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MSXPSC - Midcourse Space Experiment (MSX) Point Source Catalog, V2.3 |
HEASARC Archive |
The principal objective of the astronomy experiments onboard the MSX satellite was to complete the census of the mid-infrared (4.2-25 micron or um) sky: namely, the areas missed by the IRAS mission (about 4% of the sky was not surveyed by IRAS), and the Galactic Plane (where the sensitivity of IRAS was degraded by confusion noise in regions of high source densities or of structured extended emission). The photometry is based on co-added image plates, as opposed to single-scan data, which results in improved sensitivity and hence reliability in the fluxes. Comparison with Tycho-2 positions indicates that the astrometric accuracy of the new catalog is more than 1" better than that in Version 1.2.
The infrared instrument on MSX was named SPIRIT III; it was a 35-cm clear aperture off-axis telescope with five line scanned infrared focal-plane arrays of 18.3 arcseconds square pixels, with a high sensitivity (0.1 Jy at 8.3 um). The filter characteristics of the 6 spectral bands B1, B2, A, C, D and E are summarized below, where all wavelengths are in micron (µm):
Band Center FWHM Points ---------------------------- B1 4.29 um 4.22 - 4.36 um B2 4.35 4.24 - 4.45 A 8.28 6.8 - 10.8 C 12.13 11.1 - 13.2 D 14.65 13.5 - 15.9 E 21.34 18.2 - 25.1
The MSX catalog names of the sources have been defined according to International Astronomical Union (IAU) conventions with a unique identifier combined with the position of the source. In this case, the MSX PSC V2.3 sources are named using the convention MSX6C GLLL.llll+/-BB.bbbb, where MSX6C denotes that this is MSX data run using Version 6.0 of the CONVERT software, and GLLL.llll+/-BB.bbbb gives the Galactic coordinates of the source.
The Midcourse Space Experiment Point Source Catalog Version 2.3 (October 2003) Explanatory Guide Egan M.P., Price S.D., Kraemer K.E., Mizuno D.R., Carey S.J., Wright C.O., Engelke C.W., Cohen M., Gugliotti G. M. <Air Force Research Laboratory Technical Report AFRL-VS-TR-2003-1589 (2003)> Midcourse Space Experiment Survey of the Galactic Plane Price, S.D., Egan, M.P., Carey, S.J., Mizuno, D.R., Kuchar, T.A> <Astron. J. 121, 2819 (2001)>The explanatory guide is also available at the CDS: https://cdsarc.cds.unistra.fr/ftp/cats/V/114/guide.ps.gz
Name
The MSX PSC Catalog designation, based on the galactic position of the
infrared source and using the prefix 'MSX6C ' as explained in the Overview
section.
RA
The Right Ascension of the infrared source in the selected equinox.
This was given in J2000 degrees and with a precision of 0.0001 degrees in
the original CDS tables.
Dec
The Declination of the infrared source in the selected equinox.
This was given in J2000 degrees and with a precision of 0.0001 degrees in
the original CDS tables.
LII
The Galactic Longitude of the infrared source.
BII
The Galactic Latitude of the infrared source.
Pos_Error_Scan
The 1-sigma positional uncertainty in the in-scan
direction, in arcseconds.
Pos_Error_Cross
The 1-sigma positional uncertainty in the cross-scan
direction, in arcseconds.
Scan_Pos_Angle
The position angle of the in-scan direction, using the
usual convention increasing from 0 as the angle rotates East from the North
direction, in degrees.
Num_Scan_Sights
The number of total scan sightings.
Flux_4p29um
The flux density in the MSX B1 band centered on 4.29 um,
in Janskies (Jy). When the number of sightings in this band was zero, the
flux densities were set to the negative value of the sensitivity limit.
Quality_Flag_4p29um
The quality flag for the B1 band according to the
following rubric, where SNim and SNpsx are the image extraction and point
source extractor signal-to-noise ratios for the source in this band:
4 = excellent, SNim >= 10.0 3 = good, 7.0 <= SNim < 10.0 or SNim = -800 and SNpsx >= 10.0 2 = fair, 5.0 <= SNim < 7.0 or SNim = -800 and 5.0 <= SNpsx < 10.0 1 = limit, SNim < 5.0 0 = not detected
Flux_4p29um_Pcerr
The 1-sigma uncertainty in the flux density in the
B1 band, expressed as a percentage of the flux density. If the source was
not detected in this band, i.e., the corresponding quality flag has a value
of 0, this parameter is set to -99.0.
