical surface-density profile (before decomposition) should be introduced with an explicit equation early in the methods.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments. We address each major comment below and agree that additional explicit validation is required.

read point-by-point responses
  1. Referee: [Numerical validation / results] The central claim requires that the finite Gaussian decomposition reproduces the true lensing quantities (deflection angle and magnification) to acceptable accuracy. No quantitative error metrics, convergence tests, or comparisons against direct numerical integration of the deflection integral are presented for the lensing observables themselves (only surface-density approximation is referenced).

    Authors: We agree that the manuscript lacks direct quantitative validation of the lensing observables. While surface-density approximation accuracy is shown, we did not include error metrics or comparisons of deflection angle and magnification against numerical integration. We will add these tests in the revision, including relative errors versus number of Gaussians and direct comparisons for test profiles such as Sérsic. revision: yes

  2. Referee: [Integral transform derivation] The integral transform is asserted to enable a fast, accurate decomposition for arbitrary elliptical profiles, yet the manuscript provides no explicit demonstration that the summed analytic lensing expressions converge to the exact deflection/magnification of the original profile (as opposed to merely approximating the surface density).

    Authors: The lensing expressions for each Gaussian are analytic and exact; superposition then yields the total. Convergence of lensing quantities therefore follows from density convergence, but we acknowledge the need for explicit demonstration. We will add figures/tables in revision showing that deflection and magnification errors converge at the same rate as the density approximation error. revision: yes

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The paper introduces a new integral transform for finite Gaussian decomposition of arbitrary elliptical surface-density profiles and derives independent analytic expressions for the lensing deflection and magnification of each Gaussian component. These steps are self-contained and do not reduce to the referenced Cappellari (2008) kinematic result by construction; the lensing analysis extends that framework rather than presupposing it. No self-definitional relations, fitted inputs presented as predictions, or load-bearing self-citations appear in the derivation chain.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the domain assumption that elliptical profiles admit accurate finite Gaussian decompositions and that the integral transform yields them efficiently; no free parameters or invented entities are explicitly introduced in the abstract.

axioms (1)
  • domain assumption Elliptical surface-density profiles admit accurate representation as finite sums of Gaussian components for lensing calculations.
    This is the foundational premise enabling the decomposition method described in the abstract.

pith-pipeline@v0.9.0 · 5679 in / 1212 out tokens · 27856 ms · 2026-05-25T20:06:09.986880+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

58 extracted references · 58 canonical work pages

  1. [1]

    Abate J., Whitt W., 2006, INFORMS Journal on Computing, 18, 408

  2. [2]

    L., Whitt W., 2000, An Introduction to Numerical Transform Inversion and Its Application to Probability Models

    Abate J., Choudhury G. L., Whitt W., 2000, An Introduction to Numerical Transform Inversion and Its Application to Probability Models. Springer US, Boston, MA, pp 257--323, @doi 10.1007/978-1-4757-4828-4_8 , https://doi.org/10.1007/978-1-4757-4828-4_8

  3. [3]

    Armstrong B., 1967, @doi [ ] 10.1016/0022-4073(67)90057-X , http://adsabs.harvard.edu/abs/1967JQSRT...7...61A 7, 61

  4. [4]

    Barkana R., 1998, @doi [ ] 10.1086/305950 , http://adsabs.harvard.edu/abs/1998ApJ...502..531B 502, 531

  5. [5]

    Barnab \`e M., Czoske O., Koopmans L. V. E., Treu T., Bolton A. S., 2011, @doi [ ] 10.1111/j.1365-2966.2011.18842.x , http://adsabs.harvard.edu/abs/2011MNRAS.415.2215B 415, 2215

  6. [6]

    Bartelmann M., 1996, , http://adsabs.harvard.edu/abs/1996A

  7. [7]

    Bendinelli O., 1991, @doi [ ] 10.1086/169595 , http://adsabs.harvard.edu/abs/1991ApJ...366..599B 366, 599

  8. [8]

    A., 1982, @doi [ ] 10.1093/mnras/200.2.361 , http://adsabs.harvard.edu/abs/1982MNRAS.200..361B 200, 361

    Binney J., Mamon G. A., 1982, @doi [ ] 10.1093/mnras/200.2.361 , http://adsabs.harvard.edu/abs/1982MNRAS.200..361B 200, 361

  9. [9]

