The star cluster system of the 3 Gyr old merger remnant NGC 1316: Clues from optical and near-infrared photometry

(ABRIDGED) The ACS camera on board the Hubble Space Telescope has been used to obtain deep images of the giant elliptical galaxy NGC 3610, a well-established dissipative galaxy merger remnant. These observations supersede previous WFPC2 images which revealed the presence of a population of metal-rich globular clusters (GCs) of intermediate age (~1.5-4 Gyr). We detect a total of 580 GC candidates, 46% more than from the previous WFPC2 images. The new photometry strengthens the...

We present multi-wavelength imagery of the merger remnant galaxy NGC 1316 with an objective to study the content of dust and its association with the other phases of the ISM. Color-index maps as well as extinction maps derived for this galaxy reveal an intricate and complex dust morphology in NGC 1316, i.e., in the inner part it exists in the form of a prominent lane while at about 6--7\,kpc it apparently takes an arc-like pattern extended along the North-East direction. In a...

We present an analysis of the circumnuclear structure of NGC 1316 using both near-infrared imaging and stellar kinematics. 2D decomposition of the images suggests the presence of a structure that resembles inner gaseous spiral arms, at about 5 to 15" from the center (500 to 1500 pc). We also find a disc-like stellar structure with radius less than 200 pc. Analysis of previously published SINFONI integral field kinematics data indicates a kinematically decoupled core in the sa...

We present a photometric study of the prototype merger remnant NGC 3610 and its globular cluster (GC) system, based on new GEMINI/GMOS and ACS/HST archival images. Thanks to the large FOV of our GMOS data, larger than previous studies, we are able to detect a `classical' bimodal GC colour distribution, corresponding to metal-poor and metal-rich GCs, at intermediate radii and a small subsample of likely young clusters of intermediate colours, mainly located in the outskirts. T...

Ultraviolet, optical and near infrared images of the nearby (D ~ 5.5 Mpc) SBm galaxy NGC 1311, obtained with the Hubble Space Telescope, reveal a small population of 13 candidate star clusters. We identify candidate star clusters based on a combination of their luminosity, extent and spectral energy distribution. The masses of the cluster candidates range from ~1000 up to ~100000 Solar masses, and show a strong positive trend of larger mass with increasing with cluster age. S...

(ABBREVIATED:) The large majority of extragalactic star cluster studies done to date have essentially used two or three-passband aperture photometry, combined with theoretical stellar population synthesis models, to obtain age, mass and extinction estimates, and sometimes also metallicities. The accuracy to which this can be done depends on the choice of passband combination and, crucially, also on the wavelength range covered. Understanding the systematic uncertainties is of...

The WFPC2 Camera on board HST has been used to obtain high-resolution images of NGC 3610, a dynamically young elliptical galaxy. These observations supersede shorter, undithered HST observations where an intermediate-age population of globular clusters was first discovered. The new observations show the bimodal color distribution of globular clusters more clearly, with peaks at (V-I)o = 0.95 and 1.17. The luminosity function (LF) of the blue, metal-poor population of clusters...

We present B and I photometry for ~300 globular cluster candidates in NGC 1379, an E0 galaxy in the Fornax Cluster. Our data are from both Hubble Space Telescope (HST) and ground-based observations. The HST photometry (B only) is essentially complete and free of foreground/background contamination to ~2 mag fainter than the peak of the globular cluster luminosity function. Fitting a Gaussian to the luminosity function we find <B> =24.95+-0.30 and \sigma_B = 1.55+-0.21. We est...

As part of the Fornax Deep Survey with the ESO VLT Survey Telescope, we present new $g$ and $r$ bands mosaics of the SW group of the Fornax cluster. It covers an area of $3 \times 2$ square degrees around the central galaxy NGC1316. The deep photometry, the high spatial resolution of OmegaCam and the large covered area allow us to study the galaxy structure, to trace stellar halo formation and look at the galaxy environment. We map the surface brightness profile out to 33arcm...

The distance of NGC1316, the brightest galaxy in Fornax, is an interesting test for the cosmological distance scale. First, because Fornax is the 2nd largest cluster of galaxies at <~25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight depth; and second, because NGC1316 is the galaxy with the largest number of detected SNeIa, giving the opportunity to test the consistency of SNeIa distances internally and against other indicators. We measure SBF mags in N...