Related papers: Azimuthal Metallicity Structure in the Milky Way D…
Spectra of high-metallicity (12+log(O/H) > 8.2) HII regions where oxygen auroral lines are measurable in both the O+ and O++ zones, have been extracted from the Data Release 6 of the Sloan Digital Sky Survey (SDSS). Our final sample…
Large-scale filaments ubiquitously exist in the Galactic interstellar medium, and their radial profiles offer insights into their formation mechanisms. We present a statistical analysis of molecular hydrogen column density ($\rm N(H_2)$)…
Stellar abundances and ages afford the means to link chemical enrichment to galactic formation. In the Milky Way, individual element abundances show tight correlations with age, which vary in slope across ([Fe/H]-[$\alpha$/Fe]). Here, we…
Metallicities of both gas and stars decline toward large radii in spiral galaxies, a trend known as the radial metallicity gradient. We quantify the evolution of the metallicity gradient in the Milky Way as traced by APOGEE red giants with…
A detailed spectroscopic study, from lambda 3700 A to 1 um, was performed for a sample of 34 HII galaxies in order to derive fundamental parameters for their HII regions and ionizing sources, as well as gaseous metal abundances. All the…
The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby (d<150 pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. The oxygen abundances were inferred from a restricted non-LTE…
The circumnuclear region of the Galactic Center offers a unique laboratory to study energy balance and structure formation around Sgr A$\star$. This work investigates thermal and nonthermal processes within 7 pc distance from Sgr A$\star$.…
The study of the chemical abundances of HII regions in polar ring galaxies and their implications for the evolutionary scenario of these systems has been a step forward both in tracing the formation history of the galaxy and giving hints on…
Based on high quality observations of multiplet V1 of OII and the NLTE atomic computations of OII we study the density and temperature of a sample of HII regions. We find that the signature for oxygen rich clumps of high density and low…
We analyze the statistical properties of the circumnuclear HII regions of a sample of 52 nearby galaxies ($v < 1000km/s) from archival HST/NICMOS H-band and Pa alpha (1.87micron) observations at unprecedented spatial resolutions of between…
We present a new catalogue of spectrophotometric distances and line-of-sight systemic velocities to 103 HII regions between 90$^{\circ}\leq \ell \leq~$195$^{\circ}$ (longitude quadrants II and part of III). Two new velocities for each…
Atomic hydrogen (HI) is a vital player in the star-formation process in galaxies. It is the raw fuel for making molecules, an important shielding agent against interstellar radiation, and a buffer that soaks up the energy and momentum of…
We present an analysis of the chemical abundance properties of $\approx$650 star-forming galaxies at $z \approx0.6-1.8$. Using integral-field observations from the $K$-band Multi-Object Spectrograph (KMOS), we quantify the [NII]/H$\alpha$…
We analyse a set of very metal-poor stars for which accurate chemical abundances have been obtained as part of the ESO Large Program "First stars" in the light of the Gaia DR2 data. The kinematics and orbital properties of the stars in the…
Based on a simple, but fairly successful, model of the chemical evolution of the Milky Way disk, we study the evolution of the abundances of the elements He, C, N, O, Ne, Mg, Al, Si, S, Ar and Fe. We use metallicity dependent yields for…
The metal-poor gas continuously accreting onto the discs of spiral galaxies is unlikely to arrive from the intergalactic medium (IGM) with exactly the same rotation velocity as the galaxy itself and even a small angular momentum mismatch…
We used high resolution spectra in the optical and near-infrared wavelength range to study the abundance ratios and metallicities of the HII regions associated with the polar disk in NGC4650A, in order to put constraints on the formation of…
The exploration of the spatial distribution of chemical abundances in star-forming regions in galactic discs provides clues to understand the complex interplay of physical processes that regulate the star formation activity and the chemical…
Radial metallicity gradients are fundamental to understanding galaxy formation and evolution. In our high-resolution simulation of a NIHAO-UHD Milky Way analogue, we analyze the linearity, scatter, spatial coherence, and age-related…
We use observations of the neutral atomic hydrogen (HI) 21-cm emission line to study the spatial distribution of the HI gas in a 80$\degree\times~$90$\degree$ region of the Galaxy halo. The HI column densities in the range of…