    Birrer S., Amara A., 2018, @doi [Physics of the Dark Universe] 10.1016/j.dark.2018.11.002 , http://adsabs.harvard.edu/abs/2018PDU....22..189B 22, 189

  10. [10]

    Birrer S., et al., 2019, @doi [ ] 10.1093/mnras/stz200 , http://adsabs.harvard.edu/abs/2018arXiv180901274B 484, 4726

  11. [11]

    R., Kantowski R., 1975, @doi [ ] 10.1086/153300 , http://adsabs.harvard.edu/abs/1975ApJ...195...13B 195, 13

    Bourassa R. R., Kantowski R., 1975, @doi [ ] 10.1086/153300 , http://adsabs.harvard.edu/abs/1975ApJ...195...13B 195, 13

  12. [12]

    R., Kantowski R., Norton T

    Bourassa R. R., Kantowski R., Norton T. D., 1973, @doi [ ] 10.1086/152452 , http://adsabs.harvard.edu/abs/1973ApJ...185..747B 185, 747

  13. [13]

    Bray I., 1984, @doi [ ] 10.1093/mnras/208.3.511 , http://adsabs.harvard.edu/abs/1984MNRAS.208..511B 208, 511

  14. [14]

    Cappellari M., 2002, @doi [ ] 10.1046/j.1365-8711.2002.05412.x , http://adsabs.harvard.edu/abs/2002MNRAS.333..400C 333, 400

  15. [15]

    Cappellari M., 2008, @doi [ ] 10.1111/j.1365-2966.2008.13754.x , http://adsabs.harvard.edu/abs/2008MNRAS.390...71C 390, 71

  16. [16]

    Contopoulos G., 1956, , http://adsabs.harvard.edu/abs/1956ZA.....39..126C 39, 126

  17. [17]

    A., et al., 2011, @doi [ ] 10.1111/j.1365-2966.2011.18706.x , http://adsabs.harvard.edu/abs/2011MNRAS.417.1621D 417, 1621

    Dutton A. A., et al., 2011, @doi [ ] 10.1111/j.1365-2966.2011.18706.x , http://adsabs.harvard.edu/abs/2011MNRAS.417.1621D 417, 1621

  18. [18]

    Emsellem E., Monnet G., Bacon R., Nieto J.-L., 1994, , http://adsabs.harvard.edu/abs/1994A

  19. [19]

    E., Gorenstein M

    Falco E. E., Gorenstein M. V., Shapiro I. I., 1985, @doi [ ] 10.1086/184422 , http://adsabs.harvard.edu/abs/1985ApJ...289L...1F 289, L1

  20. [20]

    E., et al., 1999, @doi [ ] 10.1086/307758 , http://adsabs.harvard.edu/abs/1999ApJ...523..617F 523, 617

    Falco E. E., et al., 1999, @doi [ ] 10.1086/307758 , http://adsabs.harvard.edu/abs/1999ApJ...523..617F 523, 617

  21. [21]

    Golse G., Kneib J.-P., 2002, @doi [ ] 10.1051/0004-6361:20020639 , http://adsabs.harvard.edu/abs/2002A

  22. [22]

    T., 1949, @doi [Mathematical Proceedings of the Cambridge Philosophical Society] 10.1017/S0305004100024786 , 45, 241–245

    Goodwin E. T., 1949, @doi [Mathematical Proceedings of the Cambridge Philosophical Society] 10.1017/S0305004100024786 , 45, 241–245

  23. [23]

    W., Lang D., 2013, @doi [ ] 10.1086/671228 , http://adsabs.harvard.edu/abs/2013PASP..125..719H 125, 719

    Hogg D. W., Lang D., 2013, @doi [ ] 10.1086/671228 , http://adsabs.harvard.edu/abs/2013PASP..125..719H 125, 719

  24. [24]

    D., 2007, @doi [Computing in Science and Engineering] 10.1109/MCSE.2007.55 , 9, 90

    Hunter J. D., 2007, @doi [Computing in Science and Engineering] 10.1109/MCSE.2007.55 , 9, 90

  25. [25]

    Jim \'e nez-Dom \' nguez H., Flores-Llamas H., Cabral-Prieto A., Bravo-Ortega A., 1989, @doi [Nuclear Instruments and Methods in Physics Research A] 10.1016/0168-9002(89)90893-0 , http://adsabs.harvard.edu/abs/1989NIMPA.278..625J 278, 625

