Observables and Correlation Functions in OSp Invariant String Field Theory

We define BRST invariant observables in the OSp invariant closed string field theory for bosonic strings. We evaluate correlation functions of these observables and show that the S-matrix elements derived from them coincide with those of the light-cone gauge string field theory.Comment: 23 page

D-branes and Closed String Field Theory

We construct solitonic states in the OSp invariant string field theory, which are BRST invariant in the leading order of regularization parameter. One can show that these solitonic states describe D-branes and ghost D-branes, by calculating the scattering amplitudes.Comment: 8 pages, 2 figures, based on an invited talk presented at the international workshop "Progress of String Theory and Quantum Field Theory" (Osaka City University, December 7-10, 2007), to be published in the proceeding

D-branes and Closed String Field Theory

We construct BRST invariant solitonic states in the OSp invariant string field theory for closed bosonic strings. Our construction is a generalization of the one given in the noncritical case. These states are made by using the boundary states for D-branes, and can be regarded as states in which D-branes or ghost D-branes are excited. We calculate the vacuum amplitude in the presence of solitons perturbatively and show that the cylinder amplitude for the D-brane is reproduced. The results imply that these are states with even number of D-branes or ghost D-branes.Comment: 36 pages, 3 figures, LaTeX; typos correcte

D-brane States and Disk Amplitudes in OSp Invariant Closed String Field Theory

We construct solitonic states in the OSp invariant string field theory, which are BRST invariant in the leading order of regularization parameter $\epsilon$. We calculate the disk amplitudes using these solitonic states and show that they describe D-branes and ghost D-branes.Comment: 37 pages, 8 figure

ASTE CO(3-2) Observations of the Barred Spiral Galaxy M 83: I. Correlation between CO(3-2)/CO(1-0) Ratios and Star Formation Efficiencies

We present CO(J=3-2) emission observations with the Atacama Submillimeter Telescope Experiment (ASTE) toward the 5' x 5' (or 6.6 x 6.6 kpc at the distance D = 4.5 Mpc) region of the nearby barred spiral galaxy M 83. We successfully resolved the major structures, i.e., the nuclear starburst region, bar, and inner spiral arms in CO(J=3-2) emission at a resolution of 22'' (or 480 pc), showing a good spatial coincidence between CO(J=3-2) and 6 cm continuum emissions. We found a global CO(J=3-2) luminosity L'_CO(3-2) of 5.1 x 10^8 K km s^-1 pc^2 within the observed region. We also found L'_CO(3-2) in the disk region (0.5 < r < 3.5 kpc) of 4.2 x 10^8 K km s^-1 pc^2, indicating that CO(J=3-2) emission in the disk region significantly contributes to the global L'_CO(3-2). From a comparison of a CO(J=3-2) data with CO(J=1-0) intensities measured with Nobeyama 45-m telescope, we found that the radial profile of CO(J=3-2)/CO(J=1-0) integrated intensity ratio R_3-2/1-0 is almost unity in the central region (r < 0.25 kpc), whereas it drops to a constant value, 0.6--0.7, in the disk region. The radial profile of star formation efficiencies (SFEs), determined from 6 cm radio continuum and CO(J=1-0) emission, shows the same trend as that of R_3-2/1-0. At the bar-end (r ~ 2.4 kpc), the amounts of molecular gas and the massive stars are enhanced when compared with other disk regions, whereas there is no excess of R_3-2/1-0 and SFE in that region. This means that a simple summation of the star forming regions at the bar-end and the disk cannot reproduce the nuclear starburst of M 83, implying that the spatial variation of the dense gas fraction traced by R_3-2/1-0 governs the spatial variation of SFE in M 83.Comment: 13 pages, 11 figures, PASJ in press, version with high resolution figures is available via http://www.nro.nao.ac.jp/~z5001km/m83-aste.pd

High Excitation Molecular Gas in the Galactic Center Loops; 12CO(J =2-1 and J =3-2) Observations

