TY - JOUR
T1 - Unravelling the enigmatic ISM conditions in Minkowski's object
AU - Zovaro, Henry R.M.
AU - Sharp, Robert
AU - Nesvadba, Nicole P.H.
AU - Kewley, Lisa
AU - Sutherland, Ralph
AU - Taylor, Philip
AU - Groves, Brent
AU - Wagner, Alexander Y.
AU - Mukherjee, Dipanjan
AU - Bicknell, Geoffrey V.
N1 - Publisher Copyright:
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Local examples of jet-induced star formation lend valuable insight into its significance in galaxy evolution and can provide important observational constraints for theoretical models of positive feedback. Using optical integral field spectroscopy, we present an analysis of the ISM conditions in Minkowski's object (z = 0.0189), a peculiar star-forming dwarf galaxy located in the path of a radio jet from the galaxy NGC 541. Full spectral fitting with ppxf indicates that Minkowski's object primarily consists of a young stellar population ∼10 Myrold, confirming that the bulk of the object's stellar mass formed during a recent jet interaction. Minkowski's object exhibits line ratios largely consistent with star formation, although there is evidence for a low level (15) of contamination from a non-stellar ionizing source. Strong-line diagnostics reveal a significant variation in the gas-phase metallicity within the object, with rm O/H) + 12 varying by ∼0.5which cannot be explained by in-situ star formation, an enriched outflow from the jet, or enrichment of gas in the stellar bridge between NGC 541 and NGC 545/547. We hypothesize that Minkowski's object either (i) was formed as a result of jet-induced star formation in pre-existing gas clumps in the stellar bridge, or (ii) is a gas-rich dwarf galaxy that is experiencing an elevation in its star formation rate due to a jet interaction, and will eventually redden and fade, becoming an ultradiffuse galaxy as it is processed by the cluster.
AB - Local examples of jet-induced star formation lend valuable insight into its significance in galaxy evolution and can provide important observational constraints for theoretical models of positive feedback. Using optical integral field spectroscopy, we present an analysis of the ISM conditions in Minkowski's object (z = 0.0189), a peculiar star-forming dwarf galaxy located in the path of a radio jet from the galaxy NGC 541. Full spectral fitting with ppxf indicates that Minkowski's object primarily consists of a young stellar population ∼10 Myrold, confirming that the bulk of the object's stellar mass formed during a recent jet interaction. Minkowski's object exhibits line ratios largely consistent with star formation, although there is evidence for a low level (15) of contamination from a non-stellar ionizing source. Strong-line diagnostics reveal a significant variation in the gas-phase metallicity within the object, with rm O/H) + 12 varying by ∼0.5which cannot be explained by in-situ star formation, an enriched outflow from the jet, or enrichment of gas in the stellar bridge between NGC 541 and NGC 545/547. We hypothesize that Minkowski's object either (i) was formed as a result of jet-induced star formation in pre-existing gas clumps in the stellar bridge, or (ii) is a gas-rich dwarf galaxy that is experiencing an elevation in its star formation rate due to a jet interaction, and will eventually redden and fade, becoming an ultradiffuse galaxy as it is processed by the cluster.
KW - galaxies: ISM
KW - galaxies: dwarf
KW - galaxies: individual: Minkowski's object
KW - galaxies: jets
KW - galaxies: peculiar
KW - stars: formation
UR - http://www.scopus.com/inward/record.url?scp=85096931925&partnerID=8YFLogxK
U2 - 10.1093/mnras/staa3121
DO - 10.1093/mnras/staa3121
M3 - Article
SN - 0035-8711
VL - 499
SP - 4940
EP - 4960
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -