Related papers: Fe/Ni ratio in the Ant Nebula Mz 3

A study of [Fe II] lines at various positions within the H II regions M42 and M43 is presented. The relative intensities of selected optical [Fe II] lines are shown to be correlated with the intensity of the apparent nebular continuous…

We perform a homogeneous analysis of the Fe/Ni abundance ratio in eight Galactic planetary nebulae (PNe) and three Galactic H II regions that include the Orion nebula, where we study four nebular zones and one shocked region. We use [Fe…

Bipolar planetary nebulae (PNe) are thought to result from binary star interactions and, indeed, tens of binary central stars of PNe have been found, in particular using photometric time-series that allow detecting post-common envelope…

We present thermal-IR images of three extreme bipolar objects, M2-9, Mz3, and He2-104. They are bipolar planetary nebulae with bright central stars and are thought to be powered by symbiotic binary systems. The mid-IR images spatially…

NGC 2392 is a young double-shell planetary nebula (PN). Its intrinsic structure and shaping mechanism are still not fully understood. In this paper we present new spectroscopic observations of NGC 2392. The slits were placed at two…

Nebulae around symbiotic Miras look very much like genuine planetary nebulae, although they are formed in a slightly different way. We present near infrared photometry of known and suspected symbiotic nebulae obtained with the Deep Near…

We analyze the rest-optical emission-line ratios of star-forming galaxies at 2.7<=z<6.5 drawn from the Cosmic Evolution Early Release Science (CEERS) Survey, and their relationships with stellar mass (M_*). Our analysis includes both line…

It has been suggested in the literature that the (Fe/alpha) abundance ratio may be used as a chronometer, due to a delay in this ratio reaching its solar value as predicted by galactic chemical evolution models. Using grids of…

We study the current discrepancy between the model-predicted and measured concentrations of Fe++ and Fe3+ in ionized nebulae. We calculate a set of photoionization models, updated with the atomic data relevant to the problem, and compare…

We have constructed a 3D photoionisation model of a planetary nebula (PN) similar in structure to NGC 7009 with its outer pair of knots (also known as FLIERs --fast, low-ionization emission regions). The work is motivated by the fact that…

We have observed emission lines of [S IV] 10.51, H(7-6) 12.37, [Ne II] 12.81, [Ne III] 15.56, and [S III] 18.71 um in a number of extragalactic H II regions with the Spitzer Space Telescope. A previous paper presented our data and analysis…

We present new observations of O II recombination lines in ten bright planetary nebulae, along with spatially-resolved measurements of O II and [O III] in the Ring nebula NGC 6720, to study the discrepancy between abundances derived from O…

We report deep long-slit emission-line spectra, the line flux ratios, and Doppler profile shapes of various bright optical lines. The low-ionization lines (primarily [N I], [O I], [S II], and [N II]) originate in shocked knots, as reported…

The Antares nebula is a peculiar emission nebula seen in numerous Fe II lines and in radio free-free emission, probably associated with the H II region caused by alpha Sco B in the wind of alpha Sco A. High-resolution spectra with spatial…

We report the discovery, by the Chandra X-ray Observatory, of X-ray emission from the bipolar planetary nebula Menzel 3. In Chandra CCD imaging, Mz 3 displays hot (3-6x10^6 K) gas within its twin, coaxial bubbles of optical nebulosity, as…

In stars, metallicity is usually traced using Fe, while in nebulae, O serves as the preferred proxy. Both elements have different nucleosynthetic origins and are not directly comparable. Additionally, in ionized nebulae, Fe is heavily…

We present spectroscopic observations and chemical abundances of 16 planetary nebulae (PNe) in the outer disk of M31. The [O III] 4363 line is detected in all objects, allowing a direct measurement of the nebular temperature essential for…

Based on a detailed study of the temperature structure of the intracluster medium in the halo of M~87, abundance profiles of 7 elements, O, Mg, Si, S, Ar, Ca, and Fe are derived. In addition, abundance ratios are derived from the ratios of…

In this contribution, we present the results of a study on the high abundance discrepancy factor (ADF $\sim$ 10) planetary nebula (PN) NGC 6153 with MUSE. We have constructed flux maps for dozens of emission lines, that allowed us to build…

We have obtained deep optical spectrophotometry of 16 planetary nebulae in M33, mostly located in the central two kpc of the galaxy, with the Subaru and Keck telescopes. We have derived electron temperatures and chemical abundances from the…