J/MNRAS/525/1106 DESI Peculiar Velocity survey (Saulder+, 2023)
Target Selection for the DESI Peculiar Velocity Survey.
Saulder C., Howlett C., Douglass K.A., Said K., BenZvi S., Ahlen S.,
Aldering G., Bailey S., Brooks D., Davis T.M., de la Macorra A., Dey A.,
Font-Ribera A., Forero-Romero J.E., Gontcho S., Gontcho A., Honscheid K.,
Kim A.G., Kisner T., Kremin A., Landriau M., Levi M.E., Lucey J.,
Meisner A.M., Miquel R., Moustakas J., Myers A.D., Palanque-Delabrouille N.,
Percival W., Poppett C., Prada F., Qin F., Schubnell M., Tarle G.,
Vargas Magana M., Weaver B.A., Zhou R., Zhou Z., Zou H.
<Mon. Not. R. Astron. Soc. 525, 1106-1125 (2023)>
=2023MNRAS.525.1106S 2023MNRAS.525.1106S (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Galaxies ; Redshifts ; Morphology ; Photometry ; Optical
Keywords: galaxies: distances and redshifts - surveys - cosmology: observation
Abstract:
We describe the target selection and characteristics of the
DESI Peculiar Velocity Survey, the largest survey of peculiar
velocities (PVs) using both the fundamental plane (FP) and the
Tully-Fisher (TF) relationship planned to date. We detail how we
identify suitable early-type galaxies (ETGs) for the FP and suitable
late-type galaxies (LTGs) for the TF relation using the photometric
data provided by the DESI Legacy Imaging Survey DR9. Subsequently, we
provide targets for 373533 ETGs and 118637 LTGs within the DESI
5-year footprint. We validate these photometric selections using
existing morphological classifications. Furthermore, we demonstrate
using survey validation data that DESI is able to measure the
spectroscopic properties to sufficient precision to obtain PVs for our
targets. Based on realistic DESI fiber assignment simulations and
spectroscopic success rates, we predict the final DESI PV Survey will
obtain ∼133000 FP-based and ∼53000 TF-based PV measurements over
an area of 14000deg2. We forecast the ability of using these data to
measure the clustering of galaxy positions and PVs from the combined
DESI PV and Bright Galaxy Surveys (BGS), which allows for cancellation
of cosmic variance at low redshifts. With these forecasts, we
anticipate a 4% statistical measurement on the growth rate of
structure at z<0.15. This is over two times better than
achievable with redshifts from the BGS alone. The combined DESI PV and
BGS will enable the most precise tests to date of the time and scale
dependence of large-scale structure growth at z<0.15.
Description:
These tables provide the target catalogs for the DESI peculiar
velocity survey as well as all supplementary information to reproduce
them and the methods presented in our paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 131 4456142 Basic parameters of our basic sample
tableb2.dat 157 4456142 Derived photometric parameters of our basic sample
tableb3.dat 75 4456142 Flags of our basic sample
tableb4.dat 108 427273 Fibre pointings for the FP targets
tableb5.dat 108 389316 Fibre pointings for the TF relation targets
tableb6.dat 108 81611 Fibre pointings for the Siene Galaxy Atlas targets
tableb7.dat 108 20486 Fibre pointings for the extended targets
tableb8.dat 125 310643 Parameters used from the Siena Galaxy Atlas
matched to our basic sample
tableb9.dat 36 458120 Parameters used from the GalaxyZoo matched to
our basic sample
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See also:
VII/292 : DESI Legacy Imaging Surveys DR8 (Duncan, 2022)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ObjID DESI Legacy Imaging Survey DR9 object ID
7- 12 I6 --- BrickID DR9 Brick ID
14- 21 A8 --- BrickName DR9 Brick name
23- 46 E24.16 deg RAdeg Right ascension (ICRS)
48- 71 E24.16 deg DEdeg Declination (ICRS)
73- 75 A3 --- Type Type of photometric model used (G1)
77- 86 F10.8 --- Sersic Sersic index
88-101 F14.10 --- zph Median photometric redshift
103-117 E15.7 --- b_zph Lower 2-sigma bound of photometric
redshift estimate
119-131 F13.9 --- ShapeR Angular size as measured by model fit
