Wide-field study of the peculiar globular cluster system hosted by the field lenticular NGC 1172

ENNIS A.I.; CASO J. P; BASSINO L. P.; SALINAS R.; GÓMEZ, MATÍAS

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020 vol. 499 p. 2554 - 2563

0035-8711

We present a wide-field study of theglobular cluster system (GCS) of the field lenticular galaxy NGC1172, based onobservations From Gemini Multi-Object Spectrograph/Gemini (optical),FourStar/Magellan (NIR), and archival data from ACS/Hubble Space Telescope (optical). Thisanalysis covers the full extension of the GCS, and results in a value ofspecific frequency (SN =8.6±1.5) peculiarly high foran intermediate-mass galaxy in a low-density environment such as this one. Wefind that the GCS appears to be bimodal, although the colour distribution is narrow and does notallow for an accurate separation of the subpopulations.However, the combination of optical andNIR filters allows us to obtain an estimation of the metallicity distributionbased on the photometry, which supports bimodality. We conclude that thepresence of a large fraction of metal-poor globular clusters (GCs) and the highspecific frequency point to NGC1172 having accreted a significant amount of GCsfrom low-mass satellites in the past.