A MeerKAT view of pre-processing in the Fornax A group
Kleiner, D.; Serra, P.; Maccagni, F. M.; Venhola, A.; Morokuma-Matsui, K.; Peletier, R.; Iodice, E.; Raj, M. A.; de Blok, W. J. G.; Comrie, A.; Józsa, G. I. G.; Kamphuis, P.; Loni, A.; Loubser, S. I.; Molnár, D. Cs.; Passmoor, S. S.; Ramatsoku, M.; Sivitilli, A.; Smirnov, O.; Thorat, K.; Vitello, F. (2021-04-08)
Kleiner, D., Serra, P., Maccagni, F. M., Venhola, A., Morokuma-Matsui, K., Peletier, R., Iodice, E., Raj, M. A., de Blok, W. J. G., Comrie, A., Józsa, G. I. G., Kamphuis, P., Loni, A., Loubser, S. I., Molnár, D. Cs., Passmoor, S. S., Ramatsoku, M., Sivitilli, A., Smirnov, O., … Vitello, F. (2021). A MeerKAT view of pre-processing in the Fornax A group. Astronomy & Astrophysics, 648, A32. https://doi.org/10.1051/0004-6361/202039898
© ESO 2021. Published in this repository with the kind permission of the publisher.
https://rightsstatements.org/vocab/InC/1.0/
https://urn.fi/URN:NBN:fi-fe2021042927978
Tiivistelmä
Abstract
We present MeerKAT neutral hydrogen (H I) observations of the Fornax A group, which is likely falling into the Fornax cluster for the first time. Our H I image is sensitive to 1.4 × 10¹⁹ atoms cm⁻² over 44.1 km s⁻¹, where we detect H I in 10 galaxies and a total of (1.12 ± 0.02) × 10⁹ M⊙ of H I in the intra-group medium (IGM). We search for signs of pre-processing in the 12 group galaxies with confirmed optical redshifts that reside within the sensitivity limit of our H I image. There are 9 galaxies that show evidence of pre-processing and we classify each galaxy into their respective pre-processing category, according to their H I morphology and gas (atomic and molecular) scaling relations. Galaxies that have not yet experienced pre-processing have extended H I discs and a high H I content with a H₂-to-H I ratio that is an order of magnitude lower than the median for their stellar mass. Galaxies that are currently being pre-processed display H I tails, truncated H I discs with typical gas fractions, and H₂-to-H I ratios. Galaxies in the advanced stages of pre-processing are the most H I deficient. If there is any H I, they have lost their outer H I disc and efficiently converted their H I to H₂, resulting in H₂-to-H I ratios that are an order of magnitude higher than the median for their stellar mass. The central, massive galaxy in our group (NGC 1316) underwent a 10:1 merger ∼2 Gyr ago and ejected 6.6−11.2 × 10⁸ M⊙ of H I, which we detect as clouds and streams in the IGM, some of which form coherent structures up to ∼220 kpc in length. We also detect giant (∼100 kpc) ionised hydrogen (Hα) filaments in the IGM, likely from cool gas being removed (and subsequently ionised) from an in-falling satellite. The Hα filaments are situated within the hot halo of NGC 1316 and there are localised regions that contain H I. We speculate that the Hα and multiphase gas is supported by magnetic pressure (possibly assisted by the NGC 1316 AGN), such that the hot gas can condense and form H I that survives in the hot halo for cosmological timescales.
Kokoelmat
- Avoin saatavuus [31941]
Samankaltainen aineisto
Näytetään aineisto, joilla on samankaltaisia nimekkeitä, tekijöitä tai asiasanoja.
-
The Fornax Deep Survey (FDS) with the VST : XI. The search for signs of preprocessing between the Fornax main cluster and Fornax A group
Su, A. H.; Salo, H.; Janz, J.; Laurikainen, E.; Venhola, A.; Peletier, R. F.; Iodice, E.; Hilker, M.; Cantiello, M.; Napolitano, N.; Spavone, M.; Raj, M. A.; van de Ven, G.; Mieske, S.; Paolillo, M.; Capaccioli, M.; Valentijn, E. A.; Watkins, A. E.
Astronomy and astrophysics (EDP Sciences, 16.03.2021) -
Signatures of quenching in dwarf galaxies in local galaxy clusters : a comparison of the galaxy populations in the Virgo and Fornax clusters
Janz, Joachim; Salo, Heikki; Su, Alan H.; Venhola, Aku
Astronomy and astrophysics (EDP Sciences, 12.03.2021) -
Inner and outer rings are not strongly coupled with stellar bars
Díaz-García, S.; Díaz-Suárez, S.; Knapen, J. H.; Salo, H.
Astronomy and astrophysics (EDP Sciences, 29.05.2019)