FVSS: The Fornax Cluster VLT Spectroscopic Survey
| Main Author: | Spiniello, Chiara |
|---|---|
| Format: | info Proceeding Journal |
| Terbitan: |
, 2019
|
| Online Access: |
https://zenodo.org/record/3369873 |
Daftar Isi:
- The Cold-Dark Matter scenario predict that as the Universe cooled, clumps of dark matter (DM) began to condense, and within them gas began to collapse, forming the first galaxies which then experienced structure growth via the so-called "merging tree". During this growth, various physical processes (e.g tidal interactions, ram pressure stripping, gas accretion) contributed to shape galaxies and the DM surrounding them. These processes are expected to have left their imprints in the outskirts of galaxies and beyond, out to the intracluster regions. Here, dynamical times are longer and galaxy formation mechanisms leave signatures of gravitational interactions like shells or tidal tales in the kinematics of their components or in the chemical composition of the stars. Measuring kinematics in the outer parts of Early-Type Galaxies (ETGs) remains however very complicated since the signal-to-noise of the integrated light spectra drops off before the mass profile flattens. Planetary Nebulae (PNe) represent a unique tool to describe the kinematics of elusive stars in low surface brightness regions where they are easily observable through their [OIII] emission at 5007 Å. Measuring kinematics of Intracluster PNs (ICPNe) is the most effective, if not the only, way to measure the dynamical stage of the ICL, and to assess how and when its light originated. In this talk, I will present the largest and most extended planetary nebulae (PNe) catalog even obtained for the Fornax cluster. We measured velocities of 1452 PNe in a radius of about 200 kpc in the core of the Fornax cluster using a counter-dispersed slitless spectroscopic technique with data from FORS2 on the VLT. From the PNs velocity map we identify stellar streams that are possibly tracing the gravitational interaction of the central galaxy NGC 1399 with NGC 1404 and NGC 1387. We also measured the velocity dispersion profile out to large radii, confirming that indeed we are able to trace the transition from the halo of the central galaxy into the cluster potential. This PNe catalog is part of a large effort to gather as many data as possible on the internal region of the Fornax Cluster in synergy with the Fornax Deep Survey that acquired uniform imaging coverage with VST (ugri) and VISTA (J and K). This unprecedented big dataset allow us to constrain the baryonic and dark mass distribution in the core of Fornax with high precision, thus shedding light on the assembly history of massive galaxies in one of the most nearby dense environments.