We have carried out 12CO(J =2-1) and 12CO(J =3-2) observations at spatial resolutions of 1.0-3.8 pc toward the entirety of loops 1 and 2 and part of loop 3 in the Galactic center with NANTEN2 and ASTE. These new results revealed detailed distributions of the molecular gas and the line intensity ratio of the two transitions, R3-2/2-1. In the three loops, R3-2/2-1 is in a range from 0.1 to 2.5 with a peak at ~ 0.7 while that in the disk molecular gas is in a range from 0.1 to 1.2 with a peak at 0.4. This supports that the loops are more highly excited than the disk molecular gas. An LVG analysis of three transitions, 12CO J =3-2 and 2-1 and 13CO J =2-1, toward six positions in loops 1 and 2 shows density and temperature are in a range 102.2 - 104.7 cm-3 and 15-100 K or higher, respectively. Three regions extended by 50-100 pc in the loops tend to have higher excitation conditions as characterized by R3-2/2-1 greater than 1.2. The highest ratio of 2.5 is found in the most developed foot points between loops 1 and 2. This is interpreted that the foot points indicate strongly shocked conditions as inferred from their large linewidths of 50-100 km s-1, confirming the suggestion by Torii et al. (2010b). The other two regions outside the foot points suggest that the molecular gas is heated up by some additional heating mechanisms possibly including magnetic reconnection. A detailed analysis of four foot points have shown a U shape, an L shape or a mirrored-L shape in the b-v distribution. It is shown that a simple kinematical model which incorporates global rotation and expansion of the loops is able to explain these characteristic shapes.Comment: 59 pages, accepted to PAS

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)

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.

A Search for CO(J=3-2) Emission from the Host Galaxy of GRB 980425 with the Atacama Submillimeter Telescope Experiment

We report on a deep search for CO(J=3-2) line emission from the host galaxy of GRB 980425 with the Atacama Submillimeter Telescope Experiment (ASTE). We observed five points of the galaxy covering the entire region. After combining all of the spectra, we obtained a global spectrum with the rms noise level of 3.3 mK in T_mb scale at a velocity resolution of 10 km s^-1. No significant emission was detected, though we find a marginal emission feature in the velocity range corresponding to the redshift of the galaxy. We derive 3 sigma upper limits on the global properties: the velocity-integrated CO(3-2) intensity of I_CO(3-2) < 0.26 K km s^-1 by adopting a velocity width of 67 km s^-1; the H_2 column density of N(H_2) < 3 x 10^20 cm^-2; the molecular gas mass of M(H_2) < 3 x 10^8 M_sun, by assuming a CO line luminosity to H_2 molecular gas mass conversion factor of X_CO = 5.0 x 10^20 cm^-2 (K km s^-1)^-1; and the star formation rate of SFR < 0.1 M_sun yr^-1, based on the Schmidt law. The SFR is consistent with the previous results of H_alpha and mid-IR observations, thereby suggesting that there is no significant obscured star formation in the host galaxy of GRB 980425. This result implies that there is a variety of GRB hosts with regard to the presence of obscured star formation.Comment: 7 pages, 4 figure

Plant viruses and viroids in Japan

An increasing number of plant viruses and viroids have been reported from all over the world due largely to metavirogenomics approaches with technological innovation. Herein, the official changes of virus taxonomy, including the establishment of megataxonomy and amendments of the codes of virus classification and nomenclature, recently made by the International Committee on Taxonomy of Viruses were summarized. The continued efforts of the plant virology community of Japan to index all plant viruses and viroids occurring in Japan, which represent 407 viruses, including 303 virus species and 104 unclassified viruses, and 25 viroids, including 20 species and 5 unclassified viroids, as of October 2021, were also introduced. These viruses and viroids are collectively classified into 81 genera within 26 families of 3 kingdoms (Shotokuvirae, Orthornavirae, Pararnavirae) across 2 realms (Monodnaviria and Riboviria). This review also overviewed how Japan’s plant virus/viroid studies have contributed to advance virus/viroid taxonomy