J/ApJ/848/L29 Opt. follow-up of GW170817 counterpart (Diaz+, 2017)
Observations of the first electromagnetic counterpart to a gravitational-wave
source by the TOROS Collaboration.
Diaz M.C., Macri L.M., Garcia Lambas D., Mendes de Oliveira C.,
Nilo Castellon J.L., Ribeiro T., Sanchez B., Schoenell W., Abramo L.R.,
Akras S., Alcaniz J.S., Artola R., Beroiz M., Bonoli S., Cabral J.,
Camuccio R., Castillo M., Chavushyan V., Coelho P., Colazo C.,
Costa-Duarte M.V., Cuevas Larenas H., DePoy D.L., Dominguez Romero M.,
Dultzin D., Fernandez D., Garcia J., Girardini C., Goncalves D.R.,
Goncalves T.S., Gurovich S., Jimenez-Teja Y., Kanaan A., Lares M.,
Lopes de Oliveira R., Lopez-Cruz O., Marshall J.L., Melia R., Molino A.,
Padilla N., Penuela T., Placco V.M., Quinones C., Ramirez Rivera A.,
Renzi V., Riguccini L., Rios-Lopez E., Rodriguez H., Sampedro L.,
Schneiter M., Sodre L., Starck M., Torres-Flores S., Tornatore M.,
Zadrozny A.
<Astrophys. J., 848, L29 (2017)>
=2017ApJ...848L..29D 2017ApJ...848L..29D
ADC_Keywords: Gravitational wave; Stars, neutron; Photometry, SDSS
Keywords: gamma-ray burst: individual (170817A) ; stars: neutron
Abstract:
We present the results of prompt optical follow-up of the
electromagnetic counterpart of the gravitational-wave event GW170817
by the Transient Optical Robotic Observatory of the South
Collaboration. We detected highly significant dimming in the light
curves of the counterpart (Δg=0.17±0.03mag,
Δr=0.14±0.02mag, Δi=0.10±0.03mag) over the course of
only 80 minutes of observations obtained ∼35hr after the trigger with
the T80-South telescope. A second epoch of observations, obtained
∼59hr after the event with the EABA 1.5m telescope, confirms the fast
fading nature of the transient. The observed colors of the counterpart
suggest that this event was a "blue kilonova" relatively free of
lanthanides.
Description:
On 2017 August 18 (∼35hr after the GW trigger) we observed the
transient using the T80-South telescope (T80) located at CTIO.
We obtained 16, 15, and 15 one-minute exposures through SDSS g, r, and
i filters, respectively, at airmass values from 1.35 to 1.97 over the
course of 80 minutes. The typical seeing was ∼1.8".
On 2017 August 19 (∼59hr after the GW trigger) we imaged the same
source using the 1.54m telescope located at the Estacion Astrofisica
de Bosque Alegre (EABA).
Objects:
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RA (2000) DE Designation(s)
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13 09 48.09 -23 22 53.3 GrW 170817 = NAME AT 2017gfo
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 23 48 Time-series photometry
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See also:
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/ApJ/843/16 : Galaxy groups within 3500km/s (Kourkchi+, 2017)
J/ApJ/848/L16 : Counterpart of GW170817. I. DECam obs. (Soares-Santos+, 2017)
J/ApJ/848/L33 : Opt. follow-up of GW events with LCO (Arcavi+, 2017)
J/ApJ/851/L21 : UV-NIR obs. compilation of GW170817 counterpart (Villar+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 F6.4 d Time [1.4/2.5] Time since GW trigger
8 A1 --- Band [gir] Band in SDSS system
10- 15 F6.3 mag mag [17.7/19.2] Apparent magnitude in Band
17- 21 F5.3 mag e_mag [0.02/0.06] Uncertainty in mag
23 A1 --- Note [ab] Addition note (1)
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Note (1): Note as follows:
a = assuming r-i=0.19±0.03mag.
b = assuming r-i=0.84±0.08mag.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Jun-2018