- HEASARC Director: Dr. Alan P. Smale
- NASA Official: Phil Newman
- Web Curator: J.D. Myers
- Last Modified: 9-Jun-2020
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MORX - Million Optical/Radio/X-Ray Associations Catalog |
HEASARC Archive |
MORX is a compendium of optical objects which are calculated to be associated with XMM-Newton, ROSAT, Chandra or Swift X-ray sources, or with NVSS, FIRST or SUMSS radio sources or double radio lobes. The counts of the associations for this main sample are as follows:
Optical objects - 1,002,855
NVSS - 402,485 core radio associations, plus 8320 double radio lobes.
FIRST - 250,072 core radio associations, plus 16,934 double radio lobes.
SUMSS - 70,863 core radio associations, plus 2124 double radio lobes.
XMM-Newton - 184,203 X-ray associations
XMM Slew - 10,104 X-ray associations
ROSAT - 120,181 X-ray associations
Chandra - 91,674 X-ray associations
Swift - 47,200 X-ray associations
For each optical object, the J2000 coordinates, object name if any, object
class, red & blue photometry, redshift if any, likelihoods of the presented
associations and calculated odds that the object is a quasar, galaxy, star,
or erroneous association, and the radio & X-ray identifiers, are given. Also,
the details of positional offsets and optical field solutions are given, plus
references for the object name, redshift and classification.
A supplemental sample ("morxsupp.dat") of 118,200 anonymous SDSS galaxies with radio/X-ray associations has been added to the primary MORX sample. These SDSS data came to hand just as MORX was in press, so are included as a separate supplement. The information provided is the same as for MORX, and their combined total count is 1,121,055 optical objects. If citing this catalog, just refer to it as MORX, with the bibliographic reference given below.
This HEASARC table contains the union of the main and supplemental MORX tables. The HEASARC-created parameter table_sample is set to "Main" for entries from the main catalog and to "Supp" for entries from the supplemental catalog to enable users to select, if desired, a specified sample.
The radio/X-ray source prefixes, and their source catalog home pages that are cited in this table, are as follows:
FIRST: VLA FIRST survey, 13Jun05 version, http://sundog.stsci.edu
NVSS: NRAO VLA sky survey, http://www.cv.nrao.edu/nvss
SUMSS: Sydney U. Molonglo, http://www.astrop.physics.usyd.edu.au/sumsscat/
MGPS: Molonglo galactic plane survey, same attribution as SUMSS
ROSAT catalogs home page: http://www2011.mpe.mpg.de/xray/wave/rosat/catalogue/index.php
for:
- 1RXH: ROSAT HRI (high resolution imager)
- 2RXP/2RXF: ROSAT PSPC (position sensitive proportional counter)
- 1RXS: ROSAT RASS (all-sky survey, both bright and faint)
2RXS: 2nd RASS source catalog, Boller T. et al, 2016, CDS Cat.
J/A+A588/A103
1WGA: White, Giommi and Angelini,
http://wgacat.gsfc.nasa.gov/wgacat/wgacat.html
1SXPS:Swift X-ray Point Source catalog, http://www.swift.ac.uk/1SXPS
CXO: Chandra Source Catalog v1.1, http://cxc.cfa.harvard.edu/csc1
CXOG: Chandra ACIS source catalog, Wang S. et al., 2016,
CDS Cat. J/ApJS/224/40
CXOX: XAssist Chandra source list, http://xassist.pha.jhu.edu/zope/xassist
2XMM/2XMMi: XMM-Newton DR3 sources not in DR6, acknowledged as valid in
section 8.2 of the 3XMM-DR5 paper (2016, A&A, 590, A1,
CDS Cat. IX/46). Website is
http://www.cosmos.esa.int/web/xmm-newton/source-catalogue-versions
3XMM: XMM-Newton DR6, http://www.cosmos.esa.int/web/xmm-newton/xsa
XMMSL:XMM-Newton Slew survey DR6, same website as 3XMM.
XMMX: XAssist XMM-Newton source list,
http://xassist.pha.jhu.edu/zope/xassist
The Million Optical Radio/X-ray Associations (MORX) catalogue.
Flesch E.W.
<Publ. Astron. Soc. Australia, 33, 52 (2016)>
=2016PASA...33...52F (SIMBAD/NED BibCode)
=2016yCat.5148....0F
Table_Sample
This HEASARC-created parameter is set to "Main" for entries from the main
catalog and to "Supp" for entries from the supplemental catalog to enable
users to select, if desired, a specified sample.
Name
The name of the object taken from the literature or created by the author.
Previously nameless objects here are given J2000 position-based names, e.g.,
"MORX J000001.5-251706".
