Synthetic molecular line observations of the first hydrostatic core from chemical calculations

Abstract

The first stable object to develop in the low-mass star formation process has long been predicted to be the first hydrostatic core (FHSC). Despite much effort, it has still yet to be definitively observed in nature. More specific observational signatures are required to enable observers to distinguish the FHSC from young, faint, but more evolved protostars. Here we present synthetic spectral line observations for CO, SO, CS and HCO${}^{+}$ that were calculated from radiation (magneto)hydrodynamical models, chemical modelling and Monte Carlo radiative transfer. HCO${}^{+}$ $(1-0)$ and SO $(8_7-7_6)$ spectra of the FHSC show variations for observations at a low inclination which may allow a candidate FHSC to be distinguished from a more evolved object. We find that the FHSC outflow is unlikely to be detectable with ALMA, which would discount the observed sources with slow outflows that are currently identified as candidate FHSCs. We compare the results of simulated ALMA observations with observed candidate FHSCs and recommend Oph A SM1N and N6-mm as the most promising candidates to follow up.

arXiv commentAccepted to MNRAS. 23 pages, 25 figures

References in corpus (59)

• Astropy: A Community Python Package for Astronomy
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Modelling Accretion in Protobinary Systems
• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• A KInetic Database for Astrochemistry (KIDA)
• Non-thermal desorption from interstellar dust grains via exothermic surface reactions
• The 2014 KIDA network for interstellar chemistry
• Spiral Density Waves in a Young Protoplanetary Disk
• Chemistry of Dark Clouds: Databases, Networks, and Models
• Polycylcic Aromatic Hydrocarbons (PAH's) in dense cloud chemistry
• Magnetic processes in a collapsing dense core. I Accretion and Ejection
• Spiral Arms in the Asymmetrically Illuminated Disk of MWC 758 and Constraints on Giant Planets
• The impact of magnetic fields on single and binary star formation
• Outflows and Jets from Collapsing Magnetized Cloud Cores
• KROME - a package to embed chemistry in astrophysical simulations
• Molecular Evolution and Star Formation: From Prestellar Cores to Protostellar Cores
• Collapse of a Molecular Cloud Core to Stellar Densities: The First Three-Dimensional Calculations
• Collapse of Rotating Magnetized Molecular Cloud Cores and Mass Outflows
• Shadows cast on the transition disk of HD 135344B. Multiwavelength VLT/SPHERE polarimetric differential imaging
• The thermodynamics of collapsing molecular cloud cores using smoothed particle hydrodynamics with radiative transfer
• Formation of a Keplerian disk in the infalling envelope around L1527 IRS: transformation from infalling motions to Kepler motions
• Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Non-Ideal Magnetohydrodynamic Effects and Early Formation of Circumstellar Disks
• Oxygen depletion in dense molecular clouds: a clue to a low O2 abundance?
• The formation of active protoclusters in the Aquila Rift: A millimeter continuum view
• Collapse of a molecular cloud core to stellar densities: stellar core and outflow formation in radiation magnetohydrodynamics simulations
• Smoothed Particle Magnetohydrodynamics III. Multidimensional tests and the div B = 0 constraint
• A faster algorithm for smoothed particle hydrodynamics with radiative transfer in the flux-limited diffusion approximation
• Herschel observations of B1-bS and B1-bN: two first hydrostatic core candidates in the Perseus star-forming cloud
• A recent accretion burst in the low-mass protostar IRAS 15398-3359: ALMA imaging of its related chemistry
• The Spitzer c2d Survey of Nearby Dense Cores: I: First Direct Detection of the Embedded Source in IRAM 04191+1522
• Constrained Hyperbolic Divergence Cleaning for Smoothed Particle Magnetohydrodynamics
• The enigmatic core L1451-mm: a first hydrostatic core? or a hidden VeLLO?
• Collapse of a molecular cloud core to stellar densities: the formation and evolution of pre-stellar discs
• Synthetic observations of first hydrostatic cores in collapsing low-mass dense cores. I. Spectral energy distributions and evolutionary sequence
• Grain Surface Reactions in Molecular Clouds: The Effect of Cosmic Rays and Quantum Tunneling
• The collapse of a molecular cloud core to stellar densities using radiation non-ideal magnetohydrodynamics
• Nascent bipolar outflows associated with the first hydrostatic core candidates Barnard 1b-N and 1b-S
• Two Extreme Young Objects in Barnard 1-b
• Chemical and physical characterization of collapsing low-mass prestellar dense cores
• SMA and Spitzer Observations of Bok Glouble CB17: A Candidate First Hydrostatic Core?
• An algorithm for Monte-Carlo time-dependent radiation transfer
• Tracing the cold and warm physico-chemical structure of deeply embedded protostars: IRAS 16293-2422 versus VLA 1623-2417
• A switch to reduce resistivity in smoothed particle magnetohydrodynamics
• Combining radiative transfer and diffuse interstellar medium physics to model star formation
• Chemistry in the First Hydrostatic Core Stage By Adopting Three-Dimensional Radiation Hydrodynamic Simulations
• Characterizing the Youngest Herschel-detected Protostars I. Envelope Structure Revealed by CARMA Dust Continuum Observations
• Smoothed particle magnetohydrodynamic simulations of protostellar outflows with misaligned magnetic field and rotation axes
• Three-dimensional molecular line transfer: A simulated star-forming region
• The dynamical state of the First Hydrostatic Core Candidate Cha-MMS1
• ALMA detections of the youngest protostars in Ophiuchus
• Chemical modeling of the L1498 and L1517B prestellar cores: CO and HCO+ depletion
• The dependence of protostar formation on the geometry and strength of the initial magnetic field
• Modeling the chemical evolution of a collapsing prestellar core in two spatial dimensions
• Synthetic observations of first hydrostatic cores in collapsing low-mass dense cores II. Simulated ALMA dust emission maps
• Chemical segregation in the young protostars Barnard 1b-N and S: evidence of pseudo-disk rotation in Barnard 1b-S
• What can the SEDs of first hydrostatic core candidates reveal about their nature?
• Observational Identification of First Cores: Non-LTE Radiative Transfer Simulation
• 3D radiative hydrodynamic simulations of protostellar collapse with H-C-O dynamical chemistry

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