We present a summary of our spectroscopic redshift catalogue of 404 sources in the AKARI Deep Field South (ADF-S). We have used the AAOmega spectrograph to target mid-infrared and far-infrared sources selected primarily from AKARI observations in this field for which we were able to obtain optical counterparts. Our sources with identified redshifts include 316 with Hα detections at z  0:345 and 15 sources at z > 1 with MgII or Ly emission lines. About 13% of our z  0:345 sources are dominated by active galactic nuclei (AGN) emission, although many show emission from both star formation and AGNs. The median Balmer decrement is 5.9. Ultra-luminous infrared galaxies (ULIRGs) were found only in the higher-redshift sources. Optical and near infrared data will be available shortly, enabling calibration of the line luminosities and spectral energy distribution (SED) tting for these sources.

The AKARI North Ecliptic Pole Deep Field is a natural location to accomplish deep extragalactic surveys. It is supported by comprehensive ancillary data extending from radio to X-ray wavelengths, which have been used to classify radio sources as radio-loud and radio-quiet objects and to create a catalogue of Active Galactic Nuclei (AGN). This has been achieved by using a radio-optical classification and colour- colour diagrams rather than the more usual way based on spectroscopy Furthermore, we explore whether this technique can be extended by using a far-Infrared (FIR) colour-colour diagram which has been used to identify 268 high redshift candidates.

We report the results of a multi-wavelength study in the North Ecliptic Pole (NEP) deep field and examine the far infrared-radio correlation (FIRC) for high and low redshift objects. We have found a correlation between the GMRT data at 610 MHz and the Herschel data at 250μm that has been used to define a spectral index. This spectral index shows no evolution against redshift. As a result of the study, we show a radio colour-infrared diagram that can be used as a redshift indicator.

We selected 47 DOGs at z ~ 1:5 using optical R (or r' ), AKARI 18 μm, and 24 μm color in the AKARI North Ecliptic Pole (NEP) Deep survey field. Using the colors among 3, 4, 7, and 9μm, we classified them into 3 groups; bump DOGs (23 sources), power-law DOGs (16 sources), and unknown DOGs (8 sources). We built spectral energy distributions (SEDs) with optical to far-infrared photometric data and investigated their properties using SED fitting method. We found that AGN activity such as a AGN contribution to the infrared luminosity and a Chandra detection rate for bump and power-law DOGs are signicantly different, while stellar component properties like a stellar mass and a star-formation rate are similar to each other. A specific star-formation rate range of power-law DOGs is slightly higher than that of bump DOGs with wide overlap. Herschel/PACS detection rates are almost the same between bump and power-law DOGs. On the other hand SPIRE detection rates show large differences between bump and power-law DOGs. These results might be explained by differences in dust temperatures. Both groups of DOGs host hot and/or warm dust ( 50 Kelvin), and many bump DOGs contain cooler dust ( < 30 Kelvin).

We have imaged the AKARI Deep Field with the GMRT radio telescope at 610 MHz, detecting 1224 radio components, which are optically identified with 455 optical galaxies having a mean r0 magnitude brighter of 22.5 (to a completeness limit of 25.4 mag), and an average redshift ~ 0.8.

The extragalactic background suggests half the energy generated by stars was reprocessed into the infrared (IR) by dust. At z1.3, 90% of star formation is obscured by dust. To fully understand the cosmic star formation history, it is critical to investigate infrared emission. AKARI has made deep mid-IR observation using its continuous 9-band filters in the NEP field (5.4 deg2), using 10% of the entire pointed observations available throughout its lifetime. However, there remain 11,000 AKARI infrared sources undetected with the previous CFHT/Megacam imaging (r ~25.9ABmag). Redshift and IR luminosity of these sources are unknown. These sources may contribute signicantly to the cosmic star-formation rate density (CSFRD). For example, if they all lie at 1< z <2, the CSFRD will be twice as high at the epoch. We are carrying out deep imaging of the NEP eld in 5 broad bands (g; r; i; z; and y) using Hyper Suprime-Camera (HSC), which has 1.5 deg field of view in diameter on Subaru 8m telescope. This will provide photometric redshift information, and thereby IR luminosity for the previously-undetected 11,000 faint AKARI IR sources. Combined with AKARI's mid-IR AGN/SF diagnosis, and accurate mid- IR luminosity measurement, this will allow a complete census of cosmic star-formation/AGN accretion history obscured by dust.

