Related papers: Detecting the First Objects in the Mid-IR with NGS…
An object discovered during an infrared survey of the field near the quasar B2 0149+33 has an emission line at 2.25$\mu$m that we interpret as H$\alpha$ at a redshift of 2.43. The K-band image shows two compact components 10 kpc apart…
We demonstrate estimating the total infrared luminosity, LIR, and star formation rates (SFRs) of star-forming galaxies at redshift 0 < z < 2.8 from single-band 24 micron observations, using local spectral energy distributions (SED)…
Over the last decade, observations of the cool interstellar medium in distant galaxies via molecular and atomic fine structure line emission has gone from a curious look into a few extreme, rare objects, to a mainstream tool to study galaxy…
The James Webb Space Telescope (JWST) is challenging our understanding of the nature of the very first galaxies in the Universe, having discovered a surprising abundance of very massive galaxies in early cosmic epochs. By applying a model…
We present synthetic observations for the first generations of galaxies in the Universe and make predictions for future deep field observations for redshifts greater than 6. Due to the strong impact of nebular emission lines and the…
The possibility of detecting proto-galaxies in the UV band is pointed out, assuming that galaxy formation occured at z $\sim 5-6$. It is shown that the diffuse gas in collapsing galaxy sized objects with temperatures $\sim 10^{6\pm0.5}$ K,…
HII regions made of gas ionized by radiations from young massive stars, are widely distributed in the Milky Way. They are tracers for star formation, and their distributions are correlated with the Galactic spiral structure. Radio…
The formation of the first galaxies is influenced by the radiative feedback from the first generations of stars. This feedback is manisfested by the heating and ionization of the gas which lies within the H II regions surrounding the first…
Blind spectroscopy of massive lensing galaxy clusters with MUSE has revealed large numbers of gravitationally-lensed Lyman-$ \alpha $ emitters exhibiting asymmetric profiles at $ 2.9 \leq z \leq 6.7 $, suggesting abundant outflows from…
Recent observations have successfully detected UV-bright and infrared-bright galaxies in the epoch of reionization. However, the origin of their radiative properties has not been understood yet. Combining cosmological hydrodynamic…
We study the relationship between the mid-IR (5-18 $\mu$m) emission of late-type galaxies and various other star formation tracers in order to investigate the nature of the dust heating sources in this spectral domain. The analysis is…
The molecular gas, H$_2$, that fuels star formation in galaxies is difficult to observe directly. As such, the ratio of $L_{\rm IR}$ to $L^\prime_{\rm CO}$ is an observational estimation of the star formation rate compared with the amount…
The high spatial and spectral resolution offered by the new generation of infrared spectrometers at ESO is optimally suited for the observational study of outflows from young stellar objects. Models of interstellar shock waves would benefit…
We predict the space density of molecular gas reservoirs in the Universe, and place a lower limit on the number counts of carbon monoxide (CO), hydrogen cyanide (HCN) molecular and [CII] atomic emission lines in blind redshift surveys in…
As a byproduct of its search for the first star forming galaxies, NGST will obtain high-quality spectra for thousands of galaxies in the redshift range z = 0 - 6 and beyond. Most of the galaxies will possess strong emission-line spectra,…
Understanding the formation and evolution of the first stars and galaxies represents one of the most exciting frontiers in astronomy. Since the universe was filled with neutral hydrogen at early times, the most promising method for…
We present the first spectroscopic characterization of an interstellar object at mid-infrared wavelengths. Post-perihelion observations of 3I/ATLAS using the JWST/MIRI medium-resolution spectrometer were obtained on 2025 December 15--16 and…
Recent observations have successfully detected UV or infrared flux from galaxies at the epoch of reionization. However, the origin of their radiative properties has not been fully understood yet. Combining cosmological hydrodynamic…
Mid-infrared arcs of dust emission are often seen near ionizing stars within HII regions. A possible explanations for these arcs is that they could show the outer edges of asymmetric stellar wind bubbles. We use two-dimensional,…
Low-mass or dwarf galaxies (M$_{\ast}<10^{9}$ M${\odot}$) are abundant in the Universe, yet their formation and evolution remain poorly understood. Their enhanced sensitivity to feedback from star formation and active galactic nuclei (AGN)…