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J/A+A/472/805    Radio-X-ray sources in the HDF(N) region.    (Richards+, 2007)

Using VO tools to investigate distant radio starbursts hosting obscured AGN in the HDF(N) region. Richards A.M.S., Muxlow T.W.B., Beswick R., Allen M.G., Benson K., Dickson R.C., Garrett M.A., Garrington S.T., Gonzalez-Solarez E., Harrison P.A., Holloway A.J., Kettenis M.M., Laing R.A., Richards E.A., Thrall H., van Langevelde H.J., Walton N.A., Wilkinson P.N., Winstanley N. <Astron. Astrophys. 472, 805 (2007)> =2007A&A...472..805R
ADC_Keywords: Radio sources ; X-ray sources ; Active gal. nuclei Keywords: astronomical data bases: miscellaneous - X-rays: galaxies - radio continuum: galaxies -- galaxies: active -- galaxies: starburst - galaxies: evolution Description: This catalogue lists the properties of 62 radio sources in the Hubble Deep Field (North) and Flanking Fields (HDFN) which were also detected by the Chandra X-ray satellite (see Alexander et al., 2003, Cat. J/AJ/126/539, file cdfn). This includes 55/92 sources brighter than 40uJy detected by MERLIN+VLA at 1.4GHz (see Muxlow et al., 2005, Cat. J/MNRAS/358/1159, Richards, 2000, Cat. J/ApJ/533/611); some were also detected by the VLA at 8.4GHz (Richards et al., 1998AJ....116.1039R) including 7 selected at this frequency. The cross-matching, derivation of properties and analysis are described fully in the paper. The radio data have a positional accuracy of 15 mas with respect to the ICRS (Muxlow et al., 2005, Cat. J/MNRAS/358/1159) but data using the GOODS HST ACS (Giavalisco et al., 2004, Cat. II/261) positions requires a shift of -342mas in Declination for alignment with the ICRS. We use measurements taken from the radio observations and from the literature to compile the flux densities, sizes and spectral/photon indices of the cross-matched radio+X-ray sources and their redshifts (where available), enabling us to derive the rest-frame luminosities. The 1.4-GHz detections are all resolved at 0.2-2arcsec resolution. The radio emission was classified using the source morphologies and radio spectral indices; optical and IR information was used as supporting evidence only. On this basis, starbursts outnumber radio AGN 3:1. The high-redshift starbursts have typical sizes of 5-10kpc and star formation rates of around 1000 Msun/yr, an order of magnitude more extended and intense than in the local universe. The X-ray sources are unresolved but their luminosity and spectral indices allows X-ray AGN and obscured (Type II) AGN to be identified (2004A&A...424..545P). In this way, we can distinguish between the origins of radio and X-ray emission from the same object. There is no obvious correlation between radio and X-ray luminosities nor spectral indices at z>1.3. About 70% of both the radio-selected AGN and the starburst samples were detected by Chandra. The X-ray luminosity indicates the presence of an AGN in at least half of the 45 cross-matched radio starbursts. Eleven of these are type-II AGN, of which 7 are at z>1.5. This distribution overlaps closely with the X-ray detected radio sources which were also detected by SCUBA. Almost all extended radio starbursts at z>1.3 host X-ray selected obscured AGN. The radio emission from most of these ultra-luminous objects is dominated by star formation although the highest redshift (z=4.424) source has a substantial AGN contribution. Star-formation appears to contribute less than 1/3 of their X-ray luminosity. Our results support the inferences from SCUBA and IR data, that at z>1.5, star formation is observably more extended and more copious, it is closely linked to AGN activity and it is triggered differently, compared with star formation at lower redshifts. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table12.dat 244 62 Properties of radio-X-ray sources in and around the HDF(N) (table 1 and 2 of the paper)
