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We here-in demonstrate that the proposed hitherto unknown gravitomagnetic dark-force that hypothetically explains the Flat Rotation Curves of Spiral Galaxies — this same force, explains very well, the logarithmic and as-well, the barred spiral shapes of spiral galaxies. That is, much in line with Edward Arthur Milne (1896-1950)’s 1946 ideas — albeit, on a radically and asymptotically different philosophical train of thought, the galactic disk is here assumed to be in a state of free-fall around the central bulge with the hypothetical gravitomagnetic dark-force being the dominant force determining all gravity-related dynamics of the disk, thus leading to logarithmic and barred spiral orbits, hence the shape of spiral galaxies.

It has recently been suggested that a gravitational transition of the effective Newton's constant $G_{\rm eff}$ by about 10%, taking place 50-150 Myrs ago, can lead to the resolution of both the Hubble crisis and the growth tension of the standard $\Lambda$CDM model. Hints for such an abrupt transition with weaker gravity at times before the transition, have recently been identified in Tully Fisher galactic mass-velocity data and also in Cepheid SnIa calibrator data. Here we use Monte-Carlo simulations to show that such a transition could significantly increase (by a factor of 3 or more) the number of long period comets (LPCs) impacting the solar system from the Oort cloud (semi-major axis of orbits $\gtrsim 10^4AU$). This increase is consistent with observational evidence from the terrestrial and lunar cratering rates indicating that the impact flux of kilometer sized objects increased by at least a factor of 2 over that last 100 Myrs compared to the long term average. This increase may also be connected with the Chicxulub impactor event that produced the Cretaceous-Tertiary (K-T) extinction of 75% of life on Earth (including dinosaurs) about 66 Myrs ago. We use Monte-Carlo simulations to show that for isotropic Oort cloud comet distribution with initially circular orbits, random velocity perturbations (induced eg by passing stars and/or galactic tidal effects), lead to a deformation of the orbits that increases significantly when $G_{\rm eff}$ increases. A 10% increase of $G_{\rm eff}$ leads to an increase in the probability of the comets to enter the loss cone and reach the planetary region (pericenter of less than 10AU) by a factor that ranges from 5% (for velocity perturbation much smaller than the comet initial velocity) to more than 300% (for total velocity perturbations comparable with the initial comet velocity)., Comment: 9 pages, 7 figures. Comments added in subsection 1.2. References added, typos corrected

We explore the Baryonic Tully-Fisher Relation in the Local Group. Rotationally supported Local Group galaxies adhere precisely to the relation defined by more distant galaxies. For pressure supported dwarf galaxies, we determine the scaling factor $\beta_c$ that relates their observed velocity dispersion to the equivalent circular velocity of rotationally supported galaxies of the same mass such that $V_o = \beta_c \sigma_*$. For a typical mass-to-light ratio $\Upsilon_* = 2\;\mathrm{M}_{\odot}/\mathrm{L}_{\odot}$ in the $V$-band, we find that $\beta_c = 2$. More generally, $\log \beta_c = 0.25 \log \Upsilon_* +0.226$. This provides a common kinematic scale relating pressure and rotationally supported dwarf galaxies., Comment: 14 pages, 4 figures. Accepted for publication in the Astronomical Journal

We present a novel 2D flux density model for observed HI emission lines combined with a Bayesian stacking technique to measure the baryonic Tully-Fisher relation below the nominal detection threshold. We simulate a galaxy catalogue, which includes HI lines described either with Gaussian or busy function profiles, and HI data cubes with a range of noise and survey areas similar to the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. With prior knowledge of redshifts, stellar masses and inclinations of spiral galaxies, we find that our model can reconstruct the input baryonic Tully-Fisher parameters (slope and zero point) most accurately in a relatively broad redshift range from the local Universe to $z = 0.3$ for all the considered levels of noise and survey areas, and up to $z = 0.55$ for a nominal noise of $90\,\mu$Jy/channel over 5 deg$^{2}$. Our model can also determine the $M_{\rm HI} - M_{\star}$ relation for spiral galaxies beyond the local Universe, and account for the detailed shape of the HI emission line, which is crucial for understanding the dynamics of spiral galaxies. Thus, we have developed a Bayesian stacking technique for measuring the baryonic Tully-Fisher relation for galaxies at low stellar and/or HI masses and/or those at high redshift, where the direct detection of HI requires prohibitive exposure times., Comment: 13 pages, 9 figures. Accepted for publication in MNRAS

Galaxies in dense environments are subject to interactions and mechanisms which directly affect their evolution by lowering their gas fractions and reducing their star-forming capacity earlier than their isolated counterparts. The aim of our project is to get new insights about the role of environment on the stellar and baryonic content of galaxies using a kinematic approach, through the study of the Tully-Fisher relation (TFR). We study a sample of galaxies in 8 groups spanning a redshift range of $0.5, Comment: Accepted for publication in Astronomy & Astrophysics

A recent study of a sample of wide binary star systems from the Hipparcos and Gaia catalogues has found clear evidence of a gravitational anomaly of the same kind as that appearing in galaxies and galactic clusters. Instead of a relative orbital velocity decaying as the square root of the separation, &Delta, V&prop, r&minus, 1/2, it was shown that an asymptotic constant velocity is reached for distances of order 0.1 pc. If confirmed, it would be difficult to accommodate this breakdown of Kepler&rsquo, s laws within the current dark matter (DM) paradigm because DM does not aggregate in small scales, so there would be very little DM in a 0.1 pc sphere. In this paper, we propose a simple non-Newtonian model of gravity that could explain both the wide binaries anomaly and the anomalous rotation curves of galaxies as codified by the Tully-Fisher relation. The required extra potential can be understood as a Klein-Gordon field with a position-dependent mass parameter. The extra forces behave as 1/r on parsec scales and r on Solar system scales. We show that retrograde anomalous perihelion precessions are predicted for the planets. This could be tested by precision ephemerides in the near future.

We explore the use of the baryonic Tully-Fisher relation (bTFR) as a new distance indicator. Advances in near-IR imaging and stellar population models, plus precise rotation curves, have reduced the scatter in the bTFR such that distance is the dominant source of uncertainty. Using 50 galaxies with accurate distances from Cepheids or tip magnitude of the red giant branch, we calibrate the bTFR on a scale independent of $H_o$. We then apply this calibrated bTFR to 95 independent galaxies from the SPARC sample, using CosmicFlows-3 velocities, to deduce the local value of $H_o$. We find $H_o$ = 75.1 +/- 2.3 (stat) +/- 1.5 (sys) km s$^{-1}$ Mpc$^{-1}$., 21 pages, 3 figures, accepted by AJ

The relation between early type galaxy size, surface brightness and velocity dispersion, "the fundamental plane", has long been understood as resulting from equilibrium in their largely pressure supported stellar dynamics. The dissipation and feedback involved in reaching such an equilibrium through merger formation of these galaxies over cosmic time can be responsible for the orientation of the plane. We see a correlation between surface brightness enhancement and youth in the 6dF Galaxy Survey. Correlations of this `tilt' with stellar mass, age, concentration, shape and metallicity now point the direction for further work on the resolved kinematics and structure of these nearby galaxies and on their initial mass function and dark matter component. On the face of it, the Tully Fisher relation is a simpler one dimensional scaling relation. However, as late type galaxies have bulges as well as disks, and, as the surface density of disks is only standard for the more massive galaxies, additional parameters are involved., For publication in Frontiers in Astronomy and Space Sciences

We investigate the Baryonic Tully-Fisher Relation (BTFR) in the $(100\,h^{-1}{\rm Mpc})^3$ Simba hydrodynamical galaxy formation simulation together with a higher-resolution $(25\,h^{-1}{\rm Mpc})^3$ Simba run, for over $10,000$ disk-dominated, HI-rich galaxies. We generate simulated galaxy rotation curves from the mass distribution, which we show yields similar results to using the gas rotational velocities. From this we measure the galaxy rotation velocity $V_{\rm circ}$ using four metrics: $V_{\rm max}, V_{\rm flat}, V_{2R_e},$ and $V_{\rm polyex}$. We compare the predicted BTFR to the SPARC observational sample and find broad agreement. In detail, however, Simba is biased towards higher $V_{\rm circ}$ by up to 0.1 dex. We find evidence for the flattening of the BTFR in $V_{\rm circ}>300$ km s$^{-1}$ galaxies, in agreement with recent observational findings. Simba's rotation curves are more peaked for lower mass galaxies, in contrast with observations, suggesting overly bulge-dominated dwarf galaxies in our sample. We investigate for residuals around the BTFR versus HI mass, stellar mass, gas fraction, and specific star formation rate, which provide testable predictions for upcoming BTFR surveys. Simba's BTFR shows sub-optimal resolution convergence, with the higher-resolution run lowering $V$ in better agreement with data., 18 pages, 11 figures. Accepted for publication in MNRAS

Most fully developed galaxies have vivid spiral structure, but the formation and evolution of spiral structure is still a mystery that is not fully understood in astrophysics. We find that the currently used equations of galactic dynamics contain some unreasonable components. In this paper, the following three working assumptions are introduced to simplify the galactic structural equations. 1. In the research of large-scale structure, the retarded potential of the gravitational field should be taken into account. The propagating time of the gravitational field from center to border is longer than the revolution periods of the stars near the center of galaxy. Newton's gravitational potential is unreasonable for such case, and the weak field and low velocity approximation of Einstein's field equation should be adopted. 2. The stars in a fully developed galaxy should be zero-pressure and inviscid fluid, and the equation of motion is different from that of ordinary continuum mechanics. Stars move along geodesics. 3. The structure of the galaxy is only related to the total mass density distribution. The equation of state of dark halo is different from that of ordinary luminous interstellar matter, so their trajectories are also very different. Dark halo and ordinary matter in galaxy are automatically separated. The total mass density distribution can be presupposed according to the observation data, and then it can be determined by comparing the solution of the equations with the observed data. These assumptions and treatments are supported by theory and observation. The variables of the equations of simplified galactic dynamics are separated from each other, and the equations are well-posed and can be solved according to a definite procedure. Therefore, this simplified dynamic equation system provides a more reasonable and practical framework for the further study of galactic structure, and can solve many practical problems. Besides, it is closely related to the study of dark energy and dark matter.

We present a multiwavelength study of the AGN-host starburst galaxy PKS 0529-549 at z similar or equal to 2.6. We use (1) new ALMA observations of the dust continuum and of the [CI] 370 mu m line, tracing molecular gas, (2) SINFONI spectroscopy of the [OIII] 5007 angstrom line, tracing ionized gas, and (3) ATCA radio continuum images, tracing synchrotron emission. Both [CI] and [O III] show regular velocity gradients, but their systemic velocities and position angles differ by similar to 300 km s(-1) and similar to 30 degrees, respectively. The [CI] is consistent with a rotating disc, aligned with the dust and stellar continuum, while the [OIII] likely traces an outflow, aligned with two AGN-driven radio lobes. We model the [CI] cube using 3D disc models, which give best-fitting rotation velocities V-rot similar or equal to 310 km s(-1) and velocity dispersions sigma(V) less than or similar to 30 km s(-1). Hence, the [CI] disc has V-rot/sigma(V) greater than or similar to 10 and is not particularly turbulent, similar to local galaxy discs. The dynamical mass (similar to 10(11) M-circle dot) is comparable to the baryonic mass within the errors. This suggests that baryons dominate the inner galaxy dynamics, similar to massive galaxies at z similar or equal to 0. Remarkably, PKS 0529-549 lies on the local baryonic Tully-Fisher relation, indicating that at least some massive galaxies are already in place and kinematically relaxed at z similar or equal to 2.6. This work highlights the potential of the [CI] line to trace galaxy dynamics at high z, as well as the importance of multiwavelength data to interpret gas kinematics.

In a recent paper McGaugh, Lelli, and Schombert showed that in an empirical plot of the observed centripetal accelerations in spiral galaxies against those predicted by the Newtonian gravity of the luminous matter in those galaxies the data points occupied a remarkably narrow band. While one could summarize the mean properties of the band by drawing a single mean curve through it, by fitting the band with the illustrative conformal gravity theory with fits that fill out the width of the band we show here that the width of the band is just as physically significant. We show that at very low luminous Newtonian accelerations the plot can become independent of the luminous Newtonian contribution altogether, but still be non-trivial due to the contribution of matter outside of the galaxies (viz. the rest of the visible universe). We present a new empirical plot of the difference between the observed centripetal accelerations and the luminous Newtonian expectations as a function of distance from the centers of galaxies, and show that at distances greater than 10 kpc the plot also occupies a remarkably narrow band, one even close to constant. Using the conformal gravity theory we provide a first principles derivation of the empirical Tully-Fisher relation., Comment: 6 pages, 15 figures. The paper is a comment on S. S. McGaugh, F. Lelli, and J. M. Schombert, Phys. Rev. Lett. 117, 201101 (2016). Updated to include a first principles derivation of the Tully-Fisher relation using the conformal gravity theory. Submitted to Physics Letters B

The dearth of dwarf galaxies in the local universe is hard to reconcile with the large number of low mass haloes expected within the concordance $\Lambda$CDM paradigm. In this paper we perform a systematic evaluation of the uncertainties affecting the measurement of DM halo abundance using galaxy kinematics. Using a large sample of dwarf galaxies with spatially resolved kinematic data we derive a correction to obtain the observed abundance of galaxies as a function of their halo maximum circular velocity from the line-of-sight velocity function in the Local Volume. This estimate provides a direct means of comparing the predictions of theoretical models and simulations (including nonstandard cosmologies and novel galaxy formation physics) to the observational constraints. The new "galactic $V_{max}$" function is steeper than the line-of-sight velocity function but still shallower than the theoretical CDM expectation, showing that some unaccounted physical process is necessary to reduce the abundance of galaxies and/or drastically modify their density profiles compared to CDM haloes. Using this new galactic $V_{max}$ function, we investigate the viability of baryonic solutions such as feedback-powered outflows and photoevaporation of gas from an ionising radiation background. At the 3-$\sigma$ confidence level neither energetic feedback nor photoevaporation are effective enough to reconcile the disagreement. In the case of maximum baryonic effects, the theoretical estimate still deviates significantly from the observations for $V_{max} < 60$ km/s. CDM predicts at least 1.8 times more galaxies with $V_{max} = 50$ km/s and 2.5 times more than observed at $30$ km/s. Recent hydrodynamic simulations seem to resolve the discrepancy but disagree with the properties of observed galaxies with resolved kinematics. (abridged), Comment: 17 pages, 22 figures; major revisions include clarification of the method, expanded comparison with simulations with a new figure, analysis of uncertainties in model as well as pressure support corrections, and a new table with nomenclature

