J/A+A/582/A111ivo://CDS.VizieR/J/A+A/582/A111doi:10.26093/cds/vizier.35820111CDSLi M.-H.Lin H.-N.2018-01-02T13:42:56Z2015-10-21T09:46:26ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgamma-ray-astronomyredshiftedThe discovery of a statistically significant clustering in the distribution of gamma-ray bursts (GRBs) has recently been reported. Given that the cluster has a characteristic size of 2000-3000Mpc and a redshift between 1.6<=z<=2.1, it has been claimed that this structure is incompatible with the cosmological principle of homogeneity and isotropy of our Universe. In this paper, we study the homogeneity of the GRB distribution using a subsample of the Greiner GRB catalogue, which contains 314 objects with redshift 0<z<2.5 (244 of them discovered by the Swift GRB mission). We try to reconcile the dilemma between the new observations and the current theory of structure formation and growth. To test the results against the possible biases in redshift determination and the incompleteness of the Greiner sample, we also apply our analysis to the 244 GRBs discovered by Swift and the subsample presented by the Swift Gamma-Ray Burst Host Galaxy Legacy Survey (SHOALS). The real space two-point correlation function (2PCF) of GRBs, {ksi}(r), is calculated using a Landy-Szalay estimator. We perform a standard least-{Chi}^2^ fit to the measured 2PCFs of GRBs. We use the best-fit 2PCF to deduce a recently defined homogeneity scale. The homogeneity scale, R_H_, is defined as the comoving radius of the sphere inside which the number of GRBs N(<r) is proportional to r^3^ within 1%, or equivalently above which the correlation dimension of the sample D^2^ is within 1% of D^2^=3.2015A&A...582A.111Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/582/A111CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-tohttp://www.mpe.mpg.de/~jcg/grbgen.html : Greiner's GRB databasehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/582/A111https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/582/A111http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/582/A111https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/582/A111https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/582/A111http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/582/A111GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/582/A111/table1 (Data for the 314 GRBs from Greiner (2015, http://www.mpe.mpg.de/~jcg/grbgen.html) used in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/582/A111/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/582/A111/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/582/A111/table1?GETtext/xml+votable180.050000true293.725-52.831670.005555555555555556Cone search capability for table J/A+A/582/A111/table2 (Data for the 75 GRBs from Perley et al. (2015, arXiv:astro-ph/1504.02482v2) used in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/582/A111/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/582/A111/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/582/A111/table2?GETtext/xml+votable180.050000true50.4166716.866670.0055555555555555566/186 210 228 393 503 557 590 646 699 908 918 1001 2044 2315 2357 2735 2948-2949 3059 3089 3111 3536 3586 3935 4312 4323 4341 4371 4397 4449 4809 5049 5073 5376 5493 5625 5745 5840 5941 6102 6258 6261 6404 6445 6448 6521 7044 7182 7227 7532 7650 7750 8074 8103 8318 8373 8425 8493 8641 8669 8693 8761 8798 8954 9022 9100 9363 9370 9431 9643 9662 9910 9998 10080 10094 10135 10400 10407 10424 10519 10589 10680 10704 10723 10852 10912 11220 11657 11673 11713 11905 12192 12438 12597 13331 13574 13694 13701 13709 13779 13831 13924 14259 14892 14967 14977 15004 15054 15233 15246 15295 15348 15530 15915 16057 16282 16489 16546 16661 17038 17316 17406 17411 17561 17733 17749 17758 17814 17911 17980 18010 18030 18097 18325 18494 18681 18728 18911 18945 19097 19102 19293 19519 19864-19865 19890 19911 20030 20053 20191 20346 20372 20460 20710 21082 21137 21222 21482 21498 21595 22008 22422 22559 22580 22619 22624 22916 23147 23413 24007 24068 24097 24779 25061 25131 25148 25171 25174 25248 25293 25394 25426 25452 25761 25946 26036 26441 26503 27238 27541 27566 27572 27811 27841 27906 27962 27983 28058 28063 28071 28077 28234 28344 28467 28497 28546 28555 29019 29231 29731 30088 30557 31185 31281 31521 31583 32110 32239 32310 32646 32713 32790 33004 33050 33146 33265 33525 33543 33617 33679 33735 33832 33860 34364 34435 34440 34465 34590 34605 34832 35045 35227 35330 35393 35448 35566 35569 35844 35903 36066 36361 36374 36460 36468 36528 37007 37123 37383 37391 37505 38280 38844 38926 39008 39076 39327 39553 39594 40249 40433 40560 41020 41095 42545 42914 42952 43858 44021-44022 44630 45205 45347 45361 45401 45422 45510 45777 45835-45836 45938 46002 46022 46218 46250 46365 46394 46510 46517 46594 46789 47027 47031 47136 47162 47217 47245 47251 47459 47620 47991 48007 48051 48054 48189 48447 48804 48921 49004https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/582/A111?format=asciiGamma-rayOpticaldefaultJ/A+A/582/A111/table1Data for the 314 GRBs from Greiner (2015, http://www.mpe.mpg.de/~jcg/grbgen.html) used in this workSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGRBsGRB designation (NNNNNNA)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainzRedshift (spectroscopic or photometric)src.redshiftdoubleInstInstruments (1)meta.id;instrcharJ/A+A/582/A111/table2Data for the 75 GRBs from Perley et al. (2015, arXiv:astro-ph/1504.02482v2) used in this workSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGRBsGRB designation (NNNNNNA)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainzRedshift (spectroscopic or photometric)src.redshiftdoubleInstInstruments (1)meta.id;instrchar