Metallicity Determination in Seyfert 2 AGNs

Aims: To study calibrations of line ratios that can estimates metallicities of galaxies even in large redshift where the measurement of faint emission lines is not easy to obtain. Methods: We use the Cloudy Code to build a grid of photoionization models with lines ratios from the UV and, we compare with a sample of 77 object AGNs Seyfert 2. Results: We build semi-empirical calibrations between the metallicity of studied objects and the rest-frame intensity of the line ratios N V λ1240 / HeII λ1640, C43=log[(Civ λ1549 + CIII] λ1909) / HeII λ1640] and CIII] λ1909 / C IV λ1549.Fil: Monteiro, A. F.. Universidade Do Vale Do Paraíba; BrasilFil: Dors, O. L.. Universidade Do Vale Do Paraíba; BrasilFil: Cardaci, Monica Viviana. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hägele, Guillermo Federico. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaII workshop on Chemical abundances in gaseous nebulae: open problems in nebular astrophysicsSao Jose dos CamposBrasilUniversidade do Vale do Paraíb

Effective temperature of ionizing stars in extragalactic HII regions - II. Nebular parameter relationships based on CALIFA data

We calculate the effective temperature (Teff) of ionizing star(s), the oxygen abundance of the gas phase (O/H), and the ionization parameter U for a sample of HII regions located in the discs of 59 spiral galaxies in the redshift range 0.005 < z < 0.03. We use spectroscopic data taken from the CALIFA data release 3 (DR3) and theoretical (for Teff and U) and empirical (for O/H) calibrations based on strong emission lines. We consider the spatial distribution and radial gradients of these parameters in each galactic disc for the objects in our sample. Most of the galaxies in our sample (∼70 per cent) show positive Teff radial gradients, although some exhibit negative or flat ones. The median value of the Teff radial gradient is 0.762 kK/R25. We find that the radial gradients of both logUand Teff depend on the oxygen abundance gradient, in the sense that the gradient of logU increases as the log(O/H) gradient increases while there is an anti-correlation between the gradient of Teff and the oxygen abundance gradient. Moreover, galaxies with flat oxygen abundance gradients tend to have flat logU and Teff gradients as well. Although our results are in agreement with the idea of the existence of positive Teff gradients along the disc of the majority of spiral galaxies, it seems that this is not a universal property for these objects.Fil: Zinchenko, I. A.. Main Astronomical Observatory of National Academy of Sciences of Ukraine; Ucrania. Zentrum für Astronomie der Universität Heidelberg; AlemaniaFil: Dors, Oli L.. Universidade do Vale do Paraíba; BrasilFil: Hägele, Guillermo Federico. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Cardaci, Monica Viviana. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Krabbe, Angela. Universidade do Vale do Paraíba; Brasi

Chemodynamics on BCDs

This work presents a brief summary of the analysis we are performing on the physical and chemical properties of the ionizing gas in star-forming regions belonging to 2 Blue Compact Dwarf galaxies (BCDs), using high resolution echelle spectra. Our aim is to perform a detailed study of the Chemodinamics on BCDs galaxies. To do that, we use the LMFIT (python tool), Pyneb (Luridiana et al. 2015) and our own code (Hagele et al. 2008). We deconvolve the emission-line profiles fitting several gaussians to the different kinematical components to be able to estimate the properties and the nature of the ionized gas. Our next step is to use our kinematical information to performe the chemical abundance analysis and to infer the physical properties of the gas (the chemodynamical study) by using the metodology published in Hagele et al. (2012).Fil: Campuzano Castro, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hägele, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Bosch, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Firpo, Verónica. Universidad de La Serena; ChileFil: Morrell, Nidia Irene. Las Campanas Observatory; ChileFil: Cardaci, Monica Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFirst Workshop on Chemical Abundances in Gaseous NebulaeCampos do JordaoBrasilUniversidade do Vale do Paraíb

Extragalactic Star-forming Regions: a Study of the Physical Properties and Chemical Abundances

