II/379 SkyMapper Southern Sky Survey. DR4 (Onken+, 2024)
SkyMapper Southern Sky Survey: Data Release 4.
Onken C.A., Wolf C., Bessell M.S., Chang S.-W., Luvaul L.C., Tonry J.L.,
White M.C., Da Costa G.S.
<Publ. Astron. Soc. Australia, in prep. (2024)>
=2024arXiv240202015O 2024arXiv240202015O
=2024yCat.2379....0O 2024yCat.2379....0O
ADC_Keywords: Surveys ; Photometry ; Optical
Keywords: optical astronomy - sky surveys - catalogs
Abstract:
We present the fourth data release (DR4) of the SkyMapper Southern
Survey (SMSS), the last major step in our hemispheric survey with six
optical filters: u, v, g, r, i, z. SMSS DR4 covers 26000 sq.deg from
over 400,000 images acquired by the 1.3m SkyMapper telescope between
2014-03 and 2021-09. The 6-band sky coverage extends from the South
Celestial Pole to Dec=+16deg, with some images reaching Dec~+28deg. In
contrast to previous DRs, we include all good-quality images from the
facility taken during that time span, not only those explicitly taken
for the public Survey. From the image dataset, we produce a catalogue
of nearly 13 billion detections made from ∼700 million unique
astrophysical objects. The typical 10sigma depths for each field range
between 18.5 and 20.5mag, depending on the filter, but certain sky
regions include longer exposures that reach as deep as 22mag in some
filters. As with previous SMSS catalogues, we have cross-matched with
a host of other imaging and spectroscopic datasets to facilitate
additional science outcomes. SMSS DR4 is now available to the
worldwide astronomical community.
Description:
The SkyMapper telescope operates at Siding Spring Observatory
(SSO), near Coonabarabran, New SouthWales, and was inaugurated in
2009.
We present the 4th data release of the SkyMapper Southern
Survey. The data set is nearly complete relative to the original
public Survey plans; for the first time, the release includes data
taken with SkyMapper for other science programmes, such as the
SkyMapper Transient Survey (SMT; Scalzo et al., 2017PASA...34...30S 2017PASA...34...30S),
and ∼6 000 very short exposures on each of seven standard fields.
Improvements in sky coverage and data processing should enhance its
usefulness compared to previous releases.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
smssdr4.sam 1067 1000 SkyMapper DR4
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See also:
I/350 : Gaia DR3 (Gaia Collaboration, 2022)
II/328 : AllWISE Data Release (Cutri+ 2013)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/335 : Revised catalog of GALEX UV sources, GUVcat_AIS GR6+7 (Bianchi+ 2017)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
II/367 : The VISTA Hemisphere Survey (VHS) catalog DR5 (McMahon+, 2020)
II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)
Byte-by-byte Description of file: smssdr4.sam
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Bytes Format Units Label Explanations
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1- 18 A18 --- SMSS SkyMapper Southern Survey designation of
the form SMSS Jhhmmss.ss±ddmmss.s
derived from mean ICRS coordinates
(smss_j)
20- 29 F10.6 deg RAdeg Mean ICRS Right Ascension of the object
