Nuclear star-forming structures and the starburst-active galactic nucleus connection in barred spirals: NGC 3351 and NGC 4303

DOI: 
10.1086/310766
Publication date: 
20/07/1997
Main author: 
Colina, L
IAA authors: 
Alberdi, A
Authors: 
Colina, L; Vargas, MLG; MasHesse, JM; Alberdi, A; Krabbe, A
Journal: 
ASTROPHYSICAL JOURNAL
Publication type: 
Article
Volume: 
484
Pages: 
L41-&
Number: 
Abstract: 
A high-resolution Hubble Space Telescope WFPC2 F218W UV image of the barred spiral NGC 4303 (classified as a LINER-type active galactic nucleus [AGN]) reveals for the first time the existence of a nuclear spiral structure of massive star-forming regions all the way down to the UV-bright unresolved core (size less than or equal to 8 pc) of an active galaxy. The spiral structure, as traced by the UV-bright star-forming regions, has an outer radius of 225 pc and widens as the distance from the core increases. The UV luminosity of NGC 4303 is dominated by the massive star-forming regions, and the unresolved LINER-type core contributes only 16% of the integrated UV luminosity. The nature of the UV-bright LINER-type core-stellar cluster or pure AGN-is still unknown. In contrast to NGC 4303, the UV F218W image of the non-AGN barred galaxy NGC 3351 shows a nuclear star-forming ring of 315 pc (semimajor axis) with a faint core. In the ring, the star formation is arranged in clumps of about 60-85 pc in diameter. Each clump consists of a few compact UV-bright clusters embedded in a more diffuse component. The integrated IUE spectrum of NGC 3351 shows the presence of Si IV 1400 Angstrom and C IV 1550 Angstrom absorption lines, typical features of young, 4-5 Myr old, massive star clusters. The presence of ring and spiral star-forming structures in the nuclear regions of these two barred spirals supports the bar-induced gas-fueling scenario by which bars accumulate gas in the nuclear regions of galaxies, produce nuclear star-forming rings (NGC 3351), and might eventually generate or feed an AGN (NGC 4303).
Database: 
WOK
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/1997ApJ...484L..41C/abstract
ADS Bibcode: 
1997ApJ...484L..41C
Keywords: 
galaxies, active; galaxies, nuclei; galaxies, spiral galaxies, starburst; galaxies, star clusters; ultraviolet, galaxies