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dc.creatorDunham, Michael M.en_US
dc.creatorEvans, Neal J.en_US
dc.creatorTerebey, Susanen_US
dc.creatorDullemond, Cornelis P.en_US
dc.creatorYoung, Chadwick H.en_US
dc.date.accessioned2016-04-28T19:39:16Z
dc.date.available2016-04-28T19:39:16Z
dc.date.issued2010-02en
dc.identifierdoi:10.15781/T26511
dc.identifier.citationDunham, Michael M., Neal J. Evans II, Susan Terebey, Cornelis P. Dullemond, and Chadwick H. Young. "Evolutionary signatures in the formation of low-mass protostars. II. Toward reconciling models and observations." The Astrophysical Journal, Vol. 710, No. 1 (Feb., 2010): 470.en_US
dc.identifier.issn0004-637Xen_US
dc.identifier.urihttp://hdl.handle.net/2152/35034
dc.description.abstractA long-standing problem in low-mass star formation is the "luminosity problem," whereby protostars are underluminous compared to the accretion luminosity expected both from theoretical collapse calculations and arguments based on the minimum accretion rate necessary to form a star within the embedded phase duration. Motivated by this luminosity problem, we present a set of evolutionary models describing the collapse of low-mass, dense cores into protostars. We use as our starting point the evolutionary model following the inside-out collapse of a singular isothermal sphere as presented by Young & Evans. We calculate the radiative transfer of the collapsing core throughout the full duration of the collapse in two dimensions. From the resulting spectral energy distributions, we calculate standard observational signatures (L(bol), T(bol), L(bol)/L(smm)) to directly compare to observations. We incorporate several modifications and additions to the original Young & Evans model in an effort to better match observations with model predictions; we include (1) the opacity from scattering in the radiative transfer, (2) a circumstellar disk directly in the two-dimensional radiative transfer, (3) a two-dimensional envelope structure, taking into account the effects of rotation, (4) mass-loss and the opening of outflow cavities, and (5) a simple treatment of episodic mass accretion. We find that scattering, two-dimensional geometry, mass-loss, and outflow cavities all affect the model predictions, as expected, but none resolve the luminosity problem. On the other hand, we find that a cycle of episodic mass accretion similar to that predicted by recent theoretical work can resolve this problem and bring the model predictions into better agreement with observations. Standard assumptions about the interplay between mass accretion and mass loss in our model give star formation efficiencies consistent with recent observations that compare the core mass function and stellar initial mass function. Finally, the combination of outflow cavities and episodic mass accretion reduces the connection between observational class and physical stage to the point where neither of the two commonly used observational signatures (T(bol) and L(bol)/L(smm)) can be considered reliable indicators of physical stage.en_US
dc.description.sponsorshipNASA 1224608, 1288664, 1288658, RSA 1377304, NNX 07-AJ72Gen_US
dc.description.sponsorshipNSF AST0607793en_US
dc.description.sponsorshipUT Austin University Continuing Fellowshipen_US
dc.language.isoEnglishen_US
dc.relation.ispartofen_US
dc.rightsAdministrative deposit of works to Texas ScholarWorks: This works author(s) is or was a University faculty member, student or staff member; this article is already available through open access or the publisher allows a PDF version of the article to be freely posted online. The library makes the deposit as a matter of fair use (for scholarly, educational, and research purposes), and to preserve the work and further secure public access to the works of the University.en_US
dc.subjectstars: formationen_US
dc.subjectstars: low-massen_US
dc.subjectyoung stellar objectsen_US
dc.subjectnearby dense coresen_US
dc.subjectspitzer c2d surveyen_US
dc.subjectclass-ien_US
dc.subjectprotostarsen_US
dc.subjectt-tauri starsen_US
dc.subject2-dimensional radiative-transferen_US
dc.subjectspectralen_US
dc.subjectenergy-distributionsen_US
dc.subjectauriga molecular clouden_US
dc.subjectself-similar collapseen_US
dc.subjectprotostellar accretionen_US
dc.subjectastronomy & astrophysicsen_US
dc.titleEvolutionary Signatures In The Formation Of Low-Mass Protostars. II. Toward Reconciling Models And Observationsen_US
dc.typeArticleen_US
dc.description.departmentAstronomyen_US
dc.identifier.Filename2010_02_lowmassprotostars.pdfen_US
dc.rights.restrictionOpenen_US
dc.identifier.doi10.1088/0004-637x/710/1/470en_US
dc.contributor.utaustinauthorDunham, Michael M.en_US
dc.contributor.utaustinauthorEvans, Neal J.en_US
dc.relation.ispartofserialAstrophysical Journalen_US


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