dc.creatorMonica Rodriguez
dc.date2007
dc.date.accessioned2023-07-25T16:22:47Z
dc.date.available2023-07-25T16:22:47Z
dc.identifierhttp://inaoe.repositorioinstitucional.mx/jspui/handle/1009/994
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/7806193
dc.descriptionWe present echelle spectrophotometry of the blue compact dwarf galaxy NGC 5253 obtained with the VLT UVES. We have measured the intensities of a large number of permitted and forbidden emission lines in four zones of the central part of the galaxy.We detect faint C II and O II recombination lines, the first time that these are unambiguously detected in a dwarf starburst galaxy. The physical conditions of the ionized gas have been derived using a large number of different line intensity ratios. Chemical abundances of He, N, O, Ne, S, Cl, Ar, and Fe have been determined following standard methods. C++ and O++ abundances have been derived from pure recombination lines and are larger than those obtained from collisionally excited lines (from 0.30 to 0.40 dex for C++ and from 0.19 to 0.28 dex for O++). This result is consistent with a temperature fluctuation parameter (t 2) between 0.050 and 0.072.We confirm previous results that indicate the presence of a localized N enrichment in certain zones of NGC 5253 and detect a possible slight He overabundance in the same zones. The enrichment pattern agrees with that expected for the pollution by the ejecta ofWolf-Rayet (W-R) stars. The amount of enriched material needed to produce the observed overabundance is consistent with the mass lost by the number ofW-R stars estimated in the starbursts.We discuss the possible origin of the difference between abundances derived from recombination and collisionally excited lines (the so-called abundance discrepancy problem) in H II regions, finding that a recent hypothesis based on the delayed enrichment by SN ejecta inclusions seems not to explain the observed features.
dc.formatapplication/pdf
dc.languageeng
dc.publisherThe astrophysical journal
dc.relationcitation:López Sánchez, Ángel R., et al., (2007). The localized chemical pollution in ngc 5253 revisited: results from deep echelle spectrophotometry1, The astrophysical journal, Vol.656(1):168-185
dc.rightsinfo:eu-repo/semantics/openAccess
dc.rightshttp://creativecommons.org/licenses/by-nc-nd/4.0
dc.subjectinfo:eu-repo/classification/cti/1
dc.subjectinfo:eu-repo/classification/cti/21
dc.subjectinfo:eu-repo/classification/cti/21
dc.titleThe localized chemical pollution in ngc 5253 revisited: results from deep echelle spectrophotometry1
dc.typeinfo:eu-repo/semantics/article
dc.typeinfo:eu-repo/semantics/acceptedVersion
dc.audiencestudents
dc.audienceresearchers
dc.audiencegeneralPublic


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