(ICRS, Ep=J2000) (raj2000)
31- 40 F10.6 deg DEdeg Mean ICRS Declination of the object
(ICRS, Ep=J2000) (dej2000)
42- 51 I10 --- ObjectId Global unique object ID in the master
table (object_id)
53- 56 I4 mas e_RAdeg RMS variation around the mean Right
Ascension (e_raj2000)
58- 61 I4 mas e_DEdeg RMS variation around the mean Declination
(e_dej2000)
63- 72 F10.4 d EpMean Mean MJD epoch of the observations
(mean_epoch)
74- 82 F9.4 d e_EpMean RMS variation around the mean epoch
(rms_epoch)
84- 93 F10.6 deg GLON Galactic longitude derived from ICRS
coordinates. Not to be used as primary
astrometric reference. (glon)
95- 104 F10.6 deg GLAT Galactic latitude derived from ICRS
coordinates. Not to be used as primary
astrometric reference. (glat)
106- 113 I8 --- Niflags Total number of flagged pixels from bad or
saturated or crosstalk-affected pixel
masks across all observations (nimaflags)
115- 119 I5 --- flags Bitwise OR of Source Extractor flags
across all observations (flags)
121- 125 I5 --- Ngood Number of observations used across all
filters (ngood)
127- 130 I4 --- Ngoodmin Minimum number of observations used in any
filter (excluding filters with 0
observations) (ngood_min)
132- 136 I5 --- flagsu Bitwise OR of Source Extractor flags from
u-band measurements in photometry table
(u_flags)
138- 142 I5 --- Niflagsu Number of flagged pixels from bad or
saturated or crosstalk-affected pixels
masks from u-band measurements in
photometry table (u_nimaflags)
144- 147 I4 --- Ngoodu Number of u-band observations used
(u_ngood)
149- 151 I3 --- Nnclipu Number of u-band observations with
magnitudes clipped from the final PSF
magnitude estimate (u_nclip)
153- 157 I5 --- flagsv Bitwise OR of Source Extractor flags from
v-band measurements in photometry table
(v_flags)
159- 163 I5 --- Niflagsv Number of flagged pixels from bad or
saturated or crosstalk-affected pixels
masks from v-band measurements in
photometry table (v_nimaflags)
165- 168 I4 --- Ngoodv Number of v-band observations used
(v_ngood)
170- 172 I3 --- Nnclipv Number of v-band observations with
magnitudes clipped from the final PSF
magnitude estimate (v_nclip)
174- 178 I5 --- flagsg Bitwise OR of Source Extractor flags from
g-band measurements in photometry table
(g_flags)
180- 184 I5 --- Niflagsg Number of flagged pixels from bad or
saturated or crosstalk-affected pixels
masks from g-band measurements in
photometry table (g_nimaflags)
186- 189 I4 --- Ngoodg Number of g-band observations used
(g_ngood)
191- 193 I3 --- Nnclipg Number of g-band observations with
magnitudes clipped from the final PSF
magnitude estimate (g_nclip)
195- 199 I5 --- flagsr Bitwise OR of Source Extractor flags from
r-band measurements in photometry table
(r_flags)
201- 205 I5 --- Niflagsr Number of flagged pixels from bad or
saturated or crosstalk-affected pixels
masks from r-band measurements in
photometry table (r_nimaflags)
207- 210 I4 --- Ngoodr Number of r-band observations used
(r_ngood)
212- 214 I3 --- Nnclipr Number of r-band observations with
magnitudes clipped from the final PSF
magnitude estimate (r_nclip)
