J/AJ/161/191ivo://CDS.VizieR/J/AJ/161/191doi:10.26093/cds/vizier.51610191CDSDottori H.Diaz R.J.Grosbol P.Bueno A.Gimeno G.2022-01-19T12:29:49Z2021-08-16T07:40:22ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesh-ii-regionsvisible-astronomyh-alpha-photometryThe galaxy NGC7020 displays an exotic hexagonal ringlike central structure with conspicuous ansae located at two opposite vertices and a tenuous external ring populated by H ii regions. Inside and around the hexagonal structure, H{alpha} emission is also present at the inner disk. To characterize the population of the HII regions, as well as their ionizing clusters, we imaged NGC7020 with narrowband H{alpha} and nearby continuum filters attached to GMOS-S installed on the Gemini South telescope. We found 202 HII regions or complexes of HII regions evenly distributed between the outer ring and the central disk The nucleus and ansae also present H{alpha} emission. The equivalent width of the H{alpha} line (WH{alpha}) is systematically greater at the regions of the outer ring relative to those of the inner disk. We discuss the influence of the metallicity gradient of the disk and the upper limit of the masses of the initial mass function on WH{alpha}, and we conclude that the data are still consistent with the occurrence of a younger burst of HII region formation in the outer ring. The central regions present more massive clusters, M>~106M{sun}, than those of the outer ring (M<~106M{sun}). Three clusters within 5" of the nucleus present masses higher than 108M{sun}. The presence of diffuse H{alpha} emission in the inner 5" suggests gas flows in the nuclear region.2021AJ....161..191Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/161/191CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/542/A39 : NIR photometry in 10 nearby spiral galaxies (Grosboel+, 2012)J/A+A/587/A135 : Halpha images of NGC 6334 and NGC 6357 (Russeil+, 2016)J/MNRAS/465/3461 : Halpha maps of 3 LIRGS (Zaragoza-Cardiel+, 2017)J/A+A/644/A38 : Halpha images of stellar bars in galaxies (Diaz-Garcia+, 2020)J/A+A/646/A139 : IC 3476 Halpha image (Boselli+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/161/191https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/161/191http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/161/191https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/161/191https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/161/191http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/161/191GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/161/191/table5HII region physical parameterse_IHa[3E-20/6E-19] Uncertainty in IHaW.m**-2stat.errordoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/202] Sequential identifiermeta.id;meta.mainintRAoff[-71.2/73.1] Offset Right Ascension from originarcsecpos.eq.raDEoff[-68.7/76.2] Offset, Declination, from originarcsecpos.eq.decIHa[1.43E-19/1.17E-16] true H{alpha} emission line intensityW.m**-2spect.line.intensitydoubleFHa[4.68E-22/1.58E-15] Contamination corrected flux, H{alpha}W.m**-2.nm**-1phot.fluxdoublee_FHa[1E-21/6E-18] Uncertainty in FHaW.m**-2.nm**-1stat.errordoubleEWHa[0.02/791] Equivalent width, H{alpha}nmspect.line.eqWidthfloate_EWHa[0.01/928] Uncertainty in WHanmstat.errorfloatNote[*] *=See section 3.1 (7 occurrences)meta.notecharFlag[an] a = ansae (2 occurrences), n = galactic nucleus (1 occurrence)meta.code.errorchar