@misc{10481/82983,
year = {2023},
month = {4},
url = {https://hdl.handle.net/10481/82983},
abstract = {Using the PMAS Integral Field Unit on the Calar Alto 3.5 m telescope, we observed the southern component (Markarian 59) of the ‘cometary’ starburst galaxy NGC 4861. Mrk 59 is centred on a giant nebula and concentration of stars 1 kpc in diameter. Strong H α emission points to a star-formation rate (SFR) at least 0.47 M⊙ yr−1. Mrk 59 has a very high [O III] λ5007/H β ratio, reaching 7.35 in the central nebula, with a second peak at a star-forming hotspot further north. Fast outflows are not detected but nebular motion and galaxy rotation produce relative velocities up to 40 km s−1. Spectral analysis of different regions with ‘Fitting Analysis using Differential evolution Optimization’ (FADO) finds that the stars in the central and ‘spur’ nebulae are very young, ≤ 125 Myr with a large < 10 Myr contribution. Older stars (∼ 1 Gyr) make up the northern disk component, while the other regions show mixtures of 1 Gyr age with very young stars. This and the high specific SFR ∼ 3.5 Gyr−1 imply a bimodal star formation history, with Mrk 59 formed in ongoing starbursts fuelled by a huge gas inflow, turning the galaxy into an asymmetric ‘green pea’ or blue compact dwarf. We map the He II λ4686 emission, and identify a broad component from the central nebula, consistent with the emission of ∼300 Wolf–Rayet stars. About a third of the He II λ4686 flux is a narrow line emitted from a more extended area covering the central and spur nebulae, and may have a different origin.},
organization = {Centro Astronómico Hispano en Andalucía},
organization = {IPAC},
organization = {National Aeronautics and Space Administration
 	NASA},
organization = {European Commission
	PTDC/FIS-AST/29245/2017, UID/FIS/04434/2019	EC},
organization = {European Space Agency
 	ESA},
organization = {Ministerio de Economía y Competitividad
 PID2019-107408GB-C44	MINECO},
organization = {Ministerio de Ciencia e Innovación
 	MICINN},
organization = {Junta de Andalucía
 CEX2021-001131-S, P18-FR-2664},
organization = {Agencia Estatal de Investigación
 	AEI},
organization = {Instituto de Astrofísica de Andalucía
 PID2020-112949GB-I00 CAB (INTA-CSIC	IAA},
publisher = {Oxford University Press},
keywords = {Stars: Wolf},
keywords = {Rayet},
keywords = {Galaxies: evolution},
keywords = {Galaxies: individual: NGC 4861: Markarian 59},
keywords = {Galaxies: starburst},
title = {Integral Field Spectroscopy of the cometary starburst galaxy NGC 4861},
doi = {10.1093/mnras/stad1219},
author = {Roche, Nathan and Duarte Puertas, Salvador},
}