The Angular Momentum of Gas in Protogalaxies. I. Implications for the Formation of Disk Galaxies

By Frank C. van den Bosch, Tom Abel, R. Croft, L. Hernquist, Simon D. M. White. 2002

200 citations recorded by the source corpus.

We use numerical simulations of structure formation in a cold dark matter cosmology to compare the angular momentum distributions of dark matter and nonradiative gas in a large sample of halos. We show that the two components have identical spin parameter distributions and that their angular momentum distributions within individual halos are very similar, all in excellent agreement with standard assumptions. Despite these similarities, however, we find that the angular momentum vectors of the gas and dark matter are poorly aligned, with a median misalignment angle of ~30°, which might have important implications for spin correlation statistics used in weak lensing studies. We present distributions for the component of the angular momentum that is aligned with the total angular momentum of each halo and find that for between 5% and 50% of the mass, this component is negative. This disagrees with the generally adopted "universal" angular momentum distribution, for which the mass fraction with negative specific angular momentum is zero. We discuss the implications of our results for the formation of disk galaxies. Since galactic disks generally do not contain counterrotating stars or gas, disk formation cannot occur under detailed conservation of specific angular momentum. We suggest that the material with negative specific angular momentum combines with positive angular momentum material to build a bulge component, and we show that in such a scenario the remaining material can form a disk with a density distribution that is very close to exponential.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/8945caae3387d494fdb4f842b4989584a09eda10

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Citations in the corpus

Internal and External Alignment of the Shapes and Angular Momenta of ΛCDM Halos (2004, background): “Although there may be some misalignment between the angular momentum of the baryons and dark matter (van den Bosch et al. 2002; Sharma & Steinmetz 2004), spiral galaxies still provide the best targets for detecting angular momentum alignments and correlations.”
Theoretical Challenges in Galaxy Formation (2016, background): “It was again suggested that the origin of the problem lies at higher redshift (D’Onghia & Burkert 2004, van den Bosch et al. 2002).”
The Causes of Halo Shape Changes Induced by Cooling Baryons: Disks versus Substructures (2007, background): “Simulations have found that the angular momenta of the halo and gas need not be aligned (van den Bosch et al. 2002; Chen et al. 2003), although the inner halo and the disk that would form settle to a common plane (Dubinski & Kuijken 1995).”
Journey to the MBH-σ relation: the fate of low-mass black holes in the Universe (2009, methodology): “Every halo entering the merger tree is assigned a spin parameter drawn from the lognormal distribution in λspin found in numerical simulations, with mean λ̄spin = 0.05 and standard deviation σλ = 0.5 (e.g. Warren et al. 1992; Cole & Lacey 1996; Bullock et al. 2001; van den Bosch et al. 2002).”
The evolution of massive black hole seeds (2007, unknown): “…λ̄spin = 0.05 and standard deviation σλ = 0.5: p(λ) dλ = 1√ 2πσλ exp » − ln 2(λ/λ̄) 2σ2λ – dλ λ , (1) This function has been shown to provide a good fit to the N-body results of several investigations (e.g., Warren et al. 1992; Cole & Lacey 1996; Bullock et al. 2001; van den Bosch et al. 2002).”
A Merger-driven Scenario for Cosmological Disk Galaxy Formation (2005, background): “…work has shown that the specific angular momen- tum content of dark matter halos differs from exponential disks (Bullock et al. 2001; van den Bosch et al. 2001, 2002) as halos contain comparatively more low angular momentum material that might produce bulges or overly centrally…”
Scaling Relations of Spiral Galaxies (2007, background): “In addition, simultaneously accounting for the mass and angular momentum distribution of spiral galaxies in a gas dynamical context remains a major challenge for hierarchical formation models (Navarro & White 1994; van den Bosch et al. 2002b; Governato et al. 2007).”
The alignment between the distribution of satellites and the orientation of their central galaxy (2006, background): “Detailed hydrodynamical simulations, however, have shown that the spin axes of the baryons and the dark matter (in the absence of cooling) are only poorly aligned (van den Bosch et al. 2002; Chen et al. 2003; Sharma & Steinmetz 2005).”
CONNECTING ANGULAR MOMENTUM AND GALACTIC DYNAMICS: THE COMPLEX INTERPLAY BETWEEN SPIN, MASS, AND MORPHOLOGY (2015, methodology): “The misalignment of the gas and DM angular momentum vectors and their spin parameters at redshift z = 3 were investigated by van den Bosch et al. (2002).”
Galaxy–galaxy weak lensing in the Sloan Digital Sky Survey: intrinsic alignments and shear calibration errors (2004, background): “…or as an ellipsoid homologous with the ellipticity of its halo (for ellipticals), although comparison to observations (Heymans et al. 2004) and simulations of galaxy formation (Van den Bosch et al. 2002) suggest that this picture is too simple and overestimates the shear–shear correlations.”
Population III Star Formation in a ΛCDM Universe. I. The Effect of Formation Redshift and Environment on Protostellar Accretion Rate (2006, background): “Overall, the average value for is approximately 25 , which is consistent with recent numerical simulations (van den Bosch et al. 2002; Yoshida et al. 2003).”
Statistics of Physical Properties of Dark Matter Clusters (2005, result): “Spin As has been established in earlier studies (Barnes & Efstathiou 1987; Warren et al. 1992; van den Bosch 1998; Bullock et al. 2001a; van den Bosch et al. 2002; Gardner 2001; Vitvitska et al. 2002; Peirani et al. 2004), the distribution of k is well fit by a lognormal distribution, P(k) ¼ 1 k…”
Formation of supermassive black holes by direct collapse in pre-galactic haloes (2006, result): “Similar results were found in later investigations (e.g., Cole & Lacey 1996; Bullock et al. 2001; van den Bosch et al. 2002).”
Constraints on intrinsic alignment contamination of weak lensing surveys using the MegaZ-LRG sample (2010, background): “…in N-body simulations (Splinter et al. 1997; Onuora & Thomas 2000; Faltenbacher et al. 2002; Hopkins et al. 2005; Faltenbacher et al. 2007, 2008; Lee et al. 2008), to a limited degree also including the eff ct of baryonic physics (van den Bosch et al. 2002; Bett et al. 2010; Hahn et al. 2010).”
Simultaneous measurement of cosmology and intrinsic alignments using joint cosmic shear and galaxy number density correlations (2009, background): “…& Seljak 2004; Bridle & Abdalla 2007; Schneider & Bridle 2010), as well as the alignment of the spin or the shape of a galaxy with its own dark matter halo (e.g. Pen et al. 2000; van den Bosch et al. 2002; Okumura et al. 2009; Okumura & Jing 2009; Brainerd et al. 2009; see also Schäfer 2009).”
Hierarchical formation of bulgeless galaxies – II. Redistribution of angular momentum via galactic fountains (2011, background): “This is in conflict with the assumption that the distribution of the angular momentum of gas and dark matter are the same, an assumption which holds in non-radiative hydro-dynamical simulations (van den Bosch et al. 2002; Sharma & Steinmetz 2005).”
The Secular Evolution of Disk Structural Parameters (2005, background): “…side, including that the initial specific angular momentum distribution of the baryons need not be like that of the dark halo (e.g. van den Bosch et al. 2002) and angular momentum distributions favoring disks more centrally concentrated than exponential (Firmani & Avila-Reese 2000; van…”