J/MNRAS/489/5301 DES Y3 substellar LT and M catalogs (Carnero Rosell+, 2019)
Brown dwarf census with the Dark Energy Survey year 3 data and the thin disk
scale height of early L types.
Carnero Rosell A., Santiago B., dal Ponte M., Burningham B., da Costa L.N.,
James D.J., Marshall J.L., McMahon R.G., Bechtol K., De Paris L., Li T.,
Pieres A., Garcia-Bellido J., Abbott T.M.C., Annis J., Avila S.,
Bernstein G.M., Brooks D., Burke D.L., Carrasco Kind M., Carretero J.,
De Vicente J., Drlica-Wagner A., Fosalba P., Frieman J., Gaztanaga E.,
Gruendl R.A., Gschwend J., Gutierrez G., Hollowood D.L., Maia M.A.G.,
Menanteau F., Miquel R., Plazas A.A., Roodman A., Sanchez E., Scarpine V.,
Schindler R., Serrano S., Sevilla-Noarbe I., Smith M., Sobreira F.,
Soares-Santos M., Suchyta E., Swanson M.E.C., Tarle G., Vikram V.,
Walker A.R., DES Collaboration
<Mon. Not. R. Astron. Soc. 489, 5301 (2019)>
=2019MNRAS.489.5301C 2019MNRAS.489.5301C (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, faint ; Stars, M-type ; Stars, late-type ;
Photometry, infrared
Keywords: techniques: photometric - catalogues - surveys - brown dwarfs -
Galaxy: fundamental parameters - infrared: stars
Abstract:
In this paper we present a catalogue of 11745 brown dwarfs with
spectral types ranging from L0 to T9, photometrically classified using
data from the Dark Energy Survey (DES) year 3 release matched to the
Vista Hemisphere Survey (VHS) DR3 and Wide-field Infrared Survey
Explorer (WISE) data, covering ∼2400deg2 up to iAB=22. The
classification method follows the same photo-type method previously
applied to SDSS-UKIDSS-WISE data. The most significant difference
comes from the use of DES data instead of SDSS, which allow us to
classify almost an order of magnitude more brown dwarfs than any
previous search and reaching distances beyond 400 parsecs for the
earliest types. Next, we also present and validate the GalmodBD
simulation, which produces brown dwarf number counts as a function of
structural parameters with realistic photometric properties of a given
survey. We use this simulation to estimate the completeness and purity
of our photometric LT catalogue down to iAB=22, as well as to
compare to the observed number of LT types. We put constraints on the
thin disk scale height for the early L (L0-L3) population to be around
450 parsecs, in agreement with previous findings.
For completeness, we also publish in a separate table a catalogue of
20863 M dwarfs that passed our colour cut with spectral types greater
than M6. Both the LT and the late M catalogues are found at
https://des.ncsa.illinois.edu/releases/other/y3-mlt.
Description:
We apply a photometric brown dwarf classification scheme to DES + VHS
+ AllWISE data (∼2400 square degrees) using 8 bands covering a
wavelength range between 0.7um and 4.6um. Since several degeneracies
are found in colour space between spectral types M,L and T the use of
multiple bands is required for a good spectral type calibration.
We classify 11745 brown dwarfs in the spectral regime from L0 to T9
in approx 2400 square degrees, with a spectral resolution of 1
spectral type. We further estimate the contamination and completeness
of the sample. We estimate the sample to be 77 percent complete and 74
percent pure at a magnitude limit of z=22. We also publish, in a
separate table, a catalog of 20863 M dwarfs that passed our colour
cut with spectral types greater than M6.
We publish the zeropoint corrected DES magnitudes plus VHS and AllWISE
magnitudes used for classification, positions in J2000, the
photometric classification of the LT types and M types, the number of
bands used in the classification and the χ2 of the fit and its
photometry. Finally, for the LT sample only: if the source is
considered peculiar and estimated photometric distances based on the
apparent magnitudes and spectral types.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
desy3-lt.dat 287 11745 DES Y3 LT type brown dwarfs catalog
desy3-m.dat 260 20863 DES Y3 M type brown dwarfs catalog
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Byte-by-byte Description of file: desy3-lt.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID DES DR1 ID Number (COADDOBJECTID)