RA
The Right Ascension of the optical object in the selected equinox. This was
given in J2000.0 equatorial coordinates to a precision of 10-7 degrees in
the original tables. The author notes that these positions are too precise,
but accommodate a minuscule round-up which prevents inadvertent truncation
when converted to sexagesimal coordinates.
Dec
The Declination of the optical object in the selected equinox. This was given
in J2000.0 equatorial coordinates to a precision of 10-7 degrees in the
original tables. The author notes that these positions are too precise, but
accommodate a minuscule round-up which prevents inadvertent truncation when
converted to sexagesimal coordinates.
LII
The Galactic Longitude of the optical object.
BII
The Galactic Latitude of the optical object.
Broad_Type
This parameter contains information on the type classification of the object
and its possible associations with radio and/or X-ray sources, or with
double-lobed radio sources, as follows:
A = AGN, extended/Seyferts/low-luminosity type I
B = BL Lac object
C = cataclysmic variable star
G = galaxy
g = photometric galaxy from MegaZLRG, redshift rounded to 0.01z
H = HII (star-forming) galaxy or part of galaxy
K = type II object, or AGN of unclear type
L = LINER
M = main galaxy of galaxy group
N = narrow emission line galaxy (NELG)
Q = QSO from the literature, broad-line unresolved type I
q = photometric quasar candidate, SDSS-based, redshift rounded to 0.1z
R = radio association displayed
S = star
U = unknown type but with tentative SDSS redshift
W = white dwarf star
X = X-ray association displayed
2 = double radio lobes displayed (declared by data-driven algorithm)
Rmag
The red optical magnitude of the object. The type and source of this
magnitude is specified in the optical_flag parameter value. Optical data are
from the APM (http://www.ast.cam.ac.uk/~mike/apmcat/), USNO-A & USNO-B
(http://www.nofs.navy.mil/), and the SDSS (http://sdss3.org/). Magnitudes
have been recalibrated from the original APM/USNO-A values (which are POSS-I
or UKST identified in the description for the optical_flag parameter) as
documented in QORG (2004, A&A, 427, 387). Calibrated USNO-A magnitudes are
often retained in preference to USNO-B. APM galaxies brighter than 17th
magnitude are usually represented as far too bright due to PSF modeling. If
the optical_flag parameter value contains r/b/g/i/v/u/z, then the magnitudes
are from the object's source catalog, e.g., SDSS, 2QZ, etc. Note that many
SDSS magnitudes are extinction-"corrected" ~0.3 mag brighter than photometry.
Bmag
The blue optical magnitude of the object. The type and source of this
magnitude is specified in the optical_flag parameter value. Optical data are
from the APM (http://www.ast.cam.ac.uk/~mike/apmcat/), USNO-A & USNO-B
(http://www.nofs.navy.mil/), and the SDSS (http://sdss3.org/). Magnitudes
have been recalibrated from the original APM/USNO-A values (which are POSS-I
or UKST identified in the description for the optical_flag parameter) as
documented in QORG (2004, A&A, 427, 387). Calibrated USNO-A magnitudes are
often retained in preference to USNO-B. APM galaxies brighter than 17th
magnitude are usually represented as far too bright due to PSF modeling. If
the optical_flag parameter value contains r/b/g/i/v/u/z, then the magnitudes
are from the object's source catalog, e.g., SDSS, 2QZ, etc. Note that many
SDSS magnitudes are extinction-"corrected" ~0.3 mag brighter than photometry.
Optical_Flag
This field contains coded information on the optical source properties, as
follows:
p = blue magnitude is POSS-I O (violet 4050A) and
red magnitude is POSS-I E (6400A).
POSS-I photometry is always preferred because O is well-offset from E
and the red and blue plates were always taken on the same night, thus
the red-blue color is correct even for variable objects.
j = blue magnitude is SERC J (Bj 4800A blue-green) from the POSS-II or
UKST surveys. Red-blue color is less reliable because the plates were
taken in different epochs, i.e. years apart.
g = blue magnitude is SDSS green 4800A.
u = blue magnitude is SDSS ultraviolet 3850A.
b = blue magnitude is Vega 4400A.
v = red magnitude is visual, i.e., white, 5500A midpoint.
i = red magnitude is infrared 7500A.
z = red magnitude is infrared z 8500A.
k = red magnitude is infrared k 22000A.
(not v/i/z/k) = red magnitude is standard red 6400A.
