High‐Resolution Spectroscopy of Faint Emission Lines in the Orion Nebula

Baldwin, J. A.; Verner, E. M.; Verner, D. A.; Ferland, Gary J.; Martín, P. G.; Korista, K. T.; Rubin, R. H.

doi:10.1086/313416

Cited by 73 publications

(131 citation statements)

References 22 publications

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“…There are highresolution spectroscopic observations of the Orion nebula with high signal-to-noise ratios. Nevertheless, the Fe ii lines observed in the VLT/X-shooter spectra of Haro 11B and C are not present in the spectra of the Orion nebula obtained by Baldwin et al (2000), Esteban et al (2004)…”

Section: Evidence For Luminous Blue Variable (Lbv) Stars In Haro 11mentioning

confidence: 94%

VLT/X-shooter observations of blue compact galaxies Haro 11 and ESO 338-IG 004

Гусева

Izotov

Fricke

et al. 2012

A&A

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Context. Strongly star-forming galaxies of subsolar metallicities are typical of the high-redshift universe. Here we therefore provide accurate data for two low-z analogs, the well-known low-metallicity emission-line galaxies Haro 11 and ESO 338-IG 004. Aims. Our main goal is to derive their spectroscopic properties and to examine whether a previously reported near-infrared (NIR) excess in Haro 11 can be confirmed. Methods. On the basis of Very Large Telescope/X-shooter spectroscopic observations in the wavelength range ∼λλ3000-24 000 Å, we use standard direct methods to derive physical conditions and element abundances. Furthermore, we use X-shooter data together with Spitzer observations in the mid-infrared range to attempt to find hidden star formation. Results. We derive interstellar oxygen abundances of 12 + log O/H = 8.33 ± 0.01, 8.10 ± 0.04, and 7.89 ± 0.01 in the two H ii regions B and C of Haro 11 and in ESO 338-IG 004, respectively. The observed fluxes of the hydrogen lines correspond to the theoretical recombination values after correction for extinction with a single value of the extinction coefficient C(Hβ) across the entire wavelength range from the near-ultraviolet to the NIR and mid-infrared for each of the studied H ii regions. Thus, we confirm our previous findings obtained for several low-metallicity emission-line galaxies (Mrk 59, II Zw 40, Mrk 71, Mrk 996, SBS 0335-052E, PHL 293B, and GRB HG 031203) that the extinction coefficient C(Hβ) is not higher in the NIR than in the optical range and therefore that there are no emission-line regions contributing to the line emission in the NIR range, which are hidden in the optical range. The agreement between the extinction-corrected and CLOUDY-predicted fluxes implies that a H ii region model including only stellar photoionisation is able to account for the observed fluxes, in both the optical and NIR ranges. No additional excitation mechanism such as shocks from stellar winds and supernova remnants is needed. All observed spectral energy distributions (SEDs) can be reproduced quite well across the whole wavelength range by model SEDs except for Haro 11B, where there is a continuum flux excess at wavelengths >1.6 μm. It is possible that one or more red supergiant stars are responsible for the NIR flux excess in Haro 11B. We find evidence of a luminous blue variable (LBV) star in Haro 11C.

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Section: Evidence For Luminous Blue Variable (Lbv) Stars In Haro 11mentioning

confidence: 94%

VLT/X-shooter observations of blue compact galaxies Haro 11 and ESO 338-IG 004

Гусева

Izotov

Fricke

et al. 2012

A&A

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“…Spectroscopic observations of Galactic H  regions have been carried out by many investigators (Baldwin et al 1991(Baldwin et al , 2000Caplan et al 2000;Peimbert et al 1969Peimbert et al , 1977Peimbert et al , 1978Peimbert et al , 1992Peimbert et al , 1993Esteban 1999;Esteban et al 1998Esteban et al , 1999Osterbrock et al 1992;Shaver et al 1983;Vílchez & Esteban 1996, among others). The Galactic H  regions with measured temperaturesensitive line ratios are listed in Table 1.…”

