SiO Maser Survey of IRAS Sources in the Inner Galactic Disk

We have surveyed 401 color selected IRAS sources in the Galactic disk in the SiO J=1--0 v= 1 and 2 maser lines at 43 GHz, resulting in 254 (239 new) detections. The observed sources lie mostly in a strip of the inner Galactic disk with boundaries -10<l<40 deg and |b|<3 deg. This survey provides radial velocities of inner-disk stars for which optical measurements cannot be made due to interstellar extinction. The SiO $l$--$v$ diagram in the area $-10<l<40 deg exhibits fewer objects coincident with the molecular ring feature than the OH 1612 MHz source$l$--$v$ map does, indicating a slight difference of stellar type between SiO and OH emitting stars. After identifying all of the SiO detected sources in the 2MASS near-infrared catalog, we computed their luminosity distances based on the infrared fluxes. We then mapped these objects onto the first quadrant of the Galactic plane. Combining the distances with the SiO radial-velocities, we obtained a pattern speed for SiO maser sources, Omega_P=21 (+- 13) km s^{-1} kpc^{-1}, between the distances 1 and 5.5 kpc, without the use of any dynamical models. The increase of the pattern speed toward the Galactic center (up to 60 km s^{-1} kpc^{-1} between the distances, 5.5 and 7 kpc) suggests the presence of two pattern speeds in the Galaxy.Comment: 38 page 9 figures, high res. eps files are available as NRO report No. 608 (http://www.nro.nao.ac.jp/library/report/list.html). PASJ 56 No. 4 in pres

SiO Maser Survey of the Large-Amplitude Variables in the Galactic Center

We have surveyed ~400 known large-amplitude variables within 15' of the galactic center in the SiO J=1--0 v=1 and 2 maser lines at 43 GHz, resulting in 179 detections. SiO lines were also detected from 16 other resulting in 180 detections. SiO lines were also detected from 16 other sources, which are located within 20" (the telescope half beamwidth) of the program objects. The detection rate of 48 percent is comparable to that obtained in Bulge IRAS source surveys. Among the SiO detections, five stars have radial velocities greater than 200 km/s. The SiO detection rate increases steeply with the period of light variation, particularly for stars with P>500 d, where it exceeds 80%. We found that, at a given period, the SiO detection rate is approximately three times that for OH. These facts suggest that the large-amplitude variables in the Nuclear Disk region are AGB stars similar in their overall properties to the inner and outer Bulge IRAS/SiO sources. From the set of radial velocity data, the mass distribution within 30 pc of the galactic center is derived by a new method which is based on the collisionless Boltzmann equation integrated along the line of sight. The mass within 30 pc is about 6.4 [\pm 0.7] \times 10^7 M_{\odot} and the mass of the central black hole is 2.7 [\pm 1.3] \times 10^6 M_{\odot}. Consideration of the line-of-sight velocity of each star and its potential energy leads to the conclusion that the five high-velocity stars come from galactocentric distances as high as 300 pc. The high-velocity subsample of stars with negative radial velocities exhibits a tendency to have brighter K magnitudes than the subsample of stars with positive velocities. The origin of these high-velocity stars is discussed.Comment: Hires. figures are available as No.604 of NRO report at http://www.nro.nao.ac.jp/library/report/list.html . PASJ 56 (april 28 issue) in pres

Detections of SiO Masers from the Large-Amplitude Variables in the Galactic Nuclear Disk

We have surveyed known large-amplitude variables within 15' of the Galactic center in the SiO J=1-0 v=1 and 2 maser lines at 43 GHz, resulting in 79 detections and 58 non-detections. The detection rate of 58 percent is comparable to that obtained in Bulge IRAS source surveys. SiO lines were also detected from four other sources near the program objects. The SiO detection rate increases steeply with the period, particularly for stars with P>500 d, where it exceeds 80%. We found at a given period that the SiO detection rate is approximately double that for OH. These facts suggest that the large-amplitude variables in the Nuclear Disk region are AGB stars similar in their overall properties to the inner and outer bulge IRAS/SiO sources.Comment: 5 pages, 2 figures, 1 Table. PASJ 54, No 2 April 25 issue in pres

