arXiv subjects

K. Tsuge

Publications and source records attributed to K. Tsuge.

18 recordsLinked to original sources

arXiv2026

Molecular and Atomic Gas Associated with the Gamma Ray Supernova Remnant RCW 103

We present a study of the interstellar molecular and atomic gas associated with the gamma-ray supernova remnant (SNR) RCW 103 using the Mopra $^{12}$CO($J$ = 1-0), Atacama Large Millimeter/submillimeter Array $^{13}$CO($J$ = 1-0), and the Australia Telescope Compact Array & Parkes HI data. We find that CO clouds in the velocity range from $-58.7$ to $-43.5$ km s$^{-1}$ show a clear spatial correspondence with the X-ray shell of RCW 103, particularly extending from the northwestern to the southeastern regions. The position-velocity diagram of the CO emission reveals an expanding gas motion with an expansion velocity of $ΔV \sim$$7.5$ km s$^{-1}$, which may have been produced by shock waves and/or stellar winds from the progenitor system. We estimate the total cosmic-ray proton energy to be $\sim$$3.0^{+1.1}_{-0.6} \times 10^{47}$ erg, adopting a total interstellar proton density of $\sim$$810$ cm$^{-3}$. This value is more than an order of magnitude lower than those inferred for other gamma-ray emitting SNRs of comparable age. Given that a substantial amount of dense gas remains within the interior of RCW 103, where thermal X-ray emission is dominant, our results possibly suggest that a significant fraction of the shock energy may have been converted into thermal energy via gas heating, thereby reducing the efficiency of cosmic-ray acceleration.

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arXiv2026

Discovery of Molecular and Atomic Gas associated with HESS J1646-458 (Westerlund 1): Spatial TeV Gamma-Ray and Interstellar Proton Correspondence

We report CO and HI studies of molecular and atomic gas toward the TeV gamma-ray source HESS J1646$-$458, widely considered to be associated with the young massive cluster Westerlund 1 (Wd1). We found that molecular clouds at $V_\mathrm{LSR} \sim$$-32$ km s$^{-1}$ coincide with arc-like structures seen at 8 $μ$m, likely illuminated by strong FUV radiation from Wd1. $^{12}$CO($J$ = 3-2) emission at the same velocity reveals a cavity-like structure with an expansion velocity of $\sim$$5$ km s$^{-1}$ toward the central region of Wd1, suggesting a recently formed wind-blown bubble driven by the cluster. We also identify a complementary spatial distribution between the $V_\mathrm{LSR} \sim$$-55$ and $\sim$$-32$ km s$^{-1}$ clouds, connected by an intermediate-velocity component at $V_\mathrm{LSR} \sim$$-44$ km s$^{-1}$. These characteristics are consistent with signatures of triggered star formation through a cloud-cloud collision and imply that both clouds are physically associated with Wd1. On larger scales, the total interstellar proton column density at $V_\mathrm{LSR}$ $\sim$$-36$-$-23$ km s$^{-1}$ shows a moderate spatial correspondence with the TeV gamma-ray shell. Together with this correlation, a substantial gas mass of $\sim$$1.6 \times 10^6$ $M_\odot$, and the absence of bright synchrotron X-rays, the TeV gamma-ray emission surrounding Wd1 is consistent with the hadronic origin. The present finding allows us to calculate the total energy of accelerated cosmic-ray protons to be $\sim$$6 \times 10^{49}$ erg.

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arXiv2025

Multi-frequency radio-continuum study of the LMC SNR N206 (Goat's Eye) and its "zig-zag" PWN

We present new radio-continuum observations of the Large Magellanic Cloud (LMC) supernova remnant (SNR) N206, which we give the name "Goat's Eye". Goat's Eye contains an interior radio structure that is likely a pulsar wind nebula (PWN), which we analyse in further detail. We use new radio observations from the Australia Telescope Compact Array (ATCA) telescope, as well as several archival radio observations, to calculate spectral indices, and find a steep spectral index for the whole SNR ($α= -0.60\pm0.02$), and a flatter spectral index for the PWN ($α= -0.16\pm0.03$). We also measure the polarisation and magnetic field properties of the PWN. Previously reported as a linear structure, the new observations show an unusual "zig-zag"-like structure, visible in radio-continuum total intensity, linear polarisation, and magnetic field orientations. The origin of this zig-zag structure is unclear, but we propose some origin scenarios that will require further observations to differentiate between.