Section: H II Regions With Available [Oiii]λ4363 Line Intensitymentioning

confidence: 99%

On the oxygen abundance in our Galaxy

Pilyugin

Ferrini²,

Shkvarun

2003

A&A

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Abstract. The compilation of published spectra of Galactic H  regions with available diagnostic [OIII]λ4363 line information has been carried out. Our list contains 71 individual measurements of 13 H  regions in the range of galactocentric distances from 6.6 to 14.8 kpc. The oxygen abundances in all the H  regions were recomputed in the same way, using the classic T e -method. The oxygen abundance at the solar galactocentric distance traced by those H  regions is in agreement with the oxygen abundance in the interstellar medium in the solar vicinity derived with high precision from the interstellar absorption lines towards stars. The derived radial oxygen abundance distribution was compared with that for H  regions from the Shaver et al. (1983) sample which is the basis of many models for the chemical evolution of our Galaxy. It was found that the original Shaver et al.'s oxygen abundances are overestimated by 0.2-0.3 dex. Oxygen abundances in H  regions from the Shaver et al. sample have been redetermined with the recently suggested P-method. The radial distribution of oxygen abundances from the Shaver et al. sample redetermined with the P-method is in agreement with our radial distribution of (O/H) Te abundances.

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“…including H II regions (e.g., Aspin 1994;Lumsden & Puxley 1996;Luhman et al 1998;Baldwin et al 2000;Puxley et al 2000;Okumura et al 2001;Blum & McGregor 2008;RomanLopes et al 2009), starburst galaxies (Vanzi et al 2008), and active galactic nuclei (Thompson et al 1978), has demonstrated that nebular spectroscopy is a potentially powerful tool for investigating the nucleosynthesis and chemical evolution of transiron species. The abundances of n-capture elements are of particular interest in PNe, since these species can be produced in PN progenitor stars via slow n-capture nucleosynthesis (the "sprocess") during the asymptotic giant branch (AGB) stage of evolution.…”

Section: Introductionmentioning

confidence: 99%

Atomic data for neutron-capture elements

Sterling

Witthoeft

2011

A&A

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We present multi-configuration Breit-Pauli AUTOSTRUCTURE calculations of distorted-wave photoionization (PI) cross sections, and total and partial final-state resolved radiative recombination (RR) and dielectronic recombination (DR) rate coefficients for the first six ions of the trans-iron element Se. These calculations were motivated by the recent detection of Se emission lines in a large number of planetary nebulae. Se is a potentially useful tracer of neutron-capture nucleosynthesis, but accurate determinations of its abundance in photoionized nebulae have been hindered by the lack of atomic data governing its ionization balance. Our calculations were carried out in intermediate coupling with semi-relativistic radial wavefunctions. PI and recombination data were determined for levels within the ground configuration of each ion, and experimental PI cross-section measurements were used to benchmark our results. For DR, we allowed Δn = 0 core excitations, which are important at photoionized plasma temperatures. We find that DR is the dominant recombination process for each of these Se ions at temperatures representative of photoionized nebulae (∼10 4 K). In order to estimate the uncertainties of these data, we compared results from three different configuration-interaction expansions for each ion, and also tested the sensitivity of the results to the radial scaling factors in the structure calculations. We find that the internal uncertainties are typically 30-50% for the direct PI cross sections and ∼10% for the computed RR rate coefficients, while those for low-temperature DR can be considerably larger (from 15-30% up to two orders of magnitude) due to the unknown energies of near-threshold autoionization resonances. These data are available at the CDS, and fitting coefficients to the total RR and DR rate coefficients are presented. The results are suitable for incorporation into photoionization codes used to numerically simulate astrophysical nebulae, and will enable robust determinations of nebular Se abundances.

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High‐Resolution Spectroscopy of Faint Emission Lines in the Orion Nebula

Cited by 73 publications

References 22 publications

VLT/X-shooter observations of blue compact galaxies Haro 11 and ESO 338-IG 004

VLT/X-shooter observations of blue compact galaxies Haro 11 and ESO 338-IG 004

On the oxygen abundance in our Galaxy

Atomic data for neutron-capture elements

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