AEGIS20ID - All-Wavelength Extended Groth Strip Int. Survey (AEGIS) 20-cm Fully Id-ed Sample

Overview

Infrared 3.6 - 8.0 micron (µm) images of the Extended Groth Strip (EGS) yield plausible counterpart identifications for all but one of 510 radio sources in the AEGIS20 S(1.4 GHz) > 50 microJansky (µJy) sample (Ivison et al. 2007, ApJ, 660, L77, available at the HEASARC as the AEGIS20 database table). This is the first such deep sample that has been effectively 100% identified. Achieving the same identification rate at R band would require observations reaching R_AB > 27. Spectroscopic redshifts are available for 46% of the sample and photometric redshifts for an additional 47%. Almost all of the sources with 3.6-um AB magnitudes brighter than 19 have spectroscopic redshifts z < 1.1, while fainter objects predominantly have photometric redshifts with 1 <~ z <~ 3. Unlike more powerful radio sources that are hosted by galaxies having large stellar masses within a relatively narrow range, the AEGIS20 counterparts have stellar masses spanning more than a factor of 10 at z ~ 1. The sources are roughly 10% - 15% starbursts at z <~ 0.5 and 20%-25% active galactic nuclei mostly at z > 1, with the remainder of uncertain nature.

Throughout this study, magnitudes are in the AB system, and the notation [w] means the AB magnitude at wavelength w in um. Source distances are based on standard Lambda-CDM cosmology with H₀ = 71 km s^-1 Mpc^-1 and Omega_M = 0.27. Practical calculation of luminosity distances was based on the program ANGSIX (Kayser et al. 1997, A&A, 318, 680).

Catalog Bibcode

2012ApJ...756...72W

References

A Fully-Identified Sample of AEGIS20 Microjansky Radio Sources
     Willner S.P., Ashby M.L.N., Barmby P., Chapman S.C., Coil A.L.,
     Cooper M.C., Huang J., Ivison R., Koo D.C.
    <Astrophysical Journal, Volume 756, article id 72 (13pp) 2012>
    =2012ApJ...756...72W

AEGIS20: A Radio Survey of the Extended Groth Strip
     Ivison R.J., Chapman S.C., Faber S.M., Smail I., Biggs A.D.,
     Conselice C.J., Wilson G., Salim S., Huang J.-S., Willner S.P.
    <Astrophysical Journal, Volume 660, Issue 1, pp. L77-L80>
    =2007ApJ...660L..77I

Provenance

This table was created by the HEASARC in July 2013 based on the electronic versions of Tables 1, 3, 4, and 5 from the reference paper which were obtained from the ApJ web site.

HEASARC Implementation

The HEASARC has merged Table 1 from the reference paper which lists 511 radio sources from the AEGIS20 radio source catalog which lie in the region of IRAC coverage with Tables 3, 4 and 5 from the same source which list IRAC and Subaru R-band information on 511 counterparts to 508 of the radio sources (3 radio sources have 2 possible R/IR counterparts), implying that 3 of the 511 radio sources have no counterparts. These 3 radio sources are listed in Table 2 of the reference paper, thus:

          Table 2: Radio Sources with No IRAC Identifications

Source No.   AEGIS20 Name          Comments

2            J141736.35+523135.8   Radio source is hot spot in jet from src 3
434          J142213.25+532817.5   Radio source < 5 sigma,
                                   nearest IRAC source 1.6" away
488          J142306.17+533351.8   Near saturated star

The HEASARC has 2 entries for each of the 3 cases where there are 2 possible R/IR counterparts to a radio source, repeating the radio source properties listed in Table 1 for the associated radio sources in each case. There are consequently 514 (511 + 3) entries in this HEASARC table. The positions given in this table correspond to the IRAC counterpart (the ra and dec parameters) and to the R-band counterpart (the rband_ra and rband_dec parameters) for all entries except for the 3 sources (numbers 2, 434 and 488) which have no counterparts: for these 3 cases, the quoted ra and dec values correspond to those of the AEGIS20 radio sources.

Parameters

Source_Number
A unique identification number for each radio source in the part of the AEGIS20 field that was in the area of IRAC coverage.

Aegis20_Name
The IAU-style J2000.0 position-based designation of the AEGIS20 radio source, using the prefix 'EGS20' (for Extended Groth Strip, 20 cm) for these names in accordance with the naming convention registered with the Dictionary of Nomenclature of Celestial Objects.

Flux_20_cm
The peak flux density of the AEGIS20 radio source at 1.4 GHz (20 cm), in mJy/beam.

Flux_20_cm_Error
The 1-sigma uncertainty in the peak flux density of the radio source at 1.4 GHz (20 cm), in mJy/beam.

Int_Flux_20_cm
The integrated flux density of the AEGIS20 radio source at 1.4 GHz (20 cm), in mJy.

