LIGO/Virgo/KAGRA S250207bg
GCN Circular 39201
Subject
LIGO/Virgo/KAGRA S250207bg: Identification of a GW compact binary merger candidate
Date
2025-02-07T12:27:19Z (4 months ago)
From
Luise Kranzhoff at Maastricht University <luise.kranzhoff@ligo.org>
Via
Web form
The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:
We identified the compact binary merger candidate S250207bg during real-time processing of data from LIGO Livingston Observatory (L1) and Virgo Observatory (V1) at 2025-02-07 11:56:45.258 UTC (GPS time: 1422964623.258). The candidate was found by the GstLAL [1] and SPIIR [2] analysis pipelines.
S250207bg is an event of interest because its false alarm rate, as estimated by the online analysis, is 4.9e-36 Hz, or about one in 1e28 years. The event's properties can be found at this URL:
https://gracedb.ligo.org/superevents/S250207bg
After parameter estimation by RapidPE-RIFT [3], the classification of the GW signal, in order of descending probability, is BBH (>99%), NSBH (<1%), BNS (<1%), or Terrestrial (<1%).
Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [4] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [4] Both HasNS and HasRemnant consider the support of several neutron star equations of state. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is <1%.
Two sky maps are available at this time and can be retrieved from the GraceDB event page:
* bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 29 seconds after the candidate event time.
* bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 5 minutes after the candidate event time.
The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 110 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 546 +/- 98 Mpc (a posteriori mean +/- standard deviation).
For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/.
[1] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625
[2] Chu et al. PRD 105, 024023 (2022) doi:10.1103/PhysRevD.105.024023
[3] Rose et al. (2022) arXiv:2201.05263 and Pankow et al. PRD 92, 023002 (2015) doi:10.1103/PhysRevD.92.023002
[4] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe
[5] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013
GCN Circular 39206
Subject
LIGO/Virgo/KAGRA S250207bg: NED Galaxies in the Localization Volume
Date
2025-02-07T16:10:21Z (4 months ago)
From
David Cook at Caltech/IPAC-NED <dcook@ipac.caltech.edu>
Via
Web form
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-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 7591 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/3
Top 20 List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250207bg/3/20
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|
|-------------------------|--------------|--------------|-------|-----------|-----------|------------|------------|------------|------------|------------|------------|--------|----------|
|WISEA J153919.63+190427.7| 234.83187| 19.07453| G| 530.26| null| null| null| 13.627| 0.172| 10.078| 0.006|5.48e-07| 2.24e-09|
|WISEA J152319.42+240611.6| 230.83105| 24.10320| G| 663.87| 0.16| null| null| 14.431| 0.157| 10.454| 0.006|3.80e-07| 1.72e-09|
|WISEA J154012.34+184306.0| 235.05140| 18.71817| G| 417.30| 0.08| null| null| 13.309| 0.160| 9.114| 0.005|2.45e-07| 1.51e-09|
|WISEA J153645.35+185715.6| 234.18906| 18.95426| G| 614.30| 0.14| null| null| 14.462| 0.165| 11.145| 0.006|6.31e-07| 1.29e-09|
|WISEA J150631.38+283419.0| 226.63079| 28.57192| G| 515.26| 0.04| null| null| 13.286| 0.172| 10.718| 0.006|5.69e-07| 1.21e-09|
|WISEA J155025.85+130154.2| 237.60767| 13.03173| G| 581.25| 0.10| null| null| 13.459| 0.155| 10.806| 0.006|4.18e-07| 1.05e-09|
|WISEA J151550.70+275958.5| 228.96137| 27.99951| G| 504.04| 0.05| 20.968| 0.139| 13.749| 0.153| 10.538| 0.006|3.27e-07| 7.89e-10|
| [HB89] 1552+085| 238.68574| 8.37263| QSO| 557.07| 0.06| 17.225| 0.024| 12.724| 0.045| 11.383| 0.023|5.56e-07| 7.54e-10|
|WISEA J151458.01+273639.7| 228.74172| 27.61105| G| 560.27| 0.21| 22.052| 0.306| 11.568| 0.117| 11.617| 0.007|6.48e-07| 7.15e-10|
|WISEA J155856.52+032444.3| 239.73542| 3.41238| G| 408.76| 0.10| null| null| 12.955| 0.169| 10.037| 0.006|2.71e-07| 6.96e-10|
|WISEA J153250.52+200718.3| 233.21046| 20.12169| G| 681.89| 0.13| null| null| 13.831| 0.187| 10.888| 0.006|1.99e-07| 6.42e-10|
| 3C 327| 240.61406| 1.96560| G| 486.72| 2.15| 20.654| 0.174| 12.897| 0.047| 11.037| 0.006|4.26e-07| 6.11e-10|
|WISEA J155639.59+111348.0| 239.16499| 11.22994| G| 486.41| 0.14| null| null| 14.133| 0.119| 9.442| 0.006|9.76e-08| 6.04e-10|
|WISEA J154320.19+143045.0| 235.83416| 14.51254| G| 622.09| 0.04| null| null| 13.890| 0.198| 11.215| 0.006|2.64e-07| 5.21e-10|
|WISEA J151556.87+264556.0| 228.98694| 26.76548| G| 592.88| null| null| null| 13.560| 0.139| 12.348| 0.011|8.01e-07| 5.06e-10|
|WISEA J145244.45+315248.3| 223.18524| 31.88009| G| 537.68| 0.07| null| null| 12.904| 0.040| 11.775| 0.006|5.42e-07| 4.75e-10|
|WISEA J150746.48+284911.8| 226.94359| 28.81997| G| 515.60| 0.75| 20.018| 0.182| 12.395| 0.100| 12.063| 0.007|7.53e-07| 4.66e-10|
|WISEA J145519.43+321511.0| 223.83099| 32.25305| G| 538.51| 0.21| null| null| 13.017| 0.046| 11.996| 0.008|5.89e-07| 4.23e-10|
|WISEA J145331.46+302133.9| 223.38103| 30.35929| G| 566.40| 0.12| 22.065| 0.341| 14.897| 0.264| 9.870| 0.006|7.14e-08| 4.02e-10|
|WISEA J154015.93+175229.2| 235.06642| 17.87478| G| 474.23| null| null| null| 12.689| 0.157| 11.861| 0.007|6.29e-07| 3.97e-10|
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).
GCN Circular 39242
Subject
LIGO/Virgo/KAGRA S250207bg: Updated Sky localization
Date
2025-02-08T20:47:18Z (4 months ago)
From
Will Farr <will.farr@stonybrook.edu>
Via
Web form
The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:
We have conducted further analysis of the LIGO Livingston Observatory (L1) and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S250207bg (GCN Circular 39201). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S250207bg
For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 80 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 508 +/- 95 Mpc (a posteriori mean +/- standard deviation).
For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/.
[1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. (2023) arXiv:2307.13380
GCN Circular 39243
Subject
LIGO/Virgo/KAGRA S250207bg: Updated NED Galaxies in the Localization Volume
Date
2025-02-08T21:48:25Z (4 months ago)
From
David Cook at Caltech/IPAC-NED <dcook@ipac.caltech.edu>
Via
Web form
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-4-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 5657 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/4
Top 20 List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250207bg/4/20
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|
|-------------------------|--------------|--------------|-------|-----------|-----------|------------|------------|------------|------------|------------|------------|--------|----------|
|WISEA J154012.34+184306.0| 235.05140| 18.71817| G| 417.30| 0.08| null| null| 13.309| 0.160| 9.114| 0.005|4.63e-07| 4.25e-09|
|WISEA J153919.63+190427.7| 234.83187| 19.07453| G| 530.26| null| null| null| 13.627| 0.172| 10.078| 0.006|6.58e-07| 4.02e-09|
|WISEA J150631.38+283419.0| 226.63079| 28.57192| G| 515.26| 0.04| null| null| 13.286| 0.172| 10.718| 0.006|1.05e-06| 3.33e-09|
|WISEA J152319.42+240611.6| 230.83105| 24.10320| G| 663.87| 0.16| null| null| 14.431| 0.157| 10.454| 0.006|3.02e-07| 2.04e-09|
|WISEA J153645.35+185715.6| 234.18906| 18.95426| G| 614.30| 0.14| null| null| 14.462| 0.165| 11.145| 0.006|6.22e-07| 1.90e-09|
|WISEA J155856.52+032444.3| 239.73542| 3.41238| G| 408.76| 0.10| null| null| 12.955| 0.169| 10.037| 0.006|4.26e-07| 1.63e-09|
|WISEA J155910.92+030431.4| 239.79539| 3.07516| G| 280.12| 0.10| 21.046| 0.115| 13.699| 0.080| 8.330| 0.005|1.72e-07| 1.49e-09|