Outflows from the high-mass protostars NGC 7538 IRS1/2 observed with bispectrum speckle interferometry -- Signatures of flow precession

NGC 7538 IRS1 is a high-mass (approx. 30 M_sun) protostar with a CO outflow, an associated UCHII region, and a linear methanol maser structure, which might trace a Keplerian-rotating circumstellar disk. The directions of the various associated axes are misaligned with each other. We investigate the near-infrared morphology of the source to clarify the relations among the various axes. K'-band bispectrum speckle interferometry was performed at two 6-meter-class telescopes -- the BTA 6m telescope and the 6.5m MMT. Complementary IRAC images from the Spitzer Space Telescope Archive were used to relate the structures detected with the outflow at larger scales. High-dynamic range images show fan-shaped outflow structure in which we detect 18 stars and several blobs of diffuse emission. We interpret the misalignment of various outflow axes in the context of a disk precession model, including numerical hydrodynamic simulations of the molecular emission. The precession period is approx. 280 years and its half-opening angle is 40 degrees. A possible triggering mechanism is non-coplanar tidal interaction of an (undiscovered) close companion with the circumbinary protostellar disk. Our observations resolve the nearby massive protostar NGC 7538 IRS2 as a close binary with separation of 195 mas. We find indications for shock interaction between the outflow activities in IRS1 and IRS2. Indications of outflow precession have been discovered to date in a number of massive protostars, all with large precession angles 20--45 degrees. This might explain the difference between the outflow widths in low- and high-mass stars and add support to a common collimation mechanism.Comment: 20 pages; 8 figures; Accepted by A&A on April 10, 2006; Image quality reduced due to astro-ph file size limitations; Please download a version with high-quality images from http://www.mpifr-bonn.mpg.de/staff/tpreibis/ngc7538.pd

The 2006 Radio Outburst of a Microquasar Cyg X-3: Observation and Data

We present the results of the multi-frequency observations of radio outburst of the microquasar Cyg X-3 in February and March 2006 with the Nobeyama 45-m telescope, the Nobeyama Millimeter Array, and the Yamaguchi 32-m telescope. Since the prediction of a flare by RATAN-600, the source has been monitored from Jan 27 (UT) with these radio telescopes. At the eighteenth day after the quench of the activity, successive flares exceeding 1 Jy were observed successfully. The time scale of the variability in the active phase is presumably shorter in higher frequency bands. We also present the result of a follow-up VLBI observation at 8.4 GHz with the Japanese VLBI Network (JVN) 2.6 days after the first rise. The VLBI image exhibits a single core with a size of <8 mas (80 AU). The observed image was almost stable, although the core showed rapid variation in flux density. No jet structure was seen at a sensitivity of $T_b = 7.5\times 10^5$ K.Comment: 17 pages,6 figures; accepted by PAS

Very compact radio emission from high-mass protostars. II. Dust disks and ionized accretion flows

This paper reports 43 GHz imaging of the high-mass protostars W33A, AFGL 2591 and NGC 7538 IRS9 at 0.04'' and 0.6'' resolution. In each case, weak (~mJy), compact (~100 AU) emission is detected, which has an elongated shape (axis ratio ~3). For AFGL 2591 and NGC 7538 IRS9, the emission is single-peaked, while for the highest luminosity source, W33A, a `mini-cluster' of three sources is detected. The derived sizes, flux densities, and broad-band radio spectra of the sources support recent models where the initial expansion of HII regions around very young O-type stars is prevented by stellar gravity. In these models, accretion flows onto high-mass stars originate in large-scale molecular envelopes and become ionized close to the star. These models reproduce our observations of ionized gas as well as the structure of the molecular envelopes of these sources on 10^3--10^4 AU scales derived previously from single-dish submillimeter continuum and line mapping. For AFGL 2591, the 43 GHz flux density is also consistent with dust emission from a disk seen in near-infrared `speckle' images. However, the alignment of the 43 GHz emission with the large-scale molecular outflow argues against an origin in a disk for AFGL 2591 and NGC 7538 IRS9. In contrast, the outflow from W33A does not appear to be collimated. Together with previously presented case studies of W3 IRS5 and AFGL 2136, our results indicate that the formation of stars and stellar clusters with luminosities up to ~10^5 L0 proceeds through accretion and produces collimated outflows as in the solar-type case, with the `additional feature' that the accretion flow becomes ionized close to the star. Above ~10^5 L0, clusters of HII regions appear, and outflows are no longer collimated, possibly as the result of mergers of protostars or pre-stellar cores.Comment: Accepted by A&A; 11 pages, 4 b/w figure

