Uncovering the kiloparsec-scale stellar ring of NGC 5128

摘要

We reveal the stellar light emerging from the kiloparsec-scale, ring-like structure of the NGC5128 (CentaurusA) galaxy in unprecedented detail. We use arcsecond-scale resolution near infrared images to create a ``dust-free'' view of the central region of the galaxy, which we then use to quantify the shape of the revealed structure. At the resolution of the data, the structure contains several hundreds of discreet, point-like or slightly elongated sources. The typical extinction-corrected surface brightness of the structure is mag/arcsec2, and we estimate the total near infrared luminosity of the structure to be mag. We use diffraction limited (resolution of,or 1.6pc) near infrared data taken with the NACOinstrument on the VLT to show that the structure decomposes into thousands of separate, mostly point-like sources. According to the tentative photometry, the most luminous sources have mag, making them red supergiants or relatively low-mass star clusters. Wealso discuss the large-scale geometry implied by the reddening signatures of dust in our near infrared images. Key words: ISM: dust, extinction - galaxies: individual: NGC 5128 - galaxies: ISM - galaxies: structure - infrared: galaxies