Hubble Space Telescope Planetary Camera Images of NGC 1316

Abstract

We present HST Planetary Camera V and I~band images of the central region of the peculiar giant elliptical galaxy NGC 1316. The inner profile is well fit by a nonisothermal core model with a core radius of 0.41" +/- 0.02" (34 pc). At an assumed distance of 16.9 Mpc, the deprojected luminosity density reaches $\sim 2.0 \times 10^3 L_{\sun}$ pc${}^{-3}$. Outside the inner two or three arcseconds, a constant mass-to-light ratio of $\sim 2.2\pm 0.2$ is found to fit the observed line width measurements. The line width measurements of the center indicate the existence of either a central dark object of mass $2 \times 10^9 M_{\sun}$, an increase in the stellar mass-to-light ratio by at least a factor of two for the inner few arcseconds, or perhaps increasing radial orbit anisotropy towards the center. The mass-to-light ratio run in the center of NGC 1316 resembles that of many other giant ellipticals, some of which are known from other evidence to harbor central massive dark objects (MDO's). We also examine twenty globular clusters associated with NGC 1316 and report their brightnesses, colors, and limits on tidal radii. The brightest cluster has a luminosity of $9.9 \times 10^6 L_{\sun}$ ($M_V=-12.7$), and the faintest detectable cluster has a luminosity of $2.4 \times 10^5 L_{\sun}$ ($M_V=-8.6$). The globular clusters are just barely resolved, but their core radii are too small to be measured. The tidal radii in this region appear to be $\le$ 35 pc. Although this galaxy seems to have undergone a substantial merger in the recent past, young globular clusters are not detected.

21 pages, latex, postscript figures available at ftp://delphi.umd.edu/pub/outgoing/eshaya/fornaxa

Cited by in corpus (14)

• Hubble Space Telescope Imaging of Brightest Cluster Galaxies
• Kinematics, ages, and metallicities of star clusters in NGC 1316: A 3 Gyr old merger remnant
• Chandra X-ray Observations of NGC 1316 (Fornax A)
• The supermassive black hole of Fornax A
• The Internal Ultraviolet-to-Optical Color Dispersion: Quantifying the Morphological K-Correction
• The SLUGGS Survey: The globular cluster systems of three early-type galaxies using wide-field imaging
• HST Imaging of the Globular Clusters in the Fornax Cluster: Color and Luminosity Distributions
• Atomic and molecular gas in the merger galaxy NGC 1316 (Fornax A) and its environment
• Modelling of the Spectral Energy Distribution of Fornax A: Leptonic and Hadronic Production of High Energy Emission from the Radio Lobes
• The globular cluster system of NGC1316. I. Wide-field photometry in the Washington system
• Complex distribution and velocity field of molecular gas in NGC 1316 as revealed by Morita Array of ALMA
• Ongoing Mass Transfer in the Interacting Galaxy Pair NGC 1409/10
• The globular cluster system of NGC 1316. II - The extraordinary object SH2
• The globular cluster system of NGC 1316 IV. Nature of the star cluster complex SH2