Int_Flux_20_cm_Error
The 1-sigma uncertainty in the integrated flux density of the radio source at 1.4 GHz (20 cm), in mJy. Values of -1.0 for this parameter in the original version of this catalog have been converted to nulls in this HEASARC table: such values indicate that the source was poorly fitted by a Gaussian, and that the integrated flux density was measured in a polygon that included the entire source (minor axis sizes are not given for such cases, neither).

Major_Axis
The major axis of the radio source, in arcseconds, after deconvolution with the synthesized circular beam of ~ 3.8" FWHM. In cases where the value of the minor axis is set to null (these were -1.0 in the original version of this catalog) indicating a radio source well fit by a pair of Gaussians, the major axis value is actually the separation between the two components.

Minor_Axis
The minor axis of the radio source, in arcseconds, after deconvolution with the synthesized circular beam of ~ 3.8" FWHM. In cases where the value of this parameter is set to null (these were -1.0 in the original version of this catalog) indicating a radio source well fit by a pair of Gaussians, the corresponding major axis value is actually the separation between the two components.

Position_Angle
The position angle of the deconvolved major axis of the radio source, in degrees, measured eastwards from north.

Counterpart_ID
The counterpart identifier. This is the same as the radio source number for radio sources with only a single proposed counterpart. For sources with more than one counterpart, e.g., 105, 222 and 370, a letter suffix has been added, 'N', 'W', 'S', 'E', to form a unique counterpart identifier. In 4 other cases (source numbers 295, 358, 418 and 420) a letter suffix has been appended, though no other counterpart is mentioned. For the 3 radio sources with no proposed counterparts (source_number = 2, 434 and 488), the value of counterpart_id has been set to 0.

Name
The EGSIRAC identifier of the IRAC counterpart to the radio source from the published catalog of Barmby et al. (2008, ApJS, 177, 431). Not all counterparts have EGSIRAC identifications: such sources have been given null (blank) names.

RA
The Right Ascension of the IRAC counterpart to the radio source in the selected equinox, or, for the 3 sources (numbers 2, 434 and 488) which have no counterparts, the Right Ascension of the AEGIS20 radio source. The IRAC positions were given in J2000.0 equatorial coordinates to a precision of 10^-5 degrees in the original table. The IRAC positions are from the published catalog (Barmby et al. 2008, ApJS, 177, 431). For counterparts not in the published catalog, their positions were measured on the published images.

Dec
The Declination of the IRAC counterpart to the radio source in the selected equinox, or, for the 3 sources (numbers 2, 434 and 488) which have no counterparts, the Declination of the AEGIS20 radio source. The IRAC positions were given in J2000.0 equatorial coordinates to a precision of 10^-5 degrees in the original table. The IRAC positions are from the published catalog (Barmby et al. 2008, ApJS, 177, 431). For counterparts not in the published catalog, their positions were measured on the published images.

LII
The Galactic Longitude of the IRAC counterpart to the radio source, or, for the 3 sources (numbers 2, 434 and 488) which have no counterparts, the Galactic Longitude of the AEGIS20 radio source.

BII
The Galactic Latitude of the IRAC counterpart to the radio source, or, for the 3 sources (numbers 2, 434 and 488) which have no counterparts, the Galactic Longitude of the AEGIS20 radio source.

IRAC_Radio_Offset
The radial offset, in arcseconds, from the IRAC to the radio positions.

Min_Number_IRAC_Images
The number of useful images in whichever IRAC wavelength has the fewest, in units of 200 s (one image at 3.6 - 5.8 um; 4 images at 8.0 um: see Barmby et al. 2008, ApJS, 177, 431)

Rainbow_IRAC_Name
The IRAC source designation of the IRAC counterpart to the radio source in the Rainbow Database (Barro et al. 2011, ApJS, 193, 13).

IRAC_Rainbow_Offset
The radial offset, in arcseconds, from the IRAC position measured here to the source position in the Rainbow Database (Barro et al. 2011, ApJS, 193, 13).

IRAC_Comments
Additional comments, if any, on the IRAC counterpart to the radio source.

Rband_RA
The Right Ascension of the R-band counterpart to the radio source in the selected equinox, if measured independently on the R image. The R-band positions were given in J2000.0 equatorial coordinates to a precision of 10^-5 degrees in the original table.

Rband_Dec
The Declination of the R-band counterpart to the radio source in the selected equinox, if measured independently on the R image. The R-band positions were given in J2000.0 equatorial coordinates to a precision of 10^-5 degrees in the original table.

Rband_IRAC_Offset
The angular distance, in arcseconds, from the R-band to the IRAC position of the counterpart.