We use a sample of 83 high-resolution cosmological zoom-in simulations and a semi-analytic model (SAM) to study the stochasticity of galaxy formation in haloes ranging from dwarf to Milky Way masses. Our simulated galaxies reproduce the observed inefficiency of galaxy formation as expressed through the stellar, gas and baryonic Tully-Fisher relations. For HI velocities in the range (70 less than or similar to V less than or similar to 220 km s(-1)), the scatter is just 0.08 to 0.14 dex, consistent with the observed intrinsic scatter at these scales. At low velocities (20 less than or similar to V less than or similar to 70 km s(-1)), the simulated scatter is 0.2-0.25 dex, which could be tested with future observations. The scatter in the stellar mass versus dark halo velocity relation is constant for 30 less than or similar to V less than or similar to 180 km s(-1), and smaller (similar or equal to 0.17 dex) when using the maximum circular velocity of the dark-matter-only simulation, V-max(DMO), compared to the virial velocity (V-200 or V-200(DMO)). The scatter in stellar mass is correlated with halo concentration, and is minimized when using a circular velocity at a fixed fraction of the virial radius similar or equal to 0.4R(200) or with V-alpha = V-200(DMO)(V-max(DMO) / V-200(DMO))(alpha) with alpha similar or equal to 0.7, consistent with constraints from halo clustering. Using the SAM we show the correlation between halo formation time and concentration is essential in order to reproduce this result. This uniformity in galaxy formation efficiency we see in our hydrodynamical simulations and an SAM proves the simplicity and self-regulating nature of galaxy formation in a Lambda cold dark matter (Lambda CDM) universe.

We use the 2MFGC catalogue for investigation of large-scale flows on the basis of the Tully-Fisher relation (TFR). The catalogue contains 18020 galaxies selected from the extended sources of the infrared sky survey 2MASS XSC. The majority of galaxies in the catalogue are spiral galaxies of late morphological types whose discs are visible almost from the edge. For more than a decade of the catalogue usage, the number of galaxies in HyperLEDA database with the measured radial velocities and rotational velocities (that are necessary to construct the TFR) has been increased by about 17%. In this paper, an updated working sample of 2MFGC galaxies is presented and earlier results are revised taking into account new data. We have confined ourselves to comparison of only the "old" and "new" parameters of the dipole component of the velocity field. The dipole bulk motion of galaxies of this sample with respect to cosmic microwave radiation is characterised by a velocity of V=264±36 km/s in the direction l=308°±8°, b=-16°±6°.

In this paper we investigate the statistical properties of the Tully-Fisher relation for a sample of 32 galaxies with measured distances from the Cepheid period-luminosity relation and/or TRGB stars. We take advantage of panchromatic photometry in 12 bands (from FUV to 4.5 $\mu$m) and of spatially resolved HI kinematics. We use these data together with three kinematic measures ($W^{i}_{50}$, $V_{max}$ and $V_{flat}$) extracted from the global HI profiles or HI rotation curves, so as to construct 36 correlations allowing us to select the one with the least scatter. We introduce a tightness parameter $\sigma_{\perp}$ of the TFr, in order to obtain a slope-independent measure of the goodness of fit. We find that the tightest correlation occurs when we select the 3.6 $\mu$m photometric band together with the $V_{flat}$ parameter extracted from the HI rotation curve., Comment: 16 pages, 16 figures, accepted for publication in MNRAS, minor changes due to proof corrections

In $\Lambda$CDM cosmology, to first order, galaxies form out of the cooling of baryons within the virial radius of their dark matter halo. The fractions of mass and angular momentum retained in the baryonic and stellar components of disc galaxies put strong constraints on our understanding of galaxy formation. In this work, we derive the fraction of angular momentum retained in the stellar component of spirals, $f_j$, the global star formation efficiency $f_M$, and the ratio of the asymptotic circular velocity ($V_{\rm flat}$) to the virial velocity $f_V$, and their scatter, by fitting simultaneously the observed stellar mass-velocity (Tully-Fisher), size-mass, and mass-angular momentum (Fall) relations. We compare the goodness of fit of three models: (i) where the logarithm of $f_j$, $f_M$, and $f_V$ vary linearly with the logarithm of the observable $V_{\rm flat}$; (ii) where these values vary as a double power law; and (iii) where these values also vary as a double power law but with a prior imposed on $f_M$ such that it follows the expectations from widely used abundance matching models. We conclude that the scatter in these fractions is particularly small ($\sim 0.07$ dex) and that the linear model is by far statistically preferred to that with abundance matching priors. This indicates that the fundamental galaxy formation parameters are small-scatter single-slope monotonic functions of mass, instead of being complicated non-monotonic functions. This incidentally confirms that the most massive spiral galaxies should have turned nearly all the baryons associated with their haloes into stars. We call this the failed feedback problem., Comment: A&A in press (17 pages, 3 appendices)

Observations of evolution in the dust-to-metal ratio allow us to constrain the dominant dust processing mechanisms. In this work, we present a study of the dust-to-metal and dust-to-gas ratios in a sub-sample of ~500 DustPedia galaxies. Using literature and MUSE emission line fluxes, we derived gas-phase metallicities (oxygen abundances) for over 10000 individual regions and determine characteristic metallicities for each galaxy. We study how the relative dust, gas, and metal contents of galaxies evolve by using metallicity and gas fraction as proxies for evolutionary state. The global oxygen abundance and nitrogen-to-oxygen ratio are found to increase monotonically as galaxies evolve. Additionally, unevolved galaxies (gas fraction > 60%, metallicity 12 + log(O/H) < 8.2) have dust-to-metal ratios that are about a factor of 2.1 lower (a factor of six lower for galaxies with gas fraction > 80%) than the typical dust-to-metal ratio (Md/MZ ~ 0.214) for more evolved sources. However, for high gas fractions, the scatter is larger due to larger observational uncertainties as well as a potential dependence of the dust grain growth timescale and supernova dust yield on local conditions and star formation histories. We find chemical evolution models with a strong contribution from dust grain growth describe these observations reasonably well. The dust-to-metal ratio is also found to be lower for low stellar masses and high specific star formation rates (with the exception of some sources undergoing a starburst). Finally, the metallicity gradient correlates weakly with the HI-to-stellar mass ratio, the effective radius and the dust-to-stellar mass ratio, but not with stellar mass., 24 pages, 15 figures, published in A&A, bibref: 2019A&A...623A...5D, This Version 2 has increased accuracy in Table B1 in appendix B

We construct Tully–Fisher relations (TFRs), from large samples of galaxies with spatially resolved H α emission maps from the K-band Multi-Object Spectrograph (KMOS) Redshift One Spectroscopic Survey (KROSS) at z ≈ 1. We compare these to data from the Sydney-Australian-Astronomical-Observatory Multi-object Integral-Field Spectrograph (SAMI) Galaxy Survey at z ≈ 0. We stringently match the data quality of the latter to the former, and apply identical analysis methods and sub-sample selection criteria to both to conduct a direct comparison of the absolute K-band magnitude and stellar mass TFRs at z ≈ 1 and 0. We find that matching the quality of the SAMI data to that of KROSS results in TFRs that differ significantly in slope, zero-point, and (sometimes) scatter in comparison to the corresponding original SAMI relations. These differences are in every case as large as or larger than the differences between the KROSS z ≈ 1 and matched SAMI z ≈ 0 relations. Accounting for these differences, we compare the TFRs at z ≈ 1 and 0. For disc-like, star-forming galaxies we find no significant difference in the TFR zero-points between the two epochs. This suggests the growth of stellar mass and dark matter in these types of galaxies is intimately linked over this ≈8 Gyr period.

