THE DISTRIBUTION MODELS OF THERMAL AND NON-THERMAL RADIO CONTINUUM EMISSION IN THE GALACTIC DISK

SANGUANSAK N.,OSBORNE J. L. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

In the past, it. was very difficult to distinguish thermal and non-thermal emission. Broadbent et a1. (1989) has developed a new technique with the help of the IRAS 60 micron emission. The distribution of non-thermal or synchrotron emission in the Galactic disk has been modeled from the 408 MHz all sky survey of Haslam et a1. (1982) after removal of the thermal component.. At. 408 MHz, t.here is very little absorption in the interstellar medium and the distribution along the line-of-sight. is inferred mainly from its presumed relationship to other tracers of spiral structure via a. number of fitted parameters. But. at lower frequencies, free-free absorption becomes important and can give some direct. information on the line of sight. distribution. We have modeled the thermal electron density according to the spiral arm models and the distribution of ionized hydrogen in the Galactic plane by Lockman (1976) and Cersosimo et. al. (1989) and have made predictions to compare with the surveys of Dwarakanath et al. (1990) at. 34.5 MHz and .Jones and Finlay (1974) at 29.9 MHz. The result confirms that the absorption model of the synchrotron emissivity in the Galactic plane is broadly corrected and illustrates the potential of the absorption technique.

FOLLOW-UP PHOTOMETRY OF TWO NEW ECLIPSING PCEBs FROM THE SLOAN DIGITAL SKY SURVEY

WANGNOK, KITTIPONG,SANGUANSAK, NUANWAN,IRAWATI, PUJI,DHILLON, VIK,MARSH, TOM R. The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

In this work, we present the result of our follow-up observations of SDSS J092741.73+332959.1 and SDSS J130733.49+215636.7 using the 2.35 m Thai National Telescope and ULTRASPEC instrument. Both systems are listed among the recently found white dwarf main sequence binaries from the Sloan Digital Sky Survey. SDSS J092741.73+332959.1 is a new PCEB with a period of 2.3 days, the longest orbital period known to date for white dwarf binaries. SDSS J130733.49+215636.7 is confirmed to be an eclipsing system with a period of 0.21 days from the Catalina Survey's light curve, however the parameters for the white dwarf are still uncertain. Our goal is to determine precise parameters for both systems using the Binary Maker 3 software. The observation for SDSS J0927+3329 was done on 9 January 2014 in the SDSS r' filter while the data for SDSS J1307+2156 were taken in the z' filter on 27 April 2014. Our models show that the red dwarf companions in both systems are well constrained inside their Roche Lobes. We find that the binary M2/M1 ratio in SDSS J0927+3329 is close to 0.5, with white dwarf and M-dwarf temperatures of 12000 K and 3300 K, respectively. Our preliminary result for SDSS J1307+2156 show that this system has an extreme mass ratio of 0.3. The white dwarf in this system has a temperature of 7500 K and the companion star has an effective temperature of 3150 K.

NALYSIS OF THE ECLIPSING BINARY SDSS J1021+1744: A WDMS SYSTEM WITH UNUSUAL DIPS

CHANTHORN, KHUNAGORN,SANGUANSAK, NUANWAN,IRAWATI, PUJI,DHILLON, VIK S.,MARSH, TOM R. The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

We present our recent observations of SDSS J102102.25+174439.9, a new eclipsing white dwarf - main sequence WDMS binary with an orbital period of 0.14 days. This system belongs to the post common-envelope binary group as shown by the spectrum from the Sloan Digital Sky Survey. We obtained our data using the ULTRASPEC instrument installed on the 2.4-m telescope at the Thai National Observatory (TNO). Our multi-band observations reveal an unusual and persistent drop in brightness after the primary eclipse. These dips, which appear to show variations in amplitude, also have a complex shape that changes within days. Dips in WDMS systems have been observed on only one other occasion, in the light curve of QS Vir prior to the eclipse of the white dwarf. The dips in SDSS J1021+1744 are unique because they are present at different wavelengths and they occur approximately at similar phases. Hosting a DA white dwarf and an M4 companion star, this system is known to be the only WDMS to show these kind of dips in its light curve. It is possible that these dips are caused by ejected materials from an active companion star, such as in QS Vir. The light curve in the g' filter exhibits deep and narrow features, implying that the material which passes in front of the white dwarf in SDSS J1021 must be dense and small in size. Furthermore, we try to constrain the stellar and orbital parameters of SDSS J1021+1744 using the Binary Maker 3 software. We use g' and r' data for our light curve analysis to have a better approximation for the red dwarf star.

