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Related papers: Iron abundance in HII regions

200 papers

A thorough analysis of well studied giant HII regions on galactic discs for which we know the ionizing stellar population, the gas metallicity and the Wolf-Rayet population, leads to photoionization models which can only match all observed…

Astrophysics · Physics 2007-05-23 M. Castellanos , A. I. Diaz , G. Tenorio-Tagle

We present Integral Field Spectroscopy (IFS) of NGC 595, one of the most luminous HII regions in M33. This type of observations allows studying the variation of the principal emission-line ratios across the surface of the nebula. At each…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 M. Relano , A. Monreal-Ibero , J. M. Vilchez , R. C. Kennicutt

We present results on carbon, nitrogen, and oxygen abundances for a sample of unevolved metal-poor stars with metallicities in the range -0.3< [Fe/H]< -3. Oxygen abundances derived from different indicators are compared showing consistently…

Astrophysics · Physics 2016-01-27 G. Israelian , R. Garcia Lopez , Rafael Rebolo

Context. Massive star-formation leads to enrichment with heavy elements of the interstellar medium. On the other hand, the abundance of heavy elements is a key parameter to study the star-formation history of galaxies. Furthermore, the…

Abundance of iron in the atmosphere of Arcturus has been determined from the profiles or regions of the profiles of the weak lines sensitive to iron abundance. The selected lines of Fe I and Fe II were synthesized with the MARCS theoretical…

Solar and Stellar Astrophysics · Physics 2015-09-08 V. A. Sheminova

We present the non-local thermodynamic equilibrium (non-LTE) calculations for O I with the updated model atom that includes quantum-mechanical rate coefficients for O I + H I inelastic collisions from the recent study of Barklem (2018). The…

Solar and Stellar Astrophysics · Physics 2018-08-23 Tatyana Sitnova , Lyudmila Mashonkina

The spatial distribution of metals reflects, and can be used to constrain, the processes of chemical enrichment and mixing. Using PHANGS-MUSE optical integral field spectroscopy, we measure the gas phase oxygen abundances (metallicities)…

We present long slit optical spectroscopy of 67 HII regions in 21 dwarf irregular galaxies to investigate the enrichment of oxygen, nitrogen, neon, sulfur, and argon in low mass galaxies. Oxygen abundances are obtained via direct detection…

Astrophysics · Physics 2009-11-13 L. van Zee , M. P. Haynes

We have obtained multi-slit spectroscopic observations from 3700A to 9200A with LRIS at the Keck I telescope for 31 HII regions in the disk of the Andromeda galaxy (M31), spanning a range in galactocentric distance from 3.9 kpc to 16.1 kpc.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Almudena Zurita , Fabio Bresolin

The possibility of unaccounted for opacity sources in the UV for late-type stars has often been invoked to explain discrepancies between predicted and observed flux distributions and spectral line strengths. Such missing UV-opacity could…

Astrophysics · Physics 2009-11-10 M. Asplund

We use a large sample of galaxies at z~3 to establish a relationship between reddening, neutral gas covering fraction (fcov(HI)), and the escape of ionizing photons at high redshift. Our sample includes 933 galaxies at z~3, 121 of which…

Astrophysics of Galaxies · Physics 2016-09-21 Naveen A. Reddy , Charles C. Steidel , Max Pettini , Milan Bogosavljevic , Alice Shapley

We test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated-light spectra were obtained by scanning the slit of the…

Solar and Stellar Astrophysics · Physics 2017-05-10 S. S. Larsen , J. P. Brodie , J. Strader

Assuming that in the atmospheres of low-mass, metal-poor red giant stars, 1-D models based on LTE accurately predict the abundance of iron from Fe II, we derive a globular cluster metallicity scale based on the equivalent widths of Fe II…

Astrophysics · Physics 2009-07-28 Robert P. Kraft , Inese I. Ivans

We use the absorption features from neutral argon at 1048 and 1066 A to determine interstellar abundances or their lower limits toward nine early-type stars. These features were observed with the Interstellar Medium Absorption Profile…

Astrophysics · Physics 2008-11-26 Ulysses J. Sofia , Edward B. Jenkins

We present precise abundance determinations of two near-pristine damped Ly$\alpha$ systems (DLAs) to assess the nature of the [O/Fe] ratio at [Fe/H] < -3 (i.e. <1/1000 of the solar metallicity). Prior observations indicate that the [O/Fe]…

Astrophysics of Galaxies · Physics 2022-05-04 Louise Welsh , Ryan Cooke , Michele Fumagalli , Max Pettini

The similarity between observed velocity structures of Al III and singly ionized species in damped Lyman-alpha systems (DLAs) suggests the presence of ionized gas in the regions where most metal absorption lines are formed. A simplified…

Astrophysics · Physics 2009-10-31 Yuri I. Izotov , Daniel Schaerer , Corinne Charbonnel

We present XMM-Newton/EPIC observations of six merging galaxy clusters and study the distributions of their temperature, iron (Fe) abundance and pseudo-entropy along the merging axis. For the first time, we focus simultaneously, and in a…

Astrophysics of Galaxies · Physics 2019-09-11 I. Urdampilleta , F. Mernier , J. S. Kaastra , A. Simionescu , J. de Plaa , S. Kara , E. N. Ercan

There are known differences between the physical properties of HII and diffuse ionized gas (DIG), but most of the studied regions in the literature are relatively bright. We compiled a faint sample of 390 HII regions with median…

We use very deep spectra obtained with the Ultraviolet-Visual Echelle Spectrograph at the Very Large Telescope to derive physical conditions and chemical abundances of four H II regions of the Large Magellanic Cloud (LMC) and four H II…

Astrophysics of Galaxies · Physics 2022-11-22 G. Domínguez-Guzmán , M. Rodríguez , J. García-Rojas , C. Esteban , L. Toribio San Cipriano , .

We present new HST/WFC3-IR narrowband [Fe II] images of protostellar jets in the Carina Nebula. Combined with 5 previously published sources, we have a sample of 18 jets and 2 HH objects. All of the jets we targeted with WFC3 show bright…

Solar and Stellar Astrophysics · Physics 2016-09-21 Megan Reiter , Nathan Smith , John Bally