MSXUVPSC - Midcourse Space Experiment (MSX) Ultraviolet Point Source Catalog

Overview

The Midcourse Space Experiment (MSX) Ultraviolet Point Source Catalog contains 47,283 point sources (the HEASARC notes that there actually 47,318 sources in this version of the table, 35 more than this number) from a set of 201 observations that surveyed approximately half the sky and from a set of 32 pointed observations toward specific targets. For each source, the catalog provides the position, UV magnitude and uncertainty in at least one of six filters, and, where possible, an identification of a nearby source from the SIMBAD database. If a nearby source is identified, its proximity to the MSX source, and if known, the spectral type and the B and V magnitudes of the SIMBAD object are also provided. There were 11,565 matches between MSX and SIMBAD objects (the HEASARC notes that there actually 11,662 matches in this version of the table, 97 more than this number), and the authors estimate the number of false identifications to be about 3%. The limiting fluxes differ from filter to filter, and range from 10^-16 erg/s/cm²/Angstrom for IUN4 to 7.8 x 10^-12 erg/s/cm²/Angstrom for IUW3. Because of variations among the observation sets, the catalog is not complete to the limiting magnitudes for the filters.

The UV instrument on MSX was named UVISI (Mill et al., 1994, Journal of Spacecraft and Rockets, 31, 900 (1994JSpRo..31..900M in ADS); Carbary et al., 1994, Applied Optics, 33, 4201 (1994ApOpt..33.4201C in ADS)). The fields-of-view for the narrow-field and wide-field UV imagers were 1.46 x 1.19 degrees (detector pixels of 20.6" x 17.5") and 13.4 x 9.2 degrees (detector pixels of 3.12' x 2.27'), respectively. Four filters were used with the narrow-field imager (IUN) with effective wavelengths centered at 2480 Angstrom (IUN3), 2310 Angstrom (IUN4), 2230 Angstrom (IUN5), and 2930 Angstrom (IUN6). Two filters were used with the wide-field imager (IUW) and centered at 1320 Angstrom (IUW3) and 1560 Angstrom (IUW6).

The HEASARC has removed from this table the parameter describing the objects' magnitude in the IUN5 filter as all of the sources had null values for this parameter. The CDS had previously made the following modifications compared to the version of the catalog as published in the reference paper:

(1) The angular distances to the SIMBAD object (column "AngDist" of
    file catal.dat, called 'Offset' in this HEASARC table) was recomputed at
    CDS, the original values looking suspect.
(2) In the course of this modification, 17 SIMBAD IDs were removed due to a
    large offset, most likely due to a sign error in the interpretation of
    SIMBAD's declination for IDs:
    003341+001712 063054+004539 063211+005630 063754+003151 133358+001928
    142557+003939 144541+002439 155701+004808 162743+004620 185855+003355
    191033+004132 193004+005316 194525+001239 195040+004101 195717+001959
    202844+005149 234324+000729

Catalog Bibcode

References

The Midcourse Space Experiment Point Source Catalog (March 2004).
    Newcomer R.E., Murthy J., Henry R.C., Price S.D., Paxton L.
   <Air Force Research Laboratory Technical Report AFRL-VS-TR-2004-1056 (2004)>

Provenance

This table was created by the HEASARC in April 2012 based on CDS Catalog II/269 file catal.dat.

Filter and Magnitude Properties

The UVISI filter designations, effective wavelengths W(eff), bandpasses, and bandwidths DW, all given in Angstrom (A), for the filters tabulated herein are as follows:

Imager  Filter  W(eff)   Bandpass   DW     Comment
                  A         A       A

IUN       3     2480    2300-2600   300
          4     2310    1800-3000  1200
          5     2230    2000-2300   300    No non-null values
          6     2930    2600-3000   400

IUW       3     1320    1280-1380   100
          6     1560    1450-1800   350

IVN       5     2940    3050-3150   100   Note inconsistent Bandpass & DW

The tabulated magnitudes are Hayes-Latham magnitudes m and are related to the observed intensities (flux densities) F_w in erg s^-1 cm^-2 A^-1 at the specific wavelength W(eff) (the weighted filter central wavelength) for each filter by the relation

    m = -2.5 x log F_w - 21.175

Parameters

Name
The target designation based on its J2000.0 coordinates, e.g., 'MSX UV JHHMMSS+DDMMSS'.

