33 research outputs found

    A Detailed Observational Study of Molecular Loops 1 and 2 in the Galactic Center

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    Fukui et al. (2006) discovered two huge molecular loops in the Galactic center located in (l, b) ~ (355 deg-359 deg, 0 deg-2 deg) in a large velocity range of -180-40 km s^-1. Following the discovery, we present detailed observational properties of the two loops based on NANTEN 12CO(J=1-0) and 13CO(J=1-0) datasets at 10 pc resolution including a complete set of velocity channel distributions and comparisons with HI and dust emissions as well as with the other broad molecular features. We find new features on smaller scales in the loops including helical distributions in the loop tops and vertical spurs. The loops have counterparts of the HI gas indicating that the loops include atomic gas. The IRAS far infrared emission is also associated with the loops and was used to derive an X-factor of 0.7(+/-0.1){\times}10^20 cm^-2 (K km s^-1)^-1 to convert the 12CO intensity into the total molecular hydrogen column density. From the 12CO, 13CO, H I and dust datasets we estimated the total mass of loops 1 and 2 to be ~1.4 {\times} 106 Msun and ~1.9 {\times} 10^6 Msun, respectively, where the H I mass corresponds to ~10-20% of the total mass and the total kinetic energy of the two loops to be ~10^52 ergs. An analysis of the kinematics of the loops yields that the loops are rotating at ~47 km s-1 and expanding at ~141 km s^-1 at a radius of 670 pc from the center. Fukui et al. (2006) presented a model that the loops are created by the magnetic flotation due to the Parker instability with an estimated magnetic field strength of ~150 {\mu}G. We present comparisons with the recent numerical simulations of the magnetized nuclear disk by Machida et al. (2009) and Takahashi et al. (2009) and show that the theoretical results are in good agreements with the observations. The helical distributions also suggest that some magnetic instability plays a role similarly to the solar helical features.Comment: 40 pages, 22 figures, submitted to publication in PAS

    Discovery of Molecular Loop 3 in the Galactic Center: Evidence for a Positive-Velocity Magnetically Floated Loop towards L=355āˆ˜āˆ’359āˆ˜L=355^\circ-359^\circ

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    We have discovered a molecular dome-like feature towards 355āˆ˜ā‰¤lā‰¤359āˆ˜355^{\circ} \leq l \leq 359^{\circ} and 0āˆ˜ā‰¤bā‰¤2āˆ˜0^{\circ} \leq b \leq 2^{\circ}. The large velocity dispersions of 50--100 km sāˆ’1^{-1} of this feature are much larger than those in the Galactic disk and indicate that the feature is located in the Galactic center, probably within āˆ¼1\sim1 kpc of Sgr Aāˆ—^{*}. The distribution has a projected length of āˆ¼600\sim600 pc and height of āˆ¼300\sim300 pc from the Galactic disk and shows a large-scale monotonic velocity gradient of āˆ¼130\sim130 km s āˆ’1^{-1} per āˆ¼600\sim600 pc. The feature is also associated with HI gas having a more continuous spatial and velocity distribution than that of 12^{12}CO. We interpret the feature as a magnetically floated loop similar to loops 1 and 2 and name it "loop 3". Loop 3 is similar to loops 1 and 2 in its height and length but is different from loops 1 and 2 in that the inner part of loop 3 is filled with molecular emission. We have identified two foot points at the both ends of loop 3. HI, 12^{12}CO and 13^{13}CO datasets were used to estimate the total mass and kinetic energy of loop 3 to be \sim3.0 \times 10^{6} \Mo and āˆ¼1.7Ɨ1052\sim1.7 \times 10^{52} ergs. The huge size, velocity dispersions and energy are consistent with the magnetic origin the Parker instability as in case of loops 1 and 2 but is difficult to be explained by multiple stellar explosions. We argue that loop 3 is in an earlier evolutionary phase than loops 1 and 2 based on the inner-filled morphology and the relative weakness of the foot points. This discovery indicates that the western part of the nuclear gas disk of āˆ¼1\sim1 kpc radius is dominated by the three well-developed magnetically floated loops and suggests that the dynamics of the nuclear gas disk is strongly affected by the magnetic instabilities.Comment: 30 pages, 10 figures. High resolution figures are available at http://www.a.phys.nagoya-u.ac.jp/~motosuji/fujishita09_figs

    Temperature and Density in the Foot Points of the Molecular Loops in the Galactic Center; Analysis of Multi-J Transitions of 12CO(J=1-0, 3-2, 4-3, 7-6), 13CO(J=1-0) and C18O(J=1-0)