We use data from the Sydney-AAO Multi-object Integral-field spectroscopy (SAMI) Galaxy Survey to study the dynamical scaling relation between galaxy stellar mass $M_*$ and the general kinematic parameter $S_K = \sqrt{K V_{rot}^2 + \sigma^2}$ that combines rotation velocity $V_{rot}$ and velocity dispersion $\sigma$. We show that the $\log M_* - \log S_K$ relation: (1)~is linear above limits set by properties of the samples and observations; (2)~has slightly different slope when derived from stellar or gas kinematic measurements; (3)~applies to both early-type and late-type galaxies and has smaller scatter than either the Tully-Fisher relation ($\log M_* - \log V_{rot}$) for late types or the Faber-Jackson relation ($\log M_* - \log\sigma$) for early types; and (4)~has scatter that is only weakly sensitive to the value of $K$, with minimum scatter for $K$ in the range 0.4 and 0.7. We compare $S_K$ to the aperture second moment (the `aperture velocity dispersion') measured from the integrated spectrum within a 3-arcsecond radius aperture ($\sigma_{3^{\prime\prime}}$). We find that while $S_{K}$ and $\sigma_{3^{\prime\prime}}$ are in general tightly correlated, the $\log M_* - \log S_K$ relation has less scatter than the $\log M_* - \log \sigma_{3^{\prime\prime}}$ relation., Comment: 14 pages, 8 figures, Accepted 2019 May 22. Received 2019 May 18; in original form 2019 January 6

We study the gas kinematics traced by the 21-cm emission of a sample of six HI$-$rich low surface brightness galaxies classified as ultra-diffuse galaxies (UDGs). Using the 3D kinematic modelling code $\mathrm{^{3D}}$Barolo we derive robust circular velocities, revealing a startling feature: HI$-$rich UDGs are clear outliers from the baryonic Tully-Fisher relation, with circular velocities much lower than galaxies with similar baryonic mass. Notably, the baryon fraction of our UDG sample is consistent with the cosmological value: these UDGs are compatible with having no "missing baryons" within their virial radii. Moreover, the gravitational potential provided by the baryons is sufficient to account for the amplitude of the rotation curve out to the outermost measured point, contrary to other galaxies with similar circular velocities. We speculate that any formation scenario for these objects will require very inefficient feedback and a broad diversity in their inner dark matter content., Accepted for publication by The Astrophysical Journal Letters (ApJL). V2: Acknowledgments have been updated, and a typo has been corrected

Using a recent homogeneous sample of 40 high quality velocity dispersion profiles for Galactic globular clusters, we study the low gravitational acceleration regime relevant to the outskirts of these systems. We find that a simple empirical profile having a central Gaussian component and a constant large radius asymptote, $\sigma_{\infty}$, accurately describes the variety of observed velocity dispersion profiles. We use published population synthesis models, carefully tailored to each individual cluster, to estimate mass to light ratios from which total stellar masses, $M$, are inferred. We obtain a clear scaling, reminiscent of the galactic Tully-Fisher relation of $\sigma_{\infty}( km s^{-1})= 0.084^{+0.075}_{-0.040} (M/M_{\odot})^{0.3 \pm 0.051} $, which is interesting to compare to the deep MOND limit of $\sigma_{\infty} (km s^{-1})=0.2(M/M_{\odot})^{0.25}$. Under a Newtonian interpretation, our results constitute a further restriction on models where initial conditions are crafted to yield the outer flattening observed today. Within a modified gravity scheme, as the globular clusters studied are not isolated objects in the deep MOND regime, the results obtained point towards a modified gravity where the external field effect of MOND does not appear, or is much suppressed., Comment: 9 pages, 8 figures, 1 table. Revised version accepted for publication in MNRAS

We present a 3D Bayesian method to model the kinematics of strongly lensed galaxies from spatially-resolved emission-line observations. This technique enables us to simultaneously recover the lens-mass distribution and the source kinematics directly from the 3D data cube. We have tested this new method with simulated OSIRIS observations for nine star-forming lensed galaxies with different kinematic properties. The simulated rotation curves span a range of shapes which are prototypes of different morphological galaxy types, from dwarf to massive spiral galaxies. We have found that the median relative accuracy on the inferred lens and kinematic parameters are at the level of 1 and 2 per cent, respectively. We have also tested the robustness of the technique against different inclination angles, signal-to-noise ratios, the presence of warps or non-circular motions and we have found that the accuracy stays within a few per cent in most cases. This technique represents a significant step forward with respect to the methods used until now, as the lens parameters and the kinematics of the source are derived from the same 3D data. This enables us to study the possible degeneracies between the two and estimate the uncertainties on all model parameters consistently., Accepted for publication in MNRAS

Carbon monoxide (CO) observations show a luminosity$-$line-width correlation that evolves with redshift. We present a method to use CO measurements alone to infer the molecular gas fraction ($f_{\rm mol}$) and constrain the CO$-$H$_2$ conversion factor ($\alpha_{\rm CO}$). We compile from the literature spatially integrated low-$J$ CO observations of six galaxy populations, including a total of 449 galaxies between $0.01 \leq z \leq 3.26$. The CO data of each population provide an estimate of the $\alpha_{\rm CO}$-normalized mean molecular gas fraction ($f_{\rm mol}/\alpha_{\rm CO}$). The redshift evolution of the luminosity$-$line-width correlation thus indicates an evolution of $f_{\rm mol}/\alpha_{\rm CO}$. We use a Bayesian-based Monte-Carlo Markov Chain sampler to derive the posterior probability distribution functions of $f_{\rm mol}/\alpha_{\rm CO}$ for these galaxy populations, accounting for random inclination angles and measurement errors in the likelihood function. We find that the molecular gas fraction evolves rapidly with redshift, $f_{\rm mol} \propto (1+z)^\beta$ with $\beta \simeq 2$, for both normal star-forming and starburst galaxies. Furthermore, the evolution trend agrees well with that inferred from the Kennicutt-Schmidt relation and the star-forming main sequence. Finally, at $z < 0.1$ normal star-forming galaxies require a $\sim5\times$ larger $\alpha_{\rm CO}$ than starburst galaxies to match their molecular gas fractions, but at $z > 1$ both star-forming types exhibit sub-Galactic $\alpha_{\rm CO}$ values and normal star-forming galaxies appear more gas-rich than starbursts. Future applications of this method include calibrating Tully-Fisher relations without inclination correction and inferring the evolution of the atomic gas fraction with HI observations., Comment: 8 pages, 3 figures, 1 table. Accepted by ApJ Letters. The methodology is given in a Jupyter notebook here: https://github.com/fuhaiastro/py4astro/blob/main/emcee/IXF18.ipynb

We present a multiwavelength study of the AGN-host starburst galaxy PKS 0529-549 at z similar or equal to 2.6. We use (1) new ALMA observations of the dust continuum and of the [CI] 370 mu m line, tracing molecular gas, (2) SINFONI spectroscopy of the [OIII] 5007 angstrom line, tracing ionized gas, and (3) ATCA radio continuum images, tracing synchrotron emission. Both [CI] and [O III] show regular velocity gradients, but their systemic velocities and position angles differ by similar to 300 km s(-1) and similar to 30 degrees, respectively. The [CI] is consistent with a rotating disc, aligned with the dust and stellar continuum, while the [OIII] likely traces an outflow, aligned with two AGN-driven radio lobes. We model the [CI] cube using 3D disc models, which give best-fitting rotation velocities V-rot similar or equal to 310 km s(-1) and velocity dispersions sigma(V) less than or similar to 30 km s(-1). Hence, the [CI] disc has V-rot/sigma(V) greater than or similar to 10 and is not particularly turbulent, similar to local galaxy discs. The dynamical mass (similar to 10(11) M-circle dot) is comparable to the baryonic mass within the errors. This suggests that baryons dominate the inner galaxy dynamics, similar to massive galaxies at z similar or equal to 0. Remarkably, PKS 0529-549 lies on the local baryonic Tully-Fisher relation, indicating that at least some massive galaxies are already in place and kinematically relaxed at z similar or equal to 2.6. This work highlights the potential of the [CI] line to trace galaxy dynamics at high z, as well as the importance of multiwavelength data to interpret gas kinematics.