Extragalactic star-forming regions are characterized by the large number of young and massive stars that ionize the surrounding gas. These regions can be observed as very luminous spots in the disk of spiral galaxies and as large areas in Blue Compact Dwarf galaxies. We present preliminary results of the study of a sample of star-forming regions in two spiral and one Blue Compact Dwarf galaxies observed with the GMOS/Long-slit configuration on the Gemini-South Telescope. We are presenting a preliminary study of two regions of each galaxy for which we estimated: reddening, electron densities, and electron temperatures by using direct method, temperature relations based on photoionization models, and empirical relations. From the electron temperatures we de- rived ionic and total chemical abundances of, O, S, N, Ne, Ar and He. In addition we computed star formation rates and the ionization state for all regions.Fil: Muñoz Vergara, D.. Gemini Observatory; Chile. Universidad de La Serena; ChileFil: Firpo, V.. Gemini Observatory; Chile. Universidad de La Serena; ChileFil: Hägele, Guillermo Federico. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Bosch, Guillermo Luis. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Cardaci, Monica Viviana. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Sanmartim, D.. Gemini Observatory; ChileFil: Gimeno, G.. Gemini Observatory; ChileII workshop on Chemical Abundances in Gaseous Nebulae: Open problems in Nebular AstrophysicsSao Jose dos CamposBrasilUniversidade do Vale do Paraíb

The internal kinematic of star-forming regions in interacting galaxies

Star formation processes can be found in colliding galaxies, where the gas compression can trigger the formation of giant star-forming regions. We present the results from a detailed kinematic analysis in a sample of HII regions located in three strongly interacting galaxies. The velocity dispersion and the luminosity of the multiple-components analyzed in the emission-line profiles suggest that these star-forming objects correspond to giant complexes. In addition, the star formation rates and the ionization state in these regions revealed the presence of ongoing star formation events.Fil: Firpo, V.. Gemini Observatory; Chile. Universidad de La Serena; ChileFil: Muthukrishna, D.. Institute Of Astronomy; Reino UnidoFil: Campuzano Castro, Federico. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Bosch, Guillermo Luis. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hägele, Guillermo Federico. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Torres Flores, S.. Universidad de La Serena; ChileFil: Cardaci, Monica Viviana. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaII workshop on Chemical Abundances in Gaseous Nebulae: Open problems in Nebular AstrophysicsSao Jose dos CamposBrasilUniversidade do Vale do Paraíb

Interaction effects on galaxy pairs with Gemini/GMOS- I: electron density

We present an observational study about the impacts of the interactions on the electron density of HII regions located in seven systems of interacting galaxies. The data consist of long-slit spectra in the range 4400-7300 A, obtained with the Gemini Multi-Object Spectrograph at Gemini South (GMOS-S). The electron density was determined using the ratio of emission-lines [S II] lambda 6716/ lambda 6731. Our results indicate that the electron density estimates obtained of HII regions from our sample of interacting galaxies are systematically higher than those derived for isolated galaxies. The mean electron density values of interacting galaxies are in the range of Ne = 24 - 532 cm^{-3}, while those obtained for isolated galaxies are in the range of Ne = 40 - 137 cm^{-3}. Comparing the observed emission lines with predictions of photoionization models, we verified that almost all the HII regions of the galaxies AM1054A, AM2058B, AM2306B have emission lines excited by shocks, such as in AM2322B (one point) and AM 2322A (four points). No correlation is obtained between the presence of shocks and electron densities. Indeed, the highest electron density values found in our sample do not belong to the objects with gas shock excitation. We emphasize the importance of considering theses quantities especially when the metallicity is derived for this type of systems.Fil: Krabbe, A.. Universidade Do Vale Do Paraiba; BrasilFil: Rosa, D. A.. Universidade Do Vale Do Paraiba; BrasilFil: Dors Jr., Oli L.. Universidade Do Vale Do Paraiba; BrasilFil: Pastoriza, Miriani G.. Universidade Federal Do Rio Grande Do Sul; BrasilFil: Winge, C.. Gemini Observatory; ChileFil: Hägele, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Astrofísica de la Plata; Argentina; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Cardaci, Monica Viviana. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Astrofísica de La Plata; Argentina; ArgentinaFil: Rodrigues, Irapuan. Universidade Do Vale Do Paraiba; Brasi

Nature and chemical abundances of a sample of Lyman-α emitter objects at high redshift

We built a grid of photoionization models and compiled already available observational emission line intensities (1000 53. Values for C/O abundance ratio derived for the LAEs seem to be consistent with those derived for local star forming objects with similar metallicities, while an overabundance of N/O was found for most of the LAEs.Instituto de Astrofísica de La Plat

Chemodynamics of green pea galaxies - I. Outflows and turbulence driving the escape of ionizing photons and chemical enrichment

