SIMULTANEOUS OBSERVATIONS OF SiO AND H
                    <sub>2</sub>
                    O MASERS TOWARD KNOWN STELLAR SiO AND H
                    <sub>2</sub>
                    O MASER SOURCES. I.

Kim, Jaeheon; Cho, Se-Hyung; Oh, Chung Sik; Byun, Doyoung

doi:10.1088/0067-0049/188/1/209

Cited by 64 publications

(72 citation statements)

References 46 publications

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“…), respectively. These results are similar to other OH/IR stars (see Table 9 of Kim et al 2010). In the meantime, as shown in Figure 6(d), the peak velocity shift with respect to the stellar velocity always showed a redshift and appeared to be more redshifted as the SiO maser intensity increased.…”

Section: Observational Resultssupporting

confidence: 88%

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MONITORING OBSERVATIONS OF H₂O AND SiO MASERS TOWARD POST-AGB STARS

Kim¹,

Cho²,

Yoon³

2016

Journal of The Korean Astronomical Society

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We present the results of simultaneous monitoring observations of H 2 O 6 1,6 -5 2,3 (22 GHz) and SiO J=1-0, 2-1, 3-2 maser lines (43, 86, 129 GHz) toward five post-AGB (candidate) stars, using the 21-m single-dish telescopes of the Korean VLBI Network. Depending on the target objects, 7 -11 epochs of data were obtained. We detected both H 2 O and SiO maser lines from four sources: OH16.1−0.3, OH38.10−0.13, OH65.5+1.3, and IRAS 19312+1950. We could not detect H 2 O maser emission toward OH13.1+5.1 between the late OH/IR and post-AGB stage. The detected H 2 O masers show typical doublepeaked line profiles. The SiO masers from four sources, except IRAS 19312+1950, show the peaks around the stellar velocity as a single peak, whereas the SiO masers from IRAS 19312+1950 occur above the red peak of the H 2 O maser. We analyzed the properties of detected maser lines, and investigated their evolutionary state through comparison with the full widths at zero power. The distribution of observed target sources was also investigated in the IRAS two-color diagram in relation with the evolutionary stage of post-AGB stars. From our analyses, the evolutionary sequence of observed sources is suggested as OH65.5+1.3 → OH13.1+5.1 → OH16.1−0.3 → OH38.10−0.13, except for IRAS 19312+1950. In addition, OH13.1+5.1 from which the H 2 O maser has not been detected is suggested to be on the gateway toward the post-AGB stage. With respect to the enigmatic object, IRAS 19312+1950, we could not clearly figure out its nature. To properly explain the unusual phenomena of SiO and H 2 O masers, it is essential to establish the relative locations and spatial distributions of two masers using VLBI technique. We also include the 1.2 -160 µm spectral energy distribution using photometric data from the following surveys: 2MASS, W ISE, M SX, IRAS, and AKARI (IRC and FIS). In addition, from the IRAS LRS spectra, we found that the depth of silicate absorption features shows significant variations depending on the evolutionary sequence, associated with the termination of AGB phase mass-loss.

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Section: Observational Resultssupporting

confidence: 88%

“…We selected five sample sources from the results of a simultaneous survey of 22 GHz H 2 O and 43 GHz SiO masers for evolved stars (Kim et al 2010;Cho & Kim 2012;Yoon et al 2014). Four sources with doublepeaked H 2 O maser emission were included.…”

Section: Source Selection and Observationsmentioning

confidence: 99%

MONITORING OBSERVATIONS OF H₂O AND SiO MASERS TOWARD POST-AGB STARS

Kim¹,

Cho²,

Yoon³

2016

Journal of The Korean Astronomical Society

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“…Jiang et al (1996) reported −41.3 km s −1 for W Per based on their 43 GHz maser observations, in agreement with our findings. For S Per, several results can be found in the literature that agree within a km s −1 with our value (Alcolea et al 1990;Kim et al 2010). …”

Section: Perseus Ob1supporting

confidence: 92%

“…(1) Nakashima & Deguchi (2006); (2) Deguchi et al (2010); (3) Nakashima & Deguchi (2007); (4) Jiang et al (1996); (5) Cho et al (1996); (6) Hall et al (1990); (7) Kim et al (2010).…”

Section: Sio Maser Intensitiesmentioning

confidence: 99%

SiO maser emission from red supergiants across the Galaxy

Verheyen¹,

Messineo²,

Menten³

2012

A&A

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Aims. Red supergiants (RSGs) are among the most luminous of all stars, easily detectable in external galaxies, and may ideally serve as kinematic tracers of Galactic structure. Some RSGs are surrounded by circumstellar envelopes detectable by their dust and molecular and, in particular, maser emission. This study consists of a search for maser emission from silicon monoxide (SiO) toward a significant number of RSGs that are members of massive stellar clusters, many of which have only recently been discovered. Further, we aim to relate the occurrence of maser action to properties of the host stars. Methods. Using the IRAM 30 m telescope, we searched for maser emission in the J = 2−1 rotational transition within the first vibrationally excited state of SiO toward a sample of 88 RSGs. Results. With an average rms noise level of 0.25 Jy, we detected maser emission in 15% of the sample, toward most of the sources for the first time in this transition. The peak of the emission provides accurate radial velocities for the RSGs. The dependence of the detection rate on infrared colors supports a radiative pumping mechanism for the SiO masers.

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“…(1) Kim et al (2010); (2) Turner et al (1973); (3) Takano et al (1998); (4) Takano et al (1990); (5) Kawaguchi et al (1992); (6) Kaifu et al (2004); (7) Goddi et al (2009); (8) Deguchi et al (2006); (9) Haschick et al (1990).…”

Section: Commissioning Resultsunclassified

The wideband backend at the MDSCC in Robledo

Rizzo¹,

Pedreira²,

Bustos³

et al. 2012

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Context. The antennas of NASA's Madrid Deep Space Communications Complex (MDSCC) in Robledo de Chavela are available as single-dish radio astronomical facilities during a significant percentage of their operational time. Current instrumentation includes two antennas of 70 and 34 m in diameter, equipped with dual-polarization receivers in K (18-26 GHz) and Q (38-50 GHz) bands, respectively. Until mid-2011, the only backend available in MDSCC was a single spectral autocorrelator, which provides bandwidths from 2 to 16 MHz. The limited bandwidth available with this autocorrelator seriously limited the science one could carry out at Robledo. Aims. We have developed and built a new wideband backend for the Robledo antennas, with the objectives (1) to optimize the available time and enhance the efficiency of radio astronomy in MDSCC; and (2) to tackle new scientific cases that were impossible to investigate with the existing autocorrelator. Methods. The features required for the new backend include (1) a broad instantaneous bandwidth of at least 1.5 GHz; (2) high-quality and stable baselines, with small variations in frequency along the whole band; (3) easy upgradability; and (4) usability for at least the antennas that host the K-and Q-band receivers. Results. The backend consists of an intermediate frequency (IF) processor, a fast Fourier transform spectrometer (FFTS), and the software that interfaces and manages the events among the observing program, antenna control, the IF processor, the FFTS operation, and data recording. The whole system was end-to-end assembled in August 2011, at the start of commissioning activities, and the results are reported in this paper. Frequency tunings and line intensities are stable over hours, even when using different synthesizers and IF channels; no aliasing effects have been measured, and the rejection of the image sideband was characterized. Conclusions. The new wideband backend fulfills the requirements and makes better use of the available time for radio astronomy, which opens new possibilities to potential users. The first setup provides 1.5 GHz of instantaneous bandwidth in a single polarization, using 8192 channels and a frequency resolution of 212 kHz; upgrades under way include a second FFTS card, and two high-resolution cores providing 100 MHz and 500 MHz of bandwidth, and 16 384 channels. These upgrades will permit simultaneous observations of the two polarizations with instantaneous bandwidths from 100 MHz to 3 GHz, and spectral resolutions from 7 to 212 kHz.

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SIMULTANEOUS OBSERVATIONS OF SiO AND H ₂ O MASERS TOWARD KNOWN STELLAR SiO AND H ₂ O MASER SOURCES. I.

Cited by 64 publications

References 46 publications

MONITORING OBSERVATIONS OF H₂O AND SiO MASERS TOWARD POST-AGB STARS

MONITORING OBSERVATIONS OF H₂O AND SiO MASERS TOWARD POST-AGB STARS

SiO maser emission from red supergiants across the Galaxy

The wideband backend at the MDSCC in Robledo

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SIMULTANEOUS OBSERVATIONS OF SiO AND H 2 O MASERS TOWARD KNOWN STELLAR SiO AND H 2 O MASER SOURCES. I.

Cited by 64 publications

References 46 publications

MONITORING OBSERVATIONS OF H2O AND SiO MASERS TOWARD POST-AGB STARS

MONITORING OBSERVATIONS OF H2O AND SiO MASERS TOWARD POST-AGB STARS

SiO maser emission from red supergiants across the Galaxy

The wideband backend at the MDSCC in Robledo

Contact Info

Product

Resources

About

SIMULTANEOUS OBSERVATIONS OF SiO AND H ₂ O MASERS TOWARD KNOWN STELLAR SiO AND H ₂ O MASER SOURCES. I.

MONITORING OBSERVATIONS OF H₂O AND SiO MASERS TOWARD POST-AGB STARS

MONITORING OBSERVATIONS OF H₂O AND SiO MASERS TOWARD POST-AGB STARS