The preliminary data reduction, analysis and first results from the Herschel survey of the AKARI NEP field are presented. Herschel SPIRE observations of the NEP-Wide region and PACS observations of the NEP-Deep region have yielded galaxy catalogues of 4000 and 900 sources respectively down to ux density levels of approximately 15 mJy at 100-250 microns. Source counts produced from these catalogues reach cosmologically significant depths tracing the evolutionary upturn and turnover in the source counts. The source counts are in agreement with other large area surveys carried out with Herschel bridging the gap between the shallow and deep Herschel surveys.

Modelling and tting the spectral energy distribution (SED) of galaxies or regions of galaxies is one of the most useful methods available to the astronomer nowadays. By modelling the SEDs and comparing the models to the observations, we can collect important information on the physical processes at play in the formation and evolution of galaxies. The models allow to follow the evolution of the galaxies from their formation on. The versatility of code is crucial because of the diversity of galaxies. The analysis is only relevant and useful if the models can correctly reproduce this diversity now and across (as best as possible) all redshifts. On the other hand, the code needs to run fast to compare several million or tens of millions of models and to select the best (on a probabilistic basis) one that best resembles the observations. With this important point in mind, it seems logical that we should efficiently make use of the computer power available to the average astronomer. For instance, it seems difficult, today, to model and fit SEDs without a parallelized code. We present the new Python version of CIGALE SED fitting code and its characteristics. CIGALE comes in two main avours: CIGALE Classic to fit SEDs and CIGALE Model to create spectra and SEDs of galaxies at all redshifts. The latest can potentially be used in conjunction with galaxy evolution models of galaxy formation and evolution such as semi-analytic ones.

There exists strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies; however it is still under debate how such a relation comes about and whether it is relevant for all or only a subset of galaxies. An important mechanism connecting AGN to their host galaxies is AGN feedback, potentially heating up or even expelling gas from galaxies. AGN feedback may hence be responsible for the eventual quenching of star formation and halting of galaxy growth. A rich multi- wavelength dataset ranging from the X-ray regime (Chandra), to far-IR (Herschel), and radio (WSRT) is available for the North Ecliptic Pole field, most notably surveyed by the AKARI infrared space telescope, covering a total area on the sky of 5.4 sq. degrees. We investigate the star formation properties and possible signatures of radio feedback mechanisms in the host galaxies of 237 radio sources below redshift z = 2 and at a radio 1.4 GHz ux density limit of 0.1 mJy. Using broadband SED modelling, the nuclear and host galaxy components of these sources are studied simultaneously as a function of their radio luminosity. Here we present results concerning the AGN content of the radio sources in this eld, while also offering evidence showcasing a link between AGN activity and host galaxy star formation. In particular, we show results supporting a maintenance type of feedback from powerful radio-jets.

We demonstrate the luminosity dependence of the covering factor (CF) of active galactic nuclei (AGNs), based on AKARI mid-infrared all-sky survey catalog. Combining the AKARI with Sloan Digital Sky Survey (SDSS) spectroscopic data, we selected 243 galaxies at 9 m and 255 galaxies at 18 m. We then identied 64 AGNs at 9 μm and 105 AGNs at 18 μm by their optical emission lines. Following that, we estimated the CF as the fraction of type 2 AGN in all AGNs. We found that the CF decreased with increasing 18 μm luminosity, regardless of the choice of type 2 AGN classification criteria.

