Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals
MetadataShow full item record
We present the first spectroscopic confirmation of an ultramassive galaxy at redshift z > 3 using data from Keck- NIRSPEC, VLT-X-shooter, and GTC-Osiris. We detect strong [O III] and Lya emission, and weak [O II], C IV, and He II, placing C1-23152 at a spectroscopic redshift of zspec = 3.351. The modeling of the emission-line-corrected spectral energy distribution (SED) results in a best-fit stellar mass of M* = 3.1-0.7+0.6 × 1011 M?, a star formation rate of <7 M?yr-1, and negligible dust extinction. The stars appear to have formed in a short intense burst ~300-500 Myr prior to the observation epoch, setting the formation redshift of this galaxy at z ~ 4.1. From the analysis of the line ratios and widths and the observed flux at 24 µm, we confirm the presence of a luminous hidden active galactic nucleus (AGN), with bolometric luminosity of ~1046 erg s-1. Potential contamination of the observed SED from the AGN continuum is constrained, placing a lower limit on the stellar mass of 2 × 1011 M?. HST/WFC3 H160 and ACS I814 images are modeled, resulting in an effective radius of re ~ 1 kpc in the H160 band and a -Sti-errsic index n ~ 4.4. This object may be a prototype of the progenitors of local most massive elliptical galaxies in the first 2 Gyr of cosmic history, having formed most of its stars at z > 4 in a highly dissipative, intense, and short burst of star formation. C1-23152 is completing its transition to a post-starburst phase while hosting a powerful AGN, potentially responsible for the quenching of the star formation activity.
Showing items related by title, author, creator and subject.
Smith, B.; Soria, Roberto; Struck, C.; Giroux, M.; Swartz, D.; Yukita, M. (2014)Hinge clumps are luminous knots of star formation near the base of tidal features in some interacting galaxies. We use archival Hubble Space Telescope (HST) UV/optical/IR images and Chandra X-ray maps along with Galaxy ...
Ultraluminous star-forming galaxies and extremely luminous warm molecular hydrogen emission at z = 2.16 in the PKS1138-26 radio galaxy protoclusterOgle, P.; Davies, J.; Appleton, P.; Bertincourt, B.; Seymour, Nick; Helou, G. (2012)A deep Spitzer Infrared Spectrograph map of the PKS 1138–26 galaxy protocluster reveals ultraluminous polycyclic aromatic hydrocarbon (PAH) emission from obscured star formation in three protocluster galaxies, including ...
Ibar, E.; Sobral, D.; Best, P.; Ivison, R.; Smail, I.; Arumugam, V.; Berta, S.; Béthermin, M.; Bock, J.; Cava, A.; Conley, A.; Farrah, D.; Geach, J.; Ikarashi, S.; Kohno, K.; Le Floc'h, E.; Lutz, D.; Magdis, G.; Magnelli, B.; Marsden, G.; Oliver, S.; Page, M.; Pozzi, F.; Riguccini, L.; Schulz, B.; Seymour, Nick; Smith, A.; Symeonidis, M.; Wang, L.; Wardlow, J.; Zemcov, M. (2013)We describe the far-infrared (far-IR; rest-frame 8–1000-μm) properties of a sample of 443 Hα-selected star-forming galaxies in the Cosmic Evolution Survey (COSMOS) and Ultra Deep Survey (UDS) fields detected by the ...