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arXiv2024

Giant molecular clouds and their Type classification in M74: Toward understanding star formation and cloud evolution

We investigated the giant molecular clouds (GMCs) in M74 (NGC 628), using data obtained from the PHANGS project. We applied the GMC Types according to the activity of star formation: Type I without star formation, Type II with H$α$ luminosity ($L_\mathrm{Hα}$) less than $10^{37.5}~\mathrm{erg~s^{-1}}$, and Type III with $L_\mathrm{Hα}$ greater than $10^{37.5}~\mathrm{erg~s^{-1}}$. A total of 432 GMCs were identified, with 59, 201, and 172 GMCs, for Type I, II, and III, respectively. The size and mass of the GMCs range from 23 to 238 pc and $10^{4.9}$ to $10^{7.1}$ M$_{\odot}$, indicating that the mass and radius increase from Type I to III. Clusters younger than 4 Myr and HII regions are concentrated within 150 pc of a GMC, indicating a tight association between these young objects and GMCs. The virial ratio decreases from Type I to Type III, indicating that Type III GMCs are the most gravitationally relaxed among the three. We interpret that the GMCs evolve from Type I to Type III, as previously observed in the LMC. Based on a steady-state assumption, the estimated evolutionary timescales of Type I, II, and III are 1, 5, and 4 Myr, respectively. We assume that the timescale of Type III is equal to the age of the associated clusters, indicating a GMC lifetime of 10 Myr or longer. Although Chevance et al. (2020, MNRAS, 493, 2872) investigated GMCs using the same PHANGS dataset of M74, they did not define a GMC, reaching an evolutionary picture with a 20 Myr duration of the non-star-forming phase, which was five times longer than 4 Myr. We compare the present results with those of Chevance et al. (2020) and argue that defining individual GMCs is essential for understanding GMC evolution.

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arXiv2024

High-mass star formation in the Large Magellanic Cloud triggered by colliding HI flows

The galactic tidal interaction is a possible mechanism to trigger the active star formation in galaxies. The recent analyses using the HI data in the Large Magellanic Cloud (LMC) proposed that the tidally driven HI flow, the L-component, is colliding with the LMC disk, the D-component, and is triggering high-mass star formation toward the active star-forming regions R136 and N44. In order to explore the role of the collision over the entire LMC disk, we investigated the I-component, the collision-compressed gas between the L- and D-components, over the LMC disk, and found that 74% of the O/WR stars are located toward the I-component, suggesting their formation in the colliding gas. We compared four star-forming regions (R136, N44, N11, N77-N79-N83 complex). We found a positive correlation between the number of high-mass stars and the compressed gas pressure generated by collisions, suggesting that the pressure may be a key parameter in star formation.

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arXiv2023

ALMA Observations of Supernova Remnant N49 in the Large Magellanic Cloud. II. Non-LTE Analysis of Shock-heated Molecular Clouds

We present the first compelling evidence of shock-heated molecular clouds associated with the supernova remnant (SNR) N49 in the Large Magellanic Cloud (LMC). Using $^{12}$CO($J$ = 2-1, 3-2) and $^{13}$CO($J$ = 2-1) line emission data taken with the Atacama Large Millimeter/Submillimeter Array, we derived the H$_2$ number density and kinetic temperature of eight $^{13}$CO-detected clouds using the large velocity gradient approximation at a resolution of 3.5$''$ (~0.8 pc at the LMC distance). The physical properties of the clouds are divided into two categories: three of them near the shock front show the highest temperatures of ~50 K with densities of ~500-700 cm$^{-3}$, while other clouds slightly distant from the SNR have moderate temperatures of ~20 K with densities of ~800-1300 cm$^{-3}$. The former clouds were heated by supernova shocks, but the latter were dominantly affected by the cosmic-ray heating. These findings are consistent with the efficient production of X-ray recombining plasma in N49 due to thermal conduction between the cold clouds and hot plasma. We also find that the gas pressure is roughly constant except for the three shock-engulfed clouds inside or on the SNR shell, suggesting that almost no clouds have evaporated within the short SNR age of ~4800 yr. This result is compatible with the shock-interaction model with dense and clumpy clouds inside a low-density wind bubble.

