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J/A+A/602/A100    Merging groups and clusters from the SDSS data (Tempel+, 2017)

Merging groups and clusters of galaxies from the SDSS data. The catalogue of groups and potentially merging systems. Tempel E., Tuvikene T., Kipper R., Libeskind N.I. <Astron. Astrophys. 602, A100 (2017)> =2017A&A...602A.100T (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Fundamental catalog ; Galaxy catalogs Keywords: Catalogs - galaxies: groups: general - galaxies: clusters: general Abstract: Galaxy groups and clusters are the main tools to test cosmological models and to study the environmental effect of galaxy formation. This work aims to provide a catalogue of galaxy groups/clusters and potentially merging systems based on the SDSS main galaxy survey. We identify galaxy groups and clusters using the modified friends-of-friends (FoF) group finder that is designed specifically for flux-limited galaxy surveys. FoF group membership is refined by multimodality analysis to find subgroups and by using the group virial radius and escape velocity to expose unbound galaxies. We look for merging systems by comparing distances between group centres with group radii. The analysis results in a catalogue of 88 662 galaxy groups with at least two members. Among them are 6873 systems with at least 6 members which we consider as more reliable groups. We find 498 group mergers with up to six groups. Description: This work is based on catalogue data from the SDSS DR12 (Eisenstein et al., 2011AJ....142...72E; Alam et al., 2015ApJS..219...12A). We have selected galaxies only from the main contiguous area of the survey (the Legacy Survey). The final galaxy sample contains 584449 entries. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 659 584449 Catalog of galaxies table2.dat 295 88662 Catalog of galaxy groups table3.dat 50 498 Catalog of merging systems
See also: J/A+A/525/A157 : SDSS automated morphology classification (Huertas-Company+, 2011) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 6 I6 --- GalID [1/584449] Unique galaxy identification 8- 26 I19 --- specID ?=0 SDSS DR10 spectroscopic objectID (0=missing) 28- 46 I19 --- objID SDSS DR10 photometric objectID 48- 53 I6 --- GroupID [0/88662] Group/cluster id (0=isolated galaxy) 57- 59 I3 --- Ngal [1/254] Richness of group galaxy belongs 63- 65 I3 --- Rank [1/254] Luminosity rank within its group 67- 76 F10.6 Mpc Dist.g Comoving distance to group centre (G1) 78- 89 F12.9 --- zobs [-0.01/0.21] Observed redshift 91-102 F12.9 --- zcmb [0/0.2] Redshift (CMB rest frame) 104-115 F12.9 --- e_zobs Uncertainty of the redshift 117-126 F10.6 Mpc Dist Comoving distance (G1) 128-137 F10.6 Mpc Distcor Comoving distance, after suppressing the "finger-of-god" effect (G1) 139-152 F14.9 deg RAdeg Right ascension (J2000) 154-167 F14.9 deg DEdeg Declination (J2000) 169-182 F14.9 deg GLON Galactic longitude 184-197 F14.9 deg GLAT Galactic latitude 199-212 F14.9 deg SGLON Supergalactic longitude 214-227 F14.9 deg SGLAT Supergalactic latitude 229-242 F14.9 deg lambda SDSS survey coordinate, λ 244-257 F14.9 deg eta SDSS survey coordinate, η 259-269 F11.6 Mpc Xpos Cartesian x coordinate (G1) 271-281 F11.6 Mpc Ypos Cartesian y coordinate (G1) 283-293 F11.6 Mpc Zpos Cartesian z coordinate (G1) 295-305 F11.6 mag umag Extinction corrected Petrosian u magnitude 307-317 F11.6 mag gmag Extinction corrected Petrosian g magnitude 319-329 F11.6 mag rmag Extinction corrected Petrosian r magnitude 331-341 F11.6 mag imag Extinction corrected Petrosian i magnitude 343-353 F11.6 mag zmag Extinction corrected Petrosian z magnitude 355-365 F11.6 mag uMAG Absolute magnitude u-band, k+e-corrected (G1) 367-377 F11.6 mag gMAG Absolute magnitude g-band, k+e-corrected (G1) 379-389 F11.6 mag rMAG Absolute magnitude r-band, k+e-corrected (G1) 391-401 