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相关论文: ATCA observations of SiO masers in the Galactic ce…

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We have used the NASA Tidbinbilla 70-m antenna to search for emission from the 2(1)-3(0)E 19.9-GHz transition of methanol. The search was targeted towards 22 star formation regions which exhibit maser emission in the 107.0-GHz 3(1)-4(0)A+…

天体物理学 · 物理学 2009-11-10 S. P. Ellingsen , D. M. Cragg , J. E. J. Lovell , A. M. Sobolev , P. D. Ramsdale , P. D. Godfrey

We present new observations of the quiescent giant molecular cloud GCM0.253+0.016 in the Galactic center, using the upgraded Karl G. Jansky Very Large Array. Observations were made at wavelengths near 1 cm, at K (24 to 26 GHz) and Ka (27…

星系天体物理 · 物理学 2015-05-27 E. A. C. Mills , N. Butterfield , D. A. Ludovici , C. C. Lang , J. Ott , M. R. Morris , S. Schmitz

We used the Australia Telescope Compact Array (ATCA) to obtain 40 GHz and 95 GHz observations of a number of sources that were selected from the Australia Telescope Compact Array 20 GHz (AT20G) survey . The aim of the observations was to…

星系天体物理 · 物理学 2015-05-19 Paul J. Hancock , Elaine M. Sadler , Elizabeth K. Mahony , Roberto Ricci

We report a new analysis of stellar dynamics in the Galactic centre, based on improved sky and LOS velocities for >100 stars within a few arcsec of SgrA*. Overall the motions do not deviate strongly from isotropy. For 32 stars with all 3…

天体物理学 · 物理学 2009-10-31 R. Genzel , C. Pichon , A. Eckart , O. E. Gerhard , T. Ott

We present temporal scattering measurements of single pulses and average profiles of PSR J1745--2900, a magnetar recently discovered only 3 arcsec away from Sagittarius A* (Sgr A*), from 1.2 - 18.95 GHz using the Effelsberg 100-m Radio…

We present measurements of the emission from the centers of fifteen spiral galaxies in the 3P1-3P0 [CI] fine-structure transition at 492 GHz. Observed galaxy centers range from quiescent to starburst to active. The intensities of neutral…

天体物理学 · 物理学 2009-11-07 F. P. Israel , F. Baas

With 10 years of high-resolution imaging data now available on the stellar cluster in the Galactic Center, we analyze the dynamics of the stars at projected distances $\leq1.2''$ from the central black hole candidate Sagittarius A* (Sgr…

天体物理学 · 物理学 2009-11-07 R. Schoedel , R. Genzel , T. Ott , A. Eckart

We report the first detection of SiC$_2$ in the interstellar medium. The molecule was identified through six rotational transitions toward G\,+0.693$-$0.027, a molecular cloud located in the Galactic center. The detection is based on a line…

We studied the period-K magnitude (P-K) relations of nearby Mira and Mira-like variables with relatively good Hipparcos parallaxes. They form at least two prominent sequences on the P-K plane, corresponding to the sequences C (Mira…

天体物理学 · 物理学 2010-12-09 Yoshifusa Ita , Shuji Deguchi , Noriyuki Matsunaga , Hinako Fukushi

Sgr B2 is a well-known star forming molecular cloud complex in the Galactic center region showing evidence of high energy activity as traced by the K$\alpha$ neutral FeI line at 6.4 keV, as well as GeV and TeV $\gamma$-ray emission. Here we…

高能天体物理现象 · 物理学 2016-03-23 F. Yusef-Zadeh , W. Cotton , M. Wardle , H. Intema

Here we aim to characterise submillimetre water masers at 437, 439, 471, and 474 GHz towards a sample of evolved stars. We used the Atacama Pathfinder Experiment (APEX) to observe submillimetre water transitions and the CO (4-3) line…

太阳与恒星天体物理 · 物理学 2020-05-27 P. Bergman , E. M. L. Humphreys

We present the results of a survey for OH maser emission at 1612 MHz from dust-enshrouded AGB stars and supergiants in the LMC and SMC, with the Parkes radio telescope, aimed at deriving the speed of the superwind from the double-peaked OH…

H2O (22 GHz) and SiO masers (43, 86, 129 GHz) in the bipolar proto-planetary nebula OH231.8+4.2 were simultaneously monitored using the 21-m antennas of the Korean VLBI Network in 2009-2015. Both species exhibit periodic flux variations…

太阳与恒星天体物理 · 物理学 2019-07-04 J. Kim , S. -H. Cho , V. Bujarrabal , H. Imai , R. Dodson , D. -H. Yoon , B. Zhang

We report the first Very Long Baseline Array (VLBA) observations of 43 GHz v=1, J=1-0 SiO masers in the circumstellar envelope of the M-type semi-regular supergiant variable star AH Sco at 2 epochs separated by 12 days in March 2004. These…

天体物理学 · 物理学 2009-11-13 Xi Chen , Zhi-Qiang Shen

Context. Stars on the asymptotic giant branch (AGB) are long-period variables that present strong flux variations at almost all wavelengths, including the SiO maser lines. The periods of these variations are of 300-500 days in Mira-type…

We present the results of 22 GHz H_2O maser observations of a sample of 85 post-Asymptotic Giant Branch (post-AGB) candidate stars, selected on the basis of their OH 1612 MHz maser and far-infrared properties. All sources were observed with…

天体物理学 · 物理学 2009-11-13 R. M. Deacon , J. M. Chapman , A. J. Green , M. N. Sevenster

The high stellar density in the central parsecs around the Galactic Centre makes it a seemingly favourable environment for finding relativistic binary pulsars. These include pulsars orbiting other neutron stars, stellar-mass black holes or…

We report on high spatial resolution observations, using the Australia Telescope Compact Array (ATCA), of ground-state OH masers. These observations were carried out toward 196 pointing centres previously identified in the Southern Parkes…

The Galactic Center (GC), with its high density of massive stars, is a promising target for radio transient searches. In particular, the discovery and timing of a pulsar orbiting the central supermassive black hole (SMBH) of our Galaxy will…

We have investigated the central region of NGC 253 for the presence of 84.5-GHz ($5_{-1}\rightarrow4_0$E) methanol emission using the Australia Telescope Compact Array. We present the second detection of 84.5-GHz class~I methanol maser…

星系天体物理 · 物理学 2018-11-21 Tiege P. McCarthy , Simon P. Ellingsen , Shari L. Breen , Maxim A. Voronkov , Xi Chen