Comparing rotation curve observations to hydrodynamic ΛCDM simulations of galaxies

Pace, Andrew B.

doi:10.48550/arxiv.1605.05326

Cited by 8 publications

(12 citation statements)

References 197 publications

(290 reference statements)

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“…The former trend is neither seen in our data, and due to the lack of color data we can't say anything about the latter finding. The RC decompositions of Pace (2016) resulted in bimodal DC14 (Di Cintio et al 2014b) and PITS halo mass distributions, with a claimed similar degeneracy for the mass-to-light ratio. However, most of the larger masses were unrealistically high (comparable to galaxy group or cluster halo masses), thus mainly the lower mass solutions and the corresponding lower mass-to-light ratios were accepted for the best-fit decompositions of their galaxies.…”

Section: Mass-to-light Ratiomentioning

confidence: 82%

“…There is a vast literature on suggested parametrizations for total DM halo density profiles (e.g., An & Zhao 2013, for double power laws and the Einasto profile). For late-type spiral and lowluminous disk galaxies the rotation curves are particulary well described by corresponding halo density profiles with, on one hand, non-singular and non-steep ("constant") density cores, as with the Burkert (1995) profile, the PSS profile (Persic et al 1996;Borriello & Salucci 2001), or pseudo-isothermal spherical (PITS) profiles (Kormendy & Freeman 2004, 2016. On the other hand, simulations of galaxies within a lambda cold dark matter (ΛCDM) universe with hierarchical clustering predict cuspier, steep core density profiles that even become singular at the galaxy center, as with the widely used three-parameter double-power law by Zhao (1996).…”

mentioning

confidence: 99%

“…Comparing cored halo models, the results do not allow to conclusively select a single superior one, Breddels & Helmi (2013) even suspect that more than one type of parametric halo profile is necessary for realistic assessments. To give an idea, while Adams et al (2014) compares fits to the RCs of dwarf galaxies using Burkert and gNFW profiles and finds the latter to slightly perform better, Pace (2016) finds the PITS halo and the DC14 profiles to perform equally well and to outperform the Burkert and the NFW profiles. The result of Di Cintio et al (2014b) is motivated by hydrodynamical N-body simulations and includes as special cases both the isothermal and the gNFW halos, favored within the ΛCDM scenario.…”

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confidence: 99%

“…A panopticum of other scaling relations among various variables describing structural and kinematical properties of disk galaxies are known and kept being refined, such as LM parameter correlations (Giovanelli 1999;Courteau et al 2007), DM correlations among halo parameters (e.g., the supposed uniformity of halo central surface density), or DM-LM relations (e.g., Kormendy & Freeman 2004, 2016Lapi et al 2018, and references therein).…”

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confidence: 99%

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Structure-dynamics relations for late-type spiral and dwarf irregular galaxies revisited

Parodi¹

2018

Preprint

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Scaling relations among structural and kinematical features of 79 late-type spiral and dwarf irregular galaxies of the SPARC sample are revisited or newly established. The mean central surface brightness µ 0 <µ 0,[3.6] >= 19.63 ± 0.11 mag arcsec −2 allows for a clear-cut distinction between low and high surface brightness galaxies. At a given luminosity, LSB galaxies are more extended than HSB galaxies and the rotation curves have smaller inner circular velocity gradients dv(R d )/dr at one disk scale length R d . Irrespective of luminosity, the geometry of rotation curves is characterized by the relation dv(R d )/dr ≈ v max /R max , with v max being the maximum circular velocity reached at R max . For the rotation curve decompositions disk mass-tolight ratios are restricted to have constant, but semi-free best-fit values 0.2, 0.5, or 0.8 M /L at [3.6]; they exhibit an asymmetric bimodal distribution with the dominant peak located at the median value of 0.2 (minimum disks) and with the subdominant peak at 0.8 (maximum disks). Assuming dark matter halos of Burkert and of pseudo-isothermal (PITS) type, the former provide better fits for about two thirds of all galaxies. While the halo core densities ρ 0 are about equal, the core radii r 0 of PITS halos are systematically lower by a factor of about 0.6 as compared with those of the Burkert type. Focussing on the Burkert halo, the baryonic mass fraction at intermediate radii is included to address both an adjusted baryonic Tully-Fisher relation and the significance of deviations from the mean radial acceleration relation. The average radial decrease of the baryonic mass fraction within galaxies is quantified. The Burkert halo parameters obey ρ 0 ∝ r −1.5±0.1 0 with considerable scatter, but allowing v max as a third variable we find ρ 0 ∝ r −1.84±0.07 0 v 2.00±0.11 max with small scatter. The halo central surface density ρ 0 r 0 , with a sample median <ρ 0 r 0 > ≈ 121 M pc −2 (σ = 112), weakly correlates with µ 0 and with compactness C and strongly correlates with the observed radial acceleration g obs = v 2 obs (r)/r at different galactocentric radii. Consequently, because R max ∝ r 0 , we have a tight central halo column density versus maximum circular velocity relation v 2 max ∝ ρ 0 r 2 0 . Halo cores barely extend over the luminous disk, but their sizes do not correlate with the optical radii. We introduce an alternative to a prominent conventional universal rotation curve; it is based on the non-singular total matter density profile ρ total (r) = (v 2 max /4πGr 2 ) 1 − (1 − r/r c ) exp(−r/r c ) 2 , with the scaling parameter r c correlating with the halo core size r 0 . Fitting the synthetic URC to a selection of galaxies, the co-added doubly-normalized rotation curves exhibit a high degree of similarity. A couple of analytic URC decompositions into a baryonic disk and a dark matter component is accomplished.