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arXiv2021

Associated molecular and atomic clouds with X-ray shell of superbubble 30 Doradus C in the LMC

30 Doradus C is a superbubble which emits the brightest nonthermal X- and TeV gamma-rays in the Local Group. In order to explore detailed connection between the high energy radiation and the interstellar medium, we have carried out new CO and HI observations using the Atacama Large Millimeter$/$Submillimeter Array (ALMA), Atacama Submillimeter Telescope Experiment, and the Australia Telescope Compact Array with resolutions of up to 3 pc. The ALMA data of $^{12}$CO($J$ = 1-0) emission revealed 23 molecular clouds with the typical diameters of $\sim$6-12 pc and masses of $\sim$600-10000 $M_{\odot}$. The comparison with the X-rays of $XMM$-$Newton$ at $\sim$3 pc resolution shows that X-rays are enhanced toward these clouds. The CO data were combined with the HI to estimate the total interstellar protons. Comparison of the interstellar proton column density and the X-rays revealed that the X-rays are enhanced with the total proton. These are most likely due to the shock-cloud interaction modeled by the magnetohydrodynamical simulations (Inoue et al. 2012, ApJ, 744, 71). Further, we note a trend that the X-ray photon index varies with distance from the center of the high-mass star cluster, suggesting that the cosmic-ray electrons are accelerated by one or multiple supernovae in the cluster. Based on these results we discuss the role of the interstellar medium in cosmic-ray particle acceleration.

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arXiv2021

Multiwavelength analysis of the X-ray spur and southeast of the Large Magellanic Cloud

Aims: The giant HII region 30 Doradus (30 Dor) located in the eastern part of the Large Magellanic Cloud is one of the most active star-forming regions in the Local Group. Studies of HI data have revealed two large gas structures which must have collided with each other in the region around 30 Dor. In X-rays there is extended emission ($\sim 1$ kpc) south of 30 Dor called the X-ray spur, which appears to be anticorrelated with the HI gas. We study the properties of the hot interstellar medium (ISM) in the X-ray spur and investigate its origin including related interactions in the ISM. Methods: We analyzed new and archival XMM-Newton data of the X-ray spur and its surroundings to determine the properties of the hot diffuse plasma. We created detailed plasma property maps by utilizing the Voronoi tessellation algorithm. We also studied HI and CO data, as well as optical line emission data of H$α$ and [SII], and compared them to the results of the X-ray spectral analysis. Results: We find evidence of two hot plasma components with temperatures of $kT_1 \sim 0.2$ keV and $kT_2 \sim 0.5-0.9$ keV, with the hotter component being much more pronounced near 30 Dor and the X-ray spur. In 30 Dor, the plasma has most likely been heated by massive stellar winds and supernova remnants. In the X-ray spur, we find no evidence of heating by stars. Instead, the X-ray spur must have been compressed and heated by the collision of the HI gas.

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arXiv2020

ALMA CO Observations of Gamma-Ray Supernova Remnant N132D in the Large Magellanic Cloud: Possible Evidence for Shocked Molecular Clouds Illuminated by Cosmic-Ray Protons

N132D is the brightest gamma-ray supernova remnant (SNR) in the Large Magellanic Cloud (LMC). We carried out $^{12}$CO($J$ = 1-0, 3-2) observations toward the SNR using the Atacama Large Millimeter/submillimeter Array (ALMA) and Atacama Submillimeter Telescope Experiment. We find diffuse CO emission not only at the southern edge of the SNR as previously known, but also inside the X-ray shell. We spatially resolved nine molecular clouds using ALMA with an angular resolution of $5''$, corresponding to a spatial resolution of $\sim$1 pc at the distance of the LMC. Typical cloud sizes and masses are $\sim$2.0 pc and $\sim$100 $M_\odot$, respectively. High-intensity ratios of CO $J$ = 3-2 / 1-0 $> 1.5$ are seen toward the molecular clouds, indicating that shock-heating has occurred. Spatially resolved X-ray spectroscopy reveals that thermal X-rays in the center of N132D are produced not only behind a molecular cloud, but also in front of it. Considering the absence of a thermal component associated with the forward shock towards one molecular cloud located along the line of sight to the center of the remnant, this suggests that this particular cloud is engulfed by shock waves and is positioned on the near side of remnant. If the hadronic process is the dominant contributor to the gamma-ray emission, the shock-engulfed clouds play a role as targets for cosmic-rays. We estimate the total energy of cosmic-ray protons accelerated in N132D to be $\sim$0.5-$3.8 \times 10^{49}$ erg as a conservative lower limit, which is similar to that observed in Galactic gamma-ray SNRs.