See also: J/AJ/126/539 : The Chandra Deep Fields North and South (Alexander+, 2003) J/MNRAS/358/1159 : Radio sources in HDF and HFF (Muxlow+, 2005) J/ApJ/533/611 : 1.4GHz survey in HDF region (Richards+, 2000) Byte-by-byte Description of file: table12.dat
Bytes Format Units Label Explanations
1- 14 A14 --- Name IAU-like name of radio source 16- 17 I2 h RAh Right Ascension ICRS (hr) 19- 20 I2 min RAm Right Ascension ICRS (min) 22- 28 F7.4 s RAs Right Ascension ICRS (sec) 30 A1 --- DE- Declination ICRS (sign) 31- 32 I2 deg DEd Declination ICRS (deg) 34- 35 I2 arcmin DEm Declination ICRS (arcmin) 37- 42 F6.3 arcsec DEs Declination ICRS (arcsec) 44- 56 F13.9 deg RAdeg Right Ascension ICRS (decimal degrees) 58- 70 F13.10 deg DEdeg Declination ICRS (decimal degrees) 72- 77 F6.1 uJy S1.4GHz Radio Flux Density at 1.4 GHz (VLA) 79- 82 F4.1 arcsec LAS ? Largest Angular Size (MERLIN+VLA) 84 A1 --- l_R.SI [<>e] Flag on radio spectral index if it is a limit (<>) or an estimate (e) (see paper) 85- 89 F5.2 --- R.SI Radio spectral index between 1.4-8.4GHz (S varies as frequency-R.SI) 91- 94 F4.2 --- e_R.SI Error in spectral index in low direction 96- 99 F4.2 --- E_R.SI Error in spectral index in high direction 101 A1 --- n_z [sp] Redshift origin is photometric (p) or spectroscopic (s) 103-108 F6.4 --- z ? Redshift of associated optical/IR source 110-115 F6.4 --- e_z ? Error in Redshift 117-135 A19 --- r_z Redshift reference (Bibcode) 137-140 F4.2 arcsec R-Xsep Angular separation of radio and X-ray peaks 142-144 I3 --- [ABB2003] X-ray source number in J/AJ/126/539/cdfn 146-150 F5.2 aW/m2 FX Xray flux density 0.5-8.0 keV (Chandra) 152 A1 --- f_X.SI [<>e] Flag if X-ray photon index if it is a limit (<>) or an estimate (e) (see paper) 153-157 F5.2 --- X.SI X-ray photon index between 0.5-2, 2-8keV (F varies as Energy-X.SI) 159-162 F4.2 --- e_X.SI Error in photon index in low direction 164-167 F4.2 --- E_X.SI Error in photon index in low direction 169 A1 --- ISO [I] Detection by ISO at 7 and/or 15um (1) 171 A1 --- Spitzer [S] Detection by Spitzer at 16um (1) 173-175 A3 --- SMM Detection by SCUBA at 850um (SMM) (1) 177-184 E8.3 W/Hz L1.4GHz ? Rest frame 1.4-GHz radio luminosity 186-193 E8.3 W/Hz L1.4lo ? Lower bound to 1.4-GHz radio luminosity 195-202 E8.3 W/Hz L1.4up ? Upper bound to 1.4-GHz radio luminosity 204-210 A7 --- Rclass Radio source class: AGN, SB (Starburst), or U (Unknown) 211-218 E8.3 W LX ? Rest frame full-band X-ray luminosity 220-227 E8.3 W LXlo ? Rest frame full-band X-ray luminosity lower bound 229-236 E8.3 W LXup ? Rest frame full-band X-ray luminosity upper bound 238-244 A7 --- Xclass X-ray characteristics of AGN (AGN-X) or obscured AGN (AGN-II)
Note (1): ISO, Spitzer and SCUBA data used did not cover the whole radio+X-ray field.
Acknowledgements: Anita M. S. Richards, a.m.s.richards(at)
(End) Patricia Vannier [CDS] 06-Sep-2007
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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