info:eu-repo/semantics/article
The scuba half degree extragalactic survey (SHADES) – V. submillimetre properties of near-infrared–selected galaxies in the Subaru/XMM–Newton deep field
Autor
ITZIAR ARETXAGA MENDEZ
David Hughes
Resumen
We have studied the submillimetre (submm) properties of the following classes of nearinfrared
(NIR)-selected massive galaxies at high redshifts: BzK-selected star-forming
galaxies (BzKs); distant red galaxies (DRGs); and extremely red objects (EROs). We
used the SCUBA HAlf Degree Extragalactic Survey (SHADES), the largest uniform
submm survey to date. Partial overlap of SIRIUS/NIR images and SHADES in SXDF
has allowed us to identify 4 submm-bright NIR-selected galaxies, which are detected in
the mid-infrared, 24 μm, and the radio, 1.4GHz. We find that all of our submm-bright
NIR-selected galaxies satisfy the BzK selection criteria, i.e. BzK ≡ (z−K)AB−(B−
z)AB ≥ −0.2, except for one galaxy whose B − z and z −K colours are however close
to the BzK colour boundary. Two of the submm-bright NIR-selected galaxies satisfy
all of the selection criteria we considered, i.e. they belong to the BzK-DRG-ERO
overlapping population, or ‘extremely red’ BzKs. Although these extremely red BzKs
are rare (0.25 arcmin−2), up to 20% of this population could be submm galaxies. This
fraction is significantly higher than that found for other galaxy populations studied
here. Via a stacking analysis, we have detected the 850-μm flux of submm-faint BzKs
and EROs in our SCUBA maps. While the contribution of z ~ 2 BzKs to the submm
background is about 10–15% and similar to that from EROs typically at z ~1, BzKs
have a higher fraction (~ 30%) of submm flux in resolved sources compared with
EROs and submm sources as a whole. From the SED fitting analysis for both submmbright
and submm-faint BzKs, we found no clear signature that submm-bright BzKs
are experiencing a specifically luminous evolutionary phase, compared with submmfaint
BzKs. An alternative explanation might be that submm-bright BzKs are more
massive than submm-faint ones.