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arXiv2020

The formation of the HII regions N83 and N84 in the Small Magellanic Cloud triggered by colliding HI flows

LHA 115-N 83 (N83) and LHA 115-N 84 (N84) are HII regions associated with the early stage of star formation located in the Small Magellanic Cloud (SMC). We have analyzed the new HI data taken with the Galactic Australian Square Kilometre Array Pathfinder survey project at a high angular resolution of 30". We found that the two clouds, having $\sim$40 km s$^{-1}$ velocity separation, show complementary distribution with each other, and part of the HI gas is dispersed by the ionization. In addition, the Atacama Large Millimeter/submillimeter Array observations revealed clumpy CO clouds of 10$^{5}$ $M_{\odot}$ in total over an extent of 100 pc, which are also well correlated with the HII regions. There is a hint of displacement between the two complementary components, which indicate that the red-shifted HI cloud is moving from the north to the south by $\sim$100 pc. This motion is similar to what is found in NGC 602 (Fukui et al. 2020), suggesting a large scale systematic gas flow. We frame a scenario that the two components collided with each other and triggered the formation of N83, N84, and six O-type stars around them in a time scale of a few Myr ($\sim$60 pc / 40 km s$^{-1}$). The supersonic motion compressed the HI gas to form the CO clouds in the red-shifted HI cloud, some of which are forming O-type stars ionizing the HII regions in the last Myr. The red-shifted HI cloud probably flows to the direction of the Magellanic Bridge. The velocity field originated by the close encounter of the SMC with the Large Magellanic Cloud 200 Myr ago as proposed by Fujimoto & Noguchi (1990).

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arXiv2020

The formation of the open cluster NGC 602 in the Small Magellanic Cloud triggered by colliding HI flows

NGC 602 is an outstanding young open cluster in the Small Magellanic Cloud. We have analyzed the new HI data taken with the Galactic Australian Square Kilometre Array Pathfinder survey project at an angular resolution of 30". The results show that there are three velocity components in the NGC 602 region. We found that two of them having ~20 km s$^{-1}$ velocity separation show complementary spatial distribution with a displacement of 147 pc. We present a scenario that the two clouds collided with each other and triggered the formation of NGC 602 and eleven O stars. The average time scale of the collision is estimated to be ~8 Myr, while the collision may have continued over a few Myr. The red shifted HI cloud extending ~500 pc flows possibly to the Magellanic Bridge, which was driven by the close encounter with the Large Magellanic Cloud 200 Myr ago (Fujimoto & Noguchi 1990; Muller & Bekki 2007). Along with the RMC136 and LHA 120-N 44 regions the present results lend support for that the galaxy interaction played a role in forming high-mass stars and clusters.

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arXiv2019

The ASKAP-EMU Early Science Project:Radio Continuum Survey of the Small Magellanic Cloud

We present two new radio continuum images from the Australian Square Kilometre Array Pathfinder (ASKAP) survey in the direction of the Small Magellanic Cloud (SMC). These images are part of the Evolutionary Map of the Universe (EMU) Early Science Project (ESP) survey of the Small and Large Magellanic Clouds. The two new source lists produced from these images contain radio continuum sources observed at 960 MHz (4489 sources) and 1320 MHz (5954 sources) with a bandwidth of 192 MHz and beam sizes of 30.0"x30.0" and 16.3"x15.1", respectively. The median Root Mean Squared (RMS) noise values are 186$μ$Jy beam$^{-1}$ (960 MHz) and 165$μ$Jy beam$^{-1}$ (1320 MHz). To create point source catalogues, we use these two source lists, together with the previously published Molonglo Observatory Synthesis Telescope (MOST) and the Australia Telescope Compact Array (ATCA) point source catalogues to estimate spectral indices for the whole population of radio point sources found in the survey region. Combining our ASKAP catalogues with these radio continuum surveys, we found 7736 point-like sources in common over an area of 30 deg$^2$. In addition, we report the detection of two new, low surface brightness supernova remnant candidates in the SMC. The high sensitivity of the new ASKAP ESP survey also enabled us to detect the bright end of the SMC planetary nebula sample, with 22 out of 102 optically known planetary nebulae showing point-like radio continuum emission. Lastly, we present several morphologically interesting background radio galaxies.

