II/369 VEXAS DR2 catalogs (Khramtsov+, 2021)
VEXAS: VISTA EXtension to Auxiliary Surveys. Data Release 2:
Machine-learning based classification of sources in the Southern Hemisphere.
Khramtsov V., Spiniello C., Agnello A., Sergeyev A.
<Astron. Astrophys., 651, A69 (2021)>
=2021A&A...651A..69K 2021A&A...651A..69K
=2021yCat.2369....0K 2021yCat.2369....0K
ADC_Keywords: Surveys ; QSOs ; Galaxy catalogs ; Photometry
Keywords: astronomical databases: miscellaneous - catalogs - surveys -
methods: data analysis - virtual observatory tools
Abstract:
We present the second public data release of the VISTA EXtension to
Auxiliary Surveys (VEXAS DR2), where we classify objects into stars,
galaxies and quasars based on an ensemble of machine learning
algorithms.
The aim of VEXAS is to build the widest multi-wavelength catalogue,
providing reference magnitudes, colours and morphological information
for a large number of scientific uses.
We apply an ensemble of thirty-two different machine learning models,
based on three different algorithms and on different magnitude sets,
training samples and classification problems (two or three classes) on
the three VEXAS Data Release 1 (DR1) optical+infrared (IR) tables. The
tables were created in DR1 cross-matching VISTA near-infrared data
with Wide-field Infrared Survey Explorer far-infrared data and with
optical magnitudes from the Dark Energy Survey (VEXAS-DESW), the Sky
Mapper Survey (VEXAS-SMW), and the Panoramic Survey Telescope and
Rapid Response System Survey (VEXAS-PSW). We assemble a large table of
spectroscopically confirmed objects (VEXAS-SPEC-GOOD, 415 628 unique
objects), based on the combination of six different spectroscopic
surveys that we use for training. We develop feature imputation to
classify also objects for which magnitudes in one or more bands are
missing.
We classify in total 90106 objects in the Southern Hemisphere. Among
these, ∼62.9x106 (∼52.6x106) are classified as 'high confidence'
('secure') stars, ∼920000 (∼750000) as 'high confidence' ('secure')
quasars and ∼34.8 (∼34.1) millions as 'high confidence' ('secure')
galaxies, with pclass≥0.7 (pclass≥0.9). The DR2 tables update the
DR1 with the addition of imputed magnitudes and membership
probabilities to each of the three classes.
The density of high-confidence extragalactic objects varies strongly
with the survey depth: at pclass>0.7; there are 111/deg2 quasars in
the VEXAS-DESW footprint and 103/deg2 in the VEXAS-PSW footprint,
while only 10.7/deg2 in the VEXASSM footprint. Improved depth in the
midIR and coverage in the optical and nearIR are needed for the SM
footprint that is not already covered by DESW and PSW.
Description:
We present the second public data release of the VISTA EXtension to
Auxiliary Surveys (VEXAS DR2). In the VEXAS DR2, we classify objects
into stars, galaxies and QSOs using an ensemble of machine learning
models. We apply trained models on the three VEXAS optical-infrared
tables: VEXAS-DESW, VEXAS-PSW, and VEXAS-SMW. Also, we provide
imputation for missed optical-infrared magnitudes in all three tables.
As of March 2021, the VEXAS catalogue is the widest and deepest public
optical-infrared photometric dataset of the Southern Hemisphere.
The released VEXAS DR2 catalog includes three VEXAS DR1 tables:
- VISTA cross-match with Dark Energy Survey and AllWISE
(VEXAS-DESW, 35,381,482 sources)
- VISTA cross-match with Pan-STARRS and AllWISE
(VEXAS-PSW, 21,891,609 sources), and
- VISTA cross-match with SkyMapper and AllWISE
(VEXAS-SMW, 31,999,995 sources).