F11.6 mag iMAG Absolute magnitude i-band, k+e-corrected (G1) 403-413 F11.6 mag zMAG Absolute magnitude z-band, k+e-corrected (G1) 415-425 F11.6 mag k+e.u k+e-correction (u filter) 427-437 F11.6 mag k+e.g k+e-correction (g filter) 439-449 F11.6 mag k+e.r k+e-correction (r filter) 451-461 F11.6 mag k+e.i k+e-correction (i filter) 463-473 F11.6 mag k+e.z k+e-correction (z filter) 475-485 F11.6 mag ext.u Galactic extinction (u filter) 487-497 F11.6 mag ext.g Galactic extinction (g filter) 499-509 F11.6 mag ext.r Galactic extinction (r filter) 511-521 F11.6 mag ext.i Galactic extinction (i filter) 523-533 F11.6 mag ext.z Galactic extinction (z filter) 536-546 E11.6 10+10Lsun Lr Observed luminosity in the r-band (G1) 548-556 F9.6 --- w [1/9.1] Weight factor for the galaxy (1) 558-565 F8.5 --- pE [0/1] Probability of early-type (2) 567-574 F8.5 --- pS0 [0/1] Probability of S0 galaxy 576-583 F8.5 --- pSa [0/1] Probability of Sab galaxy 585-592 F8.5 --- pSc [0/1] Probability of Scd galaxy 594-603 F10.6 Mpc Dist.e Distance from survey mask border (G1) 605-617 F13.8 --- Den1 Environmental density at scale=1.5Mpc (G2) 619-631 F13.8 --- Den2 Environmental density at scale=3Mpc (G2) 633-645 F13.8 --- Den4 Environmental density at scale=6Mpc (G2) 647-659 F13.8 --- Den8 Environmental density at scale=10Mpc (G2)
Note (1): times Lr was used to calculate the luminosity density field Note (2): Data is taken from Huertas-Company et al., 2011, Cat. J/A+A/525/A157.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 6 I6 --- GroupID [1/88662] Group/cluster ID 8- 12 I5 --- Ngal [2/254] Richness 14- 27 F14.9 deg RAdeg Right ascension (J2000) 29- 42 F14.9 deg DEdeg Declination (J2000) 44- 57 F14.9 deg lambda SDSS survey coordinate, λ 59- 72 F14.9 deg eta SDSS survey coordinate, η 74- 84 F11.6 Mpc Xpos Cartesian x coordinate (G1) 86- 96 F11.6 Mpc Ypos Cartesian y coordinate (G1) 98-108 F11.6 Mpc Zpos Cartesian z coordinate (G1) 110-120 F11.8 --- zcmb [0/0.2] Redshift (CMB rest frame) 122-131 F10.6 Mpc Dist.c Comoving distance to group center (G1) 133-144 F12.6 km/s sig.v rms radial velocity deviation σV 146-155 F10.6 Mpc rms deviation of the distance in plane of sky from group center σsky (G1) 157-166 F10.6 Mpc Rmax Maximum radius of the group (G1) 168-179 E12.5 10+12Msun M200 Estimated mass of the NFW profile group 181-192 E12.5 Mpc R200 Radius, where mean density is 200 the Universe average density 194-205 E12.5 10+10Lsun Lrgroup Observed luminosity (G1) 207-216 F10.6 --- w [1/9.1] Weight factor for the group 218-230 F13.8 --- Den1 Environment density: 1.5Mpc (G2) 232-244 F13.8 --- Den2 Environment density: 3Mpc (G2) 246-258 F13.8 --- Den4 Environment density: 6Mpc (G2) 260-272 F13.8 --- Den8 Environment density: 10Mpc (G2) 274-283 F10.6 Mpc DnearestCl Distance to the nearest cluster 285-290 I6 --- IDnearestCl ID of the nearest cluster 292-295 I4 --- IDmerger ID of the group in merger catalog
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 5 I5 --- ID Merging system ID 7- 8 I2 --- N Number of mergers in the system 10- 15 I6 --- IDgr1 The 1st ID of the merging group 17- 22 I6 --- IDgr2 The 2nd ID of the merging group 24- 29 I6 --- IDgr3 The 3rd ID of the merging group 31- 36 I6 --- IDgr4 The 4th ID of the merging group 38- 43 I6 --- IDgr5 The 5th ID of the merging group 45- 50 I6 --- IDgr6 The 6th ID of the merging group
Global Notes: Note (G1): the cosmology assumes H0=67.8km/s/Mpc, Ωm=0.308 and ΩΛ=0.692. Distances are Mpc, masses in M☉, luminosities in L☉, and absolute magnitudes in mag. Note (G2): Normalised environmental density of the galaxy for the smoothing scale of a=1.5,3,6,10Mpc.
Acknowledgements: Elmo Tempel, elmo.tempel(at)
(End) Rain Kipper, Elmo Tempel [TO], Patricia Vannier [CDS] 06-Apr-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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