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arXiv2019

Discovery of Shocked Molecular Clouds Associated with the Shell-Type Supernova Remnant RX J0046.5$-$7308 in the Small Magellanic Cloud

RX J0046.5$-$7308 is a shell-type supernova remnant (SNR) in the Small Magellanic Cloud (SMC). We carried out new $^{12}$CO($J$ = 1-0, 3-2) observations toward the SNR using Mopra and the Atacama Submillimeter Telescope Experiment. We found eight molecular clouds (A-H) along the X-ray shell of the SNR. The typical cloud size and mass are $\sim$10-15 pc and $\sim$1000-3000 $M_{\odot}$, respectively. The X-ray shell is slightly deformed and has the brightest peak in the southwestern shell where two molecular clouds A and B are located. The four molecular clouds A, B, F, and G have high intensity ratios of $^{12}$CO($J$ = 3-2) / $^{12}$CO($J$ = 1-0) $> 1.2$, which are not attributable to any identified internal infrared sources or high-mass stars. The HI cavity and its expanding motion are found toward the SNR, which are likely created by strong stellar winds from a massive progenitor. We suggest that the molecular clouds A-D, F, and G and HI clouds within the wind-blown cavity at $V_\mathrm{LSR} = 117.1$-122.5 km s$^{-1}$ are to be associated with the SNR. The X-ray spectroscopy reveals the dynamical age of $26000^{+1000}_{-2000}$ yr and the progenitor mass of $\gtrsim 30$ $M_{\odot}$, which is also consistent with the proposed scenario. We determine physical conditions of the giant molecular cloud LIRS 36A using the large velocity gradient analysis with archival datasets of the Atacama Large Millimeter/submillimeter Array; the kinematic temperature is $72^{+50}_{-37}$ K and the number density of molecular hydrogen is $1500^{+600}_{-300}$ cm$^{-3}$. The next generation of $γ$-ray observations will allow us to study the pion-decay $γ$-rays from the molecular clouds in the SMC SNR.

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arXiv2019

ALMA CO Observations of Supernova Remnant N63A in the Large Magellanic Cloud: Discovery of Dense Molecular Clouds Embedded within Shock-Ionized and Photoionized Nebulae

We carried out new $^{12}$CO($J$ = 1-0, 3-2) observations of a N63A supernova remnant (SNR) from the LMC using ALMA and ASTE. We find three giant molecular clouds toward the northeast, east, and near the center of the SNR. Using the ALMA data, we spatially resolved clumpy molecular clouds embedded within the optical nebulae in both the shock-ionized and photoionized lobes discovered by previous H$α$ and [S II] observations. The total mass of the molecular clouds is $\sim$$800$ $M_{\odot}$ for the shock-ionized region and $\sim$$1700$ $M_{\odot}$ for the photoionized region. Spatially resolved X-ray spectroscopy reveals that the absorbing column densities toward the molecular clouds are $\sim$$1.5$-$6.0\times10^{21}$ cm$^{-2}$, which are $\sim$$1.5$-$15$ times less than the averaged interstellar proton column densities for each region. This means that the X-rays are produced not only behind the molecular clouds, but also in front of them. We conclude that the dense molecular clouds have been completely engulfed by the shock waves, but have still survived erosion owing to their high-density and short interacting time. The X-ray spectrum toward the gas clumps is well explained by an absorbed power-law or high-temperature plasma models in addition to the thermal plasma components, implying that the shock-cloud interaction is efficiently working for both the cases through the shock ionization and magnetic field amplification. If the hadronic gamma-ray is dominant in the GeV band, the total energy of cosmic-ray protons is calculated to be $\sim$$0.3$-$1.4\times10^{49}$ erg with the estimated ISM proton density of $\sim$$190\pm90$ cm$^{-3}$, containing both the shock-ionized gas and neutral atomic hydrogen.

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arXiv2018

Formation of the active star forming region LHA 120-N 44 triggered by tidally-driven colliding HI flows

N44 is the second active site of high mass star formation next to R136 in the Large Magellanic Cloud (LMC). We carried out a detailed analysis of HI at 60 arcsec resolution by using the ATCA & Parkes data. We presented decomposition of the HI emission into two velocity components (the L- and D-components) with the velocity separation of 60 km s$^{-1}$. In addition, we newly defined the I-component whose velocity is intermediate between the L- and D-components. The D-component was used to derive the rotation curve of the LMC disk, which is consistent with the stellar rotation curve (Alves et al. 2000). Toward the active cluster forming region of LHA 120-N 44, the three velocity components of HI gas show signatures of dynamical interaction including bridges and complementary spatial distributions. We hypothesize that the L- and D-components have been colliding with each other since 5 Myrs ago and the interaction triggered formation of the O and early B stars ionizing N44. In the hypothesis the I-component is interpreted as decelerated gas in terms of momentum exchange in the collisional interaction of the L- and D-components. In the N44 region the Planck sub-mm dust optical depth is correlated with the HI intensity, which is well approximated by a linear regression. We found that the N44 region shows a significantly steeper regression line than in the Bar region indicating less dust abundance in the N44 region, which is ascribed to the tidal interaction between the LMC with the SMC 0.2 Gyrs ago.

