Chan/DF2S ivo://nasa.heasarc/cdfn2msoid NASA/GSFC HEASARC Barger et al.; Alexander et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Optical Counterpart The Chandra Deep Field North (CDFN) 2-Megasecond (2Ms) Optical and IR Catalog is an optical and near-infrared catalog for the X-ray sources in the 2Ms Chandra observation of the Hubble Deep Field North region. It has high-quality multicolor imaging data for all 503 X-ray point sources in the X-ray-selected catalog and reliable spectroscopic redshifts for 284. The authors have spectroscopically identified six high-redshift (z > 1) type II quasars (L<sub>2-8keV</sub> > 10<sup>44</sup> ergs/s) in their sample. The spectroscopic completeness for the R <= 24 sources is 87%. The spectroscopic redshift distribution shows two broad redshift spikes that have clearly grown over those originally seen in the 1Ms exposure. The spectroscopically identified extragalactic sources already comprise 75% of the measured 2-8 keV light. Redshift slices versus 2-8 keV flux show that an impressive 54% of the measured 2-8 keV light arises from sources at z < 1 and 68% from sources at z < 2. The X-ray sample is presented in Alexander et al. (2003, AJ, 126, 539, hereafter ABB2003) and in <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/126/539">CDS Catalog <J/AJ/126/539></a>, and is also available in the HEASARC Browse system as the CHANDFN2MS table. The optical imaging data consist of Johnson B, Johnson V, Cousins R, Cousins I, and Sloan z' observations obtained with the Subaru prime-focus camera Suprime-Cam on the Subaru 8.2m telescope during February-April of 2001 and 2002. This table was created by the HEASARC in April 2004 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/126/632/table1a">CDS Catalog J/AJ/126/632/table1a</a>.dat. This is a service provided by NASA HEASARC . 2003AJ....126..632B https://heasarc.gsfc.nasa.gov/W3Browse/all/cdfn2msoid.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=cdfn2msoid& GET text/xml 180 99999 true 189.275345 62.02508 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=cdfn2msoid GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_cdfn2msoid&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public cdfn2msoid Chandra Deep Field North 2-Megasecond Optical & IR Catalog name Catalog Object Designation meta.id;meta.main char nullable ra Optical Right Ascension degree pos.eq.ra;meta.main double nullable dec Optical Declination degree pos.eq.dec;meta.main double nullable sb_flux 0.5-2keV X-Ray Flux (erg/s/cm^2) erg/s/cm^2 double nullable vmag Corrected-Aperture Johnson V Magnitude mag phot.mag;em.opt.V double nullable spect_redshift Spectroscopic Redshift double nullable phot_redshift Photometric Redshift double nullable spectrum_type Spectrum Type char nullable sequence_number Catalog Sequence Number short nullable lii Optical Galactic Longitude degree pos.galactic.lon double nullable hkmag Corrected-Aperture Wainscoat-Cowie HKprime Magnitude mag double nullable rmag Corrected-Aperture Cousins R Magnitude mag phot.mag;em.opt.R double nullable bii Optical Galactic Latitude degree pos.galactic.lat double nullable umag Corrected-Aperture U-band Magnitude mag phot.mag;em.opt.U double nullable bmag Corrected-Aperture Johnson B Magnitude mag phot.mag;em.opt.B double nullable ra_xray X-Ray Right Ascension (J2000) char nullable flag_spect_redshift Flag for Spectroscopic Redshift [os] char nullable zmag Corrected-Aperture Sloan z-prime Magnitude mag double nullable hb_flux 2-8keV X-Ray Flux (erg/s/cm^2) erg/s/cm^2 double nullable rmag_iso Isophotal Cousins R Magnitude mag double nullable dec_xray X-Ray Declination (J2000) char nullable imag Corrected-Aperture Cousins I Magnitude mag phot.mag;em.opt.I double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable