J/A+A/592/A121 SDSS-IV eBOSS emission-line galaxy pilot survey (Comparat+, 2016)
SDSS-IV eBOSS emission-line galaxy pilot survey.
Comparat J., Delubac T., Jouvel S., Raichoor A., Kneib J-P., Yeche C.,
Abdalla F.B., Le Cras C., Maraston C., Wilkinson D.M., Zhu G., Jullo E.,
Prada F., Schlegel D., Xu Z., Zou H., Bautista J., Bizyaev D., Bolton A.,
Brownstein J.R., Dawson K.S., Escoer S., Gaulme P., Kinemuchi K.,
Malanushenko E., Malanushenko V., Mariappan V., Newman J.A., Oravetz D.,
Pan K., Percival W.J., Prakash A., Schneider D.P., Simmons A.,
Abbott T.M.C., Allam S., Banerji M., Benoit-Levy A., Bertin E., Brooks D.,
Capozzi D., Carnero Rosell A., Carrasco Kind M., Carretero J.,
Castander F.J., Cunha C.E., da Costa L.N., Desai S., Doel P., Eifler T.F.,
Estrada J., Flaugher B., Fosalba P., Frieman J., Gaztanaga E., Gerdes D.W.,
Gruen D., Gruendl R.A., Gutierrez G., Honscheid K., James D.J., Kuehn K.,
Kuropatkin N., Lahav O., Lima M., Maia M.A.G., March M., Marshall J.L.,
Miquel R., Plazas A.A., Reil K., Roe N., Romer A.K., Roodman A.,
Rykoff E.S., Sako M., Sanchez E., Scarpine V., Sevilla-Noarbe I.,
Soares-Santos M., Sobreira F., Suchyta E., Swanson M.E.C., Tarle G.,
Thaler J., Thomas D., Walker A.R., Zhang Y.
<Astron. Astrophys. 592, A121 (2016)>
=2016A&A...592A.121C 2016A&A...592A.121C (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Galaxy catalogs ; Photometry ; Redshifts
Keywords: large-scale structure of Universe - galaxies: general -
methods: observational
Abstract:
The Sloan Digital Sky Survey IV extended Baryonic Oscillation
Spectroscopic Survey (SDSS-IV/eBOSS) will observe 195,000
emission-line galaxies (ELGs) to measure the Baryonic Acoustic
Oscillation standard ruler (BAO) at redshift 0.9. To test different
ELG selection algorithms, based on data from several imaging surveys,
9,000 spectra were observed with the SDSS spectrograph as a pilot
survey. First, using visual inspection and redshift quality flags, we
find that the automated spectroscopic redshifts assigned by the
pipeline meet the quality requirements for a robust BAO measurement.
Also, we show the correlations between sky emission, signal-to-noise
ratio in the emission lines and redshift error. Then we provide a
detailed description of each target selection algorithm tested and
compare them with the requirements of the eBOSS experiment. As a
result, we provide robust redshift distributions for the different
target selection schemes tested. Finally, we infer two optimal target
selection algorithms to be applied on DECam photometry that fulfill
the eBOSS survey electronic efficiency requirements.
Description:
To select targets, we used photometry coming from the following
surveys: SDSS (Alam et al., 2012ApJS..203...21A 2012ApJS..203...21A), WISE (Cutri et al.,
2012, Cat. II/311) and SCUSS (Zou et al., 2015AJ....150..104Z 2015AJ....150..104Z).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spallelg.dat 429 12516 Troncated catalog
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See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
http://www.sdss.org/dr12/ : SDSS DR12 Home Page
Byte-by-byte Description of file: spallelg.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- TS Name of the target selection algorithm
used (TS)
22- 26 I5 --- Tile SDSS tile number (TILE)
28- 31 I4 --- Plate SDSS plate number (PLATE)
33- 37 I5 --- MJD SDSS MJD number (MJD)
39- 42 I4 --- Fiber SDSS Fiber numberd (FIBERID)
44- 53 F10.6 deg RAdeg PLUG right ascension (J2000) (PLUG_RA)
55- 64 F10.6 deg DEdeg PLUG declination (J2000) (PLUG_DEC)
66- 71 A6 --- Class Classification (CLASS)
73- 91 A19 --- SubClass Sub-classification (SUBCLASS)
93-101 F9.6 --- z SDSS spectroscopic redshift (Z)
103-113 F11.6 --- e_z [] Error on e_z (Z_ERR) (1)
115-117 I3 --- zWar [0/646] z warning code (ZWARNING) (2)
