The Formation of the Primitive Star SDSS J102915+172927: Effect of the Dust Mass and the Grain-Size Distribution

Bovino, S.; Schleicher, Dominik R. G.; Banerjee, Rinti

doi:10.3847/0004-637x/832/2/154

Cited by 24 publications

(19 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown via numerical simulations, the typical densities where fragmentation occurs are on the order 10 9 cm −3 or higher (e.g., Clark et al 2011a,b;Greif et al 2011Greif et al , 2012Smith et al 2011Smith et al , 2012Latif et al 2013b), leading to the formation of dense clusters with radii of 0.1 pc or even smaller. Trace amounts of dust grains may even trigger fragmentation at still higher densities (e.g., Schleicher et al 2003Schleicher et al , 2006Schleicher et al , 2012Omukai et al 2008;Klessen et al 2012;Dopcke et al 2011Dopcke et al , 2013Bovino et al 2016;Latif et al 2016), providing ideal conditions for the formation of very dense clusters.…”

Section: Introductionmentioning

confidence: 99%

Collisions in primordial star clusters

Reinoso

Schleicher

Fellhauer

et al. 2018

A&A

Self Cite

View full text Add to dashboard Cite

Collisions were suggested to potentially play a role in the formation of massive stars in present day clusters, and have likely been relevant during the formation of massive stars and intermediate mass black holes within the first star clusters. In the early Universe, the first stellar clusters were particularly dense, as fragmentation typically only occurred at densities above 109 cm−3, and the radii of the protostars were enhanced as a result of larger accretion rates, suggesting a potentially more relevant role of stellar collisions. We present here a detailed parameter study to assess how the number of collisions and the mass growth of the most massive object depend on the properties of the cluster. We also characterize the time evolution with three effective parameters: the time when most collisions occur, the duration of the collisions period, and the normalization required to obtain the total number of collisions. We apply our results to typical Population III (Pop. III) clusters of about 1000 M⊙, finding that a moderate enhancement of the mass of the most massive star by a factor of a few can be expected. For more massive Pop. III clusters as expected in the first atomic cooling halos, we expect a more significant enhancement by a factor of 15–32. We therefore conclude that collisions in massive Pop. III clusters were likely relevant to form the first intermediate mass black holes.

show abstract

Section: Introductionmentioning

confidence: 99%

Collisions in primordial star clusters

Reinoso

Schleicher

Fellhauer

et al. 2018

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…If some fraction of the metals are in dust grains, as in the Galactic interstellar medium (ISM), dust cooling triggers fragmentation at high enough densities ( 10 10 cm −3 ) to produce sub-solar mass fragments for metallicities exceeding Z/Z⊙ = 10 −6 -10 −5 (Schneider et al 2002(Schneider et al , 2003Omukai et al 2005;Schneider et al 2006;Omukai et al 2010;Schneider & Omukai 2010;Schneider et al 2012a,b). Three-dimensional hydrodynamic calculations also demonstrate the formation of multiple low-mass stars through dust-induced fragmentation for Z/Z⊙ ∼ 10 −5 (Tsuribe & Omukai 2006;Clark et al 2008; c 2018 The Authors Dopcke et al 2013;Chiaki et al 2016;Bovino et al 2016). Therefore, dust is considered to be indispensable to form low-mass ( M ⊙ ) stars.…”

