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Related papers: Water masers in dusty environments

200 papers

Periodic flares of maser emission are thought to be induced either by variations of the seed photon flux in young binary systems or the pump rate regulated by stellar and accretion luminosities. We seek to study the variability of four…

Solar and Stellar Astrophysics · Physics 2020-02-05 Mateusz Olech , Marian Szymczak , Paweł Wolak , Eric Gérard , Anna Bartkiewicz

Mist/air two-phase flow is a promising cooling technique for many applications such as internal cooling of gas turbine blades. A significant enhancement of heat transfer can be achieved with a low mass fraction of droplets by utilizing the…

Fluid Dynamics · Physics 2024-07-09 Junxian Cao , Mengqi Ye , Haiwang Li , Tianyou Wang , Zhizhao Che

We present the results of numerically solving the rate equations for the first 31 rotational states of CS in the ground vibrational state to determine the conditions under which the J=1-0, J=2-1 and J=3-2 transitions are inverted to produce…

Astrophysics of Galaxies · Physics 2020-12-02 D. J. van der Walt , A. Ginsburg , C. Goddi

We have detected and confirmed five water maser complexes in the Andromeda Galaxy (M31) using the Green Bank Telescope. These masers will provide the high brightness temperature point sources needed for proper motion studies of M31,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Jeremy Darling

In the context of the ASAI (Astrochemical Surveys At IRAM) project, we carried out an unbiased spectral survey in the millimeter window towards the well known low-mass Class I source SVS13-A. The high sensitivity reached (3-12 mK) allowed…

Solar and Stellar Astrophysics · Physics 2016-08-03 C. Codella , C. Ceccarelli , E. Bianchi , R. Bachiller , B. Lefloch , F. Fontani , V. Taquet , L. Testi

We present a complete catalogue of 27 O VI absorbers at low redshift (0.12 < z < 0.5) from a blind survey of 16 QSO echelle spectra in the HST/STIS data archive. These absorbers are identified based only upon matching line profiles and the…

Astrophysics · Physics 2009-11-13 Christopher Thom , Hsiao-Wen Chen

A very low ortho-to-para ratio (OPR) of 0.1-0.5 was previously reported in the Orion Bar photon-dominated region (PDR), based on observations of two optically thin $\mathrm{H_2^{18}O}$ lines which were analyzed by using a single-slab large…

Astrophysics of Galaxies · Physics 2019-11-27 T. Putaud , X. Michaut , F. Le Petit , E. Roueff , D. C. Lis

We report an experimental study of peak and phase-space density of a two-stage magneto-optical trap (MOT) of 6-Li atoms, which exploits the narrower $2S_{1/2}\rightarrow 3P_{3/2}$ ultra-violet (UV) transition at 323 nm following trapping…

Atomic Physics · Physics 2015-06-22 Jimmy Sebastian , Christian Gross , Ke Li , Huat Chai Jaren Gan , Wenhui Li , Kai Dieckmann

Context: Fast surface conversion between ortho- and para-H2 has been observed in laboratory studies, and this mechanism has been proposed to play a role in the control of the ortho-para ratio in the interstellar medium. Observations of…

Astrophysics of Galaxies · Physics 2016-03-16 Emeric Bron , Franck Le Petit , Jacques Le Bourlot

Context: High-mass young stellar objects (HMYSOs) can undergo accretion episodes that strongly affect the star evolution, the dynamics of the disk, and its chemical evolution. Recently reported extraordinary bursts in the methanol maser…

Astrophysics of Galaxies · Physics 2018-09-19 Marian Szymczak , Mateusz Olech , Paweł Wolak , Eric Gérard , Anna Bartkiewicz

We present a survey of the polarization properties of mm-wavelength methanol masers, comprising both classes, and transitions from 84.5 to 157.0 GHz. Linear polarization is found in more than half of the observed objects, and circular…

Astrophysics · Physics 2009-11-10 Helmut Wiesemeyer , Clemens Thum , Malcolm Walmsley

We test emission models of circum-nuclear dust torii around quasars, at low and high redshifts, by using a large collection of photometric data for an unbiased sample of 120 optically-selected objects with millimetric and sub-millimetric…

Astrophysics · Physics 2009-10-31 Paola Andreani , Alberto Franceschini , Gianluigi Granato

Spitzer Space Telescope and Herschel Space Observatory imaging of M31 is used, with a physical dust model, to construct maps of dust surface density, dust-to-gas ratio, starlight heating intensity, and PAH abundance, out to R=25kpc. The…

Astrophysical masers are widely used in star formation studies. In particular, they are valuable in investigations of high-mass star-forming regions that are difficult to observe at optical frequencies. We used multi-transition data to…

Solar and Stellar Astrophysics · Physics 2025-03-17 A. Kobak , A. Bartkiewicz , K. L. J. Rygl , A. M. S. Richards , M. Szymczak , P. Wolak

We have used SCUBA to observe a complete sample of 104 galaxies selected at 60 microns from the IRAS BGS and we present here the 850 micron measurements. Fitting the 60,100 and 850 micron fluxes with a single temperature dust model gives…

Astrophysics · Physics 2009-10-31 L. Dunne , S. A. Eales , M. G. Edmunds , R. J. Ivison , P. Alexander , D. L. Clements

We present Very Large Array observations with 80 milliarcsecond resolution (~9 pc) of the recently discovered Galactic-analog water masers in the Antennae interacting galaxies (NGC 4038/NGC 4039; Arp244). Three regions of water maser…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Crystal Brogan , Kelsey Johnson , Jeremy Darling

We study the optical properties of the host galaxies of nuclear 22 GHz (lambda=1.35 cm) water masers. To do so, we cross-match the galaxy sample surveyed for water maser emission (123 detections and 3806 non-detections) with the SDSS…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Guangtun Zhu , Ingyin Zaw , Michael R. Blanton , Lincoln J. Greenhill

The temperature of interstellar dust particles is of great importance to astronomers. It plays a crucial role in the thermodynamics of interstellar clouds, because of the gas-dust collisional coupling. It is also a key parameter in…

Astrophysics of Galaxies · Physics 2017-08-09 S. Hocuk , L. Szucs , P. Caselli , S. Cazaux , M. Spaans , G. B. Esplugues

Interstellar dust is a key element in our understanding of the interstellar medium and star formation. The manner in which dust populations evolve with the excitation and the physical conditions is a first step in the comprehension of the…

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