Imgext_SNR_4p29um
The signal-to-noise ratio (SNR) of the source in the
B1 band for the image-based photometry method. This can take on a value of
-800 if no image plate exists at the source location and of -999 if the
image-based point response function (PRF) fitting was unable to extract a
positive irradiance value. In these cases, the catalog authors defaulted to
the point source extractor (PSX) SNR for source in this band in order to
set the flux quality flag.
Ptsrcext_SNR_4p29um
The signal-to-noise ratio (SNR) of the source in the
B1 band for the point source extractor (PSX) method.
Num_Sights_4p29um
The number of sightings of the infrared source in the B1
band.
Variation_4p29um
The (dimensionless) variation in the B1 band measurements
of the source. If the source was not detected in this band, i.e., the
corresponding quality flag has a value of 0, this parameter is set to -99.0.
Flux_4p35um
The flux density in the MSX B2 band centered on 4.35 um,
in Janskies (Jy). When the number of sightings in this band was zero, the
flux densities were set to the negative value of the sensitivity limit.
Quality_Flag_4p35um
The quality flag for the B2 band according to the
following rubric, where SNim and SNpsx are the image extraction and point
source extractor signal-to-noise ratios for the source in this band:
4 = excellent, SNim >= 10.0 3 = good, 7.0 <= SNim < 10.0 or SNim = -800 and SNpsx >= 10.0 2 = fair, 5.0 <= SNim < 7.0 or SNim = -800 and 5.0 <= SNpsx < 10.0 1 = limit, SNim < 5.0 0 = not detected
Flux_4p35um_Pcerr
The 1-sigma uncertainty in the flux density in the
B2 band, expressed as a percentage of the flux density. If the source was
not detected in this band, i.e., the corresponding quality flag has a value
of 0, this parameter is set to -99.0.
Imgext_SNR_4p35um
The signal-to-noise ratio (SNR) of the source in the
B2 band for the image-based photometry method. This can take on a value of
-800 if no image plate exists at the source location and of -999 if the
image-based point response function (PRF) fitting was unable to extract a
positive irradiance value. In these cases, the catalog authors defaulted to
the point source extractor (PSX) SNR for source in this band in order to
set the flux quality flag.
Ptsrcext_SNR_4p35um
The signal-to-noise ratio (SNR) of the source in the
B2 band for the point source extractor (PSX) method.
Num_Sights_4p35um
The number of sightings of the infrared source in the B2
band.
Variation_4p35um
The (dimensionless) variation in the B2 band measurements
of the source. If the source was not detected in this band, i.e., the
corresponding quality flag has a value of 0, this parameter is set to -99.0.
Flux_8um
The flux density in the MSX A band centered on 8.28 um,
in Janskies (Jy). When the number of sightings in this band was zero, the
flux densities were set to the negative value of the sensitivity limit.
Quality_Flag_8um
The quality flag for the A band according to the
following rubric, where SNim and SNpsx are the image extraction and point
source extractor signal-to-noise ratios for the source in this band:
4 = excellent, SNim >= 10.0 3 = good, 7.0 <= SNim < 10.0 or SNim = -800 and SNpsx >= 10.0 2 = fair, 5.0 <= SNim < 7.0 or SNim = -800 and 5.0 <= SNpsx < 10.0 1 = limit, SNim < 5.0 0 = not detected
Flux_8um_Pcerr
The 1-sigma uncertainty in the flux density in the
A band, expressed as a percentage of the flux density. If the source was
not detected in this band, i.e., the corresponding quality flag has a value
of 0, this parameter is set to -99.0.
Imgext_SNR_8um
The signal-to-noise ratio (SNR) of the source in the
A band for the image-based photometry method. This can take on a value of
-800 if no image plate exists at the source location and of -999 if the
image-based point response function (PRF) fitting was unable to extract a
positive irradiance value. In these cases, the catalog authors defaulted to
the point source extractor (PSX) SNR for source in this band in order to
set the flux quality flag.
