300: An ACA 870 $\mu$m Continuum Survey of Orion Protostars and their Evolution

Abstract

We present an 870 $\mu$m continuum survey of 300 protostars from the Herschel Orion Protostar Survey using the Atacama Compact Array (ACA). These data measure protostellar flux densities on envelope scales $\le$8000 au (20") and resolve the structure of envelopes with 1600 au (4") resolution, a factor of 3-5 improvement in angular resolution over existing single-dish 870 $\mu$m observations. We compare the ACA observations to Atacama Large Millimeter/submillimeter Array 12 m array observations at 870 $\mu$m with $\sim$0.1 (40 au) resolution. Using the 12 m data to measure the fluxes from disks and the ACA data within 2500 au to measure the combined disk plus envelope fluxes, we calculate the 12 m/ACA 870 $\mu$m flux ratios. Our sample shows a clear evolution in this ratio. Class 0 protostars are mostly envelope-dominated with ratios $<$0.5. In contrast, Flat Spectrum protostars are primarily disk-dominated with ratios near 1, although with a number of face-on protostars dominated by their envelopes. Class I protostars span the range from envelope to disk-dominated. The increase in ratio is accompanied by a decrease in the envelope fluxes and estimated mass infall rates. We estimate that 80$\%$ of the mass is accreted during the envelope-dominated phase. We find that the 12 m/ACA flux ratio is an evolutionary indicator that largely avoids the inclination and foreground extinction dependence of spectral energy distribution-based indicators.

References in corpus (49)

• On the variation of the Initial Mass Function
• A Universal Stellar Initial Mass Function? A Critical Look at Variations
• Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs
• Gravitational Instabilities in Circumstellar Disks
• The Spitzer Space Telescope Survey of the Orion A & B Molecular Clouds - Part I: A Census of Dusty Young Stellar Objects and a Study of their Mid-IR Variability
• A Steeper than Linear Disk Mass-Stellar Mass Scaling Relation
• 2-D Radiative Transfer in Protostellar Envelopes: II. An Evolutionary Sequence
• Properties of the Youngest Protostars in Perseus, Serpens, and Ophiuchus
• Star formation through gravitational collapse and competitive accretion
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. A Statistical Characterization of Class 0 and I Protostellar Disks
• The APOGEE-2 Survey of the Orion Star Forming Complex II: Six-dimensional structure
• A 0.2 solar mass protostar with a Keplerian disk in the very young L1527 IRS system
• The Herschel Orion Protostar Survey: Spectral Energy Distributions and Fits Using a Grid of Protostellar Models
• A Herschel and APEX Census of the Reddest Sources in Orion: Searching for the Youngest Protostars
• The Spitzer Space Telescope Survey of the Orion A and B Molecular Clouds II: the Spatial Distribution and Demographics of Dusty Young Stellar Objects
• Evolution of column density distributions within Orion~A
• Slingshot Mechanism in Orion: Kinematic Evidence For Ejection of Protostars by Filaments
• Complex Structure in Class 0 Protostellar Envelopes
• Characterizing the nature of embedded young stellar objects through silicate, ice and millimeter observations
• Luminosity Functions of Spitzer Identified Protostars in Nine Nearby Molecular Clouds
• HOPS 383: An Outbursting Class 0 Protostar in Orion
• The Herschel Orion Protostar Survey: Luminosity and Envelope Evolution
• Bondi-Hoyle Accretion in a Turbulent Medium
• Quantifying Variability of YSOs in the Mid-IR Over Six Years with NEOWISE
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. III. Substructures in Protostellar Disks
• The protoplanetary disk population in the rho-Ophiuchi region L1688 and the time evolution of Class II YSOs
• The Formation and Evolution of Wide-Orbit Stellar Multiples In Magnetized Clouds
• `Tail-end' Bondi-Hoyle accretion in young star clusters: Implications for disks, planets, and stars
• Multiwavelength Observations of V2775 Ori, an Outbursting Protostar in L 1641: Exploring the Edge of the FU Orionis Regime
• ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow: Structure, Entrainment and Core Impact
• A $Herschel-SPIRE$ Survey of the Mon R2 Giant Molecular Cloud: Analysis of the Gas Column Density Probability Density Function
• Orphaned Protostars
• Evolution of Mass Outflow in Protostars
• The Dependence of Protostellar Luminosity on Environment in the Cygnus-X Star-Forming Complex
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars V. A Characterization of Protostellar Multiplicity
• The outburst of an embedded low-mass YSO in L1641
• The Single-Cloud Star Formation Relation
• FRagmentation and Evolution of dense cores Judged by ALMA (FREJA). I (Overview). Inner $\sim$1000 au structures of prestellar/protostellar cores in Taurus
• On the distribution of protostar masses
• The Rate, Amplitude and Duration of Outbursts from Class 0 Protostars in Orion
• Characterizing the Youngest Herschel-detected Protostars I. Envelope Structure Revealed by CARMA Dust Continuum Observations
• Massive compact disks around FU Orionis-type young eruptive stars revealed by ALMA
• An HST Survey of Protostellar Outflow Cavities: Does Feedback Clear Envelopes?
• Results from HOPS: A Multiwavelength Census of Orion Protostars
• Low Mass Stars as Tracers of Star and Cluster Formation
• Predicted Colors and Flux Densities of Protostars in the Herschel PACS and SPIRE Filters
• Detection of Irregular, Sub-mm Opaque Structures in the Orion Molecular Clouds: Protostars within 10000 years of formation?
• The APEX Large CO Heterodyne Orion Legacy Survey (ALCOHOLS). I. Survey overview
• HOPS 136: An Edge-On Orion Protostar Near the End of Envelope Infall

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• Investigating Protostellar Accretion-Driven Outflows Across the Mass Spectrum: JWST NIRSpec IFU 3-5~$\mu$m Spectral Mapping of Five Young Protostars
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• On the magnetic field properties of protostellar envelopes in Orion
• An ALMA search for substructure and fragmentation in starless cores in Orion B North
• The NEMESIS Catalogue of Young Stellar Objects for the Orion Star Formation Complex. I. General description of data curation
• Assessing the accuracy of the star formation rate measurements by direct star count in molecular clouds
• Molecular Jets from an Evolved Protostar: Insights from JWST-ALMA Synergy
• Jets in Low-Mass Protostars
• A framework for modeling the evolution of young stellar objects