Anomalous gas in ESO 149-G003: A MeerKAT-16 View
| Autor: | Sharmila Goedhart, Elmar Körding, D. Kleiner, W. J. G. de Blok, Kshitij Thorat, L. A. L. Andati, Patrick Woudt, Steven Bloemen, Dániel Cs. Molnár, J.A. Wang, Marc Klein-Wolt, Eric Maina, L. Sebokolodi, B. Hugo, Gyula I. G. Józsa, S. Makhathini, M. Serylak, S. S. Passmoor, Vanessa McBride, M. Ramatsoku, Paul J. Groot, Paolo Serra, F. M. Maccagni, Oleg Smirnov, Peter Kamphuis, P. M. Vreeswijk, A. J. T. Ramaila, R. S. Le Poole, R. J. Dettmar, Kerry Paterson, D. L. A. Pieterse |
|---|---|
| Přispěvatelé: | Astronomy |
| Rok vydání: | 2021 |
| Předmět: |
media_common.quotation_subject
Astronomy Minimum mass FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Asymmetry Radio telescope 0103 physical sciences 010303 astronomy & astrophysics Scaling Astrophysics::Galaxy Astrophysics galaxies: kinematics and dynamics media_common Physics 010308 nuclear & particles physics Astronomy and Astrophysics galaxies: dwarf Mass ratio Astrophysics - Astrophysics of Galaxies Galaxy Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Intergalactic travel Irregular galaxy galaxies: evolution galaxies: individual: ESO 149-G003 galaxies: ISM |
| Zdroj: | Monthly Notices of the Royal Astronomical Society, 501(2), 2704-2723 Monthly Notices of the Royal Astronomical Society, 501, 2704-2723. Oxford University Press Monthly Notices of the Royal Astronomical Society, 501, 2704-2723 Monthly Notices of the Royal Astronomical Society, 501, 2, pp. 2704-2723 Monthly Notices of the RAS (0035-8711), 501(2), 2704–2723 |
| ISSN: | 2704-2723 0035-8711 |
| DOI: | 10.1093/mnras/staa3770 |
| Popis: | ESO 149-G003 is a close-by, isolated dwarf irregular galaxy. Previous observations with the ATCA indicated the presence of anomalous neutral hydrogen (HI) deviating from the kinematics of a regularly rotating disc. We conducted follow-up observations with the MeerKAT radio telescope during the 16-dish Early Science programme as well as with the MeerLICHT optical telescope. Our more sensitive radio observations confirm the presence of anomalous gas in ESO 149-G003, and further confirm the formerly tentative detection of an extraplanar HI component in the galaxy. Employing a simple tilted-ring model, in which the kinematics is determined with only four parameters but including morphological asymmetries, we reproduce the galaxy's morphology, which shows a high degree of asymmetry. By comparing our model with the observed HI, we find that in our model we cannot account for a significant (but not dominant) fraction of the gas. From the differences between our model and the observed data cube we estimate that at least 7%-8% of the HI in the galaxy exhibits anomalous kinematics, while we estimate a minimum mass fraction of less than 1% for the morphologically confirmed extraplanar component. We investigate a number of global scaling relations and find that, besides being gas-dominated with a neutral gas-to-stellar mass ratio of 1.7, the galaxy does not show any obvious global peculiarities. Given its isolation, as confirmed by optical observations, we conclude that the galaxy is likely currently acquiring neutral gas. It is either re-accreting gas expelled from the galaxy or accreting pristine intergalactic material. 16 pages, 14 figures, MNRAS, Accepted 2020 December 2, in original form 2019 September 18 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|