GCN Circular 36076

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.

*** The previous GCN listed in the text an incorrect number of galaxy candidates in the 90% volume. The correct number of galaxies is 3,252.

We spatially cross-matched the LVK S240413p-3-Initial 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 3252 galaxies within the 90% containment volume, and we list in Table 1 the top 20 galaxies located in the 90% volume sorted by the joint probability of the 3D localization and the WISE W1 luminosity (an observable proxy for stellar mass). For the full list of galaxies in the 90% volume go to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/. 

Since S240413p is likely a BBH event, we also provide a list of galaxy candidates with AGN/QSO object types in the 90% volume (see Table 2).

         Galaxy               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
                            (Deg)     (Deg)       (Mpc)                     (AB)          (Vega)         (Vega)           (Prob)     (Prob)
------------------------- ---------- --------- ------- ------- ----------- ----- --------- ----- -------- ----- -------- -------- ----------
WISEA J110649.68+135510.5 166.706959 13.919548       G  553.31        0.08    --        -- 12.66     0.02 10.55     0.01 8.34e-01   6.33e-03
WISEA J105410.09+104600.0 163.542222 10.766754       G  549.89        0.04    --        -- 15.37     0.41  9.95     0.01 4.19e-01   5.45e-03
WISEA J110211.55+090435.6 165.548127  9.076514       G  561.47        0.28    --        -- 13.49     0.20 10.88     0.01 8.66e-01   4.99e-03
WISEA J110012.38+084616.3 165.051598  8.771199     QSO  465.07        0.07 18.35      0.02 12.32     0.09 10.79     0.01 8.51e-01   3.67e-03
WISEA J104505.15+084339.0 161.271533  8.727526     QSO  587.14        0.05 17.99      0.03 13.22     0.08 11.39     0.02 7.91e-01   3.13e-03
WISEA J104600.10+090626.9 161.500424  9.107589       G  401.65        0.10    --        -- 13.17     0.20 10.66     0.01 7.00e-01   2.53e-03
WISEA J110022.85+130955.1 165.095191 13.165431       G  615.03        0.11    --        -- 12.54     0.10 11.84     0.01 8.33e-01   2.39e-03
WISEA J103925.86+051328.1 159.857765  5.224443       G  255.51          --    --        -- 13.71     0.19  9.96     0.01 8.10e-01   2.26e-03
WISEA J111006.19+115942.8 167.525667 11.995333       G  587.23        0.10 21.52      0.32 12.09     0.12 11.96     0.01 8.84e-01   2.06e-03
WISEA J103257.43+021443.9 158.239273  2.245507       G  602.96        0.25 21.84      0.17 12.50     0.12 12.04     0.01 8.97e-01   2.06e-03
WISEA J110952.96+120126.4 167.470699 12.024011       G  595.42        0.09    --        --    --       -- 11.97     0.01 8.67e-01   2.05e-03
WISEA J103402.72+013245.4 158.511323  1.545883       G  395.67        0.10    --        -- 12.44     0.13 11.16     0.01 8.87e-01   1.97e-03
WISEA J104842.58+054229.5 162.177419  5.708209       G  503.19        0.26    --        -- 12.87     0.12 11.58     0.01 7.66e-01   1.86e-03
WISEA J105244.35+083824.6 163.184588  8.640342       G  657.01        0.07    --        -- 14.70     0.26 12.28     0.01 8.17e-01   1.77e-03
WISEA J103801.57+055423.5 159.506543  5.906542       G  660.07        0.25 22.50      0.28 12.91     0.16 12.38     0.01 8.11e-01   1.62e-03
WISEA J105109.13+103827.4 162.788059 10.640952       G  620.73        0.19 22.59      0.31 12.62     0.12 12.29     0.01 8.09e-01   1.56e-03
WISEA J104327.94+054008.1 160.866315  5.668975       G  698.96        0.07    --        -- 14.38     0.17 12.62     0.01 8.64e-01   1.55e-03
WISEA J110724.12+110315.3 166.850369 11.054323       G  504.49          --    --        -- 13.77     0.13 11.45     0.01 5.64e-01   1.55e-03
WISEA J105417.15+104855.5 163.571487 10.815452       G  614.89        0.25 21.79      0.17 12.85     0.16 12.10     0.01 6.46e-01   1.45e-03
WISEA J110654.65+131825.2 166.727741 13.307005       G  581.40        0.20    --        -- 13.18     0.11 12.11     0.01 7.03e-01   1.40e-03

Table 1: Top 20 galaxies in NED-LVS that fall in the 90% probability volume for S240413p 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). 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). 


         Galaxy               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
                            (Deg)     (Deg)       (Mpc)                     (AB)          (Vega)         (Vega)           (Prob)     (Prob)
------------------------- ---------- --------- ------- ------- ----------- ----- --------- ----- -------- ----- -------- -------- ----------
WISEA J110012.38+084616.3 165.051598  8.771199     QSO  465.07        0.07 18.35      0.02 12.32     0.09 10.79     0.01 8.51e-01   3.67e-03
WISEA J104505.15+084339.0 161.271533  8.727526     QSO  587.14        0.05 17.99      0.03 13.22     0.08 11.39     0.02 7.91e-01   3.13e-03
WISEA J110226.74+130704.3 165.611471 13.117866     QSO  611.32        0.17    --        -- 14.02     0.07 12.97     0.02 6.78e-01   6.73e-04
WISEA J105555.34+110252.0 163.980621 11.047838     QSO  692.93        0.04 19.98      0.05 13.46     0.20 13.62     0.03 8.25e-01   5.78e-04
WISEA J110550.53+112701.9 166.460584 11.450589     QSO  671.49        0.17 22.96      0.27    --       -- 14.50     0.03 7.41e-01   2.17e-04
WISEA J105043.40+072500.1 162.680778  7.416794     QSO  624.79        3.07    --        --    --       -- 16.42     0.07 8.45e-01   3.67e-05
WISEA J110206.66+112104.8 165.527787 11.351373     QSO  176.68        0.87    --        -- 14.92     0.28 14.59     0.03 9.00e-01   1.68e-05
WISEA J105930.49+120532.7 164.877076 12.092448     QSO  443.25        0.70    --        --    --       -- 15.18     0.04 1.57e-01   1.07e-05

Table 2: Candidates in the 90% volume with AGN/QSO classifications.



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 followup 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.