Thermal and resonant emission of dark age halos in the rotational lines of 
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Kulinich, Yu.; Novosyadlyj, B.; Shulga, V. M.; Han, Wei

doi:10.1103/physrevd.101.083519

Cited by 7 publications

(4 citation statements)

References 58 publications

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“…is the total energy density of radiation at any redshift from cosmological recombination to reionization. We used the same approximations for excitation and de-excitation rates of rotational levels of molecules H 2 , HD, and HeH + as in our previous papers, Novosyadlyj et al (2020) and Kulinich et al (2020), and references therein. Solution of the system of equations for populations of rotational levels with J = 0 − 5 gives us the possibility to compute the excitation temperature from the i-level to the j-level:…”

Section: Luminescence Of Halo In the Molecular Linesmentioning

confidence: 99%

The first molecules in the intergalactic medium and halos of the Dark Ages and Cosmic Dawn

Novosyadlyj,

Kulinich,

Melekh

et al. 2022

Preprint

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We study the formation and destruction of the first molecules at the epochs of the Dark Ages and Cosmic Dawn to evaluate the luminosity of the protogalaxy clumps (halos) in the molecular lines. The cosmological recombination is described using the RecFast model of an effective three-level atom, while the chemistry of the molecules is examined using the relevant basic kinetic equations. We then studied the effect of collisional and radiative excitation of molecules on the intensity of molecular emission in both warm and hot halos. Using the Planck data on the reionization of the intergalactic medium at z ∼ 6 − 8, we evaluated the upper limits of the light energy density for four models of thermal light from the first sources that appeared in the Cosmic Dawn epoch. Assuming that in the halos, the light energy density may essentially be even higher, we estimated the impact of the light from the first sources (the first light) on the formation and destruction of the first molecules in them as well as between them. We show that the molecules H 2 and HD are destroyed by photodissociation processes shortly before the full reionization in the inter-halo medium, in the medium of both types of halos and for all models of the first light. At the same time, the number density of helium hydride ions, HeH + , shows essentially more complicated dependences on the kinetic temperature of halos and the models of the first light. These features characterizing the abundance of molecules also determine the intensity of the halos luminescence during their evolution. Furthermore, we calculated the evolution of the brightness temperature of the individual halo in the rotational lines of H 2 , HD and HeH + molecules relative to the temperature of the cosmic microwave background at redshifts corresponding to the Dark Ages and Cosmic Dawn epochs. It does not exceed the microkelvin, but its detection may be an important source of information about the physical processes taking place at the beginning of the formation of the first stars and galaxies at the epochs of the Dark Ages and Cosmic Dawn.

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Section: Luminescence Of Halo In the Molecular Linesmentioning

confidence: 99%

The first molecules in the intergalactic medium and halos of the Dark Ages and Cosmic Dawn

Novosyadlyj,

Kulinich,

Melekh

et al. 2022

Preprint

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“…Since the time dependence of the density and temperature of the baryonic matter in the halos at stages before, during, and after virialization differ from the background ones, the number densities of the first molecules are different too. Moreover, the warm and hot halos can slightly shine at the cosmic microwave background (Novosyadlyj et al 2020;Kulinich et al 2020). To analyze the impact of the first light on the abundance of the first molecules and their luminescence in the halos, we use the theory of cosmological perturbations and the halo model to produce accurate computations of physical conditions and integrations of the corresponding kinetics equations.…”

Section: Molecules In the Intra-proto-galactic Medium And Their Lumin...mentioning

confidence: 99%

“…Here, i > j, A i j is the rate of spontaneous transition from i-level to j-level, B i j and B ji are the rates of induced transition and absorption at frequency ν i j , accordingly, C ji and C i j are the rates of collisional excitation of i-level from j-level and de-excitation from the i-level to the j-level, U ν i j = U CMB ν i j + U fl ν i j is the total energy density of radiation at any redshift from cosmological recombination to reionization. We used the same approximations for excitation and de-excitation rates of rotational levels of molecules H 2 , HD, and HeH + as in our previous papers, Novosyadlyj et al (2020) and Kulinich et al (2020), and references therein. Solution of the system of equations for populations of rotational levels with J = 0−5 gives us the possibility to compute the excitation temperature from the i-level to the j-level:…”

