Related papers: Analytical strong line diagnostics and their redsh…
The analysis of metal-rich HII regions has a profound impact on the calibration of abundance diagnostics widely used to measure the chemical content of star-forming galaxies, both locally and at high redshift. I review the main difficulties…
High-redshift observations from JWST indicate that optical strong line ratios do not carry the same constraining power as they do at low redshifts. Critically, this prevents a separation between stellar- and black hole-driven ionizing…
Much of what is known of the chemical composition of the universe is based on emission line spectra from star forming galaxies. Emission-based inferences are, nevertheless, model-dependent and they are dominated by light from luminous star…
We present the first results from MARTA (Measuring Abundances at high Redshift with the T$_e$ Approach), a programme leveraging ultra-deep, medium-resolution JWST/NIRSpec spectroscopy to probe the interstellar medium (ISM) of star-forming…
Gas-phase abundances provide insights into the baryon cycle, with radial gradients and 2D metallicity distributions tracking how metals build up and redistribute within galaxy disks over cosmic time. We use a catalog of 22,958 HII regions…
We present the first results from MMT and Keck spectroscopy for a large sample of $0.1\leq z\leq1$ emission-line galaxies selected from our narrow-band imaging in the Subaru Deep Field. We measured the weak [OIII]$\lambda$4363 emission line…
We investigate how HII region temperature structure assumptions affect "direct-method" spatially-resolved metallicity observations using multispecies auroral lines in a galaxy from the SAMI Galaxy Survey. SAMI609396B, at redshift $z=0.018$,…
The Nitrogen-to-Oxygen (N/O) abundance ratio is an important diagnostic of galaxy evolution since the ratio is closely tied to the growth of metallicity and the star formation history in galaxies. Estimates for the N/O ratio are…
JWST's Early Release Observations of the lensing cluster SMACS J0723.3-7327 have given an unprecedented spectroscopic look into the high-redshift universe. These observations reveal five galaxies at z > 5. All five have detectable…
In an earlier paper we modeled the far-infrared emission from a star-forming galaxy using the photoionisation code CLOUDY and presented metallicity sensitive diagnostics based on far-infrared fine structure line ratios. Here, we focus on…
We present a comprehensive analysis of the nitrogen-to-oxygen (N/O) abundance ratio in a sample of ~ 660 star-forming galaxies at redshift z ~ 1-6, with a median redshift of z = 3.0, using deep JWST/NIRSpec spectroscopy. Leveraging…
We aim to derive the electron temperature Te in the gas of metal-rich star-forming galaxies, which can be obtained from their ratios of auroral lines [O II]7320,7330 to nebular lines [O II]3727, in order to establish a more robust…
(Abridged) A large fraction of the gas in galactic haloes has temperatures between 10^4.5 and 10^7 K. At these temperatures, cooling is dominated by metal-line emission if the metallicity Z>~0.1 Zsun. We explore the detectability of several…
The metal content of a galaxy is a key property for distinguishing between viable galaxy evolutionary scenarios, and it strongly influences many of the physical processes in the interstellar medium. An absolute and robust determination of…
We derive new empirical calibrations for strong-line diagnostics of gas phase metallicity in local star forming galaxies by uniformly applying the Te method over the full metallicity range probed by the Sloan Digital Sky Survey (SDSS). To…
We present a chemical analysis of selected HII regions from the PHANGS-MUSE nebular catalogue. Our intent is to empirically re-calibrate strong-line diagnostics of gas-phase metallicity, applicable across a wide range of metallicities…
Using deep narrow-band (NB) imaging and optical spectroscopy from the Keck telescope and MMT, we identify a sample of 20 emission-line galaxies (ELGs) at z=0.065-0.90 where the weak auroral emission line, [OIII]4363, is detected at…
Ultra strong emission-line galaxies (USELs) with extremely high equivalent widths (EW(H beta) > 30A) can be used to pick out galaxies of extremely low metallicity in the z=0-1 redshift range. Large numbers of these objects are easily…
The chemical composition of high redshift galaxies is an important property which gives clues to their past history and future evolution and yet is difficult to measure with current techniques. In this paper we investigate new metallicity…
We propose a methodology to perform a self-consistent analysis of the physical properties of the emitting gas of HII galaxies adequate to the data that can be obtained with the XXI century technology. This methodology requires the…