We present a multiwavelength study of the AGN-host starburst galaxy PKS 0529-549 at z~2.6. We use (1) new ALMA observations of the dust continuum and of the [CI] 370 um line, tracing molecular gas, (2) SINFONI spectroscopy of the [OIII] 5007 Ang line, tracing ionized gas, and (3) ATCA radio continuum images, tracing synchrotron emission. Both [CI] and [OIII] show regular velocity gradients, but their systemic velocities and position angles differ by ~300 km/s and ~30 degrees, respectively. The [CI] is consistent with a rotating disc, aligned with the dust and stellar continuum, while the [OIII] likely traces an outflow, aligned with two AGN-driven radio lobes. We model the [CI] cube using 3D disc models, which give best-fit rotation velocities V~310 km/s and velocity dispersions sigma10 and is not particularly turbulent, similar to local galaxy discs. The dynamical mass (~10^11 Msun) is comparable to the baryonic mass within the errors. This suggests that baryons dominate the inner galaxy dynamics, similar to massive galaxies at z=0. Remarkably, PKS 0529-549 lies on the local baryonic Tully-Fisher relation, indicating that at least some massive galaxies are already in place and kinematically relaxed at z~2.6. This work highlights the potential of the [CI] line to trace galaxy dynamics at high z, as well as the importance of multiwavelength data to interpret gas kinematics., 9 pages, 4 figures, accepted for publication in MNRAS

We construct a multiparametric Tully-Fisher (TF) relation for a large sample of edge-on galaxies from the Revised Flat Galaxy Catalog using HI data from the EDD database and parameters from the EGIS catalog. We incorporate a variety of additional parameters including structural parameters of edge-on galaxies in different bandpasses. Besides the rotation curve maximum, only the HI-to-optical luminosity ratio and optical colours play a statistically significant role in the multiparametric TF relation. We are able to decrease the standard deviation of the multiparametric TF relation down to 0.32 mag, which is at the level of best modern samples of galaxies used for studies of the matter motion in the Universe via the TF-relation., 8 pages, accepted for publication in MNRAS

The distribution of galaxies in the stellar specific angular momentum versus stellar mass plane ($j_{\star}$-$M_{\star}$) provides key insights into their formation mechanisms. In this paper, we determine the location in this plane of a sample of ten field/group unbarred lenticular (S0) galaxies from the CALIFA survey. We performed a bulge-disc decomposition both photometrically and kinematically to study the stellar specific angular momentum of the disc components alone and understand the evolutionary links between S0s and other Hubble types. We found that eight of our S0 discs have a distribution in the $j_{\star}$-$M_{\star}$ plane that is fully compatible with that of spiral discs, while only two have values of $j_{\star}$ lower than the spirals. These two outliers show signs of recent merging. Our results suggest that merger and interaction processes are not the dominant mechanisms in S0 formation in low-density environments. Instead, S0s appear to be the result of secular processes and the fading of spiral galaxies after the shutdown of star formation., 35 pages, 22 figures. Accepted for publication in MNRAS

We perform a kinematic and morphological analysis of 44 star-forming galaxies at $z\sim2$ in the COSMOS legacy field using near-infrared spectroscopy from Keck/MOSFIRE and F160W imaging from CANDELS/3D-HST as part of the ZFIRE survey. Our sample consists of cluster and field galaxies from $2.0 < z < 2.5$ with K band multi-object slit spectroscopic measurements of their H$\alpha$ emission lines. H$\alpha$ rotational velocities and gas velocity dispersions are measured using the Heidelberg Emission Line Algorithm (HELA), which compares directly to simulated 3D data-cubes. Using a suite of simulated emission lines, we determine that HELA reliably recovers input S$_{0.5}$ and angular momentum at small offsets, but $V_{2.2}/\sigma_g$ values are offset and highly scattered. We examine the role of regular and irregular morphology in the stellar mass kinematic scaling relations, deriving the kinematic measurement S$_{0.5}$, and finding $\log(S_{0.5}) = (0.38\pm0.07)\log(M/M_{\odot}-10) + (2.04\pm0.03)$ with no significant offset between morphological populations and similar levels of scatter ($\sim0.16$ dex). Additionally, we identify a correlation between M$_{\star}$ and $V_{2.2}/\sigma_g$ for the total sample, showing an increasing level of rotation dominance with increasing M$_{\star}$, and a high level of scatter for both regular and irregular galaxies. We estimate the specific angular momenta ($j_{disk}$) of these galaxies and find a slope of $0.36\pm0.12$, shallower than predicted without mass-dependent disk growth, but this result is possibly due to measurement uncertainty at M$_{\star}$ $, Comment: Accepted to ApJ

Galaxies covering several orders of magnitude in stellar mass and a variety of Hubble types have been shown to follow the "Radial Acceleration Relation" (RAR), a relationship between $g_{\rm obs}$, the observed circular acceleration of the galaxy, and $g_{\rm bar}$, the acceleration due to the total baryonic mass of the galaxy. For accelerations above $10^{10}~{\rm m \, s}^{-2}$, $g_{\rm obs}$ traces $g_{\rm bar}$, asymptoting to the 1:1 line. Below this scale, there is a break in the relation such that $\rm g_{\rm obs} \sim g_{\rm bar}^{1/2}$. We show that the RAR slope, scatter and the acceleration scale are all natural consequences of the well-known baryonic Tully-Fisher relation (BTFR). We further demonstrate that galaxies with a variety of baryonic and dark matter (DM) profiles and a wide range of dark halo and galaxy properties (well beyond those expected in CDM) lie on the RAR if we simply require that their rotation curves satisfy the BTFR. We explore conditions needed to break this degeneracy: sub-kpc resolved rotation curves inside of "cored" DM-dominated profiles and/or outside $\gg 100\,$kpc could lie on BTFR but deviate in the RAR, providing new constraints on DM., Comment: 5 pages, submitted to MNRAS

We present a comparison of the observed, spatially integrated stellar and ionized gas velocity dispersions of $\sim1000$ massive ($\log M_{\star}/M_{\odot}\gtrsim\,10.3$) galaxies in the Large Early Galaxy Astrophysics Census (LEGA-C) survey at $0.6\lesssim\,z\lesssim1.0$. The high $S/N\sim20{\rm\AA^{-1}}$ afforded by 20 hour VLT/VIMOS spectra allows for joint modeling of the stellar continuum and emission lines in all galaxies, spanning the full range of galaxy colors and morphologies. These observed integrated velocity dispersions (denoted as $\sigma'_{g, int}$ and $\sigma'_{\star, int}$) are related to the intrinsic velocity dispersions of ionized gas or stars, but also include rotational motions through beam smearing and spectral extraction. We find good average agreement between observed velocity dispersions, with $\langle\log(\sigma'_{g, int}/\sigma'_{\star, int})\rangle=-0.003$. This result does not depend strongly on stellar population, structural properties, or alignment with respect to the slit. However, in all regimes we find significant scatter between $\sigma'_{g, int}$ and $\sigma'_{\star, int}$, with an overall scatter of 0.13 dex of which 0.05 dex is due to observational uncertainties. For an individual galaxy, the scatter between $\sigma'_{g, int}$ and $\sigma'_{\star, int}$ translates to an additional uncertainty of $\sim0.24\rm{dex}$ on dynamical mass derived from $\sigma'_{g, int}$, on top of measurement errors and uncertainties from Virial constant or size estimates. We measure the $z\sim0.8$ stellar mass Faber-Jackson relation and demonstrate that emission line widths can be used to measure scaling relations. However, these relations will exhibit increased scatter and slopes that are artificially steepened by selecting on subsets of galaxies with progressively brighter emission lines., Comment: 9 pages, 5 figures, Accepted for publication in ApJ Letters

We present stellar rotation curves and velocity dispersion profiles for 104 quiescent galaxies at $z=0.6-1$ from the Large Early Galaxy Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is typically probed across 10-20kpc, or to an average of 2.7${\rm R_e}$. Combined with central stellar velocity dispersions ($\sigma_0$) this provides the first determination of the dynamical state of a sample selected by a lack of star formation activity at large lookback time. The most massive galaxies ($M_{\star}>2\times10^{11}\,M_{\odot}$) generally show no or little rotation measured at 5kpc ($|V_5|/\sigma_0, Comment: 30 pages, 18 figures, Accepted for Publication in ApJ

We investigate the Tully–Fisher relation (TFR) for a morphologically and kinematically diverse sample of galaxies from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey using two-dimensional spatially resolved H α velocity maps and find a well-defined relation across the stellar mass range of 8.0 < log (M*/M⊙) < 11.5. We use an adaptation of kinemetry to parametrize the kinematic H α asymmetry of all galaxies in the sample, and find a correlation between scatter (i.e. residuals off the TFR) and asymmetry. This effect is pronounced at low stellar mass, corresponding to the inverse relationship between stellar mass and kinematic asymmetry found in previous work. For galaxies with log (M*/M⊙) < 9.5, 25 ± 3 per cent are scattered below the root mean square (RMS) of the TFR, whereas for galaxies with log (M*/M⊙) > 9.5 the fraction is 10 ± 1 per cent. We use ‘simulated slits’ to directly compare our results with those from long slit spectroscopy and find that aligning slits with the photometric, rather than the kinematic, position angle, increases global scatter below the TFR. Further, kinematic asymmetry is correlated with misalignment between the photometric and kinematic position angles. This work demonstrates the value of 2D spatially resolved kinematics for accurate TFR studies; integral field spectroscopy reduces the underestimation of rotation velocity that can occur from slit positioning off the kinematic axis.

We present Rc-band surface photometry for 170 of the 203 galaxies in GHASP, Gassendi H-Alpha survey of SPirals, a sample of late-type galaxies for which high-resolution Fabry-Perot H{\alpha} maps have previously been obtained. Our data set is constructed by new Rc-band observations taken at the Observatoire de Haute-Provence (OHP), supplemented with Sloan Digital Sky Survey (SDSS) archival data, obtained with the purpose of deriving homogeneous photometric profiles and parameters. Our results include Rc-band surface brightness profiles for 170 galaxies and $ugriz$ profiles for 108 of these objects. We catalogue several parameters of general interest for further reference, such as total magnitude, effective radius and isophotal parameters -- magnitude, position angle, ellipticity and inclination. We also perform a structural decomposition of the surface brightness profiles using a multi-component method in order to separate disks from bulges and bars, and to observe the main scaling relations involving luminosities, sizes and maximum velocities. We determine the Rc-band Tully Fisher relation using maximum velocities derived solely from H$\alpha$ rotation curves for a sample of 80 galaxies, resulting in a slope of $-8.1 \pm 0.5$, zero point of $-3.0 \pm 1.0$ and an estimated intrinsic scatter of $0.28 \pm 0.07$. We note that, different from the TF-relation in the near-infrared derived for the same sample, no change in the slope of the relation is seen at the low-mass end (for galaxies with $V_{max} < 125$ km/s). We suggest that this different behaviour of the Tully Fisher relation (with the optical relation being described by a single power-law while the near-infrared by two) may be caused by differences in the stellar mass to light ratio for galaxies with $V_{max} < 125$ km/s., Comment: 17 pages, 11 figures

In this paper we investigate the statistical properties of the Baryonic Tully-Fisher relation (BTFr) for a sample of 32 galaxies with accurate distances based on Cepheids and/or TRGB stars. We make use of homogeneously analysed photometry in 18 bands ranging from the FUV to 160 $\mu$m, allowing us to investigate the effect of the inferred stellar mass-to-light ratio $\Upsilon_{*}$ on the statistical properties of the BTFr. Stellar masses of our sample galaxies are derived with four different methods based on full SED-fitting, studies of stellar dynamics, near-infrared colours, and the assumption of the same $\Upsilon_{*}^{[3.6]}$ for all galaxies. In addition, we use high-quality, resolved HI kinematics to study the BTFr based on three kinematic measures: $W_{50}^{i}$ from the global HI profile, and $V_{max}$ and $V_{flat}$ from the rotation curve. We find the intrinsic perpendicular scatter, or tightness, of our BTFr to be $\sigma_{\perp} = 0.026 \pm 0.013$ dex, consistent with the intrinsic tightness of the 3.6 $\mu$m luminosity-based TFr. However, we find the slope of the BTFr to be $2.99 \pm 0.2$ instead of $3.7 \pm 0.1$ for the luminosity-based TFr at 3.6 $\mu$m. We use our BTFr to place important observational constraints on theoretical models of galaxy formation and evolution by making comparisons with theoretical predictions based on either the $\Lambda$CDM framework or modified Newtonian dynamics., Comment: 21 pages, MNRAS in press, minor changes after proof corrections

[-5]The applications of Newtonian dynamics in galactic scales have shown that the inverse square law is incompatible with the amount of visible mass in the form of stars and molecular clouds. This manifests as the rotational curves of galaxies being asymptotically flat instead of decaying with the distance to the center of the galaxy. In the context of Newtonian gravity, the standard explanation requires a huge amount of dark mass in the form of hypothetical particles that still remain undetected. A different theory was provided as a modification of Newtonian dynamics (MOND) at low accelerations . This MOND theory still has many supporters and it can easily explain some features of the rotation curves, such as the Tully–Fisher (TF) phenomenological relation between luminosity and velocity. In this paper, we revisit the third approach of a non-Newtonian force, that has resurfaced from time to time, in order to reconcile it with a finite apparent dark mass and the TF relation.