Physicochemical properties of water quality were analyzed to understand the long-term variations in Lake Youngrang from 1998 to 2015. Nonparametric statistical methods were applied to deduct correlation among water quality parameters and water quality trend. In total observations (N=64), the Secchi depth (SD) transparency showed significant positive correlation with salinity (r=0.458) and highly significant negative correlation with chlorophyll-a (r= - 0.649) for p<0.0001 in two-tailed test of Spearman’s rank correlation. Significant negative correlations of SD were observed with chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN). These correlation patterns were very similar in rainy (N=25) and non-rainy (N= 39) periods too. Chlorophyll-a (Chl-a) had significant correlation with COD. Sen’s slope test was performed along with Mann-Kendall trend test (significance α=0.05, two-tailed) to find water quality trend. Positive trends were observed for SD and salinity with Sen’s slopes 0.012 and 0.385, respectively (p<0.0001). Negative significant trends were observed for total nitrogen (TN) and Chl-a with Sen’s slopes - 0.02 (p<0.0001) and - 0.346 (p=0.0010), respectively. Temperature, COD and phosphorus components had no trends. Carlson’s trophic state index (TSI) for SD, TP and Chl-a were obtained in the ranges of 46~80, 37~82 and 39~82, respectively. Trophic index values suggest that Lake Youngrang was mesoeutrophic to eutrophic and there could be possibility of anoxia during the summer and dominance of blue-green algae. Excess nutrient inputs from external and internal sources were the causes of eutrophication in this lake. The findings of this study would be helpful to recognize water quality variables to manage the water body.

The dusty torus of Active Galactic Nuclei (AGNs) is one of the important components for the unification theory of AGNs. The geometry and properties of the dusty torus are key factors in understanding the nature of AGNs as well as the formation and evolution of AGNs. However, they are still under discussion. Infrared observation is useful for understanding the dusty torus as thermal emission from hot dust with the dust sublimation temperature (~ 1500 K) has been observed in the infrared. We have analyzed infrared spectroscopic data of low-redshift and high-redshift quasars, which are luminous AGNs. For the low-redshift quasars, we constructed the spectral energy distributions (SEDs) with AKARI near-infrared and Spitzer mid-infrared spectra and decomposed the SEDs into a power-law component from the nuclei, silicate features, and blackbody components with different temperatures from the dusty torus. From the decomposition, the temperature of the innermost dusty torus shows the range between 900-2000 K. For the high-redshift quasars, AKARI traced rest-frame optical and near-infrared spectra of AGNs. Combining with WISE data, we have found that the temperature of the innermost dusty torus in high redshift quasars is lower than that in typical quasars. The hydrogen Hα emission line from the braod emission line region in the quasars also shows narrow full width at half maximum of 3000-4000 km s-1. These results indicate that the dusty torus and the broad emission line region are more extended than those of typical quasars.

Early-type galaxies (ETGs) are generally dominated by old low-mass stars, which are not very productive of dust, and hot interstellar plasmas, which are very destructive of dust. Thus ETGs provide harsh environments for survival of dust. It has been found that some ETGs contain a large amount of dust, and yet its supply mechanism is not understood well. We present the result of a systematic study of dust in ETGs with the AKARI mid- and far-infrared all-sky surveys. From the AKARI result and the Ks band data obtained by ground-based telescopes, we nd that there is a global correlation between the dust mass and stellar luminosity. We also compare the AKARI all-sky survey result with the CO data to discuss origins of dust in ETGs.

We study CO2/H2O ice abundance ratios in nearby galaxies using AKARI near-infrared slit spec- troscopy. Past studies of the ices intensively examined CO2/H2O ratios mainly in our Galaxy, and found that there were considerable variations in the CO2/H2O ratios from object to object. The cause of the variations is, however, still under debate. As a result of the analysis of our sample that includes 1031 regions in 158 galaxies, the CO2/H2O ratios are in a range of 0.05-0.30. In the dataset, we nd that the CO2/H2O ratios positively correlate with the Brα/PAH 3.3 μm ratios which re ect the massive star formation activity. Furthermore, we find that the CO2/H2O ratios positively correlate with the specific star formation rates of the galaxies where the ices are detected, that re ect the evolutionary stage of a galaxy. These results suggest that the CO2/H2O ratios are enhanced in active star-forming regions and young galaxies.