Rmag_Type
The R-band AB magnitude type, coded as follows:

      1 = SExtractor aperture magnitude in 1.53" radius;
      2 = SExtractor aperture magnitude in 2.14" radius;
      3 = SExtractor aperture magnitude in 3.06" radius;
      4 = magnitude in Kron aperture as measured by SExtractor,
      5 = apphot magnitude with 1.53" radius measured at R position if available
          otherwise IRAC position;
      6 = apphot magnitude with 2.14" radius measured at R position if available
          otherwise IRAC position;
      7 = apphot magnitude with 3.06" radius measured at R position if available
          otherwise IRAC position.

Rmag
The R-band AB magnitude of the counterpart to the radio source.

Rmag_Error
The uncertainty in the R-band AB magnitude of the counterpart to the radio source. This is statistical only, estimated from sky fluctuations. See the text of the reference paper for a discussion of the systematic uncertainties. A value of -5.0 for this parameter indicates that the quoted magnitude is a 5-sigma upper limit rather than a detection.

Redshift
The redshift of the counterpart to the radio source.

Ref_Redshift
The reference code for the source of the redshift value (in priority order if more than one redshifts exists), as follows:

      1 = DEEP3 (Cooper et al. 2011 ApJS, 193, 14; 2012, MNRAS, 419, 3018);
      2 = DEEP2 (Davis et al. 2003, Proc. SPIE, 4834, 161; Newman et al. 2012,
          ApJS, submitted, http://deep.ps.uci.edu/DR3/);
      3 = MMT Hectospec (Coil et al. 2009, ApJ, 701, 1484);
      4 = Spitzer/IRS (Huang et al. 2009, ApJ, 700, 183; 2012, ApJ, submitted);
      5 = spectroscopic redshift from Rainbow (Barro et al. 2011, ApJS, 193, 13);
      6 = photometric redshift from NMBS (Whitaker et al. 2011, ApJ, 735, 86);
      7 = photometric redshift from CFHTLS (Coupon et al. 2009, A&A, 500, 981:
          http://terapix.iap.fr/cplt/CFHTLS_deep_ugriz_T0004_zphot_1.4.tgz);
      8 = photometric redshift from (Huang et al. 2012, ApJ, submitted);
      9 = photometric redshift from Rainbow (Barro et al. 2011, ApJS, 193, 13).

Luminosity_3_GHz
The 3-GHz luminosity of the radio source, in W Hz^-1. Source distances are based on standard Lambda-CDM cosmology with H₀ = 71 km s^-1 Mpc^-1 and Omega_M = 0.27. Practical calculation of luminosity distances was based on the program ANGSIX (Kayser et al. 1997, A&A, 318, 680).

IRAC_Mag_Type
The Spitzer/IRAC AB magnitudes type, coded as follows:

      1 = aperture magnitude in 1.53" radius;
      2 = aperture magnitude in 2.14" radius;
      3 = aperture magnitude in 3.06" radius;
      4 = magnitude in Kron aperture as measured by SExtractor.

IRAC_3p6_um_Mag
The Spitzer/IRAC 3.6-um band AB magnitude [3.6] of the counterpart to the radio source.

IRAC_3p6_um_Mag_Error
The uncertainty in the Spitzer/IRAC 3.6-um band AB magnitude. The uncertainty is statistical only and is based on fluctuations in the nearby sky. It is shown as 0.00 when less than 0.005 mag, but see the text of the reference paper for discussion of systematic errors.

IRAC_4p5_um_Mag
The Spitzer/IRAC 4.5-um band AB magnitude [4.5] of the counterpart to the radio source.

IRAC_4p5_um_Mag_Error
The uncertainty in the Spitzer/IRAC 4.5-um band AB magnitude. The uncertainty is statistical only and is based on fluctuations in the nearby sky. It is shown as 0.00 when less than 0.005 mag, but see the text of the reference paper for discussion of systematic errors.

IRAC_5p8_um_Mag
The Spitzer/IRAC 5.8-um band AB magnitude [5.8] of the counterpart to the radio source.

IRAC_5p8_um_Mag_Error
The uncertainty in the Spitzer/IRAC 5.8-um band AB magnitude. The uncertainty is statistical only and is based on fluctuations in the nearby sky. It is shown as 0.00 when less than 0.005 mag, but see the text of the reference paper for discussion of systematic errors.

IRAC_8p0_um_Mag
The The Spitzer/IRAC 8.0-um band AB magnitude [8.0] of the counterpart to the radio source.

IRAC_8p0_um_Mag_Error
The uncertainty in the Spitzer/IRAC 8.0-um band AB magnitude. The uncertainty is statistical only and is based on fluctuations in the nearby sky. It is shown as 0.00 when less than 0.005 mag, but see the text of the reference paper for discussion of systematic errors.

Contact Person

Questions regarding the AEGIS20ID database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:24:06 EDT