11- 20 F10.6 deg RAdeg Right ascension (J2000.0) (RA)
22- 31 F10.6 deg DEdeg Declination (J2000.0) (DEC)
33- 36 F4.1 --- SpTypePh Photometric spectral type (SPT_PHOT) (1)
38 I1 --- NBands Number of bands for classification (NBANDS)
40- 52 F13.9 --- XI2Class xi2 for the best fit in LT spectral type
(XI2_CLASSIF)
54- 63 F10.6 pc DistAvg Average distance (DISTANCE_AVG) (2)
65- 74 F10.6 pc Distz Distance calculated using z band (DISTANCE_Z)
76- 82 I7 --- Hpix512 Healpix pixel ID (HPIX_512) (3)
84 I1 --- Pec If is peculiar based on fit (PECULIAR) (4)
86- 97 F12.6 mag ipsf ?=-9999.0 DES Y3 i band psf mag (AB)
(PSFMAGI)
99-114 F16.10 mag e_ipsf ?=-9999.0 Error in DES Y3 i band psf
(PSFMAGERRI)
116-124 F9.6 mag zpsf DES Y3 z band psf mag (AB) (PSFMAGZ)
126-137 E12.10 mag e_zpsf Error in DES Y3 z band psf mag (PSFMAGERRZ)
139-148 F10.7 mag Yauto DES Y3 Y band auto mag (AB) (AUTOMAGY)
150-161 E12.10 mag e_Yauto Error in DES Y3 Y band auto mag
(AUTOMAGERRY)
163-172 F10.7 mag Jap3 VHS DR3 J band aper3 mag (Vega) (JAPERMAG3)
174-185 F12.10 mag e_Jap3 Error in VHS DR3 J band aper3 mag
(JAPERMAG3ERR)
187-199 F13.7 mag Hap3 ?=-9999.0 VHS DR3 H band aper3 (Vega)
(HAPERMAG3)
201-216 F16.10 mag e_Hap3 ?=-9999.0 Error in VHS DR3 H band aper3
(HAPERMAG3ERR)
218-230 F13.7 mag Ksap3 ?=-9999.0 VHS DR3 Ks band aper3 (Vega)
(KSAPERMAG3)
232-247 F16.10 mag e_Ksap3 ?=-9999.0 Error in VHS DR3 Ks band aper3
(KSAPERMAG3ERR)
249-257 F9.3 mag W1mag ?=-9999.0 AllWISE W1 band pro (Vega) (W1MPRO)
259-267 F9.3 mag e_W1mag ?=-9999.0 Error in AllWISE W1 band pro
(W1SIGMPRO)
269-277 F9.3 mag W2mag ?=-9999.0 AllWISE W2 band pro (Vega) (W2MPRO)
279-287 F9.3 mag e_W2mag ?=-9999.0 Error in AllWISE W2 band pro
(W2SIGMPRO)
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Note (1): Ranging L0 to T9, with L0=10 and T9=29.
Note (2): Calculated from apparent magnitudes in all the available bands.
Note (3): Healpix pixel ID with ORDER=Nest and NSIDE=512.
Note (4): Category given if it has a chi2>3.5σ median absolute deviations
as follows:.
1 = peculiar
0 = no peculiar
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Byte-by-byte Description of file: desy3-m.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- ID DES DR1 ID Number (COADDOBJECTID)
11- 20 F10.6 deg RAdeg Right ascension (J2000.0) (RA)
22- 31 E10.6 deg DEdeg Declination (J2000.0) (DEC)
33- 35 F3.1 --- SpTypePh Photometric spectral type (SPT_PHOT) (1)
37 I1 --- NBands Number of bands for classification (NBANDS)
39- 52 F14.10 --- XI2Class xi2 for the best fit in M spec type
(XI2_CLASSIF)
54- 60 I7 --- Hpix512 Healpix pixel ID (HPIX_512) (2)
62- 73 F12.6 mag ipsf ?=-9999.0 DES Y3 i band psf mag (AB)
(PSFMAGI)
75- 86 E12.10 mag e_ipsf ?=-9999.0 Error in DES Y3 i band psf
(PSFMAGERRI)
88- 97 F10.7 mag zpsf DES Y3 z band psf mag (AB) (PSFMAGZ)
99-110 E12.10 mag e_zpsf Error in DES Y3 z band psf mag (PSFMAGERRZ)
112-121 F10.7 mag Yauto DES Y3 Y band auto mag (AB) (AUTOMAGY)
123-134 E12.10 mag e_Yauto Error in DES Y3 Y band auto mag
(AUTOMAGERRY)
136-145 F10.7 mag Jap3 VHS DR3 J band aper3 mag (Vega) (JAPERMAG3)
147-158 F12.10 mag e_Jap3 ?=-9999.0 Error in VHS DR3 J band aper3 mag
(JAPERMAG3ERR)
160-172 F13.7 mag Hap3 ?=-9999.0 VHS DR3 H band aper3 (Vega)
(HAPERMAG3)
174-189 F16.10 mag e_Hap3 ?=-9999.0 Error in VHS DR3 H band aper3
(HAPERMAG3ERR)
191-203 F13.7 mag Ksap3 ?=-9999.0 VHS DR3 Ks band aper3 (Vega)
(KSAPERMAG3)
205-220 F16.10 mag e_Ksap3 ?=-9999.0 Error in VHS DR3 Ks band aper3
(KSAPERMAG3ERR)
222-230 F9.3 mag W1mag ?=-9999.0 AllWISE W1 band pro (Vega) (W1MPRO)
232-240 F9.3 mag e_W1mag ?=-9999.0 Error in AllWISE W1 band pro
(W1SIGMPRO)
242-250 F9.3 mag W2mag ?=-9999.0 AllWISE W2 band pro (Vega) (W2MPRO)
252-260 F9.3 mag e_W2mag ?=-9999.0 Error in AllWISE W2 band pro
(W2SIGMPRO)
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Note (1): Ranging M7 to M9, with M7=7 and M9=9.
Note (2): Healpix pixel ID with ORDER=Nest and NSIDE=512.
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Acknowledgements:
Aurelio Carnero Rosell, aurelio.crosell(at)gmail.com
(End) Aurelio Carnero Rosell [CIEMAT, Spain], Patricia Vannier [CDS] 11-Oct-2019