HST photometry in NGC 6822


We present a detailed photometric study of the dwarf irregular galaxy NGC 6822 aimed at investigating the properties of its stellar populations, and in particular, the presence of stellar radial gradients. Our goal is to analyze the stellar populations in six fields, which cover the whole bar of this dwarf galaxy. We derived the quantitative star formation history (SFH) of the six fields using the IAC method, involving IAC-pop/MinnIAC codes. The solutions we derived show an enhanced star formation rate (SFR) in fields 1 and 3 during the last 500Myr. The SFRs of the other fields almost extinguish at very recent epochs. We study the radial gradients of the SFR. We consider the total mass converted into stars in two time intervals (between 0 and 0.5Gyr ago and between 0.5 and 13.5Gyr ago). We find that the scale lengths of the young and intermediate-old populations are perfectly compatible, with the exception of the young populations in fields 1 and 3. The recent SF in these two fields is larger than in the other ones. This might be an indication that in these two fields we are sampling incipient spiral arms. Further evidence and new observations are required to prove this hypothesis. In addition, we derived the age-metallicity relations. As expected, for all of the fields the metallicity increases with time. We do not observe any radial gradient in the metallicity.

Cone search capability for table J/A+A/572/A26/ngc6822 (HST/ACS photometry in the irregular galaxy)

DOI http://doi.org/10.26093/cds/vizier.35720026
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/572/A26
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/572/A26
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/572/A26
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/572/A26
Creator Fusco F.; Buonanno R.; Hidalgo S.L.; Aparicio A.; Pietrinferni A.; Bono G.,Monelli M.; Cassisi S.
Publisher CDS
Publication Year 2014
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics