相关论文: Multiple channels for nitrogen pollution by metal …

Recent JWST observations of the z=10.6 galaxy GN-z11 have revealed a very high gas-phase nitrogen abundance (higher than four times the solar value), a very small half-light radius(~ 60 pc), and a large stellar mass (M_s ~ 10^9 M_sun) for…

Spectroscopic observations by the James Webb Space Telescope (JWST) have revealed young, compact, high-redshift ($z$) galaxies with high nitrogen-to-oxygen (N/O) ratios. GN-z11 at z=10.6 is one of these galaxies. One possible scenario for…

The James Webb Space Telescope reveals anomalous nitrogen enrichment (high N/O ratios) in compact, star-forming galaxies, such as GN-z11 at $z\sim10$. The origin of this chemical signature provides an insight into the early star and galaxy…

Recent observations of GN-z11 with JWST/NIRSpec revealed numerous oxygen, carbon, nitrogen, and helium emission lines at $z=10.6$. Using the measured line fluxes, we derive abundance ratios of individual elements within the interstellar…

The first JWST spectroscopy of the luminous galaxy GN-z11 simultaneously both established its redshift at $z=10.6$ and revealed a rest-ultraviolet spectrum dominated by signatures of highly-ionized nitrogen, which has so far defied clear…

Recent JWST observations have revealed a population of high-redshift galaxies ($z\gtrsim5$) exhibiting unexpectedly bright ultraviolet (UV) nitrogen emission lines. The strong N III] and N IV] features imply nitrogen-to-oxygen abundance…

We report the chemical abundance pattern of GS\_3073, a galaxy at $z=5.55$ which was previously confirmed to host an overmassive active black hole, by leveraging the detection of about 40 emission lines, combining JWST/NIRSpec observations…

We interpret the peculiar super-solar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 ($z=10.6$) using our state-of-the-art chemical evolution models. The observed CNO ratios can be…

We explore the possibility that the N-rich young proto-galaxy GN-z11 recently observed at z=10.6 by the James Webb Space Telescope is the result of the formation of second generation stars from pristine gas and Asymptotic Giant Branch (AGB)…

The assembly of supermassive black holes poses a challenge primarily because of observed quasars at high redshift, but additionally because of the current lack of observations of intermediate mass black holes. One plausible scenario for…

The oxygen and nitrogen abundance evolutions with redshift and galaxy stellar mass in emission-line SDSS galaxies are investigated. This is the first such study for nitrogen abundances, and it provides an additional constraint for the study…

The new era of galaxy evolution studies hearkened in by JWST has led to the discovery of z > 5 galaxies exhibiting excess nitrogen with log(N/O)~1 dex or more than expected from log(N/O) vs 12+log(O/H) trends in the local Universe. A…

We present an analysis of the chemical compositions in high-redshift galaxies, with a focus on the nitrogen-enhanced galaxies GN-z11 and CEERS-1019. We use stellar models of massive stars with initial masses ranging from 9 to 120 Msol…

Over the past few years \textit{JWST} has been a major workhorse in detecting and constraining the metal enrichment of the first galaxies in the early Universe and finding the source of the ionisation of their interstellar medium. In this…

Unusually high N/O abundance ratios were recently reported for a very compact, intensively star-forming object GN-z11 at $z=10.6$ from JWST/NIRSpec observations. We present an empirical comparison with the C, N, and O abundance ratios in…

The detections of bright UV nitrogen emission lines in some high-redshift galaxies suggest unexpectedly high nitrogen-to-oxygen ratios ($\log(\rm N/O)\gtrsim-1.0$) compared to local values ($\log(\rm N/O)\gtrsim-1.5$) at similar…

We separately assess elemental abundances in AGNs' broad and narrow emission line regions (BLR and NLR), based on a critical assessment of published results together with new photoionization models. We find 1) He/H enhancements in some AGN,…

(Abbreviated) From six spectra of high-z QSOs, we select eleven metal-rich, Z>=Z_solar, and optically-thin to the ionizing radiation, N(HI)<10^17 cm^-2, absorption systems ranging between z=1.5 and z=2.9 and revealing lines of different…

Recent studies of high-redshift galaxies with James Webb Space Telescope (JWST), such as GN-z11 at $z=10.6,$ show unexpectedly significant amounts of nitrogen (N) in their spectra. As this phenomenology appears to extend to gravitionally…

The unexpectedly high nitrogen-to-oxygen (N/O) ratios observed in high-redshift (z) galaxies have challenged our understanding of early star formation. Notably, many of these nitrogen-rich galaxies show signatures of active galactic nuclei…