Kinematics of a young low-mass star forming core: Understanding the evolutionary state of the First Core Candidate L1451-mm

Abstract

We use 3mm multi-line and continuum CARMA observations towards the first hydrostatic core (FHSC) candidate L1451-mm to characterize the envelope kinematics at 1000 AU scales and investigate its evolutionary state. We detect evidence of infall and rotation in the N2H+(1-0), NH2D(1(1,1)-1(0,1)) and HCN(1-0) molecular lines. We compare the position velocity diagram of the NH2D line with a simple kinematic model and find that it is consistent with an envelope that is both infalling and rotating while conserving angular momentum around a central mass of about 0.06 Msun. The N2H+(1-0) LTE mass of the envelope along with the inferred infall velocity leads to a mass infall rate of approximately 6e-6 Msun/yr, implying a young age of 10,000 years for this FHSC candidate. Assuming that the accretion onto the central object is the same as the infall rate we obtain that the minimum source size is 1.5-5 AU consistent with the size expected for a first core. We do not see any evidence of outflow motions or signs of outflow-envelope interaction at scales > 2000 AU. This is consistent with previous observations that revealed a very compact outflow (<500 AU). We conclude that L1451-mm is indeed at a very early stage of evolution, either a first core or an extremely young Class 0 protostar. Our results provide strong evidence that L1451-mm is the best candidate for being a bonafide first core.

16 pages, 11 figures

References in corpus (20)

• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• Variable protostellar accretion with episodic bursts
• 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
• Effects of Ohmic and ambipolar diffusion on the formation and evolution of the first cores, protostars and circumstellar discs
• Formation Scenario for Wide and Close Binary Systems
• On the frequency of N2H+ and N2D+
• A Sub-arcsecond Survey Toward Class 0 Protostars in Perseus: Searching for Signatures of Protostellar Disks
• ALMA Results of the Pseudodisk, Rotating disk, and Jet in Continuum and HCO+ in the Protostellar System HH 212
• Exposed Long-lifetime First-core: A New Model of First Cores Based on Radiation Hydrodynamics
• Observations of Infalling and Rotational Motions on a 1,000-AU Scale around 17 Class 0 and 0/I Protostars: Hints of Disk Growth and Magnetic Braking?
• OVRO N2H+ Observations of Class 0 Protostars: Constraints on the Formation of Binary Stars
• A Substellar-Mass Protostar and its Outflow of IRAS 15398-3359 Revealed by Subarcsecond-Resolution Observations of H${}_2$CO and CCH
• The evolutionary state of the southern dense core Cha-MMS1
• ALMA observations of the kinematics and chemistry of disc formation
• Protostellar Jets Enclosed by Low-velocity Outflows
• Two Extreme Young Objects in Barnard 1-b
• Formation and Early Evolution of Circumstellar Disks in Turbulent Molecular Cloud Cores
• Collisional excitation of doubly and triply deuterated ammonia ND${}_2$H and ND${}_3$ by H${}_2$
• CARMA Large Area Star Formation Survey: Dense Gas in the Young L1451 Region of Perseus

Cited by in corpus (15)

• Mapping Distances Across the Perseus Molecular Cloud Using CO Observations, Stellar Photometry, and Gaia DR2 Parallax Measurements
• The specific angular momentum radial profile in dense cores: improved initial conditions for disk formation
• Synthetic observations of star formation and the interstellar medium
• ALMA detections of the youngest protostars in Ophiuchus
• Mass Assembly of Stellar Systems and their Evolution with the SMA (MASSES) -- Full Data Release
• Sub-arcsecond Kinematic Structure of the Outflow in the Vicinity of the Protostar in L483
• ALMA observations of envelopes around first hydrostatic core candidates
• Investigating the Complex Velocity Structures within Dense Molecular Cloud Cores with GBT-Argus
• A turbulent origin for the complex envelope kinematics in the young low-mass core Per-Bolo 58
• VLA and NOEMA view of the Bok Globule CB 17: the starless nature of a proposed FHSC candidate
• Studying Infall in Infrared Dark Clouds with Multiple HCO+ Transitions
• A 1000 AU Scale Molecular Outflow Driven by a Protostar with an age of <4000 Years
• Confirmation of the outflow in L1451-mm: SiO line and CH${}_3$OH maser detections
• Erosion of a dense molecular core by a strong outflow from a massive protostar
• Modeling Two First Hydrostatic Core Candidates Barnard 1b-N and 1b-S