Effect of Reionization on Structure Formation in the Universe

By Nickolay Y. Gnedin. 2000

577 citations recorded by the source corpus.

I use simulations of cosmological reionization to quantify the effect of photoionization on the gas fraction in low-mass objects, in particular the characteristic mass scale below which the gas fraction is reduced compared to the universal value. I show that this characteristic scale can be up to an order of magnitude lower than the linear-theory Jeans mass, and that even if one defines the Jeans mass at a higher overdensity, it does not track the evolution of this characteristic suppression mass. Instead, the filtering mass, which corresponds directly to the scale over which baryonic perturbations are smoothed in linear perturbation theory, provides a remarkably good fit to the characteristic mass scale. Thus, it appears that the effect of reionization on structure formation in both the linear and nonlinear regimes is described by a single characteristic scale, the filtering scale of baryonic perturbations. In contrast to the Jeans mass, the filtering mass depends on the full thermal history of the gas instead of the instantaneous value of the sound speed, so it accounts for the finite time required for pressure to influence the gas distribution in the expanding universe. In addition to the characteristic suppression mass, I study the full shape of the probability distribution to find an object with a given gas mass among all the objects with the same total mass, and I show that the numerical results can be described by a simple fitting formula that again depends only on the filtering mass. This simple description of the probability distribution may be useful for semianalytical modeling of structure formation in the early universe.

Subfields: Astronomy and Astrophysics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/d2ddd5346a9ba7f168bf822f748cd1ea7b824d53

