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相关论文: Water masers in dusty environments

200 篇论文

We review the search for the glass transition in water in its various amorphous forms, and highlight the paradoxes that the search has produced. Focussing on the glassy form of water obtained by hyperquenching, we examine its reported…

无序系统与神经网络 · 物理学 2007-05-23 V. Velikov , S. Borick , C. A. Angell

We measure the matter power spectrum from the Lyman-alpha forest of 31 quasar spectra spanning the redshift range of 1.6-3.6. The optical depth, $\tau$, for absorption of the intergalactic medium is obtained from the flux using the…

天体物理学 · 物理学 2009-11-11 S. Zaroubi , M. Viel , A. Nusser , M. Haehnelt , T. -S. Kim

Cool, evolved stars undergo copious mass loss but the details of how the matter is returned to the ISM are still under debate. We investigated the structure and evolution of the wind at 5 to 50 stellar radii from Asymptotic Giant Branch and…

太阳与恒星天体物理 · 物理学 2015-06-05 A. M. S. Richards , S. Etoka , M. D. Gray , E. E. Lekht , J. E. Mendoza-Torres , K. Murakawa , G. Rudnitskij , J. A. Yates

We report the first detection of the ground transition of the deuterated water at 464 GHz in the young proto-planetary disk surrounding the solar type protostar DM Tau. The line is observed in absorption against the continuum from the cold…

天体物理学 · 物理学 2009-11-13 C. Ceccarelli , C. Dominik , E. Caux , B. Lefloch , P. Caselli

A new methanol maser line 6(-1)-5(0)E at 133 GHz was detected with the 12-m Kitt Peak radio telescope using remote observation mode from Moscow. Moderately strong, narrow maser lines were found in DR21(OH), DR21-W, OMC-2, M8E, NGC2264,…

天体物理学 · 物理学 2009-10-30 V. I. Slysh , S. V. Kalenskii , I. E. Val'tts , V. V. Golubev

We present new Herschel-derived images of warm dust in the Andromeda Galaxy, M31, with unprecedented spatial resolution (~ 30 pc), column density accuracy, and constraints on the three-dimensional distributions of dust temperature and dust…

星系天体物理 · 物理学 2018-08-08 K. A. Marsh , A. P. Whitworth , M. W. L. Smith , O. Lomax , S. A. Eales

The deuterium fractionation of water can serve as a tracer for the chemical and physical evolution of water during star formation and can constrain the origin of water in Solar System bodies. We determine the HDO/H$_2$O ratio in the inner…

太阳与恒星天体物理 · 物理学 2019-10-16 S. S. Jensen , J. K. Jørgensen , L. E. Kristensen , K. Furuya , A. Coutens , E. F. van Dishoeck , D. Harsono , M. V. Persson

Periodic or regular flaring of class II methanol masers in nine high mass star forming regions is now a well established phenomenon. Amongst the nine star forming regions, G37.55+0.20 is the only case at present where apart from the…

星系天体物理 · 物理学 2015-06-18 D. J. van der Walt

We have studied the opacity of dust grains at submillimeter wavelengths by estimating the optical depth from imaging at 160, 250, 350, and 500 um from the Herschel Gould Belt Survey and comparing this to a column density obtained from the…

In previous laboratory experiments, we measured the temperature dependence of sticking forces between micrometer grains of chondritic composition. The data showed a decrease in surface energy by a factor ~5 with increasing temperature.…

地球与行星天体物理 · 物理学 2021-08-25 C. Pillich , T. Bogdan , J. Landers , G. Wurm , H. Wende

Observations show that 1612 MHz masers of OH/IR stars can fade on a timescale of a decade. This fading is probably associated with the switch from rapid mass loss, which is ultimately linked with an internal He-shell flash, to the much…

天体物理学 · 物理学 2009-11-13 M. D. Gray D. A. Howe , B. M. Lewis

We report the detection of ammonia masers in the non-metastable (6, 3), (7, 5) and (6, 5) transitions, the latter is the first unambiguous maser detection of that transition ever made. Our observations include the first VLBI detection of…

We present a survey of OH maser emission towards a sample of high mass protostellar objects made using the Nancay and GBT telescopes.OH maser emission was detected towards 63 objects with 36 new detections. There are 56 star-forming regions…

天体物理学 · 物理学 2009-11-13 K. A. Edris , G. A. Fuller , R. J . Cohen

We present the first interferometer map of the water maser emission in the active nucleus of NGC 4945. Although the declination of the galaxy is about -49 degrees, we were able to make the observations with the southernmost antennas of the…

天体物理学 · 物理学 2009-10-30 L. J. Greenhill , J. M. Moran , J. R. Herrnstein

The high-mass star-forming region NGC6334I-MM1 underwent an energetic accretion event in January 2015. We report the large-scale ($10 - 100$ AU) and small-scale ($\sim 1$ AU) changes in spatial and velocity structures of 22 GHz water masers…

太阳与恒星天体物理 · 物理学 2022-12-09 Jakobus M. Vorster , James O. Chibueze , Tomoya Hirota , Gordon C. MacLeod

Four Class I maser sources were detected at 44, 84, and 95 GHz toward chemically rich outflows in the regions of low-mass star formation NGC 1333I4A, NGC 1333I2A, HH25, and L1157. One more maser was found at 36 GHz toward a similar outflow,…

星系天体物理 · 物理学 2015-06-04 S. V. Kalenskii , V. I. Slysh , L. E. B. Johansson , P. Bergman , S. Kurtz , P. Hofner , C. M. Walmsley

The {\bf H}$_2${\bf O} Southern Galactic {\bf P}lane {\bf S}urvey (HOPS) has observed 100 square degrees of the Galactic plane, using the Mopra radio telescope to search for emission from multiple spectral lines in the 12\,mm band…

天体物理仪器与方法 · 物理学 2015-06-03 Andrew J. Walsh , Cormac Purcell , Steven Longmore , Christopher H. Jordan , Vicki Lowe

We present VLA and ALMA imaging of the deeply-embedded protostellar cluster NGC6334I from 5 cm to 1.3 mm at angular resolutions as fine as 0.17 (220 AU). The dominant hot core MM1 is resolved into seven components at 1.3 mm, clustered…

星系天体物理 · 物理学 2016-12-14 C. L. Brogan , T. R. Hunter , C. J. Cyganowski , C. J. Chandler , R. Friesen , R. Indebetouw

We report 250 GHz (1.2mm) observations of redshift > 3.8 quasars from the Palomar Sky Survey (PSS) sample, using the Max-Planck Millimetre Bolometer (MAMBO) array at the IRAM 30-metre telescope. Eighteen sources were detected and upper…

天体物理学 · 物理学 2009-11-06 A. Omont , P. Cox , F. Bertoldi , R. G. McMahon , C. Carilli , K. G. Isaak

Variations in the observed dust emission and extinction indicate a systematic evolution of grain properties in the transition from the diffuse interstellar medium (ISM) to denser molecular clouds. The differences in the dust spectral energy…

星系天体物理 · 物理学 2015-06-05 Melanie Köhler , Nathalie Ysard , Anthony P. Jones