We conducted an unbiased near- to mid-infrared imaging and spectroscopic survey of the Large Magellanic Cloud (LMC) as a part of the AKARI Mission Program \Large-area Survey of the LMC" (LSLMC, PI: T. Onaka). An area of about 10 square degrees of the LMC was observed by ve photometric bands (3.2, 7, 11, 15, and 24 m) and a low-resolution slitless prism (2 { 5 m, R 20) equipped with AKARI/IRC. We constructed and publicly released photometric and spectroscopic catalogues of point sources in the LMC based on the survey data. The catalogues provide a large number of near-infrared spectral data, coupled with complementary broadband photometric data. Combined use of the present AKARI LSLMC catalogues with other infrared point source catalogues of the LMC possesses scientic potential that can be applied to various astronomical studies.

We present preliminary results of supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) seen by AKARI as well as Spitzer. By examining the AKARI LMC survey and the Spitzer data, we have searched for IR counterparts to 45 known SNRs in the LMC and could identify 28 SNRs with associated IR emission. 13 SNRs among them are newly detected in IR bands. For the entire IR SNRs, we make a catalog containing general information and the AKARI and/or Spitzer fluxes. Using the catalog, their IR colors and the possible correlation of the IR fluxes with the X-ray fluxes are examined. For some interesting SNRs, we have performed NIR spectroscopy with AKARI. An aromatic feature at 3.3 μm can be identified in LMC SNR N49. We investigate the characteristics of the IR features and discuss the PAH mission mechanism in SNRs.

Understanding the birth and evolution of galaxies, and the history of star formation in them, is one of the most important problems in astronomy. Using the data from the AKARI IRC survey of the Large Magellanic Cloud at 3.2, 7, 11, 15, and 24 μm , we have constructed a multi-wavelength catalog containing data from the cross-correlation with a number of other databases at different wavelengths. We present the first approach with a Support Vector Machine (SVM)-based method to separate different classes of stars in LMC in the color-color and color-magnitude diagrams.

We present the results of far-infrared spectroscopic observations of the Large Magellanic Cloud (LMC) with FIS-FTS. We covered a large area across the LMC, including 30 Doradus (30 Dor) and N44 star-forming regions, by 191 pointings in total. As a result, we detect the [OIII] and [CII] line emission as well as far-infrared dust continuum emission throughout the LMC. We find that the [OIII] emission is widely distributed around 30 Dor. The observed size of the distribution is too large to be explained by massive stars in 30 Dor, which are assumed to be enshrouded by clouds with the constant gas density estimated from the [OIII] line intensities. Therefore the surrounding structure is likely to be highly clumpy. We also find a global correlation between the [OIII] and the far-infrared continuum emission, suggesting that the gas and dust are well mixed in the highly-ionized region where the dust survives in clumpy dense clouds shielded from energetic photons. Furthermore we find that the ratios of [CII]/CO are as high as 110,000 in 30 Dor, and 45,000 even on average, while they are typically 6,000 for star-forming regions in our Galaxy. The unusually high [CII]/CO is also consistent with the picture of clumpy small dense clouds.

We present the results of the near-infrared (NIR) to mid-infrared (MIR) slit spectroscopic observations of the diffuse emission toward nine positions in the nearby irregular galaxy Large Magellanic Cloud (LMC) with the Infrared Camera (IRC) on board AKARI. The unique characteristic of AKARI/IRC provides a great opportunity to analyze variations in the unidentified infrared (UIR) bands based on continuous spectra from 2.5 to 13.4 μm of the same slit area. The observed variation of I3.3 / I11.3 suggests destruction of small-sized UIR band carriers, polycyclic aromatic hydrocarbons (PAHs) in harsh environments. This result demonstrates that the UIR 3.3 μm band provides us powerful information on the excitation conditions and/or the size distribution of PAHs, which is of importance for understanding the evolutionary process of hydrocarbon grains in the Universe. It also suggests a new diagnostic diagram of two band ratios, such as I3.3 / I11.3 versus I7.7 / I11.3 , for the interstellar radiation conditions. We discuss on the applicability of the diagnostic diagram to other astronomical objects, comparing the LMC results with those observed in other galaxies such as NGC 6946, NGC 1313, and M51.

We observed an area of 10 d e g 2 of the Large Magellanic Cloud using the Infrared Camera (IRC) onboard AKARI. The observations were carried out using five imaging filters (3, 7, 11, 15, and 24 μm ) and the prism disperser ( 2 − 5 μm , λ/Δλ ∼ 20 ) equipped in the IRC. This paper presents an outline of the survey project and also describes very briefly the newly compiled near- to mid-infrared point source catalog. The 10σ limiting magnitudes are 17.9, 13.8, 12.4, 9.9, and 8.6 mag at 3.2, 7, 11, 15 and 24 μm , respectively. The photometric accuracy is estimated to be about 0.1 mag at 3.2 μm and 0.06 - 0.07 mag in the other bands. The position accuracy is 0.3" at 3.2, 7 and 11 μm and 1.0" at 15 and 24 μm . The sensitivities at 3.2, 7, and 24 μm are roughly comparable to those of the Spitzer SAGE LMC point source catalog, while the AKARI catalog provides the data at 11 and 15 μm , covering the near- to mid-infrared spectral range continuously.