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Citations in the corpus

Halo Substructure and the Power Spectrum (2002, background): “…feedback source on satellite galaxy scales is the ionizing background, which should suppress galaxy formation in halos with Vmax<∼ 30 km s−1 (Rees 1986; Efstathiou 1992; Kauffmann et al. 1993; Shapiro, Giroux, & Babul 1994; Thoul & Weinberg 1996; Quinn, Katz, & Efstathiou 1996; Gnedin 2000).”
CANDELS: THE CONTRIBUTION OF THE OBSERVED GALAXY POPULATION TO COSMIC REIONIZATION (2012, background): “…be suppressed, effectively cutting off the UV luminosity function at a limiting magnitude Mlim (e.g., Shapiro et al. 1994; Thoul & Weinberg 1996; Gnedin 2000; Dijkstra et al. 2004b; Okamoto et al. 2008; Finlator et al. 2011), though in the case of inhomogeneous reionization, very small halos…”
Cosmic Dawn (CoDa): the first radiation-hydrodynamics simulation of reionization and galaxy formation in the Local Universe (2015, background): “…a negative feedback on the ability of low-mass galactic haloes to form stars, by suppressing the infall of intergalactic baryons from the photoheated IGM following its local reionization (e.g. (Shapiro et al. 1994; Thoul & Weinberg 1996; Quinn et al. 1996; Kitayama & Ikeuchi 2000; Gnedin 2000).”
Self-regulated reionization (2006, methodology): “…mass since the mass scale on which baryons succeed in collapsing out of the IGM along with the dark matter must be determined, even in linear theory, by integrating the differential equation for perturbation growth over time for the evolvingIGM (Shapiro et al. 1994; Gnedin & Hui 1998; Gnedin 2000).”
Dark matter cores all the way down (2015, background): “However, several authors have argued that once satellites obtain some cold gas, they can efficiently self-shield against reionisation and continue to form stars (e.g. Gnedin 2000; Susa & Umemura 2004).”
Detecting the Earliest Galaxies through Two New Sources of 21 Centimeter Fluctuations (2004, background): “Since the gas content is strongly suppressed in halos below the filtering mass (Gnedin 2000), we estimate the maximum gas fraction in minihalos as lying between the filtering massMF and the minimum mass needed for atomic cooling.”
ETHOS - an effective theory of structure formation: dark matter physics as a possible explanation of the small-scale CDM problems (2015, background): “…through a combination of photo-evaporation and photo-heating when the Universe was reionised, and supernova feedback (e.g. Efstathiou 1992; Gnedin 2000; Benson et al. 2002; Koposov et al. 2008), although photoevaporation and photo-heating alone may not be enough to bring the predicted…”
In the Beginning: The First Sources of Light and the Reionization of the Universe (2000, background): “Recent calculations of structure formation in popular CDM cosmologies imply that the universe was ionized at z ∼ 7–12 (Haiman & Loeb 1998, 1999b,c; Gnedin & Ostriker 1997; Chiu & Ostriker 2000; Gnedin 2000a), and has remained ionized ever since.”
HIPASS High-Velocity Clouds: Properties of the Compact and Extended Populations (2001, background): “However, the amount of intergalactic neutral hydrogen at z = 0 remains highly uncertain, and its presence has important implications on the efficiency and timescales of galaxy formation and the epoch of reionization (Gnedin 2000; Rees 1986).”
Tracing Galaxy Formation with Stellar Halos. I. Methods (2005, result): “These thresholds follow from the results of Thoul & Weinberg (1996) and Gnedin (2000) who used hydrodynamic simulations to show that gas accretion in low-mass halos is indeed suppressed in the presence of an ionizing background.”
Efficient Simulations of Early Structure Formation and Reionization (2007, background): “…of tens of comoving Mpc (Furlanetto et al. 2004c; Furlanetto & Oh 2005), which is over seven orders of magnitude in mass larger than the pertinent cooling mass, corresponding to gas with a temperature of T ∼ 104 K (e.g. Efstathiou 1992; Thoul & Weinberg 1996; Gnedin 2000b; Shapiro et al. 1994).”
Signatures of X-rays in the early Universe (2012, background): “Although thermal (i.e. radiative feedback) was initially suspected of being important (e.g. Shapiro et al. 1994; Thoul & Weinberg 1996; Gnedin 2000), later studies concluded that its impact was smaller at high-redshifts (e.g. Ricotti et al. 2002; Kuhlen & Madau 2005; Mesinger & Dijkstra 2008;…”
Galaxy formation theory (2010, background): “…their low mass makes them highly sensitive to feedback effects, both internal (from supernovae for example; Font et al. 2010) and external (photoheating of the IGM by the entire population of galaxies can, in principle, inhibit the formation of these satellites; Gnedin 2000; Okamoto et al. 2008a).”
A primer on hierarchical galaxy formation: the semi-analytical approach (2006, background): “The first of these phenomena is the suppression of cooling in low mass haloes due to the presence of a background of photo-ionising radiation (Couchman & Rees 1986; Efstathiou 1992; Babul & Rees 1992; Thoul & Weinberg 1996; Nagashima, Gouda & Sugiura 1999; Gnedin 2000).”
The properties of satellite galaxies in simulations of galaxy formation (2009, background): “…of gas at early times, which suppresses gas cooling and raises the thermal pressure of the gas, preventing it from accreting onto small dark matter haloes (Babul & Rees 1992; Efstathiou 1992; Thoul & Weinberg 1996; Quinn, Katz, & Efstathiou 1996; Gnedin 2000; Okamoto, Gao, & Theuns 2008a).”
The evolution of massive black holes and their spins in their galactic hosts (2012, background): “The filtering mass as a function of redshift,Mf (z), accounts for the effect of the ionizing extragalactic UV background produced by massive stars and quasars, which is able to partially reducethe baryonic content in low-mass systems (Gnedin 2000).”
Galaxy bimodality due to cold flows and shock heating (2004, background): “The UV from stars and AGNs ionizes most of the gas after z ∼ 10 (Bullock et al. 2000; Loeb & Barkana 2001), heats it to >∼ 104K, and prevents it from falling into haloes below the Jeans scale Vv ∼ 30 km s−1 (Gnedin 2000).”