Ptsrcext_SNR_8um
The signal-to-noise ratio (SNR) of the source in the
A band for the point source extractor (PSX) method.
Num_Sights_8um
The number of sightings of the infrared source in the A
band.
Variation_8um
The (dimensionless) variation in the A band measurements
of the source. If the source was not detected in this band, i.e., the
corresponding quality flag has a value of 0, this parameter is set to -99.0.
Flux_12um
The flux density in the MSX C band centered on 12.13 um,
in Janskies (Jy). When the number of sightings in this band was zero, the
flux densities were set to the negative value of the sensitivity limit.
Quality_Flag_12um
The quality flag for the C band according to the
following rubric, where SNim and SNpsx are the image extraction and point
source extractor signal-to-noise ratios for the source in this band:
4 = excellent, SNim >= 10.0 3 = good, 7.0 <= SNim < 10.0 or SNim = -800 and SNpsx >= 10.0 2 = fair, 5.0 <= SNim < 7.0 or SNim = -800 and 5.0 <= SNpsx < 10.0 1 = limit, SNim < 5.0 0 = not detected
Flux_12um_Pcerr
The 1-sigma uncertainty in the flux density in the
C band, expressed as a percentage of the flux density. If the source was
not detected in this band, i.e., the corresponding quality flag has a value
of 0, this parameter is set to -99.0.
Imgext_SNR_12um
The signal-to-noise ratio (SNR) of the source in the
C band for the image-based photometry method. This can take on a value of
-800 if no image plate exists at the source location and of -999 if the
image-based point response function (PRF) fitting was unable to extract a
positive irradiance value. In these cases, the catalog authors defaulted to
the point source extractor (PSX) SNR for source in this band in order to
set the flux quality flag.
Ptsrcext_SNR_12um
The signal-to-noise ratio (SNR) of the source in the
C band for the point source extractor (PSX) method.
Num_Sights_12um
The number of sightings of the infrared source in the C
band.
Variation_12um
The (dimensionless) variation in the C band measurements
of the source. If the source was not detected in this band, i.e., the
corresponding quality flag has a value of 0, this parameter is set to -99.0.
Flux_15um
The flux density in the MSX D band centered on 14.65 um,
in Janskies (Jy). When the number of sightings in this band was zero, the
flux densities were set to the negative value of the sensitivity limit.
Quality_Flag_15um
The quality flag for the D band according to the
following rubric, where SNim and SNpsx are the image extraction and point
source extractor signal-to-noise ratios for the source in this band:
4 = excellent, SNim >= 10.0 3 = good, 7.0 <= SNim < 10.0 or SNim = -800 and SNpsx >= 10.0 2 = fair, 5.0 <= SNim < 7.0 or SNim = -800 and 5.0 <= SNpsx < 10.0 1 = limit, SNim < 5.0 0 = not detected
Flux_15um_Pcerr
The 1-sigma uncertainty in the flux density in the
D band, expressed as a percentage of the flux density. If the source was
not detected in this band, i.e., the corresponding quality flag has a value
of 0, this parameter is set to -99.0.
Imgext_SNR_15um
The signal-to-noise ratio (SNR) of the source in the
D band for the image-based photometry method. This can take on a value of
-800 if no image plate exists at the source location and of -999 if the
image-based point response function (PRF) fitting was unable to extract a
positive irradiance value. In these cases, the catalog authors defaulted to
the point source extractor (PSX) SNR for source in this band in order to
set the flux quality flag.
Ptsrcext_SNR_15um
The signal-to-noise ratio (SNR) of the source in the
D band for the point source extractor (PSX) method.
Num_Sights_15um
The number of sightings of the infrared source in the D
band.
Variation_15um
The (dimensionless) variation in the D band measurements
of the source. If the source was not detected in this band, i.e., the
corresponding quality flag has a value of 0, this parameter is set to -99.0.
Flux_21um
The flux density in the MSX E band centered on 21.34 um,
in Janskies (Jy). When the number of sightings in this band was zero, the
flux densities were set to the negative value of the sensitivity limit.
