TITLE:   GCN CIRCULAR
NUMBER:  21521
SUBJECT: LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume with Face-on Assumption
DATE:    17/08/17 20:12:41 GMT
FROM:    Mansi M. Kasliwal at Caltech  <mansi@astro.caltech.edu>

David O. Cook (Caltech), Angela Van Sistine (UW Milwaukee), Leo Singer
(NASA/GSFC), and M. M. Kasliwal (Caltech)

report on behalf of the GROWTH (Global Relay of Observatories Watching
Transients Happen) collaboration

We spatially cross-matched the LIGO/Virgo G298048 trigger with the
assumption of face-on orientation (90% containment volume using
bayestar-HLV-face-on.fits; LVC GCN 21513) with our Census of the Local
Universe (CLU; Cook et al. in prep) galaxy catalog and found 13 galaxies.
This catalog is a compilation of galaxies with existing redshifts from many
sources (e.g., NED, SDSS, etc) and new galaxies from a 3PI four-filter
narrow-band survey to look for redshifted Halpha emission out to 200 Mpc
with the Palomar Oschin 48-inch telescope. The narrow-band survey is
limited to a declination above -20 degrees, thus all galaxies within the
90% volume come from the compiled CLU catalog with no Halpha overlap.

We list here all 13 galaxies sorted by stellar mass (Mstar) for galaxies
whose location on the sky and distance falls in the 90% volume reported by
the BAYESTAR probability sky map (Singer et al. 2016). We also list the
dust-corrected star formation rates (SFRs) for galaxies with GALEX FUV
detections and a 'nan' for those with no detection.

Of the 13 galaxies, 4 galaxies are not in the list of 54 galaxies reported
in GCN #21519 without the face-on assumption. The new galaxies are marked
with a ‘*’.

                 name_NED                    ra      dec    distmpc
logsfr_fuv logmstar dm_kin       P
----------------------------------------- -------- -------- -------
---------- -------- ------ --------------
                                 NGC 4830 194.3663 -19.6913   47.90
-1.419    10.41  33.40 0.600362551579
                           MCG -04-31-042 198.5739 -26.5827   54.70
nan     9.98  33.69 0.820306676922*
                  2MASX J12525109-1529300 193.2130 -15.4916   52.26
nan     9.31  33.59 0.807651962502
                  2MASX J12573271-1942006 194.3863 -19.7002   52.39
-1.788     9.25  33.60 0.723692228565
                  2MASX J12551928-1456593 193.8304 -14.9499   48.56
nan     9.22  33.43 0.801217259508*
                                  IC 3825 192.6544 -14.4828   51.04
-0.985     9.17  33.54 0.776579689512
                  2MASX J13073768-2356181 196.9071 -23.9384   49.73
nan     8.92  33.48 0.634606246205
                WINGS J125412.84-153523.6 193.5534 -15.5899   50.96
nan     8.64  33.54 0.595385148382
                      6dF J1254495-160308 193.7063 -16.0523   48.02
nan     8.52  33.41 0.197814505144
             GALEXASC J125259.36-152150.9 193.2474 -15.3639   49.87
-1.321     8.41  33.49 0.419676266799
             GALEXASC J125157.02-160617.8 192.9872 -16.1047   50.30
nan     8.06  33.51 0.410982650697
             GALEXASC J125404.25-145044.4 193.5173 -14.8457   50.85
-1.659     7.75  33.53 0.823290805821*
                           MCG -02-33-014 192.3380 -13.3512   49.57
nan      nan  33.48  0.82251638918*

* Galaxies not reported in the CLU crossmatch to LIGO with no orientation
assumptions (GCN #21519).

The SFRs are derived from GALEX all sky kron FUV magnitudes via the
prescription of Murphy et al. (2011) and have been corrected for internal
dust extinction using a combination of GALEX FUV and 22um ALLWISE fluxes
(Hao et al. 2011). The quoted stellar masses are derived from 3.4um ALLWISE
fluxes and a mass-to-light ratio of 0.5 (McGaugh & Schombert et al. 2015).