{
  "bibcode": "2006GCN..4541....1M",
  "body": "D. Malesani (SISSA/ISAS), P. D'Avanzo (INAF/OABr), G. Chincarini (Univ. \nMilano-Bicocca), G. Tagliaferri, S. Campana, S. Covino, D. Fugazza \n(INAF/OABr), A. Fernandez-Soto (Univ. Valencia), M. Della Valle \n(INAF/OAA), L.A. Antonelli, F. Fiore, S. Piranomonte, and L. Stella \n(INAF/OAR), report on behalf of the MISTICI collaboration:\n\nWe observed the afterglow of GRB 060116 (Campana et al., GCN 4519; \nBarthelmy et al., GCN 4531). Observations were carried out with the ESO \nNTT telescope in the J and Ks filters. Observations were taken almost \nsimultaneously to our VLT I-band observations (D'Avanzo, Malesani & \nAntonelli, GCN 4532), that is ~17 h after the GRB.\n\nWe detect the afterglow (Kocevski, Bloom & McGrath, GCNs 4528, 4540) in \nthe J and Ks filters. Calibration was performed against the 2MASS \nsurvey. Comparing our measurements to the limit derived by the VLT \nimages, we measure the following colors after correcting for the \nGalactic absorption (E(B-V) = 0.263):\n\n  J-K = 2.5 +- 0.3;\n  I-J > 2.9.\n\nThese colors are very red. If the I-band nondetection is interpreted as \na dropout, the inferred redshift is z ~ 6. The very red J-K color may in \nthis case suggest some rest-frame dust absorption, as also hinted by the \nlarge column density present in the X-ray spectrum (Campana et al., GCN \n4529). Alternatively, an even larger redshift (z~7-8) may suppress part \nof the J-band emission.\n\nWith the present dataset, however, dust emission at lower redshift \ncannot be excluded.\n\nFurther observations and analysis are in progress.\n\nWe acknowledge the excellent support of the ESO staff, in particular \nMichael Sterzik and Cedric Foellmi.\n\nThis message can be cited.",
  "circularId": 4541,
  "createdOn": 1137579674000,
  "email": "malesani@sissa.it",
  "subject": "GRB 060116: possible I-J dropout",
  "submitter": "Daniele Malesani at SISSA-ISAS,Trieste,Italy  <malesani@sissa.it>",
  "eventId": "GRB 060116"
}