Poster details
Spectral properties of UDGs in A2152
Abstract
Ultra-Diffuse Galaxies (UDGs) are very low surface brightness objects with large sizes. It is not clear whether they are Milky Way mass-like objects with failed star formation or quenched dwarf galaxies regulated by environmental or internal processes.
We have started a program on a set of nearby galaxy clusters which have been imaged by the Kapteyn-IAC WEAVE INT Cluster Survey using the WFC@INT. This data provides us photometrical candidates of UDGs that will then be observed spectroscopically by the instrument OSIRIS@GTC.
In this poster we will focused in the spectroscopical properties of a set of UDGs located in A2152. In particular, we present the spectra of 11 UDGs candidates in the cluster and 2 cluster dwarfs used as control. The dwarfs and four candidates were confirmed as cluster members, whereas the remaining seven objects turned to be on the field. This implies that only about 36% of the UDG photometric candidates turned to be cluster members. Our data seem to suggest that the success rate of UDG detection in galaxy clusters could be seriously affected by field objects.
Both UDGs populations (field and cluster) turned to have similar masses, stellar ages and metallicities. In particular, the mean age and metallicity are: 7.34 Gyr and -0.66 dex, respectively. The masses of the UDGs are in the range 1e8 - 1e9 solar masses, confirming that they are similar to dwarf galaxies. These results point out that the cluster environment is not playing a key role in the stellar population properties of the analyzed UDGs. The relations between galaxy size, age, metallicity and mass showed by our UDGs and other from the literature point towards the star formation of these galaxies is regulated by internal processes.
We have started a program on a set of nearby galaxy clusters which have been imaged by the Kapteyn-IAC WEAVE INT Cluster Survey using the WFC@INT. This data provides us photometrical candidates of UDGs that will then be observed spectroscopically by the instrument OSIRIS@GTC.
In this poster we will focused in the spectroscopical properties of a set of UDGs located in A2152. In particular, we present the spectra of 11 UDGs candidates in the cluster and 2 cluster dwarfs used as control. The dwarfs and four candidates were confirmed as cluster members, whereas the remaining seven objects turned to be on the field. This implies that only about 36% of the UDG photometric candidates turned to be cluster members. Our data seem to suggest that the success rate of UDG detection in galaxy clusters could be seriously affected by field objects.
Both UDGs populations (field and cluster) turned to have similar masses, stellar ages and metallicities. In particular, the mean age and metallicity are: 7.34 Gyr and -0.66 dex, respectively. The masses of the UDGs are in the range 1e8 - 1e9 solar masses, confirming that they are similar to dwarf galaxies. These results point out that the cluster environment is not playing a key role in the stellar population properties of the analyzed UDGs. The relations between galaxy size, age, metallicity and mass showed by our UDGs and other from the literature point towards the star formation of these galaxies is regulated by internal processes.