ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject I-CelestialObject O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject I-CelestialObject O B-Model O O O O O O B-Model O O O O O O O O O O O O O B-Telescope O O O B-Observatory O O O B-Wavelength O B-Wavelength O O B-Wavelength O B-Telescope B-Wavelength O O O B-Wavelength I-Wavelength O B-Telescope I-Telescope I-Telescope O O O O O O O O O O O O O B-Telescope O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject I-CelestialObject O O O O O B-Telescope I-Telescope I-Telescope O O B-Citation I-Citation I-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O B-Telescope O B-Observatory O B-Telescope O O B-Telescope I-Telescope I-Telescope O O O O O O O B-Model O O O O O O O O O O O O B-CelestialObject I-CelestialObject O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength B-Wavelength I-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O B-Telescope O O O B-Observatory O O O B-Wavelength O B-Wavelength O O B-Wavelength O B-Telescope B-Wavelength O O O B-Wavelength I-Wavelength O B-Telescope I-Telescope I-Telescope O O O O O O O O O
tokens: mass) of the ejecta are mainly associated with the observational data near the peak time (∼1 day) and the optimal pulsar luminosity mainly depends on the late observations (i.e., a few days after the peak time). If a high ejecta mass is adopted in the fittings, the contribution of the PWN emission to the late phase may be low. Then, a low pulsar luminosity may be found if a high ejecta mass is adopted in the fittings. Figure 4. Fitting result (solid lines) of AT 2017gfo, where the observational data are described with circles and the upper limits are represented with triangles. Figure 5. Posterior probability density functions for the physical parameters of AT 2017gfo from MCMC simulations. Table 1 Fitting Result from MCMC Fitting In order to test our fits result, we confront our result with HST observations (left panel), Swift observations (middle panel, UVW1 , UVW2 , and UVM2 bands), MASTER optical observations (middle panel, W band), and Spitzer Space Telescope observations (right panel) in Figure 6 . We add the observational data of HST at >100 days (Lyman et al. 2018 ; Margutti et al. 2018 ; Lamb et al. 2019 ; Piro et al. 2019 ). It is found that the model curve is lower than data points, which suggests the late time observation is dominated by the afterglow of GRB 170717A. The observational data of the Spitzer Space Telescope is from Villar et al. ( 2018 ). This figure reveals that our result is consistent with the data from HST , Swift , MASTER , and Spitzer Space Telescope , which were not used in our MCMC fits. In observations, it is found that the observed radiation spectrum of AT 2017gfo gradually deviates from the thermal radiation spectrum over time (Troja et al. 2017 ). Then, we plot the radiation spectrum from 11.5 to 19.5 days after trigger based on our fits result. The radiation spectra are shown in the left panel of Figure 7 , where the circles and triangles are the observational data laying closest to our selected time. One can find that our fits result describes the observed radiation spectra nicely. It is interesting to point out that the spectral peak of the thermal component moves from ∼10 14 Hz at t = 10.5 days to the very low frequency at t = 19.5 days. Moreover, the thermal component is comparable to the nonthermal component at t ≲ 19.5 days. This behavior suggests that the bolometric luminosity at t ≲ 19.5 days can be well described with the thermal emission from the ejecta. In the right panel of Figure 7 , we compare the thermal luminosity based on our fitting result with the observed bolometric luminosity (Waxman et al. 2018 ). One can find that our thermal luminosity describes the observed bolometric luminosity very well. Figure 6. Confronting our fitting result with HST observations (left panel), Swift observations (middle panel, UVW1 , UVW2 , and UVM2 bands), MASTER optical observations (middle panel, W band), and Spitzer Space Telescope observations (right panel). Figure 7. Comparison of radiation spectra