The State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the ‘Center of Excellence Severo Ochoa’ awarded to the Instituto de Astrofísica de Andalucía; the Economic Transformation, Industry, Knowledge and Universities Council of the Regional Government of Andalusia and the European Regional Development Fund from the European Union; the South African Radio Astronomy Observatory (SARAO); BMBF Verbundforschung; DFG Sonderforschungsbereich and the European Research Council (ERC).http://mnras.oxfordjournals.orghj2022Physic

Andati, Lexy A.L.

Atemkeng, Marcellin

Carignan, Claude

De Blok, W. J.G.

Dettmar, Ralf-Jurgen

Hugo, Benjamin V.

Ianjamasimanana, Roger

Jozsa, Gyula I.G.

Kamphuis, Peter

Kleiner, Dane

Koribalski, B.S.

Loi, Francesca

Maccagni, Filippo M.

Maina, Eric

Makhathini, Sphesihle

Molnar, Daniel Cs.

Namumba, Brenda

Perkins, Simon

Ramaila, Athanaseus J.T.

Ramatsoku, M.

Serra, Paolo

Smirnov, Oleg M.

Thorat, Kshitij

Monthly Notices of the Royal Astronomical Society

arXiv

Observations of the neutral atomic hydrogen (H I) in the nuclear starburst galaxy NGC 4945 with MeerKAT are presented. We find a large amount of halo gas, previously missed by H I observations, accounting for 6.8 per cent of the total H I mass. This is most likely gas blown into the halo by star formation. Our maps go down to a 3σ column density level of 5 × 1018 cm-2. We model the H I distribution using tilted-ring fitting techniques and find a warp on the galaxy's approaching and receding sides. The H I in the northern side of the galaxy appears to be suppressed. This may be the result of ionization by the starburst activity in the galaxy, as suggested by a previous study. The origin of the warp is unclear but could be due to past interactions or ram pressure stripping. Broad, asymmetric H I absorption lines extending throughout the H I emission velocity channels are present towards the nuclear region of NGC 4945. Such broad lines suggest the existence of a nuclear ring moving at a high circular velocity. This is supported by the clear rotation patterns in the H I absorption velocity field. The asymmetry of the absorption spectra can be caused by outflows or inflows of gas in the nuclear region of NGC 4945. The continuum map shows small extensions on both sides of the galaxy's major axis that might be signs of outflows resulting from the starburst activity

Koribalski, B. S.

Józsa, Gyula I. G.

de Blok, W. J. G.

Dettmar, Ralf-Jürgen

Ramaila, Athanaseus J. T.

Andati, Lexy A. L.

Molnár, Dániel Cs

Ramatsoku, Mpati

ARTS repository - University of Groningen

English

The extended H I halo of NGC 4945 as seen by MeerKAT

UPSpace at the University of Pretoria

The extended H i halo of NGC 4945 as seen by MeerKAT

NARCIS 

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Observations of the neutral atomic hydrogen (H I) in the nuclear starburst galaxy NGC 4945 with MeerKAT are presented. We find a large amount of halo gas, previously missed by H I observations, accounting for 6.8 per cent of the total H I mass. This is most likely gas blown into the halo by star formation. Our maps go down to a 3σ column density level of 5 × 1018 cm−2. We model the H I distribution using tilted-ring fitting techniques and find a warp on the galaxy’s approaching and receding sides. The H I in the northern side of the galaxy appears to be suppressed. This may be the result of ionization by the starburst activity in the galaxy, as suggested by a previous study. The origin of the warp is unclear but could be due to past interactions or ram pressure stripping. Broad, asymmetric H I absorption lines extending throughout the H I emission velocity channels are present towards the nuclear region of NGC 4945. Such broad lines suggest the existence of a nuclear ring moving at a high circular velocity. This is supported by the clear rotation patterns in the H I absorption velocity field. The asymmetry of the absorption spectra can be caused by outflows or inflows of gas in the nuclear region of NGC 4945. The continuum map shows small extensions on both sides of the galaxy’s major axis that might be signs of outflows resulting from the starburst activity. © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Astronomical Society.RI acknowledges financial support from grant RTI2018-096228-B-C31 (MCIU/AEI/FEDER,UE) and from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the ‘Center of Excellence Severo Ochoa’ awarded to the Instituto de Astrofísica de Andalucía (SEV-2017-0709), from the grant IAA4SKA (Ref. R18-RT-3082) from the Economic Transformation, Industry, Knowledge and Universities Council of the Regional Government of Andalusia and the European Regional Development Fund from the European Union. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. This work is based upon research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation. The financial assistance of the South African Radio Astronomy Observatory (SARAO) towards this research is hereby acknowledged (www.sarao.ac.za). At Ruhr University Bochum, this research is supported by BMBF Verbundforschung grant 05A20PC4 and by DFG Sonderforschungsbereich SFB1491. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme grant agreement no. 882793, project name MeerGas. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no.679627; project name FORNAX).Peer reviewe

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The extended H I halo of NGC 4945 as seen by MeerKAT

University of Groningen

https://repository.up.ac.za/bitstream/2263/86614/1/Ianjamasimanana_Extended_2022.pdf

The extended H i halo of NGC 4945 as seen by MeerKAT

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