Dark gas in the solar neighnorhood from extinction data

When modeling infrared or gamma-ray data as a linear combination of observed gas tracers, excess emission has been detected compared to expectations from known neutral and atomic gas as traced by HI and CO measurements, respectively. This excess might correspond to an additional gas component. This so-called "dark gas" (DG) has been observed in our Galaxy, as well as the Magellanic Clouds. For the first time, we investigate the correlation between visible extinction (Av) data and gas tracers on large scales in the solar neighborhood. Our work focuses on both the solar neighborhood (|b|>10\degr), and the inner and outer Galaxy, as well as on four individual regions: Taurus, Orion, Cepheus-Polaris and Aquila-Ophiuchus. Thanks to the recent production of an all-sky Av map, we first perform the correlation between Av and both HI and CO emission over the most diffuse regions, to derive the optimal (Av/NH)^(ref) ratio. We then iterate the analysis over the entire regions to estimate the CO-to-H2 conversion factor as well as the DG mass fraction. The average extinction to gas column-density ratio in the solar neighborhood is found to be (Av/NH)^(ref)=6.53 10^(-22) mag. cm^2, with significant differences between the inner and outer Galaxy. We derive an average XCO value of 1.67 10^(20) H2 cm^(-2)/(K km s^(-1)). In the solar neighborhood, the gas mass in the dark component is found to be 19% relative to that in the atomic component and 164$$ relative to the one traced by CO. These results are compatible with the recent analysis using Planck data within the uncertainties of our measurements. We estimate the ratio of dark gas to total molecular gas to be 0.62 in the solar neighborhood. The HI-to-H2 and H2-to-CO transitions appear for Av $\simeq$0.2 mag and Av$\simeq1.5$ mag, respectively, in agreement with theoretical models of dark-H2 gas.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in A&A (in press

Extinction and dust/gas ratio in LMC molecular clouds

Aims. The goal of this paper is to measure the dust content and distribution in the Large Magellanic Cloud (LMC) by comparing extinction maps produced in the near-infrared wavelengths and the spatial distribution of the neutral and molecular gas, as traced by Hi and CO observations. Methods. In order to derive an extinction map of the LMC, we have developed a new method to measure the color excess of dark clouds, using the 2MASS all-sky survey. Classical methods to measure the color excess (including the NICE method) tend to underestimate the true color excess if the clouds are significantly contaminated by unreddened foreground stars, as is the case in the LMC. We propose a new method that uses the color of the X percentile reddest stars and which is robust against such contamination. Using this method, it is possible to infer the positions of dark clouds with respect to the star distribution by comparing the observed color excess as a function of the percentile used and that predicted by a model. Results. On the basis of the resulting extinction map, we perform a correlation analysis for a set of dark molecular clouds. Assuming similar infrared absorption properties for the dust in the neutral and molecular phases, we derive the absorption-to-column density ratio AV/NH and the CO-to-H2 conversion factor X_(CO). We show that AV/NH increases from the outskirts of the LMC towards the 30 Dor star-forming region. This can be explained either by a systematic increase of the dust abundance, or by the presence of an additional gas component not traced by Hi or CO, but strongly correlated to the Hi distribution. If dust abundance is allowed to vary, the derived X_(CO) factors for the selected regions are several times lower than those derived from a virial analysis of the CO data. This could indicate that molecular clouds in the LMC are not gravitationally bound, or that they are bounded by substantial external pressure. However, the X_(CO) values derived from absorption can be reconciled with the virial results assuming a constant value for the dust abundance and the existence of an additional, unseen gas component. These results are in agreement with those derived for the LMC from diffuse far-infrared emission

Weight Reduction by Effective Protocol of Diet and Exercise

Background: Metabolic syndrome (Met-S) and Locomotive syndrome (Loc-S) have been in focus for years. Authors have reduced weight of patients with Met-S and Loc-S by exercise and Low Carbohydrate Diet (LCD). Moreover, we continued clinical research and enlightening activity about LCD through Japan LCD Promoting Association (JLCDPA). Intervention Program: Enrolled subjects were obese patients with 715 men and 2058 women with 62.2 ± 12.1 years. They attended the intervention of weight reduction program by LCD and exercise. The advisers were registered dietitian nutritionists (RDNs) and physical/exercise therapists, and they regularly interviewed the cases for 6-12 months. LCD included 33% of carbohydrate, and exercise included aerobic and anaerobic exercises with 10 kinds of machines. Results and Discussion: The pre-weight vs post-weight is 63.7 ± 11.6 kg vs 59.4±10.8 kg in average, and 61.8 kg vs 57.5 kg in median. Further, quartiles values on 25%-75% were 55.5 kg-69.9 kg vs 51.5 kg-65.3 kg, respectively. The weight reduction was 6.6% in average, and 2.6%-9.8% in quartiles 25%-75%. The distribution shape of both pre- and post-weight in the figure showed slight shift to left direction by 4.3 kg in average. These results suggest that combined therapy would be successful in the presence of advisers, and that data would become basal data for future research

Effective Nutritional Guidance for Obesity by Low Carbohydrate Diet (LCD)

