Publication Date:
2016-02-03
Description:
We present high-resolution (0.3 arcsec) Atacama Large Millimeter Array (ALMA) 870 μm imaging of five z 1.5–4.5 X-ray detected AGN (with luminosities of L 2–8keV 〉 10 42 erg s –1 ). These data provide a 20 times improvement in spatial resolution over single-dish rest-frame far-infrared (FIR) measurements. The sub-millimetre emission is extended on scales of FWHM 0.2 arcsec–0.5 arcsec, corresponding to physical sizes of 1–3 kpc (median value of 1.8 kpc). These sizes are comparable to the majority of z =1–5 sub-millimetre galaxies (SMGs) with equivalent ALMA measurements. In combination with spectral energy distribution analyses, we attribute this rest-frame FIR emission to dust heated by star formation. The implied star-formation rate surface densities are 20–200 M yr –1 kpc –2 , which are consistent with SMGs of comparable FIR luminosities (i.e. L IR [1–5] x 10 12 L ). Although limited by a small sample of AGN, which all have high-FIR luminosities, our study suggests that the kpc-scale spatial distribution and surface density of star formation in high-redshift star-forming galaxies is the same irrespective of the presence of X-ray detected AGN.
Print ISSN:
1745-3925
Electronic ISSN:
1745-3933
Topics:
Physics
