Sanhueza, Patricio, Contreras, Yanett, Wu, Benjamin, Jackson, James M., Guzman, Andres E., Zhang, Qizhou, Li, Shanghuo ORCID: 0000-0003-1275-5251, Lu, Xing, Silva, Andrea, Izumi, Natsuko ORCID: 0000-0003-1604-9127, Liu, Tie, Miura, Rie E., Tatematsu, Ken'ichi, Sakai, Takeshi, Beuther, Henrik, Garay, Guido, Ohashi, Satoshi, Saito, Masao, Nakamura, Fumitaka, Saigo, Kazuya, Veena, V. S., Nguyen-Luong, Quang and Tafoya, Daniel (2019). The ALMA Survey of 70 mu m Dark High-mass Clumps in Early Stages (ASHES). I. Pilot Survey: Clump Fragmentation. Astrophys. J., 886 (2). BRISTOL: IOP PUBLISHING LTD. ISSN 1538-4357

Full text not available from this repository.

Abstract

The ALMA Survey of 70 ?m dark High-mass clumps in Early Stages (ASHES) is designed to systematically characterize the earliest stages and constrain theories of high-mass star formation. Twelve massive (>500 <CDATA<i), cold (?15 K), 3.6?70 ?m dark prestellar clump candidates, embedded in infrared dark clouds, were carefully selected in the pilot survey to be observed with the Atacama Large Millimeter/submillimeter Array (ALMA). We have mosaicked each clump (?1 arcmin(2)) in continuum and line emission with the 12 m, 7 m, and Total Power (TP) arrays at 224 GHz (1.34 mm), resulting in ?12 resolution (?4800 au, at the average source distance). As the first paper in the series, we concentrate on the continuum emission to reveal clump fragmentation. We detect 294 cores, from which 84 (29%) are categorized as protostellar based on outflow activity or ?warm core? line emission. The remaining 210 (71%) are considered prestellar core candidates. The number of detected cores is independent of the mass sensitivity range of the observations and, on average, more massive clumps tend to form more cores. We find a large population of low-mass (<1 <CDATA<i) cores and no high-mass (>30 <CDATA<i) prestellar cores (maximum mass 11 <CDATA<i). From the prestellar core mass function, we derive a power-law index of 1.17.10, which is slightly shallower than Salpeter. We used the minimum spanning tree (MST) technique to characterize the separation between cores and their spatial distribution, and to derive mass segregation ratios. While there is a range of core masses and separations detected in the sample, the mean separation and mass per clump are well explained by thermal Jeans fragmentation and are inconsistent with turbulent Jeans fragmentation. Core spatial distribution is well described by hierarchical subclustering rather than centrally peaked clustering. There is no conclusive evidence of mass segregation. We test several theoretical conditions and conclude that overall, competitive accretion and global hierarchical collapse scenarios are favored over the turbulent core accretion scenario.

Item Type: Journal Article
Creators:
CreatorsEmailORCIDORCID Put Code
Sanhueza, PatricioUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Contreras, YanettUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Wu, BenjaminUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Jackson, James M.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Guzman, Andres E.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Zhang, QizhouUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Li, ShanghuoUNSPECIFIEDorcid.org/0000-0003-1275-5251UNSPECIFIED
Lu, XingUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Silva, AndreaUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Izumi, NatsukoUNSPECIFIEDorcid.org/0000-0003-1604-9127UNSPECIFIED
Liu, TieUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Miura, Rie E.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Tatematsu, Ken'ichiUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Sakai, TakeshiUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Beuther, HenrikUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Garay, GuidoUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Ohashi, SatoshiUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Saito, MasaoUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Nakamura, FumitakaUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Saigo, KazuyaUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Veena, V. S.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Nguyen-Luong, QuangUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Tafoya, DanielUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
URN: urn:nbn:de:hbz:38-126338
DOI: 10.3847/1538-4357/ab45e9
Journal or Publication Title: Astrophys. J.
Volume: 886
Number: 2
Date: 2019
Publisher: IOP PUBLISHING LTD
Place of Publication: BRISTOL
ISSN: 1538-4357
Language: English
Faculty: Unspecified
Divisions: Unspecified
Subjects: no entry
Uncontrolled Keywords:
KeywordsLanguage
STAR-FORMATION; INITIAL CONDITIONS; MOLECULAR LINE; CLOUDS; OUTFLOW; INFALL; CORES; TURBULENT; FILAMENTS; COLLAPSEMultiple languages
Astronomy & AstrophysicsMultiple languages
Refereed: Yes
URI: http://kups.ub.uni-koeln.de/id/eprint/12633

Downloads

Downloads per month over past year

Altmetric

Export

Actions (login required)

View Item View Item