A Virgo Environmental Survey Tracing Ionised Gas Emission. VESTIGE VIII. Bridging the cluster-ICM-galaxy evolution at small scales

A. Longobardi , A. Boselli (1) , M. Fossati , J. A. Villa-Vélez , S. Bianchi , V. Casasola , E. Sarpa , F. Combes , G. Hensler8 , D. Burgarella , C. Schimd , A. Nanni , P. Côté , V. Buat1 , P. Amram , L. Ferrarese , J. Braine , G. Trinchieri , S. Boissier , M. Boquien , P. Andreani , S. Gwyn , J. C. Cuillandre , G. Hensler , V. Buat

1 LAM - Laboratoire d'Astrophysique de Marseille

We measure FIR emission from tails of stripped dust following the ionised and atomic gas components in galaxies undergoing ram pressure stripping. We study the dust-to-gas relative distribution and mass ratio in the stripped interstellar medium and relate them to those of the intra-cluster medium, thus linking the cluster-ICM-galaxy evolution at small-scales. The galaxy sample consists of three Scd Virgo galaxies with stellar masses in the range $10^9\lesssim \mathrm{M_{*}} \lesssim 10^{10}\, \mathrm{M_{\odot}}$, and within 1 Mpc from the cluster centre, namely NGC 4330, NGC 4522, and NGC 4654. Through the analysis of VESTIGE H$\alpha$, $Herschel$ SPIRE far-infrared, and VIVA HI data, we trace the spatial distribution of the tails and infer the dust and gas masses from the measured far-infrared 250 $\mu$m and HI flux densities. Dust-to-gas mass ratios (DGRs) in the tails are analysed as a function of the galaxy mass, metallicity, and dust temperature. Along the stripped component, the dust distribution closely follows the HI and H$\alpha$ emitting gas, all extending beyond the optical disc. In these regions, the DGRs are $2.0\pm0.6\times10^{-3}$, $0.7\pm0.1\times10^{-3}$, and $0.4\pm0.03\times10^{-3}$, for NGC 4330, NGC 4522, and NGC 4654, respectively, i.e. up to a factor of 15 less than the values measured in the main body of nearby galaxies. We also find a negative trend in the DGR as a function of the metallicity that can be explained in terms of a dust component more centrally concentrated in more metal-rich systems. Together with the finding that the stripped dust is cold, $T_{d} \lesssim 25\, K$, our results support an outside-in stripping scenario of the galaxy interstellar medium. This study shows that ram pressure stripping is a key mechanism in the building up of the Virgo intra-cluster component injecting dust grains into the ICM, thus contributing to its metal enrichment.

Domaines: Planète et Univers [physics]; Astrophysique [astro-ph]

A. Longobardi, A. Boselli, M. Fossati, J. A. Villa-Vélez, S. Bianchi, et al.. A Virgo Environmental Survey Tracing Ionised Gas Emission. VESTIGE VIII. Bridging the cluster-ICM-galaxy evolution at small scales. Astronomy and Astrophysics - A&A, 2020, 644, pp.A161. ⟨10.1051/0004-6361/202039020⟩. ⟨hal-03366436⟩