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We report on a large 44 GHz ($7_0-6_1$ A$^+$) methanol (CH$_3$OH) maser survey of the Galactic Center (GC). The Karl G. Jansky Very Large Array was used to search for CH$_3$OH maser emission covering a large fraction of the region around…

太阳与恒星天体物理 · 物理学 2016-12-07 Bridget McEwen , Loránt Sjouwerman , Ylva Pihlström

We report the results of our observations of HI absorption towards the central region of the rejuvenated radio galaxy 4C29.30 (J0840+2949) with the Giant Metrewave Radio Telescope (GMRT). The radio source has diffuse, extended emission with…

宇宙学与河外天体物理 · 物理学 2015-05-14 Yogesh Chandola , D. J. Saikia , Neeraj Gupta

Accurate position and posture measurements of the freely-falling test mass are crucial for the success of spaceborne gravitational wave detection missions. This paper presents a novel laboratory-developed test mass motion readout that…

天体物理仪器与方法 · 物理学 2023-10-27 Xin Xu , Jinsong Liu , Henglin Mu , Yan Li , Yidong Tan

The infrared dark cloud G359.94+0.17 is a conspicuous, opaque cloud, which is seen in silhouette against the Galactic center. We found unexpectedly strong (~50 Jy) maser emission of CH3OH at 44 GHz with additional weak 22 GHz H2O maser and…

星系天体物理 · 物理学 2015-05-30 S. Deguchi , D. Tafoya , N. Shino

We have discovered two compact sources of shocked H2 2.12-micron emission coincident with Mol 160 (IRAS 23385+6053), a massive star-forming core thought to be a precursor to an ultracompact HII region. The 2.12-micron sources lie within 2"…

星系天体物理 · 物理学 2015-06-03 Grace Wolf-Chase , Michael Smutko

The increasing use of portable and wireless technologies has led to a growing focus on radio-frequency identification (RFID) tags. Among the various devices in RFID tags, rectifying diodes are the most demanding in terms of high-frequency…

应用物理 · 物理学 2023-07-04 Peng Jin , Xuehui Xu , Zeng Chen , Xu Chen , Tianyu Liu , Hanbo Zhu , Xinya Chen , Yang , Yang

We present the first internal motion measurement of the 6.7-GHz methanol maser within S269, a small HII region in the outer Galaxy, which was carried out in 2006 and 2011 using the Japanese VLBI Network (JVN). Several maser groups and weak…

星系天体物理 · 物理学 2015-06-16 Satoko Sawada-Satoh , Kenta Fujisawa , Koichiro Sugiyama , Kiyoaki Wajima , Mareki Honma

We demonstrate ultra-broadband optoelectronic mixing of frequency combs that provides phase-coherent detection of a repetition frequency up to 500 GHz, using a high-speed modified uni-traveling carrier (MUTC) photodiode. Nonlinear…

光学 · 物理学 2024-10-30 Jizhao Zang , Jesse S. Morgan , Andreas Beling , Scott B. Papp

We have searched for 22 GHz H2O and 43/86/129 GHz SiO masers in bright IRAS point sources in the SMC and LMC, to test whether the kinematics of the mass loss from these stars depends on metallicity. H2O masers were detected in the red…

天体物理学 · 物理学 2009-11-06 Jacco Th. van Loon , Albert A. Zijlstra , Valentin Bujarrabal , Lars-Ake Nyman

Methanol masers at 6.7 GHz are the brightest of class II methanol masers and have been found exclusively towards massive star forming regions. These masers can thus be used as a unique tool to probe the early phases of massive star…

星系天体物理 · 物理学 2020-01-08 Sonu Tabitha Paulson , Jagadheep D. Pandian

We present the results of a monitoring campaign using the KAT-7 and HartRAO 26m telescopes, of hydroxyl, methanol and water vapour masers associated with the high-mass star forming region G9.62+0.20E. Periodic flaring of the main line…

太阳与恒星天体物理 · 物理学 2019-03-20 S. Goedhart , R. van Rooyen , D. J. van der Walt , J. P. Maswanganye , A. Sanna , G. C. MacLeod , S. P. van den Heever

We report the discovery of the first 14NH3 (2,2) maser, seen in the Sgr B2 Main star forming region near the center of the Milky Way, using data from the Very Large Array radio telescope. The maser is seen in both lower resolution (3" or…

Weak transitions in the (2,0) overtone band of the HD molecule at $\lambda = 1.38 \, \mu$m were measured in saturated absorption using the technique of noise-immune cavity-enhanced optical heterodyne molecular spectroscopy. Narrow…

原子物理 · 物理学 2018-04-18 F. M. J. Cozijn , P. Dupre , E. J. Salumbides , K. S. E. Eikema , W. Ubachs

The observed interaction product of Cosmic Rays (CRs) and Galactic magnetic fields (GMF) is the Galactic synchrotron emission integrated over the line-of-sight (LOS). The GMF strength and morphology and the CR density can be probed by…

星系天体物理 · 物理学 2020-04-08 I. M. Polderman , M. Haverkorn , T. R. Jaffe

Maser lines from different molecular species, including water, hydroxyl, and methanol, are common observational phenomena associated with massive star forming regions. In particular, the methanol maser appears as an ideal tool to study the…

星系天体物理 · 物理学 2014-06-04 L. Olmi , E. D. Araya , P. Hofner , S. Molinari , J. Morales Ortiz , L. Moscadelli , M. Pestalozzi

Light sources utilizing \c{hi}(2) parametric conversion combine high brightness with attractive operation wavelengths in the near and mid-infrared. In optical fibers it is possible to use \c{hi}(3) degenerate four-wave mixing in order the…

Long term monitoring observations with the Hitachi 32-m radio telescope of the 6.7 GHz methanol masers associated with the high mass star-forming region G5.900-0.430 is presented. A period of flux variability at approximately 1260 days, is…

太阳与恒星天体物理 · 物理学 2023-02-08 Yoshihiro Tanabe , Yoshinori Yonekura , MacLeod C. Gordon

Rapid progress in cooling and trapping of molecules has enabled first experiments on high resolution spectroscopy of trapped diatomic molecules, promising unprecedented precision. Extending this work to polyatomic molecules provides unique…

原子物理 · 物理学 2021-10-22 Alexander Prehn , Martin Ibrügger , Gerhard Rempe , Martin Zeppenfeld

Context: Maser emission from the H2O molecule probes the warm, inner circumstellar envelopes of oxygen-rich red giant and supergiant stars. Multi-maser transition studies can be used to put constraints on the density and temperature of the…

天体物理学 · 物理学 2009-11-13 K. M. Menten , A. Lundgren , A. Belloche , S. Thorwirth , M. J. Reid

We report the first detection of magnetic fields associated with the Smith High Velocity Cloud. We use a catalog of Faraday rotation measures towards extragalactic radio sources behind the Smith Cloud, new HI observations from the Green…

星系天体物理 · 物理学 2013-11-05 Alex S. Hill , S. A. Mao , Robert A. Benjamin , Felix J. Lockman , Naomi M. McClure-Griffiths