Distributed star formation throughout the galactic center cloud sgr B2
Author
dc.contributor.author
Ginsburg, Adam
Author
dc.contributor.author
Garay Brignardello, Guido
Admission date
dc.date.accessioned
2018-07-24T19:23:49Z
Available date
dc.date.available
2018-07-24T19:23:49Z
Publication date
dc.date.issued
2018
Cita de ítem
dc.identifier.citation
Astrophisical Journal Volumen: 853 Número: 2 Número de artículo: 171
es_ES
Identifier
dc.identifier.other
10.3847/1538-4357/aaa6d4
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/150218
Abstract
dc.description.abstract
We report ALMA observations with resolution approximate to 0 ''.5 at 3 mm of the extended Sgr B2 cloud in the Central Molecular Zone (CMZ). We detect 271 compact sources, most of which are smaller than 5000 au. By ruling out alternative possibilities, we conclude that these sources consist of a mix of hypercompact H II regions and young stellar objects (YSOs). Most of the newly detected sources are YSOs with gas envelopes that, based on their luminosities, must contain objects with stellar masses M* greater than or similar to 8M(circle dot). Their spatial distribution spread over a similar to 12 x 3 pc region demonstrates that Sgr B2 is experiencing an extended star formation event, not just an isolated "starburst" within the protocluster regions. Using this new sample, we examine star formation thresholds and surface density relations in Sgr B2. While all of the YSOs reside in regions of high column density (N(H-2) greater than or similar to 2 x 10(23) cm(-2) not all regions of high column density contain YSOs. The observed column density threshold for star formation is substantially higher than that in solar vicinity clouds, implying either that high-mass star formation requires a higher column density or that any star formation threshold in the CMZ must be higher than in nearby clouds. The relation between the surface density of gas and stars is incompatible with extrapolations from local clouds, and instead stellar densities in Sgr B2 follow a linear Sigma(*)-Sigma(gas) relation, shallower than that observed in local clouds. Together, these points suggest that a higher volume density threshold is required to explain star formation in CMZ clouds.
es_ES
Patrocinador
dc.description.sponsorship
National Science Foundation
AST-1615311
German Research Foundation (DFG)
KR4801/1-1
European Research Council (ERC) under the European Union's Horizon research and innovation program via the ERC Starting Grant MUSTANG
714907
DFG
Sonderforschungsbereich SFB 881
UNAM-PAPIIT program
IA102817
NSF through the Grote Reber Fellowship Program
Deutsche Forschungsgemeinschaft
SFB956
European Research Council (ERC)
PALs 320620