TITLE: GCN CIRCULAR NUMBER: 39607 SUBJECT: LIGO/Virgo/KAGRA S250207bg: Update-5 NED Galaxies in the Localization Volume DATE: 25/03/06 17:03:36 GMT FROM: David Cook at Caltech/IPAC-NED dcook@ipac.caltech.edu
David O. Cook (Caltech/IPAC), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), Joseph M. Mazzarella (Caltech/IPAC), Marion Schmitz (Caltech/IPAC), and Leo Singer (NASA/GSFC)
On behalf of the NASA/IPAC Extragalactic Database (NED) Team.
We spatially cross-matched the LVK S250207bg-5-Update sky localization with the NED Local Volume Sample (NED-LVS; Cook et al. 2023), which is a subset of NED with a redshift or redshift-independent distance less than 1000 Mpc. We find 369 galaxies within the 90% containment volume, and we list here the top 20 galaxies sorted by the joint probability of the 3D localization and the WISE W1 luminosity (an observable proxy for stellar mass). For the full or top 20 list of galaxies in the 90% volume go either to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/ or click on the following links:
Full List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250207bg/5 Top 20 List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250207bg/5/20
*** We note that the version of NED-LVS used in this analysis is from Jan 2025 that was released on Feb 10 2025, whereas the S250207bg-4-Update analysis used the previous version. This new version has an additional 203K galaxies in the full sample the majority of which are from DESI-EDR.
The NED-GWF service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic follow-up observations. The NED top 20 list is sorted by the joint probability of the 3D localization and the WISE W1 luminosity, but users can sort on additional pre-computed prioritization metrics (star formation rate, P_3D * P_SFR; and specific star formation rate, P_3D * P_sSFR; etc.) which are available via downloading the entire galaxy list inside the event's probability volume.
| objname| ra| dec|objtype| DistMpc|DistMpc_unc| m_NUV| m_NUV_unc| m_Ks| m_Ks_unc| m_W1| m_W1_unc| P_3D|P_3D_LumW1| |-------------------------|--------------|--------------|-------|-----------|-----------|------------|------------|------------|------------|------------|------------|--------|----------| | CGCG 184-039| 164.42690| 37.65455| G| 162.22| 26.21| null| null| 10.680| 0.054| 10.878| 0.006|8.03e-05| 1.12e-06| | MCG +06-24-041| 164.47481| 37.54192| G| 162.22| 26.21| 20.279| 0.148| 11.298| 0.055| 11.331| 0.007|9.63e-05| 8.84e-07| | CGCG 184-023| 162.54517| 35.03369| G| 183.12| 0.03| 17.688| 0.031| 12.087| 0.052| 11.752| 0.008|8.79e-05| 6.97e-07| | CGCG 184-033| 163.24603| 37.61345| G| 187.51| 0.05| null| null| 11.034| 0.043| 11.024| 0.006|4.07e-05| 6.62e-07| |WISEA J105523.87+362209.7| 163.84948| 36.36938| G| 151.73| 0.05| 21.139| 0.087| 12.289| 0.075| 12.390| 0.018|2.11e-04| 6.38e-07| |WISEA J105133.05+360501.0| 162.88772| 36.08364| G| 188.40| 44.45| null| null| 12.941| 0.092| 12.598| 0.010|1.58e-04| 6.09e-07| | MCG +06-24-040| 164.47226| 37.51474| G| 149.83| 0.04| 19.652| 0.099| 11.734| 0.062| 11.636| 0.007|1.01e-04| 5.94e-07| | 2MFGC 08396| 161.78556| 34.83804| G| 195.44| 0.05| null| null| 12.218| 0.063| 11.971| 0.009|7.37e-05| 5.44e-07| |WISEA J105802.45+364004.6| 164.51022| 36.66795| G| 141.05| 33.28| 21.365| 0.346| 12.356| 0.057| 12.181| 0.007|1.63e-04| 5.17e-07| |WISEA J104944.42+362416.4| 162.43511| 36.40456| G| 181.79| 0.05| null| null| 12.607| 0.089| 12.522| 0.009|1.21e-04| 4.65e-07| |WISEA J105909.94+371504.2| 164.79142| 37.25117| G| 187.86| null| 18.157| 0.034| 11.855| 0.050| 11.585| 0.007|4.77e-05| 4.64e-07| | 2MFGC 08535| 164.22259| 37.59752| G| 157.75| 0.07| 21.513| 0.332| 12.030| 0.059| 11.685| 0.007|7.16e-05| 4.48e-07| |WISEA J105800.68+374606.5| 164.50287| 37.76849| G| 151.47| 0.04| 20.580| 0.135| 11.774| 0.046| 11.693| 0.007|7.45e-05| 4.27e-07| |WISEA J104451.00+353606.0| 161.21250| 35.60167| G| 229.57| 0.05| null| null| 13.208| 0.103| 11.860| 0.009|3.62e-05| 4.09e-07| | 2MFGC 08400| 161.86882| 36.82418| G| 158.37| 0.05| null| null| 10.992| 0.033| 10.891| 0.006|2.92e-05| 3.83e-07| |WISEA J105511.98+365943.1| 163.79993| 36.99531| G| 194.37| 0.04| 19.438| 0.024| 12.725| 0.093| 12.580| 0.012|7.82e-05| 3.26e-07| |WISEA J105456.98+375126.3| 163.73744| 37.85731| G| 153.99| 0.12| null| null| 15.333| 0.275| 11.308| 0.007|3.85e-05| 3.25e-07| |WISEA J105258.79+371636.7| 163.24498| 37.27688| G| 190.48| 0.05| null| null| 12.533| 0.066| 12.424| 0.008|6.96e-05| 3.21e-07| |WISEA J105855.76+370625.3| 164.73237| 37.10705| G| 157.95| 0.10| 18.116| 0.038| 12.805| 0.115| 12.824| 0.010|1.29e-04| 2.83e-07| |WISEA J105412.49+373218.9| 163.55205| 37.53859| G| 135.45| 0.04| 20.135| 0.181| 11.549| 0.047| 11.403| 0.006|4.57e-05| 2.73e-07|
Table 1: Top 20 galaxies in NED-LVS that fall in the 90% probability volume for S250207bg sorted by the joint probability of 3D position and WISE W1 luminosity (P_3D * P_LumW1). Galaxy is the NED preferred name. RA and Dec are the Equatorial coordinates in degrees (J2000). Objtype is the object type of the galaxy candidate. Distance is the distance to the galaxy in Mpc. m_NUV and mErr_NUV are the apparent magnitude and error from GALEX. m_Ks and mErr_Ks are the apparent magnitude and error from 2MASS. m_W1 and mErr_W1 are the apparent magnitude and error from AllWISE. P_3D is the probability that the galaxy is in the volume given the distance of GW event. P_3D_LumW1 is the joint probability within the volume weighted by the WISE1 luminosity of the galaxy (P_3D * P_LumW1).
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