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arXiv2018

Molecular Clouds associated with the Type Ia SNR N103B in the Large Magellanic Cloud

N103B is a Type Ia supernova remnant (SNR) in the Large Magellanic Cloud (LMC). We carried out new $^{12}$CO($J$ = 3-2) and $^{12}$CO($J$ = 1-0) observations using ASTE and ALMA. We have confirmed the existence of a giant molecular cloud (GMC) at $V_\mathrm{LSR}$ $\sim$245 km s$^{-1}$ towards the southeast of the SNR using ASTE $^{12}$CO($J$ = 3-2) data at an angular resolution of $\sim$25$"$ ($\sim$6 pc in the LMC). Using the ALMA $^{12}$CO($J$ = 1-0) data, we have spatially resolved CO clouds along the southeastern edge of the SNR with an angular resolution of $\sim$1.8$"$ ($\sim$0.4 pc in the LMC). The molecular clouds show an expanding gas motion in the position-velocity diagram with an expansion velocity of $\sim5$ km s$^{-1}$. The spatial extent of the expanding shell is roughly similar to that of the SNR. We also find tiny molecular clumps in the directions of optical nebula knots. We present a possible scenario that N103B exploded in the wind-bubble formed by the accretion winds from the progenitor system, and is now interacting with the dense gas wall. This is consistent with a single-degenerate scenario.

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arXiv2018

ALMA observations of supernova remnant N49 in the LMC: I. Discovery of CO clumps associated with X-ray and radio continuum shells

N49 (LHA 120-N49) is a bright X-ray supernova remnant (SNR) in the Large Magellanic Cloud. We present new $^{12}$CO($J$ = 1-0, 3-2), HI, and 1.4 GHz radio-continuum observations of the SNR N49 using Mopra, ASTE, ALMA, and ATCA. We have newly identified three HI clouds using ATCA with an angular resolution of ~20": one associated with the SNR and the others located in front of the SNR. Both the CO and HI clouds in the velocity range from 280-291 km s$^{-1}$ are spatially correlated with both the soft X-rays (0.2-1.2 keV) and the hard X-rays (2.0-7.0 keV) of N49 on a ~10 pc scale. CO 3-2/1-0 intensity ratios indicate higher values of the CO cloud toward the SNR shell with an angular resolution of ~45", and thus a strong interaction was suggested. Using the ALMA, we have spatially resolved CO clumps embedded within or along the southeastern rim of N49 with an angular resolution of ~3''. Three of the CO clumps are rim-brightened on a 0.7-2 pc scale in both hard X-rays and the radio continuum$:$ this provides further evidence for dynamical interactions between the CO clumps and the SNR shock wave. The enhancement of the radio synchrotron radiation can be understood in terms of magnetic-field amplification around the CO clumps via a shock-cloud interaction. We also present a possible scenario in which the recombining plasma that dominates the hard X-rays from N49 was formed via thermal conduction between the SNR shock waves and the cold$/$dense molecular clumps.

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arXiv2017

Discovery of Molecular and Atomic Clouds Associated with the Magellanic Superbubble 30 Doradus C

We analyzed the 2.6-mm CO and 21-cm HI lines toward the Magellanic superbubble 30 Doradus C, in order to reveal the associated molecular and atomic gas. We uncovered five molecular clouds in a velocity range from 251 to 276 km s$^{-1}$ toward the western shell. The non-thermal X-rays are clearly enhanced around the molecular clouds on a pc scale, suggesting possible evidence for magnetic field amplification via shock-cloud interaction. The thermal X-rays are brighter in the eastern shell, where there are no dense molecular or atomic clouds, opposite to the western shell. The TeV $γ$-ray distribution may spatially match the total interstellar proton column density as well as the non-thermal X-rays. If the hadronic $γ$-ray is dominant, the total energy of the cosmic-ray protons is at least $\sim1.2 \times 10^{50}$ erg with the estimated mean interstellar proton density $\sim60$ cm$^{-3}$. In addition the $γ$-ray flux associated with the molecular cloud (e.g., MC3) could be detected and resolved by the Cherenkov Telescope Array (CTA). This should permit CTA to probe the diffusion of cosmic-rays into the associated dense ISM.

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