Gas and dust temperature in pre-stellar cores revisited: New limits on cosmic-ray ionization rate

Abstract

We develop a self-consistent model for the equilibrium gas temperature and size-dependent dust temperature in cold, dense pre-stellar cores, assuming an arbitrary power-law size distribution of dust grains. Compact analytical expressions applicable to a broad range of physical parameters are derived and compared with predictions of the commonly used standard model. It is suggested that combining the theoretical results with observations should allow us to constrain the degree of dust evolution and the cosmic-ray ionization rate in dense cores, and to help in discriminating between different regimes of cosmic-ray transport in molecular clouds. In particular, assuming a canonical MRN distribution of grain sizes, our theory demonstrates that the gas temperature measurements in the pre-stellar core L1544 are consistent with an ionization rate as high as $\sim 10^{-16}$ s${}^{-1}$, an order of magnitude higher than previously thought.

arXiv commentAccepted to ApJ

References in corpus (40)

• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Cold Dark Clouds: The Initial Conditions for Star Formation
• Systematic Molecular Differentiation in Starless Cores
• Probing the evolutionary status of starless cores through N2H+ and N2D+ observations
• Tracing the Mass during Low-Mass Star Formation. II. Modelling the Submillimeter Emission from Pre-Protostellar Cores
• Radiation thermo-chemical models of protoplanetary disks I. Hydrostatic disk structure and inner rim
• Investigating the Cosmic-Ray Ionization Rate in the Galactic Diffuse Interstellar Medium through Observations of H3+
• Observing the gas temperature drop in the high-density nucleus of L 1544
• Formation of Complex Molecules in Prestellar Cores: a Multilayer Approach
• Cosmic-ray ionisation in circumstellar discs
• Dynamics and Depletion in Thermally Supercritical Starless Cores
• Numerical Modeling of the Coagulation and Porosity Evolution of Dust Aggregates
• The earliest phases of star formation - A Herschel key project. The thermal structure of low-mass molecular cloud cores
• The dust temperature distribution in prestellar cores
• The cosmic ray ionization rate in the Galactic disk, as determined from observations of molecular ions
• The structure and stability of molecular cloud cores in external radiation fields
• The Different Structures of the Two Classes of Starless Cores
• On Cosmic Ray-Driven Grain Chemistry in Cold Core Models
• The dynamics of collapsing cores and star formation
• Cosmic-ray and X-ray Heating of Interstellar Clouds and Protoplanetary Disks
• Molecular ions in the protostellar shock L1157-B1
• Protoplanetary Disk Structure With Grain Evolution: the ANDES Model
• Photoelectric Emission from Dust Grains Exposed to Extreme Ultraviolet and X-ray Radiation
• Freeze-out and coagulation in pre-protostellar collapse
• The central 1000 AU of a pre-stellar core revealed with ALMA. I. 1.3 mm continuum observations
• Chemistry and Radiative Transfer of Water in Cold, Dense Clouds
• Cosmic ray induced ionisation of a molecular cloud shocked by the W28 supernova remnant
• Parameterizing the interstellar dust temperature
• Effect of Grain Size on Differential Desorption of Volatile Species and on Non-ideal MHD Diffusivity
• Penetration of cosmic rays into dense molecular clouds: role of diffuse envelope
• Why does ammonia not freeze out in the center of pre-stellar cores?
• Production of atomic hydrogen by cosmic rays in dark clouds
• Deuteration of ammonia in the starless core Ophiuchus/H-MM1
• Diffusive Versus Free-Streaming Cosmic Ray Transport in Molecular Clouds
• Dust Emissivity in the Star-Forming Filament OMC 2/3
• Dust opacity variations in the pre-stellar core L1544
• Hydrodynamics with gas-grain chemistry and radiative transfer: comparing dynamical and static models
• The EDIBLES survey IV. Cosmic ray ionization rates in diffuse clouds from near-ultraviolet observations of interstellar OH${}^{+}$
• Prestellar core modeling in the presence of a filament - The dense heart of L1689B
• Search for grain growth towards the center of L1544

Cited by in corpus (26)

• Formation of the Musca filament: Evidence for asymmetries in the accretion flow due to a cloud-cloud collision
• The cosmic-ray ionisation rate in the pre-stellar core L1544
• Isomers in Interstellar Environments (I): The Case of Z- and E-Cyanomethanimine
• Survey of ortho-H${}_2$D${}^{+}$ in high-mass star-forming regions
• Rapid Elimination of Small Dust Grains in Molecular Clouds
• Magnetically regulated collapse in the B335 protostar? II. Observational constraints on gas ionization and magnetic field coupling
• An Interferometric View of H-MM1. I. Direct Observation of NH3 Depletion
• A new proxy to estimate the cosmic-ray ionisation rate in dense cores
• Identification of prestellar cores in high-mass star forming clumps via ${\mathrm{H}}_2{\mathrm{D}}^{+}$ observations with ALMA
• First ALMA maps of cosmic ray ionisation rate in high-mass star-forming regions
• Dense gas formation in the Musca filament due to the dissipation of a supersonic converging flow
• Transition from Coherent Cores to Surrounding Cloud in L1688
• Cold Clouds as Cosmic-Ray Detectors
• Rigorous theory for secondary cosmic-ray ionization
• Effect of grain size distribution and size-dependent grain heating on molecular abundances in starless and pre-stellar cores
• The DR21(OH) Trident -- Resolving the Massive Ridge into Three Entangled Fibers As the Initial Condition of Cluster Formation
• Seeds of Life in Space SOLIS. IX. Chemical segregation of $\mathrm{S}{\mathrm{O}}_2$ and SO toward the low-mass protostellar shocked region of L1157
• Cosmic-ray-induced H${}_2$ line emission: Astrochemical modeling and implications for JWST observations
• VLA and NOEMA view of the Bok Globule CB 17: the starless nature of a proposed FHSC candidate
• Exclusion of cosmic rays from molecular clouds by self-generated electric fields
• A low cosmic-ray ionisation rate in the prestellar core Ophiuchus/H-MM1. Mapping of the molecular ions ortho-H2D+, N2H+, and DCO+
• Thermal damping of Weak Magnetosonic Turbulence in the Interstellar Medium
• The impact of attenuation on cosmic-ray chemistry: I. Abundances and chemical calibrators in molecular clouds
• One-dimensional and time-dependent modelling of complex organic molecules in protostars
• Grain alignment and dust evolution physics with polarisation (GRADE-POL). I. Dust polarisation modelling for isolated starless cores
• Chemical analysis of prestellar cores in Ophiuchus yields short timescales and rapid collapse