+ = variability nominally (from USNO-B or Flesch & Hardcastle, 2004,
Cat. J/A+A/427/387, section A.1 end) detected for both red & blue.
m = proper motion nominally (from USNO-B or Flesch & Hardcastle, 2004,
Cat. J/A+A/427/387, section A.1 end) detected.
x = object is from the ARXA catalog which was later dropped due to changes
in the optical or radio/X-ray data, thus causing either the likelihood
calculation or the optical field solution to change. 39,157 of these
are included, and the displayed likelihood is still indicative.
? = "inferred" object -- position and magnitude is approximate for either
red or blue or both, where PSF is listed as "n". These were derived
by overlaying USNO-A point sources onto APM ellipses.
Red_PSF_Flag
A coded representation for the point spread function (PSF) of the optical
source in the red. The APM, USNO-B, and SDSS provide PSF class, albeit using
different criteria. The codes are as follows:
- = point source / stellar PSF (APM notation: -1, here truncated)
1 = fuzzy / galaxy shape (APM notation: 1 and some 2)
n = no PSF available, whether borderline or too faint to tell, etc.
x = not seen in this color (fainter than plate depth, or confused, etc.)
Blue_PSF_Flag
A coded representation for the point spread function (PSF) of the optical
source in the blue. The APM, USNO-B, and SDSS provide PSF class, albeit using
different criteria. The codes are as follows:
- = point source / stellar PSF (APM notation: -1, here truncated)
1 = fuzzy / galaxy shape (APM notation: 1 and some 2)
n = no PSF available, whether borderline or too faint to tell, etc.
x = not seen in this color (fainter than plate depth, or confused, etc.)
Redshift
The redshift of the object, taken from the literature as specified
in the ref_redshift parameter. Photometric redshifts are rounded here to 0.1z
for objects classified as "q" (photometric quasars) and to 0.01z for "g"
(photometric galaxies). If the cited reference is MORX, then it is a
photometric redshift calculated as described in Appendix B of the HMQ paper
(Flesch 2015, PASA, 32, 10).
Opt_Radio_Offset
The astrometric offset of the optical from the radio source, in arcseconds,
after the radio field specified by the survey_obsid parameter has been
shifted by its optical field solution values as specified by the ra_shift and
dec_shift parameters. For double-lobe-only associations, the quoted value is
the length of the shorter lobe.
Radio_Likelihood
The likelihood of the radio association with the optical object, in percent.
These likelihoods are calculated from areal densities as described in the
QORG (Flesch and Hardcastle 2004, A&A, 427, 387) and ARXA (Flesch 2010, PASA,
27, 283, CDS Cat. V/134) papers. The radio and X-ray likelihoods are
calculated independently of each other.
Opt_Xray_Offset
The astrometric offset of the optical from the X-ray source, in arcseconds,
after the X-ray field specified by the survey_obsid parameter has been
shifted by its optical field solution values as specified by the ra_shift and
dec_shift parameters. For double-lobe-only associations, the quoted value is
the length of the shorter lobe.
Xray_Likelihood
The likelihood of the X-ray association with the optical object, in percent.
These likelihoods are calculated from areal densities as described in the
QORG (Flesch and Hardcastle 2004, A&A, 427, 387) and ARXA (Flesch 2010, PASA,
27, 283, CDS Cat. V/134) papers. The radio and X-ray likelihoods are
calculated independently of each other.
QSO_Prob
The calculated probability that the object is a QSO, in percent. These
probabilities are derived from the radio/X-ray association(s) by counting
fellow objects (of similar photometry and associations) which are already
fully classified. Values are also displayed for those fully classified
objects to show the performance.
Galaxy_Prob
The calculated probability that the object is a galaxy, in percent. These
probabilities are derived from the radio/X-ray association(s) by counting
fellow objects (of similar photometry and associations) which are already
fully classified. Values are also displayed for those fully classified
objects to show the performance.
Star_Prob
The calculated probability that the object is a star, in percent. These
probabilities are derived from the radio/X-ray association(s) by counting
fellow objects (of similar photometry and associations) which are already
fully classified. Values are also displayed for those fully classified
objects to show the performance.
False_Prob
The calculated probability that the association is false, in percent. The
false association probability is in general just 100% minus the sum of the
probabilities that the object is a QSO, galaxy or star. However, if the
object has both radio and X-ray source associations, the joint likelihood is
calculated by overlaying their areal densities, and is thus increased, and
consequently the false association probability is lessened.
NVSS_Name
The NVSS core radio source identification, if any.
FIRST_Or_Sumss_Name
The FIRST or SUMSS core radio source identification, if any.
XMM_Name
The XMM-Newton X-ray source identification, if any.
ROSAT_Name
The ROSAT X-ray source identification, if any.
CXO_Name
The Chandra X-ray source identification, if any.
Swift_Name
The Swift X-ray source identification, if any.