GalICS 2.0 is a new semianalytic code to model the formation and evolution of galaxies in a cosmological context. N-body simulations based on a Planck cosmology are used to construct halo merger trees, track subhaloes, compute spins and measure concentrations. The accretion of gas onto galaxies and the morphological evolution of galaxies are modelled with prescriptions derived from hydrodynamic simulations. Star formation and stellar feedback are described with phenomenological models (as in other semianalytic codes). GalICS 2.0 computes rotation speeds from the gravitational potential of the dark matter, the disc and the central bulge. As the rotation speed depends not only on the virial velocity but also on the ratio of baryons to dark matter within a galaxy, our calculation predicts a different Tully-Fisher relation from models in which the rotation speed is proportional to the virial velocity. This is why GalICS 2.0 is able to reproduce the galaxy stellar mass function and the Tully-Fisher relation simultaneously. Our results are also in agreement with halo masses from weak lensing and satellite kinematics, gas fractions, the relation between star formation rate (SFR) and stellar mass, the evolution of the cosmic SFR density, bulge-to-disc ratios, disc sizes and the Faber-Jackson relation., 31 pages, 19 figures, 1 table, submitted to MNRAS

We report a tight linear relation between the HI circular velocity measured at 6 $R_{\rm e}$ and the stellar velocity dispersion measured within 1 $R_{\rm e}$ for a sample of 16 early-type galaxies with stellar mass between $10^{10}$ and $10^{11}$ $\mathrm{M}_\odot$. The key difference from previous studies is that we only use spatially resolved $v_\mathrm{circ}$(HI) measurements obtained at large radius for a sizeable sample of objects. We can therefore link a kinematical tracer of the gravitational potential in the dark-matter dominated outer regions of galaxies with one in the inner regions, where baryons control the distribution of mass. We find that $v_\mathrm{circ}$(HI) = 1.33 $\sigma_\mathrm{e}$ with an observed scatter of just 12 percent. This indicates a strong coupling between luminous and dark matter from the inner- to the outer regions of early-type galaxies, analogous to the situation in spirals and dwarf irregulars. The $v_\mathrm{circ}$(HI)-$\sigma_\mathrm{e}$ relation is shallower than those based on $v_\mathrm{circ}$ measurements obtained from stellar kinematics and modelling at smaller radius, implying that \vcirc\ declines with radius -- as in bulge-dominated spirals. Indeed, the value of $v_\mathrm{circ}$(HI) is typically 25 percent lower than the maximum $v_\mathrm{circ}$ derived at $\sim0.2\ R_\mathrm{e}$ from dynamical models. Under the assumption of power-law total density profiles $\rho \propto r^{-\gamma}$, our data imply an average logarithmic slope $\langle\gamma\rangle=2.18\pm0.03$ across the sample, with a scatter of 0.11 around this value. The average slope and scatter agree with recent results obtained from stellar kinematics alone for a different sample of early-type galaxies., Comment: MNRAS, accepted

(Abridged version) We explore whether a scenario that combines an origin by mergers at $z\sim$1.8-1.5 with a subsequent passive evolution of the resulting S0 remnants since $z \sim$0.8-1 is compatible with observational data of S0s in the Tully-Fisher relation (TFR). We studied a set of major and minor merger experiments from the GalMer database that generate massive S0 remnants. We analysed the location of these remnants in the photometric and stellar TFRs assuming that they correspond to $z\sim0.8$ galaxies. We then estimated their evolution in these planes over the last 7 Gyr. The results were compared with data of real S0s and spirals at different redshifts. We also tested how the use of Vcirc or Vrot,max affects the results. We found that just after $\sim$1-2 Gyr of coalescence, major mergers generate S0 remnants that are outliers of the local photometric and stellar TFRs at $z\sim0.8$. After $\sim$4-7 Gyr of passive evolution in isolation, the S0 remnants move towards the local TFR, although the initial scatter among them persists. This scatter is sensitive to the indicator used for the rotation velocity: Vcirc values yield a lower scatter than when Vrot,max values are considered instead. In the planes involving Vrot,max, a clear segregation of the S0 remnants in terms of the spin-orbit coupling of the model is observed, in which the remnants of retrograde encounters overlap with local S0s hosting counter-rotating discs. The location of the S0 remnants at $z\sim 0$ agrees well with the observed distribution of local S0 galaxies in the $\sigma_0$-$M_K$, Vcirc-$\sigma_0$ and Vrot,max-$\sigma_0$ planes. Thus, massive S0 galaxies may have been formed through major mergers that occurred at high redshift and have later evolved towards the local TFR through passive evolution in relative isolation, a mechanism that would also contribute to the scatter observed in this relation., Comment: 19 pages, 15 figures. Accepted for publication in A&A

We investigate the stellar-mass Tully-Fisher relation (TFR) between the stellar mass and the integrated gas velocity dispersion, quantified by the kinematic estimator S_0.5 measured from strong emission lines in spectra of galaxies at 03 the scatter increases and the existence of a correlation is not obvious. The high-luminosity sample exhibits a flatter slope of 1.5$\pm$0.2 at z, Comment: 12 pages, Accepted for publication in MNRAS

Dwarf Irregular galaxies (dIrrs) are the smallest stellar systems with extended HI discs. The study of the kinematics of such discs is a powerful tool to estimate the total matter distribution at these very small scales. In this work, we study the HI kinematics of 17 galaxies extracted from the `Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey' (LITTLE THINGS). Our approach differs significantly from previous studies in that we directly fit 3D models (two spatial dimensions plus one spectral dimension) using the software $^\text{3D}$BAROLO, fully exploiting the information in the HI datacubes. For each galaxy we derive the geometric parameters of the HI disc (inclination and position angle), the radial distribution of the surface density, the velocity-dispersion ($\sigma_v$) profile and the rotation curve. The circular velocity (V$_{\text{c}}$), which traces directly the galactic potential, is then obtained by correcting the rotation curve for the asymmetric drift. As an initial application, we show that these dIrrs lie on a baryonic Tully-Fisher relation in excellent agreement with that seen on larger scales. The final products of this work are high-quality, ready-to-use kinematic data ($\textrm{V}_\textrm{c}$ and $\sigma_v$) that we make publicly available. These can be used to perform dynamical studies and improve our understanding of these low-mass galaxies., Comment: 36 pages, 28 figures, 2 tables. Submitted to MNRAS (revised version after the referee report). The final rotation curves can be downloaded from http://www.filippofraternali.com/styled-9/index.html

We investigate the stellar mass and baryonic mass Tully-Fisher relations (TFRs) of massive star-forming disk galaxies at redshift z~2.3 and z~0.9 as part of the KMOS^3D integral field spectroscopy survey. Our spatially resolved data allow reliable modelling of individual galaxies, including the effect of pressure support on the inferred gravitational potential. At fixed circular velocity, we find higher baryonic masses and similar stellar masses at z~2.3 as compared to z~0.9. Together with the decreasing gas-to-stellar mass ratios with decreasing redshift, this implies that the contribution of dark matter to the dynamical mass at the galaxy scale increases towards lower redshift. A comparison to local relations reveals a negative evolution of the stellar and baryonic TFR zero-points from z=0 to z~0.9, no evolution of the stellar TFR zero-point from z~0.9 to z~2.3, and a positive evolution of the baryonic TFR zero-point from z~0.9 to z~2.3. We discuss a toy model of disk galaxy evolution to explain the observed, non-monotonic TFR evolution, taking into account the empirically motivated redshift dependencies of galactic gas fractions, and of the relative amount of baryons to dark matter on galaxy and halo scales., 27 pages, 14 figures, accepted for publication in ApJ