Section: Introductionmentioning

confidence: 99%

Condition for low-mass star formation in shock-compressed metal-poor clouds

Nakauchi

Omukai

Schneider

2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Shocks may have been prevalent in the early Universe, associated with virialization and supernova explosions, etc. Here, we study thermal evolution and fragmentation of shock-compressed clouds, by using a one-zone model with detailed thermal and chemical processes. We explore a large range of initial density (1-10 5 cm −3 ), metallicity (0-10 −2 Z ⊙ ), UV strength (0-500 times Galactic value), and cosmic microwave background temperature (10 and 30 K). Shock-compressed clouds contract isobarically via atomic and molecular line cooling, until self-gravitating clumps are formed by fragmentation. If the metals are only in the gas-phase, the clump mass is higher than ∼ 3 M ⊙ in any conditions we studied. Although in some cases with a metallicity higher than ∼ 10 −3 Z ⊙ , re-fragmentation of a clump is caused by metal-line cooling, this fragment mass is higher than ∼ 30 M ⊙ . On the other hand, if about half the mass of metals is condensed in dust grains, as in the Galactic interstellar medium, dust cooling triggers re-fragmentation of a clump into sub-solar mass pieces, for metallicities higher than ∼ 10 −5 Z ⊙ . Therefore, the presence of dust is essential in low-mass ( M ⊙ ) star formation from a shock-compressed cloud.

show abstract

“…2010. While most of the extremely metal poor stars still have carbon and oxygen abundances that are consistent with metal line cooling (Frebel and Norris 2015), the discovery of DSS J102915+172927 (Caffau et al 2011a,b;Schneider et al 2012) suggests that dust cooling must be relevant in some cases Bovino et al 2016). Clark et al (2008) focusing on star formation in the early universe at very low metallicities have suggested a connection between the presence of angular momentum and fragmentation in self gravitating disks.…”

Section: Introductionmentioning

confidence: 99%

Do fragmentation and accretion affect the stellar initial mass function?

Riaz

Schleicher

Vanaverbeke

et al. 2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

While the stellar Initial Mass Function (IMF) appears to be close to universal within the Milky Way galaxy, it is strongly suspected to be different in the primordial Universe, where molecular hydrogen cooling is less efficient and the gas temperature can be higher by a factor of 30. In between these extreme cases, the gas temperature varies depending on the environment, metallicity and radiation background. In this paper we explore if changes of the gas temperature affect the IMF of the stars considering fragmentation and accretion. The fragmentation behavior depends mostly on the Jeans mass at the turning point in the equation of state where a transition occurs from an approximately isothermal to an adiabatic regime due dust opacities. The Jeans mass at this transition in the equation of state is always very similar, independent of the initial temperature, and therefore the initial mass of the fragments is very similar. Accretion on the other hand is strongly temperature dependent. We argue that the latter becomes the dominant process for star formation efficiencies above 5−7 %, increasing the average mass of the stars.The formation of low-mass stars in the primordial regime has also been suggested in earlier studies (e.g. Nakamura and Umemura 2002; Palla et al. 1983). Already at metallicities Z ∼ 10 −5 Z Clark et al. (2008) have reported vigorous fragmentation due to efficient dust cooling that leads to densely-packed clusters of low-mass stars in which the IMF of stars peaks below 1 M .With the ejection of metals, the stellar mass decreases due to the increasing efficiency of cooling. In particular, metal line cooling predominantly proceeds via oxygen, carbon and nitrogen lines (Bromm and Loeb 2003). This cooling mechanism becomes quite efficient for metal abundances of about 0.3 % of the solar value, and operates already at low densities, of the order 1−100 cm −3 depending on metallicity (Omukai and Palla 2001;Glover and Jappsen 2007;Safranek et al. 2014).An alternative cooling mechanism is provided by the injection of dust via AGB stars or supernovae, which provides a cooling mechanism that operates even at ∼ 0.01% of the dust abundance in the solar neighborhood, but kicks in at much higher densities (> 10 6 cm −3 ) than the metal line cooling (Schneider et al. 2003; Schneider and Omukai arXiv:2003.07639v1 [astro-ph.GA]

show abstract

The Formation of the Primitive Star SDSS J102915+172927: Effect of the Dust Mass and the Grain-Size Distribution

Cited by 24 publications

References 66 publications

Collisions in primordial star clusters

Collisions in primordial star clusters

Condition for low-mass star formation in shock-compressed metal-poor clouds

Do fragmentation and accretion affect the stellar initial mass function?

Contact Info

Product

Resources

About