216- 220 I5 --- flagsi Bitwise OR of Source Extractor flags from
i-band measurements in photometry table
(i_flags)
222- 226 I5 --- Niflagsi Number of flagged pixels from bad or
saturated or crosstalk-affected pixels
masks from i-band measurements in
photometry table (i_nimaflags)
228- 231 I4 --- Ngoodi Number of i-band observations used
(i_ngood)
233- 235 I3 --- Nnclipi Number of i-band observations with
magnitudes clipped from the final PSF
magnitude estimate (i_nclip)
237- 241 I5 --- flagsz Bitwise OR of Source Extractor flags from
z-band measurements in photometry table
(z_flags)
243- 247 I5 --- Niflagsz Number of flagged pixels from bad or
saturated or crosstalk-affected pixels
masks from z-band measurements in
photometry table (z_nimaflags)
249- 252 I4 --- Ngoodz Number of z-band observations used
(z_ngood)
254- 256 I3 --- Nnclipz Number of z-band observations with
magnitudes clipped from the final PSF
magnitude estimate (z_nclip)
258- 262 F5.3 --- ClassStar Maximum stellarity index from photometry
table (between 0=no star and 1=star)
(class_star)
264- 275 E12.6 --- chi2PSF ? Maximum chi-squared from photometry
table (chi2_psf)
277- 281 F5.2 pix RadrPetro ? Mean r-band Petrosian radius
(radius_petro)
283- 295 E13.6 pix FWHM Mean FWHM of detections (mean_fwhm)
297- 303 F7.4 mag uPSF ? Weighted mean u-band PSF magnitude
(u_psf)
305- 310 F6.4 mag e_uPSF ? Error in weighted mean u-band PSF
magnitude (eupsf)
312- 318 F7.4 mag uPetro ? Weighted mean u-band Petrosian magnitude
(u_petro)
320- 328 F9.4 mag e_uPetro ? Error in weighted mean u-band Petrosian
magnitude (eupetro)
330- 336 F7.4 mag uapc05 ? Weighted mean u-band aperture-corrected
magnitude from flux in 5 arcsec diameter
(u_apc05)
338- 343 F6.4 mag e_uapc05 ? Error in weighted mean u-band
aperture-corrected magnitude from flux
in 5 arcsec diameter (euapc05)
345- 350 F6.4 mag ummvar ? Magnitude range between minimum and
maximum unclipped u-band PSF magnitudes
(u_mmvar)
352- 358 F7.4 mag vPSF ? Weighted mean v-band PSF magnitude
(v_psf)
360- 365 F6.4 mag e_vPSF ? Error in weighted mean v-band PSF
magnitude (evpsf)
367- 373 F7.4 mag vPetro ? Weighted mean v-band Petrosian
magnitude (v_petro)
375- 385 F11.4 mag e_vPetro ? Error in weighted mean v-band Petrosian
magnitude (evpetro)
387- 393 F7.4 mag vapc05 ? Weighted mean v-band aperture-corrected
magnitude from flux in 5 arcsec diameter
(v_apc05)
395- 400 F6.4 mag e_vapc05 ? Error in weighted mean v-band
aperture-corrected magnitude from flux
in 5 arcsec diameter (evapc05)
402- 407 F6.4 mag vmmvar ? Magnitude range between minimum and
maximum unclipped v-band PSF magnitudes
(v_mmvar)
409- 415 F7.4 mag gPSF ? Weighted mean g-band PSF magnitude
(g_psf)
417- 422 F6.4 mag e_gPSF ? Error in weighted mean g-band PSF
magnitude (egpsf)
424- 430 F7.4 mag gPetro ? Weighted mean g-band Petrosian magnitude
(g_petro)
432- 441 F10.4 mag e_gPetro ? Error in weighted mean g-band Petrosian
magnitude (egpetro)
443- 449 F7.4 mag gapc05 ? Weighted mean g-band aperture-corrected
magnitude from flux in 5 arcsec diameter
(g_apc05)
451- 456 F6.4 mag e_gapc05 ? Error in weighted mean g-band
aperture-corrected magnitude from flux