Quality_Flag_21um
The quality flag for the E band according to the
following rubric, where SNim and SNpsx are the image extraction and point
source extractor signal-to-noise ratios for the source in this band:
4 = excellent, SNim >= 10.0 3 = good, 7.0 <= SNim < 10.0 or SNim = -800 and SNpsx >= 10.0 2 = fair, 5.0 <= SNim < 7.0 or SNim = -800 and 5.0 <= SNpsx < 10.0 1 = limit, SNim < 5.0 0 = not detected
Flux_21um_Pcerr
The 1-sigma uncertainty in the flux density in the
E band, expressed as a percentage of the flux density. If the source was
not detected in this band, i.e., the corresponding quality flag has a value
of 0, this parameter is set to -99.0.
Imgext_SNR_21um
The signal-to-noise ratio (SNR) of the source in the
E band for the image-based photometry method. This can take on a value of
-800 if no image plate exists at the source location and of -999 if the
image-based point response function (PRF) fitting was unable to extract a
positive irradiance value. In these cases, the catalog authors defaulted to
the point source extractor (PSX) SNR for source in this band in order to
set the flux quality flag.
Ptsrcext_SNR_21um
The signal-to-noise ratio (SNR) of the source in the
E band for the point source extractor (PSX) method.
Num_Sights_21um
The number of sightings of the infrared source in the E
band.
Variation_21um
The (dimensionless) variation in the E band measurements
of the source. If the source was not detected in this band, i.e., the
corresponding quality flag has a value of 0, this parameter is set to -99.0.
Var_Flag_4p29um
The B1 band variability flag: this flag is set to 1 when
the variation of the measurements over the mission exceeds the 3-sigma limit,
compared to a default value of 0.
Var_Flag_4p35um
The B2 band variability flag: this flag is set to 1 when
the variation of the measurements over the mission exceeds the 3-sigma limit,
compared to a default value of 0.
Var_Flag_8um
The A band variability flag: this flag is set to 1 when
the variation of the measurements over the mission exceeds the 3-sigma limit,
compared to a default value of 0.
Var_Flag_12um
The C band variability flag: this flag is set to 1 when
the variation of the measurements over the mission exceeds the 3-sigma limit,
compared to a default value of 0.
Var_Flag_15um
The D band variability flag: this flag is set to 1 when
the variation of the measurements over the mission exceeds the 3-sigma limit,
compared to a default value of 0.
Var_Flag_21um
The E band variability flag: this flag is set to 1 when
the variation of the measurements over the mission exceeds the 3-sigma limit,
compared to a default value of 0.
Conf_Flag_4p29um
The B1 band confusion flag: this flag is set to 1 when
there is a possible confusion problem, compared to a default (not confused)
value of 0.
Conf_Flag_4p35um
The B2 band confusion flag: this flag is set to 1 when
there is a possible confusion problem, compared to a default (not confused)
value of 0.
Conf_Flag_8um
The A band confusion flag: this flag is set to 1 when
there is a possible confusion problem, compared to a default (not confused)
value of 0.
Conf_Flag_12um
The C band confusion flag: this flag is set to 1 when
there is a possible confusion problem, compared to a default (not confused)
value of 0.
Conf_Flag_15um
The D band confusion flag: this flag is set to 1 when
there is a possible confusion problem, compared to a default (not confused)
value of 0.
Conf_Flag_21um
The E band confusion flag: this flag is set to 1 when
there is a possible confusion problem, compared to a default (not confused)
value of 0.
Rel_Flag_4p29um
The B1 band measurement reliability flag, being a measure
of SNR and fit quality. This flag is set to 9 if the source was not detected
in this band, else it is the sum of I(psf) and I(snr), where I(psf) is
0 there is a good fit to the point spread function (PSF) for all measurements,
1 if there is a good fit for some but not all measurements, and 2 if there is
a poor fit for all measurements; and I(snr) is 0 if all measurements have an
SNR > 3, 3 if the lowest-SNR measurement is < 3, and 6 if all measurements
have an SNR < 3. Notice that these latter values of this flag thus uniquely
fill the range from 0 to 8, and that the individual values of I(psf) and I(snr)
can thus be reconstructed by the user: e.g., a value of 5 for this flag
implies that I(psf) = 2 and I(snr) = 3.