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ObjID DESI Legacy Imaging Survey DR9 object ID
7- 12 I6 --- BrickID DR9 Brick ID
14- 21 A8 --- BrickName DR9 Brick name
23- 32 F10.7 mag gmag Extinction-corrected apparent g band magnitude
34- 43 F10.7 mag rmag Extinction-corrected apparent r band magnitude
51- 60 F10.7 mag zmag ? Extinction-corrected apparent z band
magnitude
61 A1 --- n_zmag [I] I for infinity
62- 77 E16.10 mag e_gmag Error of the g band magnitude
79- 94 E16.10 mag e_rmag Error of the r band magnitude
96-111 E16.10 mag e_zmag ? Error of the z band magnitude
112 A1 --- nezmag [I] I for infinity
113-126 E14.8 --- b/a Minor to major axis ratio (b/a)
128-141 F14.10 arcsec RadCirc Circularised angular radius
143-157 E15.9 deg PA [] Position angle
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Byte-by-byte Description of file: tableb3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ObjID DESI Legacy Imaging Survey DR9 object ID
7- 12 I6 --- BrickID DR9 Brick ID
14- 21 A8 --- BrickName DR9 Brick name
23- 27 A5 --- etgFlag [false/true ] is early type galaxy
29- 33 A5 --- ltgFlag [false/true ] is late type galaxy
35- 39 A5 --- inSGA [false/true ] in Siena Galaxy Atlas
41- 45 A5 --- inBGSold [false/true ] in old DESI BGS selection
47- 51 A5 --- inbright [false/true ] is a bright object
53- 57 A5 --- is-lowz [false/true ] has redshift below 0.15
59- 63 A5 --- in-spec [false/true ] in DESI spectroscopic footprint
65- 69 A5 --- in-sdssdr7 [false/true ] in SDSS DR7 footprint
71- 75 A5 --- in-galaxyzoo [false/true ] in GalaxyZoo
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Byte-by-byte Description of file: tableb[4567].dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ObjID DESI Legacy Imaging Survey DR9 object ID
7- 12 I6 --- BrickID DR9 Brick ID
14- 21 A8 --- BrickName DR9 Brick name
23- 45 E23.19 deg RAdeg Right ascension (ICRS)
47- 69 E23.19 deg DEdeg Declination (ICRS)
71- 76 F6.1 --- RefEpoch [2015.5] reference epoch
78- 82 A5 --- Override [false/true ] override flag needed for DESI
84- 86 A3 --- PVType Peculiar velocity target type (G1)
88 I1 --- PVPriority Peculiar velocity priority
90- 91 I2 --- PointingID Pointing id for this galaxy
93-108 I16 --- TargetID DESI target ID
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Byte-by-byte Description of file: tableb8.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ObjID DESI Legacy Imaging Survey DR9 object ID
7- 12 I6 --- BrickID DR9 Brick ID
14- 21 A8 --- BrickName DR9 Brick name
23- 29 I7 --- SGAID Siena Galaxy Atlas ID
31- 45 E15.7 deg PA Position angle from SGA
47- 57 F11.9 --- b/a Axis ratio from SGA
59- 68 F10.7 mag gmagSB25 ?=-1 g band magnitude within 25mag
surface brightness isophotes
70- 79 F10.7 mag rmagSB25 ?=-1 r band magnitude within 25mag
surface brightness isophotes
81- 90 F10.7 mag zmagSB25 ?=-1 z band magnitude within 25mag
surface brightness isophotes
92-103 F12.8 arcsec RadSB25 ?=-1 radius of the 25mag
surface brightness isophotes
105-115 F11.8 arcmin Diam ?=-1 galaxy diameter from HyperLEDA
117-125 A9 --- MType Morphological type
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Byte-by-byte Description of file: tableb9.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ObjID DESI Legacy Imaging Survey DR9 object ID
7- 12 I6 --- BrickID DR9 Brick ID
14- 21 A8 --- BrickName DR9 Brick name
23- 27 F5.3 --- peldebiased Debiased GalaxyZoo vote fraction
for elliptical
29- 33 F5.3 --- pcsdebiased Debiased GalaxyZoo vote fraction for spirals
35- 36 I2 --- Nvote Number of GalaxyZoo votes
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Blobal notes:
Note (G1): Model used for best fit as follows:
PSF = point spread function
REX = round exponential galaxy model
DEV = de Vaucouleurs model
EXP = exponential model
SER = Sersic model
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Acknowledgements:
Christoph Saulder, csaulder(at)mpe.mpg.de
(End) Patricia Vannier [CDS] 01-Aug-2023