SMC-Last Extracted Photometry Catalog Definitions
Overview
We present point-source photometry from the Spitzer Space Telescope's final survey of the Small Magellanic Cloud (SMC). We mapped nearly 30 square degrees in two epochs in 2017, with the second extending to early 2018 at 3.6 and 4.5 um using the Infrared Array Camera. This survey duplicates the footprint from the SAGE-SMC program in 2008. Together, these surveys cover a nearly 10 yr temporal baseline in the SMC. We performed aperture photometry on the mosaicked maps produced from the new data. We did not use any prior catalogs as inputs for the extractor in order to be sensitive to any moving objects (e.g., foreground brown dwarfs) and other transient phenomena (e.g., cataclysmic variables or FU Ori-type eruptions). We produced a point-source catalog with high-confidence sources for each epoch as well as a combined-epoch catalog. For each epoch and the combined-epoch data, we also produced a more complete archive with lower-confidence sources.
If you use the SMC-Last Catalogs, please cite Kuchar et al. (2024).
| Name |
Intype |
Units |
Description |
| designation |
char |
none |
Designation |
| ra |
float |
deg |
Right Ascension (J2000) |
| dec |
float |
deg |
Declination (J2000) |
| posunc |
float |
arcsec |
Radial positional uncertainty |
| flux_36 |
float |
mJy |
3.6 micron flux |
| uncflux_36 |
float |
mJy |
3.6 micron flux uncertainty |
| aper_36 |
int |
arcsec |
3.6 micron extraction aperture diameter |
| fwhm_36 |
float |
arcsec |
3.6 micron FWHM |
| elong_36 |
float |
none |
3.6 micron elongation |
| meanmjd_36 |
double |
days |
Mean MJD of 3.6 micron observations |
| minmjd_36 |
double |
days |
Minimum MJD of 3.6 micron observations |
| maxmjd_36 |
double |
days |
Maximum MJD of 3.6 micron observations |
| satfill_36 |
int |
none |
Saturation filling flag; 1 indicates use of 0.6sec data within the aperture |
| aper_frac_36 |
float |
none |
Fraction of pixels within the 3.6 micron aperture with valid data |
| sky_36 |
float |
MJy/sr |
Average sky brightness in the 3.6 micron background annulus |
| rms_36 |
float |
MJy/sr |
RMS in the 3.6 micron background annulus |
| cvg_36 |
int |
none |
Number of 3.6 micron BCDs contributing to the source |
| plate_36 |
char |
none |
3.6 micron plate |
| dpos |
float |
arcsec |
Radial separation between 3.6um and 4.5um extracted positions |
| nearest_src |
float |
arcsec |
Distance to nearest neighbor within 20 arcsec |
| nproximity |
int |
arcsec |
Number of neighbors within 5 arcsec |
| brgt_nbr |
int |
none |
Bright neighbor flag: source >10 mJy within 1.2 arcsec |
| flux_45 |
float |
none |
4.5 micron flux |
| uncflux_45 |
float |
mJy |
4.5 micron flux uncertainty |
| aper_45 |
int |
mJy |
4.5 micron extraction aperture diameter |
| fwhm_45 |
float |
arcsec |
4.5 micron FWHM |
| elong_45 |
float |
arcsec |
4.5 micron elongation |
| meanmjd_45 |
double |
none |
Mean MJD of 4.5 micron observations |
| minmjd_45 |
double |
days |
Minimum MJD of 4.5 micron observations |
| maxmjd_45 |
double |
days |
Maximum MJD of 4.5 micron observations |
| satfill_45 |
int |
days |
Saturation filling flag; 1 indicates use of 0.6sec data within the aperture |
| aper_frac_45 |
float |
none |
Fraction of pixels within the 4.5 micron aperture with valid data |
| sky_45 |
float |
none |
Average sky brightness in the 4.5 micron background annulus |
| rms_45 |
float |
MJy/sr |
RMS in the 4.5 micron background annulus |
| cvg_45 |
int |
MJy/sr |
Number of 4.5 micron BCDs contributing to the source |
| plate_45 |
char |
none |
4.5 micron plate |