  26. [26]

    Jones E., Oliphant T., Peterson P., Others 2001, SciPy : Open source scientific tools for Python, http://www.scipy.org/

  27. [27]

    Kassiola A., Kovner I., 1993, @doi [ ] 10.1086/173325 , http://adsabs.harvard.edu/abs/1993ApJ...417..450K 417, 450

  28. [28]

    pp 87 -- 90, @doi 10.3233/978-1-61499-649-1-87

    Kluyver T., et al., 2016, in Loizides F., Schmidt B., eds, Positioning and Power in Academic Publishing: Players, Agents and Agendas. pp 87 -- 90, @doi 10.3233/978-1-61499-649-1-87

  29. [29]

    Koopmans L. V. E., et al., 2009, @doi [ ] 10.1088/0004-637X/703/1/L51 , http://adsabs.harvard.edu/abs/2009ApJ...703L..51K 703, L51

  30. [30]

    Kormann R., Schneider P., Bartelmann M., 1994, , http://adsabs.harvard.edu/abs/1994A

  31. [31]

    Kovner I., 1987, @doi [ ] 10.1038/325507a0 , http://adsabs.harvard.edu/abs/1987Natur.325..507K 325, 507

  32. [32]

    A., okas E

    Mamon G. A., okas E. L., 2005, @doi [ ] 10.1111/j.1365-2966.2005.09400.x , http://adsabs.harvard.edu/abs/2005MNRAS.363..705M 363, 705

  33. [33]

    Meneghetti M., Bartelmann M., Moscardini L., 2003, @doi [ ] 10.1046/j.1365-8711.2003.06276.x , http://adsabs.harvard.edu/abs/2003MNRAS.340..105M 340, 105

  34. [34]

    Merritt D., 1985a, @doi [ ] 10.1086/113810 , http://adsabs.harvard.edu/abs/1985AJ.....90.1027M 90, 1027

  35. [35]

    Merritt D., 1985b, @doi [ ] 10.1093/mnras/214.1.25P , http://adsabs.harvard.edu/abs/1985MNRAS.214P..25M 214, 25P

  36. [36]

    F., Frenk C

    Navarro J. F., Frenk C. S., White S. D. M., 1997, @doi [ ] 10.1086/304888 , http://adsabs.harvard.edu/abs/1997ApJ...490..493N 490, 493

  37. [37]

    W., Massey R

    Nightingale J. W., Massey R. J., Harvey D. R., Cooper A. P., Etherington A., Tam S.-I., Hayes R. G., 2019, arXiv e-prints, http://adsabs.harvard.edu/abs/2019arXiv190107801N

  38. [38]

    E., 2015, Guide to NumPy, 2nd edn

    Oliphant T. E., 2015, Guide to NumPy, 2nd edn. CreateSpace Independent Publishing Platform, USA

  39. [39]

    P., 1979, Pisma v Astronomicheskii Zhurnal, http://adsabs.harvard.edu/abs/1979PAZh....5...77O 5, 77

    Osipkov L. P., 1979, Pisma v Astronomicheskii Zhurnal, http://adsabs.harvard.edu/abs/1979PAZh....5...77O 5, 77

  40. [40]

    Y., Impey C

    Peng C. Y., Impey C. D., Rix H.-W., Kochanek C. S., Keeton C. R., Falco E. E., Leh \'a r J., McLeod B. A., 2006, @doi [ ] 10.1086/506266 , http://adsabs.harvard.edu/abs/2006ApJ...649..616P 649, 616

  41. [41]

    L., Pooley D., Blackburne J

    Schechter P. L., Pooley D., Blackburne J. A., Wambsganss J., 2014, @doi [ ] 10.1088/0004-637X/793/2/96 , http://adsabs.harvard.edu/abs/2014ApJ...793...96S 793, 96

  42. [42]

    Schneider P., Sluse D., 2013, @doi [ ] 10.1051/0004-6361/201321882 , http://adsabs.harvard.edu/abs/2013A

  43. [43]

    Schneider P., Sluse D., 2014, @doi [ ] 10.1051/0004-6361/201322106 , http://adsabs.harvard.edu/abs/2014A

  44. [44]

    Schramm T., 1990, , http://adsabs.harvard.edu/abs/1990A

  45. [45]