in 5 arcsec diameter (egapc05)
458- 464 F7.4 mag gmmvar ? Magnitude range between minimum and
maximum unclipped g-band PSF magnitudes
(g_mmvar)
466- 472 F7.4 mag rPSF ? Weighted mean r-band PSF magnitude
(r_psf)
474- 479 F6.4 mag e_rPSF ? Error in weighted mean r-band PSF
magnitude (erpsf)
481- 487 F7.4 mag rPetro ? Weighted mean r-band Petrosian magnitude
(r_petro)
489- 498 F10.4 mag e_rPetro ? Error in weighted mean r-band Petrosian
magnitude (erpetro)
500- 506 F7.4 mag rapc05 ? Weighted mean r-band aperture-corrected
magnitude from flux in 5 arcsec diameter
(r_apc05)
508- 513 F6.4 mag e_rapc05 ? Error in weighted mean r-band
aperture-corrected magnitude from flux
in 5 arcsec diameter (erapc05)
515- 520 F6.4 mag rmmvar ? Magnitude range between minimum and
maximum unclipped -band PSF magnitudes
(r_mmvar)
522- 528 F7.4 mag iPSF ? Weighted mean i-band PSF magnitude
(i_psf)
530- 535 F6.4 mag e_iPSF ? Error in weighted mean i-band PSF
magnitude (eipsf)
537- 543 F7.4 mag iPetro ? Weighted mean i-band Petrosian magnitude
(i_petro)
545- 555 F11.4 mag e_iPetro ? Error in weighted mean i-band Petrosian
magnitude (eipetro)
557- 563 F7.4 mag iapc05 ? Weighted mean i-band aperture-corrected
magnitude from flux in 5 arcsec diameter
(i_apc05)
565- 570 F6.4 mag e_iapc05 ? Error in weighted mean i-band
aperture-corrected magnitude from flux
in 5 arcsec diameter (eiapc05)
572- 577 F6.4 mag immvar ? Magnitude range between minimum and
maximum unclipped i-band PSF magnitudes
(i_mmvar)
579- 585 F7.4 mag zPSF ? Weighted mean z-band PSF magnitude
(z_psf)
587- 592 F6.4 mag e_zPSF ? Error in weighted mean z-band PSF
magnitude (ezpsf)
594- 600 F7.4 mag zPetro ? Weighted mean z-band Petrosian magnitude
(z_petro)
602- 612 F11.4 mag e_zPetro ? Error in weighted mean z-band Petrosian
magnitude (ezpetro)
614- 620 F7.4 mag zapc05 ? Weighted mean z-band aperture-corrected
magnitude from flux in 5 arcsec diameter
(z_apc05)
622- 627 F6.4 mag e_zapc05 ? Error in weighted mean z-band
aperture-corrected magnitude from flux
in 5 arcsec diameter (ezapc05)
629- 634 F6.4 mag zmmvar ? Magnitude range between minimum and
maximum unclipped z-band PSF magnitudes
(z_mmvar)
636- 645 I10 --- selfId1 Unique identifier (object_id) of closest
SMSS DR4 source (self_id1)
647- 656 I10 --- selfId2 Unique identifier (object_id) of
second-closest SMSS DR4 source (self_id2)
658- 667 I10 --- selfId3 Unique identifier (object_id) of
third-closest SMSS DR4 source (self_id3)
669- 673 F5.2 arcsec selfDist1 Distance on sky to closest SMSS DR4 source
(self_dist1)
675- 679 F5.2 arcsec selfDist2 Distance on sky to second-closest
SMSS DR4 source (self_dist2)
681- 685 F5.2 arcsec selfDist4 Distance on sky to third-closest
SMSS DR4 source (self_dist3)
687- 689 I3 --- Nself-15 Number of SMSS DR4 sources within
15 arcsec (cntself15)
691- 699 I9 --- Refcat2Id Unique identifier (objid) of closest ATLAS
Refcat2 source (only useful for this copy
of Refcat2) (refcat2_id)
701- 719 I19 --- Gaia3Id1 Unique identifier (source_id) of closest
Gaia DR3 source (gaiadr3id1)
721- 739 I19 --- Gaia3Id2 Unique identifier (source_id) of
second-closest Gaia DR3 source
(gaiadr3id2)
