GRB 151222A

Last updated: 12/24/2015

The figure below shows the 3\,\sigma error box of the GRB localized by the InterPlanetary Network (IPN), and all galaxies in the GLADE catalog within a \pm\, 0.2^{\circ} environment from its edges along both axes. Numbers in the plot indicate distances of the galaxies in megaparsecs.

For more details about the GRB and its localization, check out the corresponding GCN Circular where the GRB data was taken from.

Symbols in the plot represent different methods for distance measurement:

blue + distance calculated from spectroscopic redshift (2MPZ)
green x distance calculated from photometric redshift (2MPZ)
red ☐ distance estimated with a random forest machine learning technique based on 2MASS J, H, and Ks magnitudes (GLADE)
orange O distance derived using various other methods (GWGC or HyperLEDA; see GLADE documentation for more details)

We use cosmological parameters H_0=70 \ \mathrm{km}\ \mathrm{s}^{-1}\ \mathrm{Mpc}^{-1}}, \Omega_{\mathrm{M}}=0.3 and \Omega_{\Lambda}=0.7 when calculating a distance from redshift.
Sky area near the 90% error box of 151222A

We have identified 10 galaxies inside the error box. Distances of these galaxies are 169 Mpc, 170 Mpc, 181 Mpc, 252 Mpc, 279 Mpc, 304 Mpc, 330 Mpc, 400 Mpc, 472 Mpc and 539 Mpc.

We have not identified any galaxies outside the error box from which a pair of merging neutron stars (BNSs) could have kicked out from to reach a position inside the GRB error box. Note that we identify such galaxies as the ones being within a 100 kpc radius outside the GRB error box. According to Fong & Berger 2013, 95% of all BNSs kicked out from a galaxy should merge within a 100 kpc range around its host.

Click HERE if you want to download all GLADE parameters of galaxies shown in the figure. Each row in the linked ascii file correspond to a galaxy indicated in the plot. For an explanation on what different columns represent, click HERE.