    L., 1968, Atlas de Galaxias Australes

    S\'ersic J. L., 1968, Atlas de Galaxias Australes . http://adsabs.harvard.edu/abs/1968adga.book.....S

  46. [46]

    J., et al., 2019, @doi [ ] 10.1093/mnras/sty3397 , http://adsabs.harvard.edu/abs/2019MNRAS.483.5649S 483, 5649

    Shajib A. J., et al., 2019, @doi [ ] 10.1093/mnras/sty3397 , http://adsabs.harvard.edu/abs/2019MNRAS.483.5649S 483, 5649

  47. [47]

    Sonnenfeld A., 2018, @doi [ ] 10.1093/mnras/stx3105 , http://adsabs.harvard.edu/abs/2018MNRAS.474.4648S 474, 4648

  48. [48]

    H., Treu T., Marshall P

    Sonnenfeld A., Gavazzi R., Suyu S. H., Treu T., Marshall P. J., 2013, @doi [ ] 10.1088/0004-637X/777/2/97 , http://adsabs.harvard.edu/abs/2013ApJ...777...97S 777, 97

  49. [49]

    H., et al., 2013, @doi [ ] 10.1088/0004-637X/766/2/70 , http://adsabs.harvard.edu/abs/2013ApJ...766...70S 766, 70

    Suyu S. H., et al., 2013, @doi [ ] 10.1088/0004-637X/766/2/70 , http://adsabs.harvard.edu/abs/2013ApJ...766...70S 766, 70

  50. [50]

    H., et al., 2014, @doi [ ] 10.1088/2041-8205/788/2/L35 , http://adsabs.harvard.edu/abs/2014ApJ...788L..35S 788, L35

    Suyu S. H., et al., 2014, @doi [ ] 10.1088/2041-8205/788/2/L35 , http://adsabs.harvard.edu/abs/2014ApJ...788L..35S 788, L35

  51. [51]

    B., 2015, @doi [ ] 10.1051/0004-6361/201526773 , http://adsabs.harvard.edu/abs/2015A

    Tessore N., Metcalf R. B., 2015, @doi [ ] 10.1051/0004-6361/201526773 , http://adsabs.harvard.edu/abs/2015A

  52. [52]

    Treu T., Koopmans L. V. E., 2004, @doi [ ] 10.1086/422245 , http://adsabs.harvard.edu/abs/2004ApJ...611..739T 611, 739

  53. [53]

    J., McKean J

    Vegetti S., Lagattuta D. J., McKean J. P., Auger M. W., Fassnacht C. D., Koopmans L. V. E., 2012, @doi [ ] 10.1038/nature10669 , http://adsabs.harvard.edu/abs/2012Natur.481..341V 481, 341

  54. [54]

    Vegetti S., Koopmans L. V. E., Auger M. W., Treu T., Bolton A. S., 2014, @doi [ ] 10.1093/mnras/stu943 , http://adsabs.harvard.edu/abs/2014MNRAS.442.2017V 442, 2017

  55. [55]

    C., et al., 2017, @doi [ ] 10.1093/mnras/stw3077 , http://adsabs.harvard.edu/abs/2017MNRAS.465.4895W 465, 4895

    Wong K. C., et al., 2017, @doi [ ] 10.1093/mnras/stw3077 , http://adsabs.harvard.edu/abs/2017MNRAS.465.4895W 465, 4895

  56. [56]

    H., Halkola A., 2019, arXiv e-prints, https://ui.adsabs.harvard.edu/abs/2019arXiv190407237Y p

    Y ld r m A., Suyu S. H., Halkola A., 2019, arXiv e-prints, https://ui.adsabs.harvard.edu/abs/2019arXiv190407237Y p. arXiv:1904.07237

  57. [57]

    R., 2017, @doi [ACM Trans

    Zaghloul M. R., 2017, @doi [ACM Trans. Math. Softw.] 10.1145/3119904 , 44, 22:1

  58. [58]

    R., 2009, @doi [ ] 10.1111/j.1365-2966.2009.15167.x , http://adsabs.harvard.edu/abs/2009MNRAS.398..607V 398, 607

    van de Ven G., Mandelbaum R., Keeton C. R., 2009, @doi [ ] 10.1111/j.1365-2966.2009.15167.x , http://adsabs.harvard.edu/abs/2009MNRAS.398..607V 398, 607