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Related papers: Photodissociation of H2 in Protogalaxies: Modeling…

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The Lyman-Werner (LW) radiation field is a key ingredient in the chemo-thermal evolution of gas in the Early Universe, as it dissociates H2 molecules, the primary cooling channel in an environment devoid of metals and dust. Despite its…

Astrophysics of Galaxies · Physics 2023-04-12 Andrea Incatasciato , Sadegh Khochfar , Jose Oñorbe

The first stars are expected to form through molecular-hydrogen (H$_2$) cooling, a channel that is especially sensitive to the thermal and ionization state of gas, and can thus act as a probe of exotic energy injection from decaying or…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-28 Wenzer Qin , Julian B. Munoz , Hongwan Liu , Tracy R. Slatyer

Molecular clouds (MCs) are the birthplaces of new stars in galaxies. A key component of MCs are photodissociation regions (PDRs), where far-ultraviolet radiation plays a crucial role in determining the gas's physical and chemical state.…

Thermal dissociation and recombination of molecular hydrogen, H_2, in the atmospheres of ultra-hot Jupiters (UHJs) has been shown to play an important role in global heat redistribution. This, in turn, significantly impacts their planetary…

Earth and Planetary Astrophysics · Physics 2021-05-12 Alexander Roth , Benjamin Drummond , Eric Hébrard , Pascal Tremblin , Jayesh Goyal , Nathan Mayne

The HRS is a complete volume-limited sample of nearby objects including Virgo cluster and isolated objects. Using a recent compilation of HI and CO data we study the effects of the cluster on the molecular gas content of spiral galaxies. We…

Astrophysics of Galaxies · Physics 2015-06-18 A. Boselli , L. Cortese , M. Boquien , S. Boissier , B. Catinella , G. Gavazzi , C. Lagos , A. Saintonge

We have reviewed the chemistry and cooling behaviour of low-density (n<10^4 cm^-3) primordial gas and devised a cooling model wich involves 19 collisional and 9 radiative processes and is applicable for temperatures in the range (1 K < T <…

Astrophysics · Physics 2008-11-26 T. Abel , P. Anninos , Y. Zhang , M. L. Norman

We present a cosmological hydrodynamic simulation of the formation of dwarf galaxies at redshifts z>~2.5 using a physically-motivated model for H2-regulated star formation. Our simulation, performed using the Enzo code and reaching a peak…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Michael Kuhlen , Piero Madau , Mark Krumholz

We study the influence of low levels of metal enrichment on the cooling and collapse of ionized gas in small protogalactic halos using three-dimensional, smoothed particle hydrodynamics simulations. Our initial conditions represent…

Astrophysics · Physics 2008-11-26 A. -K. Jappsen , S. C. O. Glover , R. S. Klessen , M. -M. Mac Low

We study the effects of the ionizing and dissociating photons produced by PopIII objects on the surrounding intergalactic medium. We find that the typical size of a H_2 photodissociated region, R_d ~ 1-5 kpc, is smaller than the mean…

Astrophysics · Physics 2007-05-23 Benedetta Ciardi , Andrea Ferrara , Tom Abel

Recent three-dimensional cosmological simulations of protogalaxy formation have suggested that supermassive stars (SMSs) can form in gas clouds in which H$_2$ cooling is suppressed by dynamical heating prior to the activation of atomic…

Astrophysics of Galaxies · Physics 2020-10-28 Yuya Sakurai , Zoltán Haiman , Kohei Inayoshi

The first generation of stars produces a background of Lyman-Werner (LW) radiation which can photo-dissociate molecular hydrogen, increasing the mass of dark matter halos required to host star formation. Previous studies have determined the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Eli Visbal , Zoltan Haiman , Bryan Terrazas , Greg L. Bryan , Rennan Barkana

Molecular hydrogen allows cooling in primordial gas, facilitating its collapse into Population III stars within primordial halos. Lyman-Werner (LW) radiation from these stars can escape the halo and delay further star formation by…

Astrophysics of Galaxies · Physics 2023-01-25 Lewis R. Prole , Anna T. P. Schauer , Paul C. Clark , Simon C. O. Glover , Felix D. Priestley , Ralf S. Klessen

We model gas cooling in high-resolution N-body simulations in order to investigate the formation of the first generation of stars. We follow a region of a LCDM universe especially selected to contain a rich cluster by the present day. The…

In this study, we present a suite of high-resolution numerical simulations of an isolated galaxy to test a sub-grid framework to consistently follow the formation and dissociation of H$_2$ with non-equilibrium chemistry. The latter is…

Astrophysics of Galaxies · Physics 2017-12-27 Alessandro Lupi , Stefano Bovino , Pedro R. Capelo , Marta Volonteri , Joseph Silk

We present numerical simulations of the photoevaporation of cosmological halos clustered around a 120 M$_\odot$ primordial star, confining our study to structures capable of hosting Population III star formation. The calculations include…

Astrophysics · Physics 2008-11-26 Daniel Whalen , Brian W. O'Shea , Joseph Smidt , Michael L. Norman

We present an integrated thermal-chemical model for the atmosphere of the inner region of a protoplanetary disk that includes irradiation by both far ultraviolet (FUV) and X-ray radiation. We focus on how the photodissociation of water and…

Earth and Planetary Astrophysics · Physics 2015-06-19 Máté Ádámkovics , Alfred E. Glassgold , Joan R. Najita

The opacity due to photodissociation of 24MgH is investigated in the atmospheres of cool stars. The lowest two electronic transitions A 2Pi -- X 2Sigma+ and B' 2Sigma+ -- X 2 Sigma+ are considered where the cross sections for the latter…

Astrophysics · Physics 2009-11-07 P. F. Weck , A. Schweitzer , P. C. Stancil , P. H. Hauschildt , K. Kirby

H2 is the most abundant molecule in the interstellar medium and is a useful tool to study photodissociation regions, where radiative feedback from massive stars on molecular clouds is dominant. The James Webb Space Telescope, with its high…

Molecular predissociation is the spontaneous, nonradiative bond breaking process that can occur upon excitation. In the context of laser cooling, predissociation is an unwanted consequence of molecular structure that limits the ability to…

We describe cosmological galaxy formation simulations with the adaptive mesh refinement code Enzo that incorporate a star formation prescription regulated by the local abundance of molecular hydrogen. We show that this H2-regulated…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. Kuhlen , M. Krumholz , P. Madau , B. Smith , J. Wise