Section: Luminescence Of Halo In the Molecular Linesmentioning

confidence: 99%

“…In ours previous papers (Novosyadlyj et al 2017(Novosyadlyj et al , 2018(Novosyadlyj et al , 2020Kulinich et al 2020) we studied the formation and destruction of the first molecules, H 2 , HD, and HeH + , in the halos of the Dark Ages and their luminescence in the rotational lines of these molecules. Here, we elucidate the matter of how the radiation of the first sources, arising at Cosmic Dawn, influences the abundances of the first molecules and their luminescence in the same rotational lines.…”

Section: Introductionmentioning

confidence: 99%

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The first molecules in the intergalactic medium and halos of the Dark Ages and Cosmic Dawn

Novosyadlyj

Kulinich

Melekh

et al. 2022

A&A

Self Cite

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We study the formation and destruction of the first molecules at the epochs of the Dark Ages and Cosmic Dawn to evaluate the luminosity of the protogalaxy clumps (halos) in the molecular lines. The cosmological recombination is described using the RecFast model of an effective three-level atom, while the chemistry of the molecules is examined using the relevant basic kinetic equations. We then studied the effect of collisional and radiative excitation of molecules on the intensity of molecular emission in both warm and hot halos. Using the Planck data on the reionization of the intergalactic medium at z ∼ 6−8, we evaluated the upper limits of the light energy density for four models of thermal light from the first sources that appeared in the Cosmic Dawn epoch. Assuming that in the halos, the light energy density may essentially be even higher, we estimated the impact of the light from the first sources (the first light) on the formation and destruction of the first molecules in them as well as between them. We show that the molecules H 2 and HD are destroyed by photodissociation processes shortly before the full reionization in the inter-halo medium, in the medium of both types of halos and for all models of the first light. At the same time, the number density of helium hydride ions, HeH + , shows essentially more complicated dependences on the kinetic temperature of halos and the models of the first light. These features characterizing the abundance of molecules also determine the intensity of the halos luminescence during their evolution. Furthermore, we calculated the evolution of the brightness temperature of the individual halo in the rotational lines of H 2 , HD and HeH + molecules relative to the temperature of the cosmic microwave background at redshifts corresponding to the Dark Ages and Cosmic Dawn epochs. It does not exceed the microkelvin, but its detection may be an important source of information about the physical processes taking place at the beginning of the formation of the first stars and galaxies at the epochs of the Dark Ages and Cosmic Dawn.

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Energy-transfer quantum dynamics of HeH+ with He atoms: Rotationally inelastic cross sections and rate coefficients

Gianturco

Giri

González-Sánchez

et al. 2021

The Journal of Chemical Physics

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Two different ab initio potential energy surfaces are employed to investigate the efficiency of the rotational excitation channels for the polar molecular ion HeH+ interacting with He atoms. We further use them to investigate the quantum dynamics of both the proton-exchange reaction and the purely rotational inelastic collisions over a broad range of temperatures. In current modeling studies, this cation is considered to be one of the possible cooling sources under early universe conditions after the recombination era and has recently been found to exist in the interstellar medium. The results from the present calculations are able to show the large efficiency of the state-changing channels involving rotational states of this cation. In fact, we find them to be similar in size and behavior to the inelastic and reaction rate coefficients obtained in previous studies, where H atoms were employed as projectiles. The same rotational excitation processes, occurring when free electrons are the collision partners of this cation, are also compared with the present findings. The relative importance of the reactive, proton-exchange channel and the purely inelastic channels is also analyzed and discussed. The rotational de-excitation processes are also investigated for the cooling kinetics of the present cation under cold trap conditions with He as the buffer gas. The implications of the present results for setting up more comprehensive numerical models to describe the chemical evolution networks in different environments are briefly discussed.

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Thermal and resonant emission of dark age halos in the rotational lines of HeH+

Cited by 7 publications

References 58 publications

The first molecules in the intergalactic medium and halos of the Dark Ages and Cosmic Dawn

The first molecules in the intergalactic medium and halos of the Dark Ages and Cosmic Dawn

The first molecules in the intergalactic medium and halos of the Dark Ages and Cosmic Dawn

Energy-transfer quantum dynamics of HeH+ with He atoms: Rotationally inelastic cross sections and rate coefficients

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