THE NEW ECLIPSING POST COMMON-ENVELOPE BINARY SDSS J074548.63+263123.4

HEMHA, NIWAT,SANGUANSAK, NUANWAN,IRAWATI, PUJI,DHILLON, VIK,MARSH, TOM R. The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

The common-envelope process is a complicated phase in binary evolution. A lot of effort has been dedicated to study the common-envelope stage, but many questions related to this process are yet to be answered. If one member of the binary survives the common-envelope phase, the binary will emerge as a white dwarf accompanied by a low-mass main sequence star in close orbit, often referred as a post common-envelope binary (PCEB). SDSS J0745+2631 is among the list of newly found PCEBs from the Sloan Digital Sky Survey (SDSS). This star is proposed to be a strong eclipsing system candidate due to the ellipsoidal modulation in its light curve. In this work, we aim to confirm the eclipsing nature of SDSS J0745+2631 and to determine the stellar and orbital parameters using the software Binary Maker 3.0 (BM3.0). We detected the primary eclipse in the light curve of SDSS J0745+2631 in our follow-up observation from January 2014 using the ULTRASPEC instrument at the Thai National Observatory. The data obtained on 7th and 8th January 2014 in g filter show an evident drop in brightness during the eclipse of the white dwarf, but this eclipse is less prominent in the data taken on the next night using a clear filter. According to our preliminary model, we find that SDSS J0745+2631 hosts a rather hot white dwarf with an effective temperature of 11500K. The companion star is a red dwarf star with a temperature of 3800K and radius of 0.3100 $R_{\odot}$. The red dwarf star almost fills its Roche lobe, causing a large ellipsoidal modulation. The mass ratio of the binary given by the Binary Maker 3.0 (BM3.0) model is M2/M1 = 0.33.

VOIDS LENSING OF THE CMB AT HIGH RESOLUTION

SANGKA, ANUT,SAWANGWIT, UTANE,SANGUANSAK, NUANWAN The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

Recently, cosmic voids have been recognized as a powerful cosmological probe. A number of studies have focused on the effects of the gravitational lensing by voids on the temperature (and in some cases polarization) anisotropy of the Cosmic Microwave Background (CMB) background at relatively large to medium scales, l ~ 1000. Many of these studies attempt to explain the unusually large cold spot in CMB temperature maps and dynamical evidence of dark energy via detections of late-time integrated Sachs Wolfe (ISW) effect. Here, the effects of lensing by voids on the CMB temperature anisotropy at small scales, up to l = 3000, will be investigated. This work is carried out in the light of the benefits of adding large catalogues of cosmic voids, to be identified by future large galaxy surveys such as EUCLID and LSST, to the analysis of CMB data such as those from Planck mission. Our numerical simulation utilizes two methods, namely, the small-de ectionangle approximation and full ray-tracing analysis. Using the fitted void density profiles and radius (RV ) distribution available in the literature from N-body simulations, we simulated the secondary temperature anisotropy (lensing) of CMB photons induced by voids along a line of sight from redshift 0 to 2. Each line of sight contains approximately 1000 voids of effective radius $RV_{,eff}=35h^{-1}Mpc$ with randomly distributed radial and projected positions. Both methods are used to generate temperature maps. The two methods will be compared for their accuracy and effciency in the implementation of theoretical modeling.

Burden of Respiratory Disease in Korea: An Observational Study on Allergic Rhinitis, Asthma, COPD, and Rhinosinusitis

유광하,안해련,박재경,김종웅,남귀현,홍순관,김미자,Aloke Gopal Ghoshal,Abdul Razak Bin Abdul Muttalif,Horng-Chyuan Lin,Sanguansak Thanaviratananich,Shalini Bagga,Rab Faruqi,Shiva Sajjan,Santwona Baidya,De Yun Wang, MD, PhD 대한천식알레르기학회 2016 Allergy, Asthma & Immunology Research Vol.8 No.6

Purpose: The Asia-Pacific Burden of Respiratory Diseases (APBORD) study is a cross-sectional, observational one which has used a standard protocol to examine the disease and economic burden of allergic rhinitis (AR), asthma, chronic obstructive pulmonary disorder (COPD), and rhinosinusitis across the Asia-Pacific region. Here, we report on symptoms, healthcare resource use, work impairment, and associated costs in Korea. Methods: Consecutive participants aged ≥18 years with a primary diagnosis of asthma, AR, COPD, or rhinosinusitis were enrolled. Participants and their treating physician completed a survey detailing respiratory symptoms, healthcare resource use, and work productivity and activity impairment. Costs included direct medical cost and indirect cost associated with lost work productivity. Results: The study enrolled 999 patients. Patients were often diagnosed with multiple respiratory disorders (42.8%), with asthma/AR and AR/rhinosinusitis the most frequently diagnosed combinations. Cough or coughing up phlegm was the primary reason for the medical visit in patients with a primary diagnosis of asthma and COPD, whereas nasal symptoms (watery runny nose, blocked nose, and congestion) were the main reasons in those with AR and rhinosinusitis. The mean annual cost for patients with a respiratory disease was US$8,853 (SD 11,245) per patient. Lost productivity due to presenteeism was the biggest contributor to costs. Conclusions: Respiratory disease has a significant impact on disease burden in Korea. Treatment strategies for preventing lost work productivity could greatly reduce the economic burden of respiratory disease.