RA
The Right Ascension of the source in the selected equinox. This was derived from the position-based name and thus is based on the J2000.0 position given to an accuracy of 1 second of time.

Dec
The Declination of the source in the selected equinox. This was derived from the position-based name and thus is based on the J2000.0 position given to an accuracy of 1 arcsecond.

LII
The Galactic Longitude of the source.

BII
The Galactic Latitude of the source.

Data_Collect_Event
The data collection event (DCE) tag of the source. This is a unique identifier for the observation. The initial two letters in the label identify the team responsible for the experiment, in this case, CB for the Celestial Background team. This is followed by numbers that define the observing profile, the first two digits of which denote the experiment number and the last three denote the specific observation.

RR_Number
The relative reference number of the source. This is an integer, only assigned to sources where more than one narrow field (IUN or IVN) source corresponds to a single IUW source. These values are relative to the DCE. For example, a source in DCE of CB10.100 that refers to a source with a relative reference value of 2 would correspond to only the source in CB10.100 that has a value of 2 in this column, and not to the source with a relative reference value of 2 in CB10.101. For example, MSX UV J061715+012248 CB11.029 has rr_number = 1 and rr_number_iuw1 = 2; the first MSX UV J061728+012033 CB11.029 entry has rr_number = 3 and rr_number_iun1 = 2, and the second MSX UV J061728+012033 CB11.029 entry has rr_number = 2, rr_number_iun1 = 3 and rr_number_iun2 = 1. The IUW detection was rr_number = 2; both MSX UV J061728+012033 CB11.029 rr_number = 3 and MSX UV J061715+012248 CB11.029 rr_number=1 are in the IUW PSF.

Mag_2480_A
The magnitude of the source in the IUN 3 filter (2480 Angstrom).

Mag_2310_A
The magnitude of the source in the IUN 4 filter (2310 Angstrom).

NUV_Filter_ID
The narrow-band filter identification for the near-UV magnitude, being either IUN6 (2930 Angstrom)or IVN5 (2940 Angstrom).

Mag_NUV
The magnitude of the source in the near UV, relative to the other filters, in the filter specified by the nuv_filter_id parameter.

FUV_Filter_ID
The wide-band filter identification for the far-UV magnitude, being either IUW3 (1320 Angstrom) or IUW6 (1560 Angstrom).

Mag_FUV
The magnitude of the source in the far UV, relative to the other filters, in the filter specified by the fuv_filter_id parameter.

RR_Number_IUW
The relative reference number of the IUW detection (see the description of the rr_number parameter above).

RR_Number_IUN1
The relative reference number of the 1st IUN detection (see the description of the rr_number parameter above).

RR_Number_IUN2
The relative reference number of the 2nd IUN detection (see the description of the rr_number parameter above).

RR_Number_IUN3
The relative reference number of the 3rd IUN detection (see the description of the rr_number parameter above).

RR_Number_IUN4
The relative reference number of the 4th IUN detection (see the description of the rr_number parameter above).

SIMBAD_ID
The SIMBAD cross-identification of the source as of 2004, if available.

Offset
The angular distance between the MSX source position and the SIMBAD cross-identification, in arcminutes.

Spect_Type
The spectral type of the SIMBAD cross-identification.

Vmag
The V magnitude of the SIMBAD cross-identification.

Bmag
The B magnitude of the SIMBAD cross-idnetification.

Class
The HEASARC Browse bbject classification, based on the spect_type parameter value.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:31:17 EDT