The unusual NIV]-emitter galaxy GDS J033218.92-275302.7: star formation or AGN-driven winds from a massive galaxy at z=5.56

Abstract

Aims: We investigate the nature of the source GDS J033218.92-275302.7at redshift ~ 5.56. Methods: The SED of the source is well sampled by 16 bands photometry, from UV-optical, near infrared and mid-infrared (MID-IR).The detection of signal in the MID-IR Spitzer/IRAC bands 5.8, 8.0 um -- where the nebular emission contribution is less effective -- suggests the presence of a Balmer break, signature of an underlying stellar population formed at earlier epochs. The optical spectrum shows a clear Lya emission line together with semi-forbidden NIV] 1483.3-1486.5 also in emission. Results: From the SED fitting and the Lya modelling it turns out that the source seems to have an evolved component with stellar mass of ~5 x10^(10) Msolar and age ~ 0.4 Gyrs, and a young component with an age of ~ 0.01 Gyrs and SFR in the range of 30-200 Msolar yr^(-1). The limits on the effective radius derived from the ACS/z850 and VLT/Ks bands indicate that this galaxy is denser than the local ones with similar mass. A relatively high nebular gas column density is favored from the Lya line modelling (NHI>=10^(21) cm^(-2)). A vigorous outflow (~ 450 km/s) has been measured from the optical spectrum,consistent with the Lya modelling. From ACS observations it turns out that the region emitting Lya photons is spatially compact and of the same order of the effective radius estimated at the ~1400A rest-frame wavelength, whose emission is dominated by the stellar continuum and/or AGN. The gas is blown out from the central region,but given the mass of the galaxy it is uncertain whether it will pollute the IGM to large distances. We argue that a burst of star formation in a dense gas environment is active (possibly containing hot and massive stars and/or a low luminosity AGN), superimposed to an already formed fraction of stellar mass (abridged).

13 pages, 9 figures (published on A&A). Here replaced with a typo fixed in the footnote of Sect. 4.2 and with four updated references. Results unchanged

References in corpus (35)

• The Hubble Ultra Deep Field
• UV Luminosity Functions at z~4, 5, and 6 from the HUDF and other Deep HST ACS Fields: Evolution and Star Formation History
• Mass, Metal, and Energy Feedback in Cosmological Simulations
• 3D Lyman-alpha radiation transfer. I. Understanding Lyman-alpha line profile morphologies
• A Close Look at Star Formation around Active Galactic Nuclei
• Size evolution of the most massive galaxies at 1.7<z<3 from GOODS NICMOS survey imaging
• The Galaxy Mass Function up to z=4 in the GOODS-MUSIC sample: into the epoch of formation of massive galaxies
• On the X-ray, optical emission line and black hole mass properties of local Seyfert galaxies
• The GOODS-MUSIC sample: a multicolour catalog of near-IR selected galaxies in the GOODS-South field
• Star formation and mass assembly in high redshift galaxies
• z~7-10 Galaxies in the HUDF and GOODS fields, and their UV Luminosity Functions
• The Great Observatories Origins Deep Survey - VLT/VIMOS Spectroscopy in the GOODS-South Field: Part II
• The impact of nebular emission on the ages of z~6 galaxies
• The Great Observatories Origins Deep Survey. VLT/VIMOS Spectroscopy in the GOODS-South Field
• The Structures of Distant Galaxies I: Galaxy Structures and the Merger Rate to z~3 in the Hubble Ultra-Deep Field
• Chandra and Spitzer unveil heavily obscured quasars in the SWIRE/Chandra Survey
• 3D Lyman-alpha radiation transfer. III. Constraints on gas and stellar properties of z~3 Lyman break galaxies (LBG) and implications for high-z LBGs and Lyman-alpha emitters(LAEs)
• The Morphological Diversities Among Star-forming Galaxies at High Redshifts in the Great Observatories Origins Deep Survey (GOODS)
• The VLA 1.4GHz Survey of the Extended Chandra Deep Field South: First Data Release
• The Stellar Mass Density at z~6 from Spitzer Imaging of i-drop Galaxies
• A Population of Massive and Evolved Galaxies at z$\ga$5
• Deficiency of large equivalent width Lyman-alpha emission in luminous Lyman break galaxies at z~5-6?
• The Luminosity Function of high-redshift QSOs - A combined analysis of GOODS and SDSS
• A comparison among LBGs, DRGs and BzK galaxies: their contribution to the stellar mass density in the GOODS-MUSIC sample
• Lyman alpha emission in high-redshift galaxies
• The physical properties of Lyalpha emitting galaxies: not just primeval galaxies?
• Physical properties of z~4 LBGs: differences between galaxies with and without Ly-alpha emission
• A photometric survey for Lyalpha-HeII dual emitters: Searching for Population III stars in high-redshift galaxies
• Witnessing the assembly at z=1.6 of a galaxy cluster (GMASS ultradeep spectroscopy of galaxies at z~2 - V)
• 3D Lya radiation transfer. II. Fitting the Lyman break galaxy MS 1512-cB58 and implications for Lya emission in high-z starbursts
• A Sample of Quasars with Strong Nitrogen Emission Lines from the Sloan Digital Sky Survey
• Ly-alpha emitters in the GOODS-S field: a powerful pure nebular SED with N IV] emission at z=5.563
• A Photometrically Detected Forming Cluster of Galaxies at Redshift 1.6 in the GOODS Field
• The starburst-AGN connection: the role of young stellar populations in fueling supermassive black holes
• Obscured and powerful AGN and starburst activities at z~3.5

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• Electron impact excitation of N IV: calculations with the DARC code and a comparison with ICFT results
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• The ALPINE-ALMA [CII] survey: double stellar population and AGN activity in a galaxy at $z\sim 5.5$
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• Discovery of new N-emitters over a wide redshift range