|WISEA J151550.70+275958.5| 228.96137| 27.99951| G| 504.04| 0.05| 20.968| 0.139| 13.749| 0.153| 10.538| 0.006|3.97e-07| 1.43e-09|
|WISEA J154844.37+123355.8| 237.18490| 12.56552| G| 445.05| 0.19| 18.149| 0.040| 12.533| 0.102| 11.704| 0.007|1.20e-06| 1.15e-09|
|WISEA J155025.85+130154.2| 237.60767| 13.03173| G| 581.25| 0.10| null| null| 13.459| 0.155| 10.806| 0.006|2.99e-07| 1.12e-09|
|WISEA J151458.01+273639.7| 228.74172| 27.61105| G| 560.27| 0.21| 22.052| 0.306| 11.568| 0.117| 11.617| 0.007|6.75e-07| 1.11e-09|
|WISEA J150746.48+284911.8| 226.94359| 28.81997| G| 515.60| 0.75| 20.018| 0.182| 12.395| 0.100| 12.063| 0.007|1.16e-06| 1.07e-09|
|WISEA J154015.93+175229.2| 235.06642| 17.87478| G| 474.23| null| null| null| 12.689| 0.157| 11.861| 0.007|1.13e-06| 1.06e-09|
|WISEA J151503.66+265734.0| 228.76522| 26.95947| G| 507.59| 0.10| 20.870| 0.165| 12.543| 0.112| 12.330| 0.009|1.31e-06| 9.22e-10|
|WISEA J155420.39+092929.4| 238.58486| 9.49159| G| 479.41| 0.09| null| null| 12.282| 0.120| 12.132| 0.010|1.22e-06| 9.19e-10|
| [HB89] 1552+085| 238.68574| 8.37263| QSO| 557.07| 0.06| 17.225| 0.024| 12.724| 0.045| 11.383| 0.023|4.08e-07| 8.25e-10|
|WISEA J153844.73+174212.6| 234.68642| 17.70348| G| 436.35| 0.22| 17.650| 0.046| 12.354| 0.105| 11.900| 0.007|1.06e-06| 8.19e-10|
|WISEA J152816.73+224844.1| 232.06975| 22.81227| G| 469.92| 0.17| null| null| 12.642| 0.095| 12.342| 0.007|1.33e-06| 7.95e-10|
|WISEA J153116.63+220554.7| 232.81929| 22.09851| G| 456.31| 0.21| null| null| 12.372| 0.077| 11.994| 0.008|9.92e-07| 7.69e-10|
| 3C 327| 240.61406| 1.96560| G| 486.72| 2.15| 20.654| 0.174| 12.897| 0.047| 11.037| 0.006|3.51e-07| 7.51e-10|
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).
GCN Circular 39605
Subject
LIGO/Virgo/KAGRA S250207bg: Updated Sky localization
Date
2025-03-06T16:37:39Z (3 months ago)
From
Sylvia Biscoveanu at Northwestern CIERA <sylvia.biscoveanu@ligo.org>
Via
Web form
The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:
We have conducted further analysis of the LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S250207bg (GCN Circulars 39201 and 39242). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline1.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S250207bg
For the Bilby.offline1.multiorder.fits,0 sky map, the 90% credible region is well fit by an ellipse with an area of 19 deg2 described by the following DS9 region (right ascension, declination, semi-major axis, semi-minor axis, position angle of the semi-minor axis):
icrs; ellipse(10h51m, +36d04m, 3.72d, 1.66d, 139.66d)
Marginalized over the whole sky, the a posteriori luminosity distance estimate is 180 +/- 38 Mpc (a posteriori mean +/- standard deviation).
At the time of the candidate, the Hanford detector was being brought online and was not in observing mode. However, it was determined that the Hanford data are sufficiently robust to inform our estimate of the sky localization. The well-measured arrival time of the signal at Hanford, while consistent with the Livingston and Virgo data, breaks the degeneracy in sky localization inherent in a 2-detector analysis, and significantly shifts the posterior distribution with respect to the earlier localization. Further investigations are ongoing to understand how the operational state of Hanford at the time of the event impacts this analysis. The estimated sky localization may change slightly based on these studies, but this skymap represents our best understanding of the event at this time.
For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/.
[1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. (2023) arXiv:2307.13380
GCN Circular 39607
Subject
LIGO/Virgo/KAGRA S250207bg: Update-5 NED Galaxies in the Localization Volume
Date
2025-03-06T17:03:36Z (3 months ago)
From
David Cook at Caltech/IPAC-NED <dcook@ipac.caltech.edu>
Via
Web form
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).