One of the core principle's of Alexandre Deur's efforts to explain dark matter and dark energy phenomena as due to the self-interaction of weak gravitational fields is that these phenomena disappear in truly spherically symmetric matter distributions, while growing stronger in the case for disk-like matter distributions and reaching their greatest extremes in matter distributions that approximate two point-like matter sources.
A new study confirms this observational result the the stellar-to-halo mass ratio is larger in more spherically symmetric galaxies (i.e. they have less inferred dark matter) and smaller in spiral galaxies (i.e. they have more inferred dark matter), while trying to explain it in a LambdaCDM dark matter particle paradigm (unconvincingly in my opinion). The main result of the paper is in the figure below in which the top of the chart involve systems with less dark matter relative to stellar mass and the bottom involves systems with more dark matter relative to stellar mass, the left of each chart involves lower masses and the right of each chart involves higher masses.
Fig. 3. SHMR in the form of the ratio f(*) ≡ M(*)/ f(b)M(h) as a function of stellar mass (left) or halo mass (right) for the sample of spiral galaxies in SPARC (blue diamonds, PFM19) and for the sample of ellipticals and lenticulars in SLUGGS (red circles, this work). The halo masses of late types are estimated from HI rotation curves, those of early types from the kinematics of the GC system. We compare to the SHMR from the abundance matching model by Moster et al. (2013, grey band).
The paper and its abstract are as follows (small print and original font retained in abstract to preserve formatting):
We derive the stellar-to-halo mass relation (SHMR), namely versus and , for early-type galaxies from their near-IR luminosities (for ) and the position-velocity distributions of their globular cluster systems (for ). Our individual estimates of are based on fitting a dynamical model with a distribution function expressed in terms of action-angle variables and imposing a prior on from the concentration-mass relation in the standard CDM cosmology.
We find that the SHMR for early-type galaxies declines with mass beyond a peak at and (near the mass of the Milky Way). This result is consistent with the standard SHMR derived by abundance matching for the general population of galaxies, and with previous, less robust derivations of the SHMR for early types. However, it contrasts sharply with the monotonically rising SHMR for late types derived from extended HI rotation curves and the same CDM prior on as we adopt for early types. The SHMR for massive galaxies varies more or less continuously, from rising to falling, with decreasing disc fraction and decreasing Hubble type.
We also show that the different SHMRs for late and early types are consistent with the similar scaling relations between their stellar velocities and masses (Tully-Fisher and Faber-Jackson relations). Differences in the relations between the stellar and halo virial velocities account for the similarity of the scaling relations.
We argue that all these empirical findings are natural consequences of a picture in which galactic discs are built mainly by smooth and gradual inflow, regulated by feedback from young stars, while galactic spheroids are built by a cooperation between merging, black-hole fuelling, and feedback from AGNs.
with the index approximately equal to 4.
the Tully–Fisher relation (TFR) is an empirical relationship between the mass or intrinsic luminosity of a spiral galaxy and its asymptotic rotation velocity or emission line width. It was first published in 1977 by astronomers R. Brent Tully and J. Richard Fisher. The luminosity is calculated by multiplying the galaxy's apparent brightness by , where is its distance from us, and the spectral-line width is measured using long-slit spectroscopy.
Several different forms of the TFR exist, depending on which precise measures of mass, luminosity or rotation velocity one takes it to relate. Tully and Fisher used optical luminosity, but subsequent work showed the relation to be tighter when defined using microwave to infrared (K band) radiation (a good proxy for stellar mass), and even tighter when luminosity is replaced by the galaxy's total baryonic mass (the sum of its mass in stars and gas). This latter form of the relation is known as the Baryonic Tully–Fisher relation (BTFR), and states that baryonic mass is proportional to velocity to the power of roughly 4.
The body text of the new paper notes that:
Another similar relationship not mentioned (because it isn't relevant here) is the
M–sigma (or M–σ) relation is an empirical correlation between the stellar velocity dispersion σ of a galaxy bulge and the mass M of the supermassive black hole at its center.The M–σ relation was first presented in 1999 during a conference at the Institut d'astrophysique de Paris in France. The proposed form of the relation, which was called the "Faber–Jackson law for black holes", was
where is the solar mass. Publication of the relation in a refereed journal, by two groups, took place the following year. One of many recent studies, based on the growing sample of published black hole masses in nearby galaxies, gives
Earlier work demonstrated a relationship between galaxy luminosity and black hole mass, which nowadays has a comparable level of scatter. The M–σ relation is generally interpreted as implying some source of mechanical feedback between the growth of supermassive black holes and the growth of galaxy bulges, although the source of this feedback is still uncertain.Discovery of the M–σ relation was taken by many astronomers to imply that supermassive black holes are fundamental components of galaxies.
Other Works By The Authors
I'll provide below some cut and post arXiv paper summaries for other works by some of the same authors:
The impact of the halo spin-concentration relation on disc scaling laws
Galaxy scaling laws, such as the Tully-Fisher, mass-size and Fall relations, can provide extremely useful clues on our understanding of galaxy formation in a cosmological context. Some of these relations are extremely tight and well described by one single parameter (mass), despite the theoretical existence of secondary parameters such as spin and concentration, which are believed to impact these relations. In fact, the residuals of these scaling laws appear to be almost uncorrelated with each other, posing significant constraints on models where secondary parameters play an important role.
Here, we show that a possible solution is that such secondary parameters are correlated amongst themselves, in a way that removes correlations in observable space. In particular, we focus on how the existence of an anti-correlation between the dark matter halo spin and its concentration -- which is still debated in simulations -- can weaken the correlation of the residuals of the Tully-Fisher and mass-size relations. Interestingly, using simple analytic galaxy formation models, we find that this happens only for a relatively small portion of the parameter space that we explored, which suggests that this idea could be used to derive constraints to galaxy formation models that are still unexplored.
[Submitted on 14 Sep 2020 (v1), last revised 1 Feb 2021 (this version, v3)]
The baryonic specific angular momentum of disc galaxies
(Abridged) Specific angular momentum is one of the key parameters that control the evolution of galaxies. We derive the baryonic specific angular momentum of disc galaxies and study its relation with the dark matter specific angular momentum. Using a combination of high-quality HI rotation curves and HI/near-IR surface densities, we homogeneously measure the stellar () and gas ( ) specific angular momenta for a large sample of local disc galaxies. This allows us to determine the baryonic specific angular momentum ( ) with high accuracy and across a very wide range of masses.
Therelation is an unbroken power-law from log( / , with slope . For the gas component, we find that the relation is also an unbroken power-law from log( / , with a steeper slope of . Regarding the baryonic relation, our data support a correlation characterized by single power-law with slope . Our most massive spirals and smallest dwarfs lie along the same sequence.
While the relations are tight and unbroken, we find internal correlations inside them: At fixed, galaxies with larger have larger disc scale lengths, and at fixed , gas-poor galaxies have lower than expected. We estimate the retained fraction of baryonic specific angular momentum, finding it constant across our entire mass range with a value of , indicating that the of present-day disc galaxies is comparable to the initial specific angular momentum of their dark matter haloes. These results set important constraints for hydrodynamical simulations and semi-analytical models aiming to reproduce galaxies with realistic specific angular momenta.