We have performed systematic studies of the properties of dust in various environments of nearby galaxies with AKARI. The unique capabilities of AKARI, such as near-infrared (near-IR) spectroscopy combined with all-sky coverage in the mid- and far-IR, enable us to study processing of dust, particularly carbonaceous grains includings polycyclic aromatic hydrocarbons (PAHs), for unbiased samples of nearby galaxies. In this paper, we first review our recent results on individual galaxies, highlighting the uniqueness of AKARI data for studies of nearby galaxies. Then we present results of our systematic studies on nearby starburst and early-type galaxies. From the former study based on the near-IR spectroscopy and mid-IR all-sky survey data, we find that the properties of PAHs change systematically from IR galaxies to ultra- luminous IR galaxies, depending on the IR luminosity of a galaxy or galaxy population. From the latter study based on the mid- and far-IR all-sky survey data, we find that there is a global correlation between the amounts of dust and old stars in early-type galaxies, giving an observational constraint on the origin of the dust.

We present our AKARI study of massive star forming regions where a large-scale cloud-cloud collision possibly contributes to massive star formation. Our targets are Spitzer bubbles, which consist of two types of bubbles, closed and broken ones; the latter is a candidate of the objects created by cloud-cloud collisions. We performed mid- and far-infrared surface photometry toward Spitzer bubbles to obtain the relationship between the total infrared luminosity, LIR, and the bubble radius, R. As a result, we nd that LIR is roughly proportional to R where  = 2:10:4. Broken bubbles tend to have larger radii than closed bubbles for the same LIR.

We present results of AKARI/IRC near-infrared (NIR) slit-spectroscopy (2.5{5.0 m, R  100) of Galactic sources, focusing on ice absorption features. We investigate the abundance of H2O and CO2 ices and other ice species (CO and XCN ices) along lines of sight towards Galactic Hii regions, massive YSOs, and infrared diuse sources. Even among those dierent kinds of astronomical objects, the abundance ratio of CO2 to H2O ices does not vary signicantly, suggesting that the pathway to CO2 ice formation driven by UV irradiation is not eective at least among the present targets.

Our understanding of dust emission, interaction, and evolution, is evolving. In recent years, electric dipole emission by spinning dust has been suggested to explain the anomalous microwave excess (AME), appearing between 10 and 90 Ghz. The observed frequencies suggest that spinning grains should be on the order of 10nm in size, hinting at polycyclic aromatic hydrocarbon molecules (PAHs). We present data from the AKARI/Infrared Camera (IRC) due to its high sensitivity to the PAH bands. By inspecting the IRC data for a few AME regions, we nd a preliminary indication that regions well-tted by a spinning- dust model have a higher 9 m than 18 m intensity vs. non-spinning-dust regions. Ongoing eorts to improve the analysis by using DustEM and including data from the AKARI Far Infrared Surveyor (FIS), IRAS, and Planck High Frequency Instrument (HFI) are described.

A wide spectral coverage from near-infrared (NIR) to far-infrared (FIR) of AKARI both for imaging and spectroscopy enables us to eciently study the emission from gas and dust in the interstellar medium (ISM). In particular, the Infrared Camera (IRC) onboard AKARI oers a unique opportunity to carry out sensitive spectroscopy in the NIR (2{5 m) for the rst time from a spaceborn telescope. This spectral range contains a number of important dust bands and gas lines, such as the aromatic and aliphatic emission bands at 3.3 and 3.4{3.5 m, H2O and CO2 ices at 3.0 and 4.3 m, CO, H2, and HI gas emission lines. In this paper we concentrate on the aromatic and aliphatic emission and ice absorption features. The balance between dust supply and destruction suggests signicant dust processing taking place as well as dust formation in the ISM. Detailed analysis of the aromatic and aliphatic bands of AKARI observations for a number of Hii regions and Hii region-like objects suggests processing of carbonaceous dust in the ISM. The ice formation process can also be studied with IRC NIR spectroscopy eciently. In this review, dust processing in the ISM divulged by recent analysis of AKARI data is discussed.