tokens: ejecta and a shock-heated ISM (Park et al. 2003 , 2012 ; Uchida et al. 2015 ). It is also notable that N49 is in an overionized state (Uchida et al. 2015 ) and is interacting with dense molecular clouds on the eastern side (Banas et al. 1997 ; Yamane et al. 2018 ). Due to the interaction with molecular clouds, the thermal X-ray emission of N49 is particularly bright on the southeastern rim. N49 is an attractive object since Kaastra Mewe ( 1995 ) pointed out that the effect of RS can show up if an SNR has such a spherically asymmetric structure. Here, we present a high-resolution X-ray spectroscopy of N49 with the Reflection Grating Spectrometer (RGS) on board XMM-Newton. The obtained G-ratio of O vii He α and other line ratios as well imply a nonnegligible contribution of RS in N49. Throughout the paper, errors are given at a 68% confidence level. We assume the distance to N49 (LMC) to be 50 kpc (Pietrzyński et al. 2013 ). 2. Observation and Data Reduction N49 was observed with the XMM-Newton satellite (Jansen et al. 2001 ) in 2001 (Obs.ID 0113000201) and 2007 (Obs.ID 0505310101). The observation in 2007 was performed with a roll angle which placed N49 and a nearby SNR, N49B, along the dispersion direction of the RGS, making it difficult to extract RGS spectra of N49. We thus analyzed only the data obtained in 2001. For our spectral analysis, we used the RGS (den Herder et al. 2001 ) and the European Photon Imaging Camera MOS (Turner et al. 2001 ) data. We reduced the data using XMM Science Analysis Software version 16.1.0. The RGS data were processed with the RGS pipeline tool rgsproc . To discard periods of background flares, we applied good time intervals based on the count rate in CCD9, which is the closest to the optical axis of the mirror and has the least X-ray counts from the source and most affected by the background flares. The resulting effective exposure time is 11 ks for both RGS1 and RGS2. Since the second-order spectra are of low statistical quality, we analyzed only the first-order spectra. Figure 1. EPIC-MOS image (0.4–8.0 keV) of N49. The cross-dispersion width of the RGS (5 arcmin) is in between the white solid line. The spectral extraction region is enclosed by the white dashed line. N49B is another SNR near N49. 3. Analysis We analyzed the spectra using version 3.04.0 of the SRON SPEX package (Kaastra et al. 1996 ) with the maximum likelihood C-statistic (Cash 1979 ; Kaastra 2017 ). The RGS spectra were fitted simultaneously with those of MOS1 and 2. To account for the spatial broadening of the source, we multiplied spectral models with the SPEX model lpro , to which we input the MOS1 image of the source. Our models have two absorption models: one for the Milky Way and the other for the LMC. The column density of the former was fixed to (Dickey Lockman 1990 ) whereas that of the latter is left free. The elemental abundances for the LMC absorption were fixed to values found in the literature (∼ 0.3 solar; Russell Dopita
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