SIMBAD references

2012ApJ...752..111N - Astrophys. J., 752, 111 (2012/June-3)

Shocked superwinds from the z ∼ 2 clumpy star-forming galaxy, ZC406690.

NEWMAN S.F., SHAPIRO GRIFFIN K., GENZEL R., DAVIES R., FORSTER-SCHREIBER N.M., TACCONI L.J., KURK J., WUYTS S., GENEL S., LILLY S.J., RENZINI A., BOUCHE N., BURKERT A., CRESCI G., BUSCHKAMP P., CAROLLO C.M., EISENHAUER F., HICKS E., LUTZ D., MANCINI C., NAAB T., PENG Y. and VERGANI D.

Abstract (from CDS):

We have obtained high-resolution data of the z ∼ 2 ring-like, clumpy star-forming galaxy (SFG) ZC406690 using the VLT/SINFONI with adaptive optics (in K band) and in seeing-limited mode (in H and J bands). Our data include all of the main strong optical emission lines: [O II], [O III], Hα, Hβ, [N II], and [S II]. We find broad, blueshifted Hα and [O III] emission line wings in the spectra of the galaxy's massive, star-forming clumps (σ ∼ 85 km/s) and even broader wings (up to 70% of the total Hα flux, with σ ∼ 290 km/s) in regions spatially offset from the clumps by ∼2 kpc. The broad emission likely originates from large-scale outflows with mass outflow rates from individual clumps that are 1-8x the star formation rate (SFR) of the clumps. Based on emission line ratio diagnostics ([N II]/Hα and [S II]/Hα) and photoionization and shock models, we find that the emission from the clumps is due to a combination of photoionization from the star-forming regions and shocks generated in the outflowing component, with 5%-30% of the emission deriving from shocks. In terms of the ionization parameter (6x107 to 108 cm/s, based on both the SFR and the O32 ratio), density (local electron densities of 300-1800/cm3 in and around the clumps, and ionized gas column densities of 1200-8000 M/pc2^), and SFR (10-40 M/yr), these clumps more closely resemble nuclear starburst regions of local ultraluminous infrared galaxies and dwarf irregulars than H II regions in local galaxies. However, the star-forming clumps are not located in the nucleus as in local starburst galaxies but instead are situated in a ring several kpc from the center of their high-redshift host galaxy, and have an overall disk-like morphology. The two brightest clumps are quite different in terms of their internal properties, energetics, and relative ages, and thus we are given a glimpse at two different stages in the formation and evolution of rapidly star-forming giant clumps at high-z.

Abstract Copyright:

Journal keyword(s): galaxies: evolution - galaxies: high-redshift - galaxies: star formation - ISM: jets and outflows

Simbad objects: 5

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