Alt_Name_1
The 1st radio lobe identification, if any.
Alt_Name_2
The 2nd radio lobe identification, if any.
Survey_ObsID
This parameter shows the catalog and field/sequence of the best matching
radio/X-ray source, i.e., that of the highest likelihood association,
although an accompanying successful optical field solution (with a high value
for the ratio of the number of associations used to calculate the optical
solution to the number of radio/X-ray sources in the field
(Nobj/Nsources) is also preferred. For example, "XMMX:0302580501" shows
that the XMMX X-ray source is the one described (since others might also be
displayed), which stems from the XMMX field 0302580501 which is shifted by
the optical field solution values given in ra_shift and dec_shift. X-ray
fields (aka "sequences") are operational satellite fields of view for which
the best optical-X-ray fit is found via RMS of shared source offsets, see the
QORG paper (Flesch and Hardcastle, 2004 A&A, 427, 387), section A.3 for
details. Note, however, that 1RXS/2RXS (RASS) processing used convenient sky
fields which were not in fact operational fields -- thus this method is not
so useful for placing RASS sources.
Radio fields are astrometrically accurate but still need shifting into the optical background used here because that background can have errors of order 1-2 arcseconds, so the radio astrometry must be "corrected" to it for best results. For objects whose only radio/X-ray association is to double radio lobes, the radio field is inconsequential, and can be different for each of the two lobes, and thus is left blank.
A value of "from ARXA" for this parameter means that this optical object was not identified in the MORX calculations, but was identified in the earlier ARXA catalog (Flesch 2010, PASA, 27, 283, CDS Cat. V/134). Such objects were lost (and many others gained) due to the inclusion of USNO-B optical data which modified the photometry and astrometry of much optical background data, thus impacting the likelihood-of-association and optical field solution calculations. 39,157 such objects have been copied over from ARXA, and spot checks by the author confirm that these are useful candidates. Also, 474 of these are faint FIRST detections which slipped below the FIRST 1-mJy threshold in transition from their 2008 catalog to their 2012 catalog, but look true on the FIRST image cutouts, in general.
RA_Shift
The E/W field shift given by the optical solution, in arcseconds. Optical
field solutions are calculated from the raw source positions of all
radio/X-ray catalogs as described in my QORG paper (Flesch and Hardcastle
2004, A&A, 427, 387). The displayed field shift is identical for every
instance of that field in MORX. In the processing, the candidate field shifts
are considered in integer
units of RA degree-based seconds of time and Dec arcseconds, and the
"winning" field shift is here presented in arcsec. Where the field was not able
to be shifted (due to too few associations, Nobj), this parameter is left
blank.
Dec_Shift
The N/S field shift given by the optical solution, in arcseconds. Optical
field solutions are calculated from the raw source positions of all
radio/X-ray catalogs as described in my QORG paper (Flesch and Hardcastle
2004, A&A, 427, 387). The displayed field shift is identical for every
instance of that field in MORX. In the processing, the candidate field shifts
are considered in integer
units of RA degree-based seconds of time and Dec arcseconds, and the
"winning" field shift is here presented in arcsec. Where the field was not able
to be shifted (due to too few associations, Nobj), this parameter is left
blank.
Num_Assocs_For_Shift
The number of associations used to calculate the optical solution for the
specified field, Nobj.
Num_Rx_Sources
The number of radio/X-ray sources detected in the specified field,
Nsources.
Ref_Source
The reference code for the citation of the named object. The file
http://cdsarc.u-strasbg.fr/ftp/cats/V/148/refs.dat lists all of the citations
given in this table in sequence. Each row in this file has 2 columns, the
first being: (a) the citation number as it appears in the data. These numbers
are consistent with those used in the Half Million Quasars catalog (HMQ:
2015, CDS Cat. VII/273), and (b) the citation, i.e., the bibcode and authors
list, and sometimes a brief description or website URL. The citation for the
classification given in the broad_type parameter, e.g., that the object is a
quasar, can be from either the name or redshift citation.
Ref_Redshift
The reference code for the cited redshift of the object. The file
http://cdsarc.u-strasbg.fr/ftp/cats/V/148/refs.dat lists all of the citations
given in this table in sequence. Each row in this file has 2 columns, the
first being: (a) the citation number as it appears in the data. These numbers
are consistent with those used in the Half Million Quasars catalog (HMQ:
2015, CDS Cat. VII/273), and (b) the citation, i.e., the bibcode and authors
list, and sometimes a brief description or website URL. The citation for the
classification given in the broad_type parameter, e.g., that the object is a
quasar, can be from either the name or redshift citation.
Class
The HEASARC Browse object classification, based on the value of the
broad_type parameter.