Background: Authors have continued treating patients with obesity and metabolic syndrome by application of Low Carbohydrate Diet (LCD). Furthermore, we have continued presenting various reports about nutrition and educational guidance and developing LCD medically and socially through the activity of Japan LCD Promoting Association (JLCDPA). Study Protocol: Subjects enrolled were 2773 patients with obesity who received nutritional guidance in our clinic. Methods include i) weight reduction program on the intervention of LCD and guidance by registered dietitian nutritionist (RDN), ii) LCD with 33% of carbohydrate, and iii) Practice of guidance including self-monitoring, lifestyle, motivation, determination for the goal, evaluation. Results and Discussion: Nutritional guidance has been carried out on a regular basis by three RDNs. Weight reduction was: 10% or more was observed in 666 (24.0%), and 5.0 - 9.9% was in 863 (31.2%). In other words, the reduction of 5.0% or more was 55.2%, and 3.0% or more was 71.4%. Our nutritional guidance has been made as a manual for weight reduction program. It includes various factors, such as Self-Regulation Empowerment, cognitive behavioral therapy and motivational interviewing. These results would become basal and reference data for future research in the field of weight reduction

Extinction map of the Small Magellanic Cloud based on SIRIUS and 6X 2MASS point source catalogs

In this paper, we present the first extinction map of the Small Magellanic Cloud (SMC) constructed using the color excess at near-infrared wavelengths. Using a new technique named "X percentile method", which we developed recently to measure the color excess of dark clouds embedded within a star distribution, we have derived an E(J – H) map based on the SIRIUS and 6X Two Micron All Sky Survey (2MASS) star catalogs. Several dark clouds are detected in the map derived from the SIRIUS star catalog, which is deeper than the 6X 2MASS catalog. We have compared the E(J – H) map with a model calculation in order to infer the locations of the clouds along the line of sight, and found that many of them are likely to be located in or elongated toward the far side of the SMC. Most of the dark clouds found in the E(J – H) map have counterparts in the CO clouds detected by Mizuno et al. with the NANTEN telescope. A comparison of the E(J – H) map with the virial mass derived from the CO data indicates that the dust-to-gas ratio in the SMC varies in the range A_V /N_H = 1-2 × 10^(–22) mag H^-1 cm^2 with a mean value of ~1.5 × 10^(–22) mag H^-1 cm^2. If the virial mass underestimates the true cloud mass by a factor of ~2, as recently suggested by Bot et al., the mean value would decrease to ~8×10^(–23) mag H^-1 cm^2, in good agreement with the value reported by Gordon et al., 7.59 × 10^(–23) mag H^-1 cm^2

A New Galactic Extinction Map of the Cygnus Region

We have made a Galactic extinction map of the Cygnus region with 5' spatial resolution. The selected area is 80^\circ to 90^\circ in the Galactic longitude and -4^\circ to 8^\circ in the Galactic latitude. The intensity at 140 \mum is derived from the intensities at 60 and 100 \mum of the IRAS data using the tight correlation between 60, 100, and 140 \mum found in the Galactic plane. The dust temperature and optical depth are calculated with 5' resolution from the 140 and 100 \mum intensity, and Av is calculated from the optical depth. In the selected area, the mean dust temperature is 17 K, the minimum is 16 K, and the maximum is 30 K. The mean Av is 6.5 mag, the minimum is 0.5 mag, and the maximum is 11 mag. The dust temperature distribution shows significant spatial variation on smaller scales down to 5'. Because the present study can trace the 5'-scale spatial variation of the extinction, it has an advantage over the previous studies, such as the one by Schlegel, Finkbeiner, & Davis, who used the COBE/DIRBE data to derive the dust temperature distribution with a spatial resolution of 1^\circ. The difference of Av between our map and Schlegel et al.'s is \pm 3 mag. A new extinction map of the entire sky can be produced by applying the present method.Comment: 27 pages, 14 figures, accepted for publication in Ap

Shadow bands in single-layered Bi_2Sr_2CuO_6 studied by angle-resolved photoemission spectroscopy

We have performed systematic angle-resolved photoemission spectroscopy (ARPES) on single-layered cuprate superconductor Bi2Sr2CuO6 to elucidate the origin of shadow band. We found that the shadow band is exactly the c(2x2) replica of the main band irrespective of the carrier concentration and its intensity is invariable with respect to temperature, doping, and substitution constituents of block layers. This result rules out the possibility of antiferromagnetic correlation and supports the structural origin of shadow band. ARPES experiments on optimally doped La1.85Sr0.15CuO4 also clarified the existence of the c(2x2) shadow band, demonstrating that the shadow band is not a unique feature of Bi-based cuprates. We conclude that the shadow band is related to the orthorhombic distortion at the crystal surface.Comment: 6 pages, 4figure

Existence of Dynamical Scaling in the Temporal Signal of Time Projection Chamber

The temporal signals from a large gas detector may show dynamical scaling due to many correlated space points created by the charged particles while passing through the tracking medium. This has been demonstrated through simulation using realistic parameters of a Time Projection Chamber (TPC) being fabricated to be used in ALICE collider experiment at CERN. An interesting aspect of this dynamical behavior is the existence of an universal scaling which does not depend on the multiplicity of the collision. This aspect can be utilised further to study physics at the device level and also for the online monitoring of certain physical observables including electronics noise which are a few crucial parameters for the optimal TPC performance.Comment: 5 pages, 6 figure