FORMATION RATES OF POPULATION III STARS AND CHEMICAL ENRICHMENT OF HALOS DURING THE REIONIZATION ERA

By M. Trenti, M. Stiavelli. 2009

141 citations recorded by the source corpus.

The first stars in the universe formed out of pristine primordial gas clouds that were radiatively cooled to a few hundreds of degrees kelvin either via molecular or atomic (Lyman-α) hydrogen lines. This primordial mode of star formation was eventually quenched once radiative and/or chemical (metal enrichment) feedbacks marked the transition to Population II stars. In this paper, we present a model for the formation rate of Population III stars based on Press–Schechter modeling coupled with analytical recipes for gas cooling and radiative feedback. Our model also includes a novel treatment for metal pollution based on self-enrichment due to a previous episode of Population III star formation in progenitor halos. With this model, we derive the star formation history of Population III stars, their contribution to the reionization of the universe and the time of the transition from Population III star formation in minihalos (M ≈ 106 M☉, cooled via molecular hydrogen) to that in more massive halos (M ≳ 2 × 107 M☉, where atomic hydrogen cooling is also possible). We consider a grid of models highlighting the impact of varying the values for the free parameters used, such as star formation and feedback efficiency. The most critical factor is the assumption that only one Population III star is formed in a halo. In this scenario, metal-free stars contribute only to a minor fraction of the total number of photons required to reionize the universe. In addition, metal-free star formation is primarily located in minihalos, and chemically enriched halos become the dominant locus of star formation very early in the life of the universe—at redshift z ≈ 25—even assuming a modest fraction (0.5%) of enriched gas converted in stars. If instead multiple metal-free stars are allowed to form out of a single halo, then there is an overall boost of Population III star formation, with a consequent significant contribution to the reionizing radiation budget. In addition, the bulk of metal-free stars are produced in halos with M ≳ 2 × 107 M☉.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/4d1d2c332b059b835a4869efb4cb61dc9e0e3c2d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. P. Hopkins
2. John H. Wise
3. Tom Abel
4. M. Trenti
5. M. Norman
6. L. Hernquist
7. P. Oesch
8. R. Bouwens

In Atomic and Molecular Physics, and Optics

1. Tom Abel
2. M. McQuinn
3. A. Benson
4. M. Begelman
5. John H. Wise
6. M. Norman
7. Matthew J. Turk
8. Britton D. Smith

In Instrumentation

1. R. Bouwens
2. P. Oesch
3. M. Trenti
4. G. Illingworth
5. John H. Wise
6. M. Franx
7. Tom Abel
8. Richard S. Ellis

Citations in the corpus

• The birth of a galaxy – II. The role of radiation pressure (2012, methodology): “This fits the model data within 1 per cent in 6 6 z 6 30 and is consistent with J21 values in Trenti & Stiavelli (2009).”
• Evolution of supermassive stars as a pathway to black hole formation (2009, background): “One can debate the likelihood that a supermassive star with such low CNO abundance (ZCNO 10−8) could ever form under cosmological conditions (e.g. Trenti & Stiavelli 2009; Trenti, Stiavelli & Shull 2009).”
• Ubiquitous seeding of supermassive black holes by direct collapse (2012, result): “We also find a good agreement with Trenti & Stiavelli (2009) as our SFRD andJ outputs resemble their estimates, but it is difficult to draw exact comparisons as they used an analytical Press-Schetcher modelling and the parameter choices of the studies differ considerably.”
• The Evolution of the Intergalactic Medium (2015, background): “Trenti & Stiavelli (2009) estimate that the Universe reached a saturation-level of POPIII star formation in minihalos of ∼ 10−5 − 10−4M yr−1 comoving Mpc−3 at z ∼ 20 − 30, with saturation set by their 11 − 13 eV radiative backgrounds destroying the molecular hydrogen coolant that had created them…”
• THE SPECTRAL EVOLUTION OF THE FIRST GALAXIES. I. JAMES WEBB SPACE TELESCOPE DETECTION LIMITS AND COLOR CRITERIA FOR POPULATION III GALAXIES (2011, background): “…emitted from population III stars may have played an important role in the cosmic reionization at redshifts z > 6 (e.g. Sokasian et al. 2004; Trenti & Stiavelli 2009), and the remnants left behind by these objects may also have acted as seeds for the supermassive black holes (e.g. Trenti &…”
• ENZO: AN ADAPTIVE MESH REFINEMENT CODE FOR ASTROPHYSICS (2013, methodology): “Types 8, 9, and 14 have only a photo-dissociating Lyman-Werner flux, with Type 8 being constant and Type 9 using the redshift-dependent results of Trenti & Stiavelli (2009).”
• THE GALAXY LUMINOSITY FUNCTION DURING THE REIONIZATION EPOCH (2010, methodology): “…(ICLF) model, rather than ǫDC 1, we modify Equation 1 to include only halos with M ≥ Mh that have been formed within time interval ∆t: ∆N(Mh, z) = ∫ +∞ Mh [n(MH , z)− n(MH , z∆t)] dMH , (2) where ∆t = tH(z) − tH(z∆t), with tH(z) being the local Hubble time (Equation 6 of Trenti & Stiavelli 2009).”
• What drives the growth of black holes (2011, background): “…idea that the first stars are very massive, due to either fragmentation or feedback effects (e.g., Glover et al., 2008; McKee & Tan, 2008; Turk et al., 2009; Trenti & Stiavelli, 2009; Stacy et al., 2010; Greif et al., 2011), casting some doubt on the the role of Population III remnants as BH seeds.”
• Galaxy formation theory (2010, background): “…properties of Population III stars, their various feedback processes (both positive andnegative) and initial mass function (Glover and Abel 2008; Trenti and Stiavelli 2009; Ohkubo et al. 2009; Machida et al.2008; Lawlor et al. 2008; O’Shea and Norman 2007, 2008; Harris et al. 2007; Stacy and…”