Nebular Excitation in z 2 Star-forming Galaxies from the SINS and LUCI Surveys: The Influence of Shocks and Active Galactic Nuclei
| Autor: | R. D. Davies, Alvio Renzini, N. M. Förster Schreiber, Reinhard Genzel, A. Burkert, T. Naab, Frank Eisenhauer, Amiel Sternberg, Dieter Lutz, Linda J. Tacconi, Ben Weiner, Y. Peng, Shy Genel, Orly Gnat, S. J. Lilly, K. Shapiro Griffin, G. Zamorani, J. D. Kurk, Peter Buschkamp, E. K. S. Hicks, Chiara Mancini, D. Vergani, Giovanni Cresci, David J. Rosario, Stijn Wuyts, C. M. Carollo, S. Newman |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Physics
Active galactic nucleus Stellar mass Astrophysics::High Energy Astrophysical Phenomena Metallicity Astronomy and Astrophysics Astrophysics Photoionization Astrophysics::Cosmology and Extragalactic Astrophysics Galaxy Redshift Space and Planetary Science Ionization Emission spectrum Astrophysics::Galaxy Astrophysics |
| Zdroj: | Newman, S F, Buschkamp, P, Genzel, R, Förster Schreiber, N M, Kurk, J, Sternberg, A, Gnat, O, Rosario, D, Mancini, C, Lilly, S J, Renzini, A, Burkert, A, Carollo, C M, Cresci, G, Davies, R, Eisenhauer, F, Genel, S, Shapiro Griffin, K, Hicks, E K S, Lutz, D, Naab, T, Peng, Y, Tacconi, L J, Wuyts, S, Zamorani, G, Vergani, D & Weiner, B J 2014, ' Nebular Excitation in z 2 Star-forming Galaxies from the SINS and LUCI Surveys: The Influence of Shocks and Active Galactic Nuclei ', Astrophysical Journal, vol. 781, no. 1 . https://doi.org/10.1088/0004-637X/781/1/21 |
| DOI: | 10.1088/0004-637X/781/1/21 |
| Popis: | Based on high-resolution, spatially resolved data of 10 z ~ 2 star-forming galaxies from the SINS/zC-SINF survey and LUCI data for 12 additional galaxies, we probe the excitation properties of high-z galaxies and the impact of active galactic nuclei (AGNs), shocks, and photoionization. We explore how these spatially resolved line ratios can inform our interpretation of integrated emission line ratios obtained at high redshift. Many of our galaxies fall in the "composite" region of the z ~ 0 [N II]/Hα versus [O III]/Hβ diagnostic (BPT) diagram, between star-forming galaxies and those with AGNs. Based on our resolved measurements, we find that some of these galaxies likely host an AGN, while others appear to be affected by the presence of shocks possibly caused by an outflow or from an enhanced ionization parameter as compared with H II regions in normal, local star-forming galaxies. We find that the Mass-Excitation (MEx) diagnostic, which separates purely star-forming and AGN hosting local galaxies in the [O III]/Hβ versus stellar mass plane, does not properly separate z ~ 2 galaxies classified according to the BPT diagram. However, if we shift the galaxies based on the offset between the local and z ~ 2 mass-metallicity relation (i.e., to the mass they would have at z ~ 0 with the same metallicity), we find better agreement between the MEx and BPT diagnostics. Finally, we find that metallicity calibrations based on [N II]/Hα are more biased by shocks and AGNs at high-z than the [O III]/Hβ/[N II]/Hα calibration. |
| Databáze: | OpenAIRE |
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