Rel_Flag_4p35um
The B2 band measurement reliability flag, being a measure
of SNR and fit quality. This flag is set to 9 if the source was not detected
in this band, else it is the sum of I(psf) and I(snr), where I(psf) is
0 there is a good fit to the point spread function (PSF) for all measurements,
1 if there is a good fit for some but not all measurements, and 2 if there is
a poor fit for all measurements; and I(snr) is 0 if all measurements have an
SNR > 3, 3 if the lowest-SNR measurement is < 3, and 6 if all measurements
have an SNR < 3. Notice that these latter values of this flag thus uniquely
fill the range from 0 to 8, and that the individual values of I(psf) and I(snr)
can thus be reconstructed by the user: e.g., a value of 5 for this flag
implies that I(psf) = 2 and I(snr) = 3.
Rel_Flag_8um
The A band measurement reliability flag, being a measure
of SNR and fit quality. This flag is set to 9 if the source was not detected
in this band, else it is the sum of I(psf) and I(snr), where I(psf) is
0 there is a good fit to the point spread function (PSF) for all measurements,
1 if there is a good fit for some but not all measurements, and 2 if there is
a poor fit for all measurements; and I(snr) is 0 if all measurements have an
SNR > 3, 3 if the lowest-SNR measurement is < 3, and 6 if all measurements
have an SNR < 3. Notice that these latter values of this flag thus uniquely
fill the range from 0 to 8, and that the individual values of I(psf) and I(snr)
can thus be reconstructed by the user: e.g., a value of 5 for this flag
implies that I(psf) = 2 and I(snr) = 3.
Rel_Flag_12um
The C band measurement reliability flag, being a measure
of SNR and fit quality. This flag is set to 9 if the source was not detected
in this band, else it is the sum of I(psf) and I(snr), where I(psf) is
0 there is a good fit to the point spread function (PSF) for all measurements,
1 if there is a good fit for some but not all measurements, and 2 if there is
a poor fit for all measurements; and I(snr) is 0 if all measurements have an
SNR > 3, 3 if the lowest-SNR measurement is < 3, and 6 if all measurements
have an SNR < 3. Notice that these latter values of this flag thus uniquely
fill the range from 0 to 8, and that the individual values of I(psf) and I(snr)
can thus be reconstructed by the user: e.g., a value of 5 for this flag
implies that I(psf) = 2 and I(snr) = 3.
Rel_Flag_15um
The D band measurement reliability flag, being a measure
of SNR and fit quality. This flag is set to 9 if the source was not detected
in this band, else it is the sum of I(psf) and I(snr), where I(psf) is
0 there is a good fit to the point spread function (PSF) for all measurements,
1 if there is a good fit for some but not all measurements, and 2 if there is
a poor fit for all measurements; and I(snr) is 0 if all measurements have an
SNR > 3, 3 if the lowest-SNR measurement is < 3, and 6 if all measurements
have an SNR < 3. Notice that these latter values of this flag thus uniquely
fill the range from 0 to 8, and that the individual values of I(psf) and I(snr)
can thus be reconstructed by the user: e.g., a value of 5 for this flag
implies that I(psf) = 2 and I(snr) = 3.
Rel_Flag_21um
The E band measurement reliability flag, being a measure
of SNR and fit quality. This flag is set to 9 if the source was not detected
in this band, else it is the sum of I(psf) and I(snr), where I(psf) is
0 there is a good fit to the point spread function (PSF) for all measurements,
1 if there is a good fit for some but not all measurements, and 2 if there is
a poor fit for all measurements; and I(snr) is 0 if all measurements have an
SNR > 3, 3 if the lowest-SNR measurement is < 3, and 6 if all measurements
have an SNR < 3. Notice that these latter values of this flag thus uniquely
fill the range from 0 to 8, and that the individual values of I(psf) and I(snr)
can thus be reconstructed by the user: e.g., a value of 5 for this flag
implies that I(psf) = 2 and I(snr) = 3.