We investigate the ionized gas kinematics, physical properties, and chemical abundances of Sloan Digital Sky Survey J142947, a Green Pea galaxy at redshift z ∼ 0.17 with strong, double-peak Ly α emission and indirect evidence of Lyman continuum (LyC) leakage. Using high-dispersion spectroscopy, we perform a multicomponent analysis of emission-line profiles. Our model consistently fits all lines as a narrow component with intrinsic velocity dispersion σ ∼ 40 km s-1, and two broader blue-shifted components with σ ∼ 90 and ∼250 km s-1. We find electron densities and temperatures, ionization conditions, and direct O/H and N/O abundances for each component. A highly ionized, metal-poor, young and compact starburst dominates narrow emission, showing evidence of hard radiation fields and elevated N/O. The blue-shifted broader components are consistent with highly turbulent, possibly clumpy ionized gas at the base of a strong photoionized outflow, which accounts for ≳50 per cent of the integrated emission-line fluxes. The outflow is dense and metal-enriched compared to the HII regions, with expansion velocities larger than those obtained from UV interstellar absorption lines under standard assumptions. Some of these metals may be able to escape, with outflows loading factors comparable to those found in high-z galaxies of similar SFR/Area. Our findings depict a two-stage starburst picture; hard radiation fields from young star clusters illuminate a turbulent and clumpy ISM that has been eroded by SNe feedback. Whilst UV data suggest an extended Ly α halo with high average HI column density, LyC photons could only escape from SDSS J142947 through low HI density channels or filaments in the ISM approaching density-bounded conditions, traced by outflowing gas.Fil: Hogarth, L.. Colegio Universitario de Londres; Reino UnidoFil: Amorín, R.. Universidad de La Serena; ChileFil: Vílchez, J. M.. Instituto de Astrofísica de Andalucía - Csic; EspañaFil: Hägele, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Cardaci, Monica Viviana. Instituto de Astrofísica de la Plata (conicet- Universidad Nacional de la Plata); ArgentinaFil: Pérez Montero, E.. Instituto de Astrofísica de Andalucía - Csic; EspañaFil: Firpo, Verónica. Gemini Observatorysouthern Operations Center; ChileFil: Jaskot, A.. Williams College; Estados UnidosFil: Chávez, R.. Instituto de Radioastronomía y Astrofísica; Méxic

On the central abundances of Active Galactic Nuclei and Star-forming Galaxies

We examine the relation between oxygen abundances in the narrow-line regions (NLRs) of active galactic nuclei (AGNs) estimated from the optical emission lines through the strong-line method (the theoretical calibration of Storchi-Bergmann et al. 1998), via the direct Te-method, and the central intersect abundances in the host galax- ies determined from the radial abundance gradients. We found that the Te-method underestimates the oxygen abundances by up to ∼2 dex (with average value of ~0.8 dex) compared to the abundances derived through the strong-line method. This con- firms the existence of the so-called ?temperature problem? in AGNs. We also found that the abundances in the centres of galaxies obtained from their spectra trough the strong-line method are close to or slightly lower than the central intersect abun- dances estimated from the radial abundance gradient both in AGNs and Star-forming galaxies. The oxygen abundance of the NLR is usually lower than the maximum at- tainable abundance in galaxies (~2 times the solar value). This suggests that there is no extraordinary chemical enrichment of the NLRs of AGNs.Fil: Dors Jr., O. L.. Universidade Do Vale Do Paraíba; BrasilFil: Cardaci, Monica Viviana. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Astrofísica de La Plata; ArgentinaFil: Hägele, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Astrofísica de la Plata; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Rodrigues, I.. Universidade Do Vale Do Paraíba; BrasilFil: Grebel, E. K. . Universität Heidelberg. Astronomisches Rechen-Institut. Zentrum für Astronomie; AlemaniaFil: Pilyugin, L. S. . Universität Heidelberg; Alemania. National Academy of Sciences of Ukraine; Ucrania. Kazan Federal University; RusiaFil: Freitas Lemes, P. . Universidade Do Vale Do Paraíba; BrasilFil: Krabbe, A. C. . Universidade Do Vale Do Paraíba; Brasi

Nature and chemical abundances of a sample of Lyman-α emitter objects at high redshift

We built a grid of photoionization models and compiled already available observational emission line intensities (1000 53. Values for C/O abundance ratio derived for the LAEs seem to be consistent with those derived for local star forming objects with similar metallicities, while an overabundance of N/O was found for most of the LAEs.Instituto de Astrofísica de La Plat