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    Fukui et al. (2006) discovered two molecular loops in the Galactic center and argued that the foot points of the molecular loops, two bright spots at both loops ends, represent the gas accumulated by the falling motion along the loops, subsequent to magnetic flotation by the Parker instability. We have carried out sensitive CO observations of the foot points toward l=356 deg at a few pc resolution in the six rotational transitions of CO; 12CO(J=1-0, 3-2, 4-3, 7-6), 13CO(J=1-0) and C18O(J=1-0). The high resolution image of 12CO (J=3-2) has revealed the detailed distribution of the high excitation gas including U shapes, the outer boundary of which shows sharp intensity jumps accompanying strong velocity gradients. An analysis of the multi-J CO transitions shows that the temperature is in a range from 30-100 K and density is around 10^3-10^4 cm^-3, confirming that the foot points have high temperature and density although there is no prominent radiative heating source such as high mass stars in or around the loops. We argue that the high temperature is likely due to the shock heating under C-shock condition caused by the magnetic flotation. We made a comparison of the gas distribution with theoretical numerical simulations and note that the U shape is consistent with numerical simulations. We also find that the region of highest temperature of ~100 K or higher inside the U shape corresponds to the spur having an upward flow, additionally heated up either by magnetic reconnection or bouncing in the interaction with the narrow neck at the bottom of the U shape. We note these new findings further reinforce the magnetic floatation interpretation.Comment: 40 pages, 23 figures, accepted by PASJ on Vol.62 No.

    Sub-millimeter Observations of Giant Molecular Clouds in the Large Magellanic Cloud: Temperature and Density as Determined from J=3-2 and J=1-0 transitions of CO

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    We have carried out sub-mm 12CO(J=3-2) observations of 6 giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC) with the ASTE 10m sub-mm telescope at a spatial resolution of 5 pc and very high sensitivity. We have identified 32 molecular clumps in the GMCs and revealed significant details of the warm and dense molecular gas with n(H2) āˆ¼\sim 103āˆ’5^{3-5} cmāˆ’3^{-3} and Tkin āˆ¼\sim 60 K. These data are combined with 12CO(J=1-0) and 13CO(J=1-0) results and compared with LVG calculations. We found that the ratio of 12CO(J=3-2) to 12CO(J=1-0) emission is sensitive to and is well correlated with the local Halpha flux. We interpret that differences of clump propeties represent an evolutionary sequence of GMCs in terms of density increase leading to star formation.Type I and II GMCs (starless GMCs and GMCs with HII regions only, respectively) are at the young phase of star formation where density does not yet become high enough to show active star formation and Type III GMCs (GMCs with HII regions and young star clusters) represents the later phase where the average density is increased and the GMCs are forming massive stars. The high kinetic temperature correlated with \Halpha flux suggests that FUV heating is dominant in the molecular gas of the LMC.Comment: 74 pages, including 41 figures, accepted for publication in ApJ

    PD-1 blockade therapy promotes infiltration of tumor-attacking exhausted T cell clonotypes

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    PD-1 blockade exerts clinical efficacy against various types of cancer by reinvigorating T cells that directly attack tumor cells (tumor-specific T cells) in the tumor microenvironment (TME), and tumor-infiltrating lymphocytes (TILs) also comprise nonspecific bystander T cells. Here, using single-cell sequencing, we show that TILs include skewed T cell clonotypes, which are characterized by exhaustion (T-ex) or nonexhaustion signatures (Tnon-ex). Among skewed clonotypes, those in the T-ex, but not those in the Tnon-ex, cluster respond to autologous tumor cell lines. After PD-1 blockade, non-preexisting tumor-specific clonotypes in the T-ex cluster appear in the TME. Tumor-draining lymph nodes (TDLNs) without metastasis harbor a considerable number of such clonotypes, whereas these clonotypes are rarely detected in peripheral blood. We propose that tumor-infiltrating skewed T cell clonotypes with an exhausted phenotype directly attack tumor cells and that PD-1 blockade can promote infiltration of such T-ex clonotypes, mainly from TDLNs

    Analgesia Is Enhanced by Providing Information regarding Good Outcomes Associated with an Odor: Placebo Effects in Aromatherapy?

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    No previous report has described whether information regarding an odor used in aromatherapy has placebo effects. We investigated whether placebo analgesia was engendered by verbal information regarding the analgesic effects of an odor. Twelve of 24 subjects were provided with the information that a lavender odor would reduce pain (informed), whereas the other 12 subjects were not (not-informed). Concurrent with respiration recording, the subjects were administered a lavender-odor or no-odor treatment during application of painful stimulation to the forefinger. The subjects reported their experience of pain and its unpleasantness on a visual analogue scale after the painful stimulation. The lavender-odor treatment significantly alleviated pain and unpleasantness compared with the no-odor treatment in the informed (P<0.01) and not-informed groups (P<0.05). The no-odor treatment in the informed group significantly alleviated pain and unpleasantness compared with both the no-odor and lavender-odor treatments in the not-informed group (P<0.05). Rapid and shallow breathing induced by the painful stimulation became slow and deep during the lavender-odor and no-odor treatments in both groups. Information regarding a lavender odor, the lavender odor itself, and slower breathing contributed to reduced perceptions of pain and unpleasantness during painful stimulation, suggesting that placebo effects significantly contribute to analgesia in aromatherapy
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