Bibcode
DOI
Gonzalez-Delgado, Rosa M.; Perez, Enrique; Diaz, Angeles I.; Garcia-Vargas, Maria Luisa; Terlevich, Elena; Vilchez, Jose M.
Bibliographical reference
The Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 439, no. 2, p. 604-622
Advertised on:
2
1995
Journal
Citations
98
Refereed citations
88
Description
Narowband H alpha imaging and long-slit optical and near-infrared
spectroscopy are analyzed in a study of the starburst galaxy NGC 7714.
The data indicate that the galaxy as a whole is experiencing intense
star formation activity; this is more conspicuous in the nucleus, where
the star formation rate and the star formation rate per unit area are
higher than in the rest of the galaxy. Evidence for this intense star
formation activity comes from the detection of broad emission He II
lambda 4686, attributed to WN stars; this suggests an age of the present
burst between 3 and 5 Myr. Evidence of the existence of previous bursts
come from the detection of the infrared Ca II triplet in absorption,
which indicates the presence of red giant or supergiant stars.
Spectroscopic data are taken at two position angles (P.A. = 110 deg and
216 deg) across the nucleus and comprise also three giant H II regions
located in the circumnuclear region and in the spiral arms. The physical
conditions and chemical composition of the gas are derived. Abundances
are moderately low, with an excess of N in and around the nucleus. The
velocity curve at P.A. = 216 deg is very distorted, indicating large
departures from circular motion. Higher velocity dispersion of the gas
in the circumnuclear region has also been found and could be related to
enhanced star formation.