For each source, we provide optical-NIR-MIR photometric information
(including imputed magnitudes), classification (STAR, QSO, GALAXY).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
vexasdes.dat 330 35381482 VEXAS-DESW catalogue
vexasps.dat 339 21891609 VEXAS-PSW catalogue
vexassm.dat 373 31999995 VEXAS-SMW catalogue
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See also:
II/359 : The VISTA Hemisphere Survey (VHS) catalog DR4.1 (McMahon+, 2013)
II/357 : The Dark Energy Survey (DES) Data Release 1 (Abbott+, 2018)
II/349 : The Pan-STARRS release 1 (PS) Survey - DR1 (Chambers+, 2016)
II/358 : SkyMapper Southern Sky Survey (SM). DR1.1 (Wolf+, 2018)
II/328 : AllWISE catalog (Cutri+ 2013)
https://www.eso.org/rm/api/v1/public/releaseDescriptions/146 : VEXAS DR1
release documentation
https://www.eso.org/rm/api/v1/public/releaseDescriptions/172 : VEXAS DR2
release documentation
Byte-by-byte Description of file: vexasdes.dat
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Bytes Format Units Label Explanations
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1- 12 I12 --- VISTA ID in VISTA (SOURCEID_VISTA)
14- 22 I9 --- DES ID in DES (coaddobjid_DES)
24- 42 A19 --- AllWISE ID in AllWISE (ID_AllWISE)
44- 55 F12.8 deg RAdeg Right Ascension (J2000.0) in DES (RA_DES)
57- 68 F12.8 deg DEdeg Declination (J2000.0) in DES (DEC_DES)
70- 76 F7.3 mag Ymag ?=- Magnitude in Y-band from VISTA (Y_VISTA)
78- 84 F7.3 mag e_Ymag ?=- Error in Y_VISTA (EY_VISTA)
86- 92 F7.3 mag Jmag Magnitude in J-band from VISTA (J_VISTA)
94-100 F7.3 mag e_Jmag ?=- Error in J_VISTA (EJ_VISTA) (G1)
102-108 F7.3 mag Hmag ?=- Magnitude in H-band from VISTA (H_VISTA)
110-116 F7.3 mag e_Hmag ?=- Error in H_VISTA (EH_VISTA)
118-124 F7.3 mag Ksmag Magnitude in Ks-band from VISTA (KS_VISTA)
126-132 F7.3 mag e_Ksmag ?=- Error in KS_VISTA (EKS_VISTA) (G1)
134-140 F7.3 mag gmag Magnitude in g-band from DES (magautog_DES)
142-148 F7.3 mag e_gmag ?=- Error in magautog_DES
(magerrautog_DES) (G1)
150-156 F7.3 mag rmag Magnitude in r-band from DES (magautor_DES)
158-164 F7.3 mag e_rmag ?=- Error in magautor_DES
(magerrautor_DES) (G1)
166-172 F7.3 mag imag Magnitude in i-band from DES (magautoi_DES)
174-180 F7.3 mag e_imag ?=- Error in magautoi_DES
(magerrautoi_DES) (G1)
182-188 F7.3 mag zmag Magnitude in z-band from DES (magautoz_DES)
190-196 F7.3 mag e_zmag ?=- Error in magautoz_DES
(magerrautoz_DES) (G1)
198-204 F7.3 mag ymag Magnitude in y-band from DES (magautoy_DES)
206-212 F7.3 mag e_ymag ?=- Error in magautoy_DES
(magerrautoy_DES) (G1)
214-220 F7.3 mag W1mag Magnitude in W1-band from WISE (W1mag)
222-228 F7.3 mag e_W1mag ?=- Error in W1mag (e_W1mag) (G1)
230-236 F7.3 mag W2mag Magnitude in W2-band from WISE (W2mag)
238-244 F7.3 mag e_W2mag ?=- Error in W2mag (e_W2mag) (G1)
246-252 F7.3 mag W3mag ?=- Magnitude in W3-band from WISE (W3mag)
254-260 F7.3 mag e_W3mag ?=- Error in W3mag (e_W3mag)
262-268 F7.3 mag W4mag ?=- Magnitude in W4-band from WISE (W4mag)
270-276 F7.3 mag e_W4mag ?=- Error in W4mag (e_W4mag)
278-284 F7.5 --- pStarVISTA [0/1] Probability that the source is a star
from VISTA (PSTAR_VISTA)
286-292 F7.5 mag E(B-V) The galactic dust extinction value measured
from the Schlegel maps (EBV_VISTA) (G2)
294-300 F7.5 --- pSTAR [0/1] Probability of being a STAR (p_STAR)
302-308 F7.5 --- pQSO [0/1] Probability of being a QSO (p_QSO)
310-316 F7.5 --- pGALAXY [0/1] Probability of being a GALAXY
(p_GALAXY)
318 I1 --- Class Object classification (CLASS) (G3)
320-328 A9 --- Impflag String indicating which magnitudes are
imputed (Imputation_flag) (G4)
330 I1 --- Warflag Flag which highlights if the objects is
within the safe ranges or not and if it is
an outlier or not (Warning_flag) (G5)
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Byte-by-byte Description of file: vexasps.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 I12 --- VISTA ID in VISTA (SOURCEID_VISTA)
14- 31 I18 --- PS ID in Pan-STARRS DR1 (objID_PS)
33- 51 A19 --- AllWISE ID in AllWISE (ID_AllWISE)
53- 64 F12.8 deg RAdeg Right Ascension (J2000.0) in PS (RA_PS)
66- 77 F12.8 deg DEdeg Declination (J2000.0) in DES (DEC_PS)
79- 85 F7.3 mag Ymag ?=- Magnitude in Y-band from VISTA (Y_VISTA)
87- 93 F7.3 mag e_Ymag ?=- Error in Y_VISTA (EY_VISTA)
95-101 F7.3 mag Jmag Magnitude in J-band from VISTA (J_VISTA)
103-109 F7.3 mag e_Jmag ?=- Error in J_VISTA (EJ_VISTA) (G1)
111-117 F7.3 mag Hmag ?=- Magnitude in H-band from VISTA (H_VISTA)
119-125 F7.3 mag e_Hmag ?=- Error in H_VISTA (EH_VISTA)
127-133 F7.3 mag Ksmag Magnitude in Ks-band from VISTA (KS_VISTA)
135-141 F7.3 mag e_Ksmag ?=- Error in KS_VISTA (EKS_VISTA) (G1)
143-149 F7.3 mag gmag Magnitude in g-band from PS (gpetMag_PS)
151-157 F7.3 mag e_gmag ?=- Error in gmag (gpetMagErr_PS) (G1)
159-165 F7.3 mag rmag Magnitude in r-band from PS (rpetMag_PS)
167-173 F7.3 mag e_rmag ?=- Error in rmag (rpetMagErr_PS) (G1)
175-181 F7.3 mag imag Magnitude in i-band from PS (ipetMag_PS)
183-189 F7.3 mag e_imag ?=- Error in imag (ipetMagErr_PS) (G1)
191-197 F7.3 mag zmag Magnitude in z-band from PS (zpetMag_PS)
199-205 F7.3 mag e_zmag ?=- Error in zmag (zpetMagErr_PS) (G1)
207-213 F7.3 mag ymag Magnitude in y-band from PS (ypetMag_PS)
215-221 F7.3 mag e_ymag ?=- Error in ymag (ypetMagErr_PS) (G1)
223-229 F7.3 mag W1mag Magnitude in W1-band from WISE (W1mag)
231-237 F7.3 mag e_W1mag ?=- Error in W1mag (e_W1mag) (G1)
239-245 F7.3 mag W2mag Magnitude in W2-band from WISE (W2mag)
247-253 F7.3 mag e_W2mag ?=- Error in W2mag (e_W2mag) (G1)
255-261 F7.3 mag W3mag ?=- Magnitude in W3-band from WISE (W3mag)
263-269 F7.3 mag e_W3mag ?=- Error in W3mag (e_W3mag)
271-277 F7.3 mag W4mag ?=- Magnitude in W4-band from WISE (W4mag)
279-285 F7.3 mag e_W4mag ?=- Error in W4mag (e_W4mag)
287-293 F7.5 --- PSTARVISTA [0/1] Probability that the source is a star
from VISTA (PSTAR_VISTA)
295-301 F7.3 mag E(B-V) The galactic dust extinction value measured
from the Schlegel maps (EBV_VISTA) (G2)
303-309 F7.5 --- pSTAR [0/1] Probability of being a STAR (p_STAR)
311-317 F7.5 --- pQSO [0/1] Probability of being a QSO (p_QSO)
319-325 F7.5 --- pGALAXY [0/1] Probability of being a GALAXY
(p_GALAXY)
327 I1 --- CLASS Object classification (CLASS) (G3)
329-337 A9 --- Impflag String indicating which magnitudes are
imputed (Imputation_flag) (G4)
339 I1 --- Warflag Flag which highlights if the objects is
within the safe ranges or not and if it is
an outlier or not (Warning_flag) (G5)
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Byte-by-byte Description of file: vexassm.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 I12 --- VISTA ID in VISTA (SOURCEID_VISTA)
14- 22 I9 --- SM ID in SkyMapper (objectidSM)
24- 42 A19 --- AllWISE ID in AllWISE (ID_AllWISE)
44- 55 F12.8 deg RAdeg Right Ascension (J2000.0) in SM (RA_SM)
57- 68 F12.8 deg DEdeg Declination (J2000.0) in SM (DEC_SM)