We test whether advanced galaxy models and analysis techniques of simulations can alleviate the Too Big To Fail problem (TBTF) for late-type galaxies, which states that isolated dwarf galaxy kinematics imply that dwarfs live in lower-mass halos than is expected in a {\Lambda}CDM universe. Furthermore, we want to explain this apparent tension between theory and observations. To do this, we use the MoRIA suite of dwarf galaxy simulations to investigate whether observational effects are involved in TBTF for late-type field dwarf galaxies. To this end, we create synthetic radio data cubes of the simulated MoRIA galaxies and analyse their HI kinematics as if they were real, observed galaxies. We find that for low-mass galaxies, the circular velocity profile inferred from the HI kinematics often underestimates the true circular velocity profile, as derived directly from the enclosed mass. Fitting the HI kinematics of MoRIA dwarfs with a theoretical halo profile results in a systematic underestimate of the mass of their host halos. We attribute this effect to the fact that the interstellar medium of a low-mass late-type dwarf is continuously stirred by supernova explosions into a vertically puffed-up, turbulent state to the extent that the rotation velocity of the gas is simply no longer a good tracer of the underlying gravitational force field. If this holds true for real dwarf galaxies as well, it implies that they inhabit more massive dark matter halos than would be inferred from their kinematics, solving TBTF for late-type field dwarf galaxies., Comment: 21 pages, 21 figures. Accepted for publication in A&A. Corrected certain values in Table 1

The scaling of disk galaxy rotation velocity with baryonic mass (the "Baryonic Tully-Fisher" relation, BTF) has long confounded galaxy formation models. It is steeper than the M ~ V^3 scaling relating halo virial masses and circular velocities and its zero point implies that galaxies comprise a very small fraction of available baryons. Such low galaxy formation efficiencies may in principle be explained by winds driven by evolving stars, but the tightness of the BTF relation argues against the substantial scatter expected from such vigorous feedback mechanism. We use the APOSTLE/EAGLE simulations to show that the BTF relation is well reproduced in LCDM simulations that match the size and number of galaxies as a function of stellar mass. In such models, galaxy rotation velocities are proportional to halo virial velocity and the steep velocity-mass dependence results from the decline in galaxy formation efficiency with decreasing halo mass needed to reconcile the CDM halo mass function with the galaxy luminosity function. Despite the strong feedback, the scatter in the simulated BTF is smaller than observed, even when considering all simulated galaxies and not just rotationally-supported ones. The simulations predict that the BTF should become increasingly steep at the faint end, although the velocity scatter at fixed mass should remain small. Observed galaxies with rotation speeds below ~40 km/s seem to deviate from this prediction. We discuss observational biases and modeling uncertainties that may help to explain this disagreement in the context of LCDM models of dwarf galaxy formation., Comment: 10 pages, 7 figures, submitted to MNRAS

In recent work, Lelli et al. (2016) argue that the tightness of the baryonic Tully-Fisher relation (BTFR) of the SPARC galaxy sample, and the weakness of the correlation of its residuals with effective radius, pose challenges to LCDM cosmology. In this Letter we calculate the statistical significance of these results in the framework of halo abundance matching, which imposes a canonical galaxy-halo connection. Taking full account of sample variance among SPARC-like realisations of the parent halo population, we find the scatter in the predicted BTFR to be 3.6 sigma too high, but the correlation of its residuals with galaxy size to be naturally weak. Further, we find abundance matching to generate BTFR curvature in 3.0 sigma disagreement with the data, and a fraction of galaxies with non-flat rotation curves somewhat larger than observed., Comment: 5 pages, 2 figures; revised to match MNRAS Letters accepted version

We derive peculiar velocities for the 6dF Galaxy Survey (6dFGS) and describe the velocity field of the nearby ($z, 22 pages, 14 figures, accepted for publication in MNRAS. Table 1 is available in its entirety as an ancillary file. Fully interactive 3D versions of Figures 11 and 12 are also available as ancillary files. A version of this paper with the 3D versions of Figs. 11 and 12 embedded within the pdf can also be accessed from http://www.6dfgs.net/vfield/veldata.pdf

We investigate the amount and spatial distribution of interstellar dust in edge-on spiral galaxies, using detailed radiative transfer modeling of a homogeneous sample of 12 galaxies selected from the CALIFA survey. Our automated fitting routine, FitSKIRT, was first validated against artificial data. This is done by simultaneously reproducing the SDSS $g$-, $r$-, $i$- and $z$-band observations of a toy model in order to combine the information present in the different bands. We show that this combined, oligochromatic fitting, has clear advantages over standard monochromatic fitting especially regarding constraints on the dust properties. We model all galaxies in our sample using a three-component model, consisting of a double exponential disc to describe the stellar and dust discs and using a S\'ersic profile to describe the central bulge. The full model contains 19 free parameters, and we are able to constrain all these parameters to a satisfactory level of accuracy without human intervention or strong boundary conditions. Apart from two galaxies, the entire sample can be accurately reproduced by our model. We find that the dust disc is about 75% more extended but only half as high as the stellar disc. The average face-on optical depth in the V-band is $0.76$ and the spread of $0.60$ within our sample is quite substantial, which indicates that some spiral galaxies are relatively opaque even when seen face-on., Comment: 18 pages, 6 figures, 4 tables, Accepted for publication in MNRAS

A new model of galaxy rotation based on the cyclostrophic model of vortices found in nature is developed. The model is tested using the SPARC dataset of 175 galaxies and a smaller dataset comprising of 60 galaxies. Analysis of the datasets showed that galactic rotation can be adequately described using the observed surface brightness of galaxies and the newly developed cyclostrophic velocity model. The use of the luminosity and the inverse mass-to-light ratio in lieu of the surface brightness, also yield a very good fit of the observed and computed galaxy rotation velocity. Evidently, galactic rotation greatly depends on the cyclostrophic balance of the pressure gradient and the centrifugal forces and the seismic-induced radial expansion occurring in various stars. This is the most probable origin of the action of a single force law that has been overlooked in previous studies. Therefore, the need for a super-massive black hole at the center of galaxies or hidden dark matter can be eliminated. Attractive gravitational force can occur even without a massive black hole at the center of galaxies. There appears to be a pressure gradient force between the center and the outer parts of galaxies that sustains attraction. The cyclostrophic model appears to be the physical basis of the Tully-Fisher relation. Furthermore, the missing mass problem associated with galactic rotation can be attributed to the orbital expansion of celestial objects perturbed by seismic-induced forces. In addition, massive tremors or starquakes may create a domino effect in perturbing nearby stars along the axis of the seismic-induced force and this could result in the formation of elliptical galaxies as the orbits of seismic-perturbed neighboring stars become larger.

We investigate the relation between stellar mass and specific stellar angular momentum, or `Fall relation', for a sample of 17 isolated, regularly rotating disc galaxies at z=1. All galaxies have a) rotation curves determined from Halpha emission-line data; b) HST imaging in optical and infrared filters; c) robust determinations of their stellar masses. We use HST images in f814w and f160w filters, roughly corresponding to rest-frames B and I bands, to extract surface brightness profiles for our systems. We robustly bracket the specific angular momentum by assuming that rotation curves beyond the outermost Halpha rotation point stay either flat or follow a Keplerian fall-off. By comparing our measurements with those determined for disc galaxies in the local Universe, we find no evolution in the Fall relation in the redshift range 0, Comment: 11 pages, 4 figures, 1 table. Accepted by A&A

We analyse the Tully-Fisher relation at moderate redshift from the point of view of the underlying stellar populations, by comparing optical and NIR photometry with a phenomenological model that combines population synthesis with a simple prescription for chemical enrichment. The sample comprises 108 late-type galaxies extracted from the FORS Deep Field (FDF) and William Herschel Deep Field (WHDF) surveys at z, 10 pages, 11 figures, accepted for publication in MNRAS