Large Binocular Telescope observations of new six compact star-forming galaxies with [NeV] 3426A emission
Y. I. Izotov (1), T. X. Thuan (2), N. G. Guseva (1) ((1) Bogolyubov, Institute for Theoretical Physics, National Academy of Sciences of Ukraine,, Kyiv, Ukraine, (2) Astronomy Department, University of Virginia,, Charlottesville, USA)

TL;DR
This study reports the discovery of [NeV]3426 emission in six compact star-forming galaxies, revealing high ionization states and suggesting the presence of shocks or active galactic nuclei, expanding understanding of ionization mechanisms in such galaxies.
Contribution
It presents new observations of six galaxies with [NeV] emission, highlighting the role of shocks and AGN activity in ionizing dense star-forming regions, which was not previously documented.
Findings
All galaxies show high ionization ratios and dense HII regions.
Most galaxies exhibit Wolf-Rayet features indicating young starbursts.
[NeV] emission suggests contributions from shocks or AGN activity.
Abstract
We report the discovery of [NeV]3426 emission, in addition to HeII4686 emission, in six compact star-forming galaxies. These observations considerably increase the sample of eight such galaxies discovered earlier by our group. For four of the new galaxies, the optical observations are supplemented by near-infrared spectra. All galaxies, but one, have HII regions that are dense, with electron number densities of ~300-700 cm-3. They are all characterised by high Hbeta equivalent widths EW(Hbeta)~190-520A and high O32=[OIII]5007/[OII]3727 ratios of 10-30, indicating young starburst ages and the presence of high ionization radiation. All are low-metallicity objects with 12+logO/H=7.46-7.88. The spectra of all galaxies show a low-intensity broad component of the Halpha line and five out of six objects show Wolf-Rayet features. Comparison with photoionization models shows that pure stellar…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