Clinical and Genetic Characteristics of 18 Patients from 13 Japanese Families with CRX-associated retinal disorder: Identification of Genotype-phenotype Association

Inherited retinal disorder (IRD) is a leading cause of blindness, and CRX is one of a number of genes reported to harbour autosomal dominant (AD) and recessive (AR) causative variants. Eighteen patients from 13 families with CRX-associated retinal disorder (CRX-RD) were identified from 730 Japanese families with IRD. Ophthalmological examinations and phenotype subgroup classification were performed. The median age of onset/latest examination was 45.0/62.5 years (range, 15–77/25–94). The median visual acuity in the right/left eye was 0.52/0.40 (range, −0.08–2.00/−0.18–1.70) logarithm of the minimum angle of resolution (LogMAR) units. There was one family with macular dystrophy, nine with cone-rod dystrophy (CORD), and three with retinitis pigmentosa. In silico analysis of CRX variants was conducted for genotype subgroup classification based on inheritance and the presence of truncating variants. Eight pathogenic CRX variants were identified, including three novel heterozygous variants (p.R43H, p.P145Lfs*42, and p.P197Afs*22). A trend of a genotype-phenotype association was revealed between the phenotype and genotype subgroups. A considerably high proportion of CRX-RD in ADCORD was determined in the Japanese cohort (39.1%), often showing the mild phenotype (CORD) with late-onset disease (sixth decade). Frequently found heterozygous missense variants located within the homeodomain underlie this mild phenotype. This large cohort study delineates the disease spectrum of CRX-RD in the Japanese population

Genetic Spectrum of EYS-associated Retinal Disease in a Large Japanese Cohort: Identification of Disease-associated Variants with Relatively High Allele Frequency

Biallelic variants in the EYS gene are a major cause of autosomal recessive inherited retinal disease (IRD), with a high prevalence in the Asian population. The purpose of this study was to identify pathogenic EYS variants, to determine the clinical/genetic spectrum of EYS-associated retinal disease (EYS-RD), and to discover disease-associated variants with relatively high allele frequency (1%-10%) in a nationwide Japanese cohort. Sixty-six affected subjects from 61 families with biallelic or multiple pathogenic/disease-associated EYS variants were ascertained by whole-exome sequencing. Three phenotype groups were identified in EYS-RD: retinitis pigmentosa (RP; 85.94%), cone-rod dystrophy (CORD; 10.94%), and Leber congenital amaurosis (LCA; 3.12%). Twenty-six pathogenic/disease-associated EYS variants were identified, including seven novel variants. The two most prevalent variants, p.(Gly843Glu) and p.(Thr2465Ser) were found in 26 and twelve families (42.6%, 19.7%), respectively, for which the allele frequency (AF) in the Japanese population was 2.2% and 3.0%, respectively. These results expand the phenotypic and genotypic spectrum of EYS-RD, accounting for a high proportion of EYS-RD both in autosomal recessive RP (23.4%) and autosomal recessive CORD (9.9%) in the Japanese population. The presence of EYS variants with relatively high AF highlights the importance of considering the pathogenicity of non-rare variants in relatively prevalent Mendelian disorders