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dc.contributor.authorSimons, Raymond C.
dc.contributor.authorKassin, Susan A.
dc.contributor.authorTrump, Jonathan R.
dc.contributor.authorWeiner, Benjamin
dc.contributor.authorHeckman, Timothy M.
dc.contributor.authorBarro, Guillermo
dc.contributor.authorKoo, David C.
dc.contributor.authorGuo, Yicheng
dc.contributor.authorPacifici, Camilla
dc.contributor.authorKoekemoer, A.
dc.contributor.authorStephens, Andrew W.
dc.date.accessioned2017-06-12T23:55:45Z
dc.date.available2017-06-12T23:55:45Z
dc.date.issued2016-10-03
dc.identifier.citationKINEMATIC DOWNSIZING AT z similar to 2. 2016, 830 (1):14 The Astrophysical Journalen
dc.identifier.issn1538-4357
dc.identifier.doi10.3847/0004-637X/830/1/14
dc.identifier.urihttp://hdl.handle.net/10150/624072
dc.description.abstractWe present results from a survey of the internal kinematics of 49 star-forming galaxies at z similar to 2 in the CANDELS fields with the Keck/MOSFIRE spectrograph, Survey in the near-Infrared of Galaxies with Multiple position Angles (SIGMA). Kinematics (rotation velocity V-rot and gas velocity dispersion sg) are measured from nebular emission lines which trace the hot ionized gas surrounding star-forming regions. We find that by z similar to 2, massive star-forming galaxies (log M-*/M-circle dot less than or similar to 10.2) have assembled primitive disks: their kinematics are dominated by rotation, they are consistent with a marginally stable disk model, and they form a Tully-Fisher relation. These massive galaxies have values of V-rot sg that are factors of 2-5 lower than local well-ordered galaxies at similar masses. Such results are consistent with findings by other studies. We find that low-mass galaxies (log M-*/M-circle dot less than or similar to 10.2) at this epoch are still in the early stages of disk assembly: their kinematics are often dominated by gas velocity dispersion and they fall from the Tully-Fisher relation to significantly low values of V-rot. This "kinematic downsizing" implies that the process(es) responsible for disrupting disks at z similar to 2 have a stronger effect and/or are more active in low-mass systems. In conclusion, we find that the period of rapid stellar mass growth at z similar to 2 is coincident with the nascent assembly of low-mass disks and the assembly and settling of high-mass disks.
dc.description.sponsorshipSTScI JDF; NASA through Hubble Fellowship grant - Space Telescope Science Institute [51330]; NASA [NAS 5-26555]en
dc.language.isoenen
dc.publisherIOP PUBLISHING LTDen
dc.relation.urlhttp://stacks.iop.org/0004-637X/830/i=1/a=14?key=crossref.fff89233ad01a38d0de63e5e715b4eccen
dc.rights© 2016. The American Astronomical Society. All rights reserved.en
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectgalaxies: evolutionen
dc.subjectgalaxies: formationen
dc.subjectgalaxies: fundamental parametersen
dc.subjectgalaxies: kinematics and dynamicsen
dc.titleKINEMATIC DOWNSIZING AT z similar to 2en
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Steward Observen
dc.identifier.journalThe Astrophysical Journalen
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
refterms.dateFOA2018-08-14T01:40:22Z
html.description.abstractWe present results from a survey of the internal kinematics of 49 star-forming galaxies at z similar to 2 in the CANDELS fields with the Keck/MOSFIRE spectrograph, Survey in the near-Infrared of Galaxies with Multiple position Angles (SIGMA). Kinematics (rotation velocity V-rot and gas velocity dispersion sg) are measured from nebular emission lines which trace the hot ionized gas surrounding star-forming regions. We find that by z similar to 2, massive star-forming galaxies (log M-*/M-circle dot less than or similar to 10.2) have assembled primitive disks: their kinematics are dominated by rotation, they are consistent with a marginally stable disk model, and they form a Tully-Fisher relation. These massive galaxies have values of V-rot sg that are factors of 2-5 lower than local well-ordered galaxies at similar masses. Such results are consistent with findings by other studies. We find that low-mass galaxies (log M-*/M-circle dot less than or similar to 10.2) at this epoch are still in the early stages of disk assembly: their kinematics are often dominated by gas velocity dispersion and they fall from the Tully-Fisher relation to significantly low values of V-rot. This "kinematic downsizing" implies that the process(es) responsible for disrupting disks at z similar to 2 have a stronger effect and/or are more active in low-mass systems. In conclusion, we find that the period of rapid stellar mass growth at z similar to 2 is coincident with the nascent assembly of low-mass disks and the assembly and settling of high-mass disks.


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