119-122 F4.1 --- zQ [-2/4.5] Redshift flag zQ (zQ) (3)
124-127 F4.1 --- zCont [0/2.5] Redshift flag zCont (zCont) (4)
129-135 F7.4 mag USmag ?=- Model SCUSS U magnitude (SCUSS_modeladd)
137-144 F8.6 mag e_USmag ?=- Error on USmag (SCUSS_modeladderr)
146-152 F7.4 mag umag ?=- Model SDSS u magnitude (SDSSmodelmagu)
154-160 F7.4 mag gmag ?=- Model SDSS g magnitude (SDSSmodelmagg)
162-168 F7.4 mag rmag ?=- Model SDSS r magnitude (SDSSmodelmagr)
170-176 F7.4 mag imag ?=- Model SDSS i magnitude (SDSSmodelmagi)
178-184 F7.4 mag zmag ?=- Model SDSS z magnitude (SDSSmodelmagz)
186-193 F8.6 mag e_umag ?=- Error on umag (SDSSmodelmagerru)
195-202 F8.6 mag e_gmag ?=- Error on gmag (SDSSmodelmagerrg)
204-211 F8.6 mag e_rmag ?=- Error on rmag (SDSSmodelmagerrr)
213-220 F8.6 mag e_imag ?=- Error on imag (SDSSmodelmagerri)
222-229 F8.6 mag e_zmag ?=- Error on zmag (SDSSmodelmagerrz)
231-238 F8.6 mag Extu ?=- Extinction in u band (EXTINCTION_U)
240-247 F8.6 mag Extg ?=- Extinction in g band (EXTINCTION_G)
249-256 F8.6 mag Extr ?=- Extinction in r band (EXTINCTION_R)
258-265 F8.6 mag Exti ?=- Extinction in i band (EXTINCTION_I)
267-274 F8.6 mag Extz ?=- Extinction in z band (EXTINCTION_Z)
276-291 E16.11 deg RACdeg ?=- CFHT right ascension (J2000) (CFHT_alpha)
293-308 E16.11 deg DECdeg ?=- CFHT declination (J2000) (CFHT_delta)
310-312 I3 --- fCFHT ?=- CFTH flag (CFHT_flag) (5)
314 I1 --- S/G [0/1]?=- CFHT galaxy/star parameter
(CFHT_starGal)
316-320 F5.2 pix r2 ?=- radius enclosing half the flux (CFHT_r2)
322-331 F10.6 --- zph ?=- CFHT photometric redshift (CFHT_zphot)
333-339 F7.3 mag Umag ?=- CFHT u magnitude (CFHT_U)
341-346 F6.3 mag Gmag ?=- CFHT g magnitude (CFHT_G)
348-353 F6.3 mag Rmag ?=- CFHT r magnitude (CFHT_R)
355-361 F7.3 mag Imag ?=- CFHT i magnitude (CFHT_I)
363-369 F7.3 mag Ymag ?=- CFHT y magnitude (CFHT_Y)
371-377 F7.3 mag Zmag ?=- CFHT z magnitude (CFHT_Z)
379-385 F7.3 mag e_Umag ?=- Error on Umag (CFHT_eU)
387-391 F5.3 mag e_Gmag ?=- Error on Gmag (CFHT_eG)
393-397 F5.3 mag e_Rmag ?=- Error on Rmag (CFHT_eR)
399-405 F7.3 mag e_Imag ?=- Error on Imag (CFHT_eI)
407-413 F7.3 mag e_Ymag ?=- Error on Ymag (CFHT_eY)
415-421 F7.3 mag e_Zmag ?=- Error on Zmag (CFHT_eZ)
423-425 I3 mag Wmag [-99] WISE W1 or W2 magnitude,
not used (WISE_WABmag)
427-429 I3 mag e_Wmag [-99] Error on Wmag, not used (WISE_WABmagerr)
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Note (1): Negative values (-1, -4, -5 and -6) correspond to non-value codes.
Note (2): z warning code defined at
http://www.sdss.org/dr12/algorithms/bitmasks/#ZWARNING
Note (3): zQ code as follows:
-2.0 = e_z>0.005(1+z) or zWar different of 0 or 4
-1.0 = CLASS = 'STAR'
1.0 = one line at low SNR
1.5 = two lines at low SNR
2.0 = one line at high SNR
2.5 = three or more lines at low SNR
3.0 = one line at high SNR and at least one line at low SNR
3.5 = [OII] 3728 at high SNR
4.0 = two lines at high SNR
4.5 = three or more lines at high SNR
0.0 = none of the conditions above are met
Note (4): zCont code as follows:
2.5 = magnitude u or g or i or z < 19.5
2.0 = magnitude u or g or i or z < 20
1.5 = magnitude u or g or i or z < 20.5
1.0 = >3 lines with the continuum detected at SNR 10
0.5 = >3 lines with the continuum detected at SNR 8
0.0 = none of the conditions above are met
Note (5): CFHT flag derived from the Sextractor r2 parameter, the saturation
and the masking. The flag value is a combination of the following
binary flags :
0/1 : galaxy/star
0/2 : saturated object in at least one filter
0/4 : masked in z band
0/8 : masked in y band
0/16 : masked in i band
0/32 : masked in r band
0/64 : masked in g band
0/128 : masked in u band
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Acknowledgements:
Johan Comparat, j.comparat(at)csic.es
(End) Patricia Vannier [CDS] 21-Jun-2016