741- 759 I19 --- ALLWISECntr Unique identifier (cntr) of closest
AllWISE source (allwise_cntr)
761- 778 I18 --- PS1dr1Id Unique identifier (objid) of closest
Pan-STARRS1 DR1 source (ps1dr1id)
780- 798 I19 --- GALEXId Unique identifier (objid) of closest
GALEX GUVcat AIS source
(Bianchi et al. 2017) (galexguvid)
800- 811 I12 --- VHS6Id Unique identifier (objid) of closest
VHS DR6 source (vhsdr6id)
813- 830 I18 --- LS9Id Unique identifier (unique_id) of closest
Legacy Survey DR9 source (lsdr9id)
832- 841 I10 --- DES2Id Unique identifier (coaddobjectid) of
closest DES DR2 source (desdr2id)
843- 852 I10 --- 2MASSKey Unique identifier (pts_key) of closest
2MASS PSC source (twomass_key)
854- 858 F5.2 arcsec Refcat2Dist ? Distance on sky to closest ATLAS
Refcat2 source (refcat2_dist)
860- 864 F5.2 arcsec Gaia3Dist1 ? Distance on sky to closest Gaia DR3
source (gaiadr3dist1)
866- 870 F5.2 arcsec Gaia3Dist2 ? Distance on sky to second-closest
Gaia DR3 source (gaiadr3dist2)
872- 876 F5.2 arcsec CATWISEDist ? Distance on sky to closest
CatWISE2020 source (catwise_dist)
878- 882 F5.2 arcsec PS1dr1Dist ? Distance on sky to closest
Pan-STARRS1 DR1 source (ps1dr1dist)
884- 888 F5.2 arcsec GALEXDist ? Distance on sky to closest
GALEX GUVcat AIS source (galexguvdist)
890- 894 F5.2 arcsec VHS6Dist ? Distance on sky to closest
VHS DR6 source (vhsdr6dist)
896- 900 F5.2 arcsec LS9Dist ? Distance on sky to closest Legacy Survey
DR9 source (lsdr9dist)
902- 906 F5.2 arcsec DES2Dist ? Distance on sky to closest DES DR2
source (desdr2dist)
908- 912 F5.2 arcsec ALLWISEDist ? Distance on sky to closest AllWISE
source (allwise_dist)
914- 918 F5.2 arcsec 2MASSDist ? Distance on sky to closest 2MASS PSC
source (twomass_dist)
920- 924 F5.2 arcsec NSC2Dist ? Distance on sky to closest NSC DR2
source (nscdr2dist)
926- 930 F5.2 arcsec SPLUS3Dist ? Distance on sky to closest S-PLUS DR3
source (splusdr3dist)
932- 939 F8.4 mag E(B-V)sfd E(B-V) from Schlegel+1998 extinction maps
at the ICRS coordinates (ebmv_sfd)
941- 948 F8.4 mag E(B-V)gnilc E(B-V) from Planck satellite GNILC
reddening maps at the ICRS coordinates
(ebmv_gnilc)
950- 956 F7.4 mag e_E(B-V)gnilc Error in the E(B-V) from GNILC
(ebmvgerr)
958- 959 I2 --- flagsPSF Bitmask indicating whether photometry is
likely biased by neighbours at >1%;
bits 0-5 correspond to filters z-u
(flags_psf)
961- 963 I3 --- NGaia3-15 Number of Gaia DR3 sources within
15 arcsec (cntgaiadr3_15)
965- 982 A18 --- ALLWISEId Unique identifier (id) of closest
CatWISE2020 source (catwise_id)
984- 997 A14 --- NSC2Id Unique identifier (id) of closest NSC DR2
source (nscdr2id)
999-1022 A24 --- SPLUS3Id Unique identifier of closest S-PLUS DR3
source (splusdr3id)
1024-1031 F8.4 mag u-v ? u-v colour (upsf-vpsf) (u_v)
1033-1040 F8.4 mag v-g ? v-g colour (vpsf-gpsf) (v_g)
1042-1049 F8.4 mag g-r ? g-r colour (gpsf-rpsf) (g_r)
1051-1058 F8.4 mag r-i ? r-i colour (rpsf-ipsf) (r_i)
1060-1067 F8.4 mag i-z ? i-z colour (ipsf-zpsf) (i_z)
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Acknowledgements:
SkyMapper team, Christopher Onken, christopher.onken(at)anu.edu.au
(End) Patricia Vannier [CDS] 02-Feb-2024