ALMA resolves extended star formation in high-z AGN host galaxies

Harrison, C. M.; Simpson, J. M.; Stanley, F.; Alexander, D. M.; Daddi, E.; Mullaney, J. R.; Pannella, M.; Rosario, D. J. und Smail, Ian (2016): ALMA resolves extended star formation in high-z AGN host galaxies. In: Monthly Notices of the Royal Astronomical Society, Bd. 457, Nr. 1: L122-L126

Abstract

We present high-resolution (0.3 arcsec) Atacama Large Millimeter Array (ALMA) 870 mu m imaging of five z approximate to 1.5-4.5 X-ray detected AGN (with luminosities of L2-8keV > 10(42) erg s(-1)). These data provide a greater than or similar to 20 times improvement in spatial resolution over single-dish restframe far-infrared (FIR) measurements. The sub-millimetre emission is extended on scales of FWHM approximate to 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 approximate to 20-200 M-circle dot yr(-1) kpc(-2), which are consistent with SMGs of comparable FIR luminosities (i.e. L-IR approximate to [1-5] x 10(12) L-circle dot). 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.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0035-8711
• Sprache: Englisch