LOCKMANOIR - Lockman Hole AGN Optical and Infrared Properties Catalog

Overview

This table contains the observed-frame optical, near-infrared, and mid-infrared properties of X-ray-selected active galactic nuclei (AGN) in the Lockman Hole. Using a likelihood ratio method on optical, near-infrared or mid-infrared catalogs, the authors assigned counterparts to 401 out of the 409 X-ray sources of the XMM-Newton catalog (Brunner et al. 2008, A&A, 479, 283). Accurate photometry was collected for all the sources from U to 24 microns. The authors used X-ray and optical criteria to remove any normal galaxies, galactic stars, or X-ray clusters among them and studied the multi-wavelength properties of the remaining 377 AGN in their paper. They used a mid-IR colour-colour selection to understand the AGN contribution to the optical and infrared emission. Using this selection, they identified different behaviours of AGN-dominated and host-dominated sources in X-ray-optical-infrared color-color diagrams. More specifically, the AGN-dominated sources show a clear trend in the f_x/f_RC vs. R_C - K and f_24um/f_RC vs. R_C - K diagrams, while the hosts follow the behaviour of non-X-ray detected galaxies. In the optical-near-infrared color-magnitude diagram, the known trend of redder objects to be more obscured in X-rays is seen to be stronger for AGN-dominated than for host-dominated systems. This is an indication that the trend is more related to the AGN, which contaminate the overall colors, than to any evolutionary effects, the authors believe. Finally, the authors find that a significant fraction (~30%) of the reddest AGN are not obscured in X-rays.

The X-ray observations of the Lockman Hole took place between April 2000 and December 2002 with XMM-Newton. The optical observations of the Lockman Hole were conducted with the Large Binocular Telescope (U, B, V bands) and the Subaru Telescope (R_C, I_C, z' bands). The LBT observations were taken from February 2007 to March 2009. The R_C, I_C, and z' bands have been observed with the Suprime-Cam of the Subaru telescope between November 2001 and April 2002.

This table contains the properties of the counterparts to all 409 X-ray sources listed in the Lockman Hole XMM-Newton source catalog of Brunner et al. (2008, A&A, 479, 283), including the 377 AGN and also the 32 objects classified as Galactic stars, galaxy clusters or galaxies. For 8 (2%) of the 409 X-ray sources no optical or IR counterparts were found. These 8 objects are listed in this table with null positional values.

Catalog Bibcode

2011A&A...529A.135R

References

Optical and infrared properties of active galactic nuclei in the Lockman Hole.
    Rovilos E., Fotopoulou S., Salvato M., Burwitz V., Egami E., Hasinger G.,
    Szokoly G.
   <Astron. Astrophys., 529, A135 (2011)>
   =2011A&A...529A.135R

Provenance

This table was created by the HEASARC in January 2012 based on CDS Catalog J/A+A/529/A135 file table2.dat.

Parameters

Source_Number
The sequential identification number for each X-ray source in the Brunner et al. (2008, A&A, 479, 283) catalog (available at the HEASARC as the LOCKMANXM2 table).

Name
The X-ray source designation as given in the Brunner et al. (2008, A&A, 479, 283) catalog (available at the HEASARC as the LOCKMANXM2 table), being the prefix '[BCH2008]' (for Brunner, Cappelluti, Hasinger 2008) and the source number value. .

Flux
The flux of the X-ray source in the 0.5 - 10 keV band, f_{(0.5-10 keV)}, in erg cm^-2 s^-1.

Hardness_Ratio
The hardness ratio of the X-ray source between the 0.5 - 2.0 keV (S) and 2.0 - 4.5 keV (M) band counts, presumably defined as (M - S)/(M + S).

Log_Lx
The logarithm of the X-ray luminosity L_x of the source in the 0.5 - 10 keV band, L_{(0.5-10 keV)}, in erg s^-1, for those sources with spectroscopic redshifts. This was calculated using either the fitted value Gamma of the X-ray power-law spectral slope, or a fixed value of Gamma = 2.0 when a fitted value was not available.

RA
The Right Ascension of the optical counterpart in the R_C Subaru image (or, in a few cases flagged by non-blank values of the ref_position parameter, the infrared counterpart) to the X-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates in decimal degrees to a precision of 10^-6 degrees in the original table.

Dec
The Declination of the optical counterpart in the R_C Subaru image (or, in a few cases flagged by non-blank values of the ref_position parameter, the infrared counterpart) to the X-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates in decimal degrees to a precision of 10^-6 degrees in the original table.

LII
The Galactic Longitude of the optical counterpart to the X-ray source.

BII
The Galactic Latitude of the optical counterpart to the X-ray source.

Ref_Position
This parameter flags those cases in which the reference source for the position of the counterpart to the X-ray source is an infared rather than an optical observation: a value of 1 means that the position is from the UKIDSS K-band source position, while a value of 2 means that the position is from the IRAC 3.6-micron source position.

Log_Flux_Fr_Limit
This flag parameter is set to '>' if the number given in the corresponding parameter value is a lower limit rather than an actual value.

Log_Flux_FR
The logarithm of the ratio of the X-ray to the R_C optical flux for the AGN, calculated as given by equation (2) of the reference paper, viz.,

  log (f_x/f_Rc) = log (f_{(0.5-10 keV)}) + R_C(AB)/2.5 + 5.5

Log_Flux_Fk_Limit
This flag parameter is set to '>' if the number given in the corresponding parameter value is a lower limit rather than an actual value.

Log_Flux_FK
The logarithm of the ratio of the X-ray to the K-band IR flux for the AGN, calculated as given by the equation on page 7 of the reference paper, viz.,

  log (f_x/f_K) = log (f_{(0.5-10 keV)}) + K(Vega)/2.5 + 6.9

RK_Color_Limit
This flag parameter is set to '<' or '>' if the number given in the corresponding parameter value is an upper or lower limit, respectively, rather than an actual value.

RK_Color
The Johnson-Cousins R_C- K color index of the AGN, in magnitudes.

S_3p6_4p5_um_Color
The Spitzer IRAC 3.6-micron to 4.5-micron bands color index, [3.6]-[4.5], in AB magnitudes.

S_5p8_8p0_um_Color
The Spitzer IRAC 5.8-micron to 8.0-micron bands color index, [5.8]-[8.0], in AB magnitudes.

Log_F24_um_Fr_Limit
This flag parameter is set to '<' or '>' if the number given in the corresponding parameter value is an upper or lower limit, respectively, rather than an actual value.

Log_F24_um_FR
The logarithm of the ratio of the Spitzer MIPS 24-micron flux to the R_C-band optical flux for the AGN.

Redshift
The spectroscopic redshift z of the AGN as obatined from either the literature (118 cases) or via a recent spectroscopic campaign at Keck/DEIMOS (PI: Scoville). There are 9 (Galactic) stellar objects with z = 0 that were identified by optical spectroscopy, and 1 other object (source number 526) that was flagged as a star based on its low R - [3.6] color, low X-ray to optical flux ratio, and soft X-ray spectrum (hardness ratio = -0.73).

Ref_Redshift
The reference code for the source of the spectroscopic redshift value:

     a = Low-quality redshift
     3 = Redshift from Schmidt et al. (1998, A&A, 329, 495)
     4 = Redshift from Lehmann et al. (2001, A&A, 371, 833)
     5 = Redshift from Mateos et al. (2005, A&A, 444, 79)
     6 = Redshift from Keck/DEIMOS

Notes
Notes identifying those 32 sources which the authors do not consider to be AGN, but rather are stars, galaxies, or clusters.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Wednesday, 23-Nov-2022 19:35:12 EST