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Section: Mass-to-light Ratiomentioning

confidence: 82%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Structure-dynamics relations for late-type spiral and dwarf irregular galaxies revisited

Parodi¹

2018

Preprint

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“…for a more detailed discussion). Regarding the measurement from Pace (2016), we only plot the well-constrained sub-sample from the paper. While this sample only contains galaxies with well behaved posteriors regarding the halo mass estimates, one should keep in mind that such an a posterio selection could lead to a bias with respect to the mean stellar-tohalo-mass relation.…”

Section: The Stellar-to-halo Mass Relationmentioning

confidence: 99%

Dark acoustic oscillations: Imprints on the matter power spectrum and the halo mass function

Schaeffer,

Schneider

2021

Preprint

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Many non-minimal dark matter scenarios lead to oscillatory features in the matter power spectrum induced by interactions either within the dark sector or with particles from the standard model. Observing such dark acoustic oscillations would therefore be a major step towards understanding dark matter. We investigate what happens to oscillatory features during the process of nonlinear structure formation. We show that at the level of the power spectrum, oscillations are smoothed out by nonlinear mode coupling, gradually disappearing towards lower redshifts. In the halo mass function, however, the same oscillations remain visible until the present epoch. As a consequence, dark acoustic oscillations could be detectable in observations that are either based on the halo mass function or on the high-redshift power spectrum. We investigate the effect of such oscillations on different observables, namely, the cluster mass function, the stellar-to-halo mass relation, and the Lyman-𝛼 flux power spectrum. We find that dark acoustic oscillations remain visible in all of these observables, but they are very extended and of low amplitude, making it challenging to detect them as distinct features in the data.

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The no-spin zone: rotation versus dispersion support in observed and simulated dwarf galaxies

Wheeler

Pace

Bullock

et al. 2016

Mon. Not. R. Astron. Soc.

Self Cite

110

104

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We perform a systematic Bayesian analysis of rotation vs. dispersion support (v rot /σ) in 40 dwarf galaxies throughout the Local Volume (LV) over a stellar mass range 10 3.5 M < M < 10 8 M . We find that the stars in ∼ 80% of the LV dwarf galaxies studied -both satellites and isolated systems -are dispersion-supported. In particular, we show that 6/10 isolated dwarfs in our sample have v rot /σ 1.0, while all have v rot /σ 2.0. These results challenge the traditional view that the stars in gas-rich dwarf irregulars (dIrrs) are distributed in cold, rotationally-supported stellar disks, while gas-poor dwarf spheroidals (dSphs) are kinematically distinct in having dispersion-supported stars. We see no clear trend between v rot /σ and distance to the closest L galaxy, nor between v rot /σ and M within our mass range. We apply the same Bayesian analysis to four FIRE hydrodynamic zoom-in simulations of isolated dwarf galaxies (10 9 M < M vir < 10 10 M ) and show that the simulated isolated dIrr galaxies have stellar ellipticities and stellar v rot /σ ratios that are consistent with the observed population of dIrrs and dSphs without the need to subject these dwarfs to any external perturbations or tidal forces. We posit that most dwarf galaxies form as puffy, dispersion-dominated systems, rather than cold, angular momentum-supported disks. If this is the case, then transforming a dIrr into a dSph may require little more than removing its gas.

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Comparing rotation curve observations to hydrodynamic ΛCDM simulations of galaxies

Cited by 8 publications

References 197 publications

Structure-dynamics relations for late-type spiral and dwarf irregular galaxies revisited

Structure-dynamics relations for late-type spiral and dwarf irregular galaxies revisited

Dark acoustic oscillations: Imprints on the matter power spectrum and the halo mass function

The no-spin zone: rotation versus dispersion support in observed and simulated dwarf galaxies

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