Diverse protostellar evolutionary states in the young cluster AFGL961

Abstract

We present arcsecond resolution mid-infrared and millimeter observations of the center of the young stellar cluster AFGL961 in the Rosette molecular cloud. Within 0.2 pc of each other, we find an early B star embedded in a dense core, a neighboring star of similar luminosity with no millimeter counterpart, a protostar that has cleared out a cavity in the circumcluster envelope, and two massive, dense cores with no infrared counterparts. An outflow emanates from one of these cores, indicating a deeply embedded protostar, but the other is starless, bound, and appears to be collapsing. The diversity of states implies either that protostellar evolution is faster in clusters than in isolation or that clusters form via quasi-static rather than dynamic collapse. The existence of a pre-stellar core at the cluster center shows that that some star formation continues after and in close proximity to massive, ionizing stars.

22 pages, 7 figures, accepted for publication in ApJ

References in corpus (23)

• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• Toward Understanding Massive Star Formation
• Interpreting Spectral Energy Distributions from Young Stellar Objects. II. Fitting observed SEDs using a large grid of pre-computed models
• Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs
• The Formation of a Star Cluster: Predicting the Properties of Stars and Brown Dwarfs
• The hierarchical formation of a stellar cluster
• A Search for Infall Motions Toward Nearby Young Stellar Objects
• The Importance of Radiative Feedback for the Stellar Initial Mass Function
• Tracing the Mass during Low-Mass Star Formation. I. Submillimeter Continuum Observations
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. III. Perseus Observed with IRAC
• Equilibrium Star Cluster Formation
• {Millimeter Multiplicity in NGC 6334 I and I(N)
• Detection of interstellar H_2D^+ emission
• Molecular Line Profile Fitting with Analytic Radiative Transfer Models
• Resolved 24.5 micron emission from massive young stellar objects
• Synthetic infrared images and spectral energy distributions of a young low-mass stellar cluster
• A FLAMINGOS Deep Near Infrared Imaging Survey of the Rosette Complex I: Identification and Distribution of the Embedded Population
• Millimeter interferometry of W3 IRS5: A Trapezium in the making
• A Case Study of Low-Mass Star Formation
• The Nature of the Massive Young Stars in W75 N
• A large-scale CO survey of the Rosette Molecular Cloud: assessing the effects of O stars on surrounding molecular gas
• A Contracting, Turbulent, Starless Core in the Serpens Cluster
• The Rosette Eye: the key transition phase in the birth of a massive star

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• A sub-millimeter Mapping Survey of Herbig AeBe Stars
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• A Chandra Study of the Rosette Star-Forming Complex. III. The NGC 2237 Cluster and the Region's Star Formation History
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