70- 76 F7.3 mag Ymag ?=- Magnitude in Y-band from VISTA (Y_VISTA)
78- 84 F7.3 mag e_Ymag ?=- Error in Y_VISTA (EY_VISTA)
86- 92 F7.3 mag Jmag Magnitude in J-band from VISTA (J_VISTA)
94-100 F7.3 mag e_Jmag ?=- Error in J_VISTA (EJ_VISTA) (G1)
102-108 F7.3 mag Hmag ?=- Magnitude in H-band from VISTA (H_VISTA)
110-116 F7.3 mag e_Hmag ?=- Error in H_VISTA (EH_VISTA)
118-124 F7.3 mag Ksmag Magnitude in Ks-band from VISTA (KS_VISTA)
126-132 F7.3 mag e_Ksmag ?=- Error in KS_VISTA (EKS_VISTA) (G1)
134-140 F7.3 mag umag Magnitude in u-band from SM (upetroSM)
142-148 F7.3 mag e_umag ?=- Error in upetroSM (eupetro_SM) (G1)
150-156 F7.3 mag vmag ?=- Magnitude in v-band from SM (vpetroSM)
158-164 F7.3 mag e_vmag ?=- Error in vpetroSM (evpetro_SM) (G1)
166-172 F7.3 mag gmag Magnitude in g-band from SM (gpetroSM)
174-180 F7.3 mag e_gmag ?=- Error in gpetroSM (egpetro_SM) (G1)
182-188 F7.3 mag rmag Magnitude in r-band from SM (rpetroSM)
190-196 F7.3 mag e_rmag ?=- Error in rpetroSM (erpetro_SM) (G1)
198-204 F7.3 mag imag Magnitude in i-band from SM (ipetroSM)
206-212 F7.3 mag e_imag ?=- Error in ipetroSM (eipetro_SM) (G1)
214-220 F7.3 mag zmag Magnitude in z-band from SM (zpetroSM)
222-228 F7.3 mag e_zmag ?=- Error in zpetroSM (ezpetro_SM) (G1)
230-236 F7.3 mag W1mag Magnitude in W1-band from WISE (W1mag)
238-244 F7.3 mag e_W1mag ?=- Error in W1mag (e_W1mag) (G1)
246-252 F7.3 mag W2mag Magnitude in W2-band from WISE (W2mag)
254-260 F7.3 mag e_W2mag ?=- Error in W2mag (e_W2mag) (G1)
262-268 F7.3 mag W3mag ?=- Magnitude in W3-band from WISE (W3mag)
270-276 F7.3 mag e_W3mag ?=- Error in W3mag (e_W3mag)
278-284 F7.3 mag W4mag ?=- Magnitude in W4-band from WISE (W4mag)
286-292 F7.3 mag e_W4mag ?=- Error in W4mag (e_W4mag)
294-300 F7.5 --- pStarVISTA [0/1] Probability that the source is a star
from VISTA (PSTAR_VISTA)
302-308 F7.3 mag E(B-V) The galactic dust extinction value measured
from the Schlegel maps (EBV_VISTA) (G2)
310-316 F7.5 --- pSTAR [0/1] Probability of being a STAR (p_STAR)
318-324 F7.5 --- pQSO [0/1] Probability of being a QSO (p_QSO)
326-332 F7.5 --- pGALAXY [0/1] Probability of being a GALAXY
(p_GALAXY)
334 I1 --- CLASS Object classification (CLASS) (G3)
336-342 F7.5 --- pSTAR25 [0/1] Probability of being a STAR
from MODEL_25 (pSTAR25)
344-350 F7.5 --- pQSO25 [0/1] Probability of being a QSO
from MODEL_25 (pQSO25)
352-358 F7.5 --- pGALAXY25 [0/1] Probability of being a GALAXY
from MODEL_25 (pGALAXY25)
360 I1 --- CLASS25 Object classification from MODEL_25
(CLASS_25) (G3)
362-371 A10 --- Impflag String indicating which magnitudes are
imputed (Imputation_flag) (G4)
373 I1 --- Warflag Flag which highlights if the objects is
within the safe ranges or not and if it is
an outlier or not (Warning_flag) (G5)
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Global notes:
Note (G1): Imputed magnitudes have no corresponding magnitude errors (---)
Note (G2): We used extinction maps presented in Schlegel et al.
(1998ApJ...500...525)
Note (G3): Code as follows:
0 = STAR
1 = QSO
2 = GALAXY
Note (G4): For example, "gzW1" means that magautog_DES (gmag),
magautoz_DES (zmag), and W1mag are imputed.
Note (G5): Code as follows:
0 = source is within safe ranges
1 = source is outside safe ranges but is not outlier
2 = source is outlier in colour space
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Acknowledgements:
Alexey Sergeyev, alexey.v.sergeyev(at)gmail.com
(End) Patricia Vannier [CDS] 17-Jun-2021