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Related papers: Imaging the oxygen-rich disk toward the silicate c…

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In the generally accepted, but poorly documented model, silicate J-type C-stars are binary objects for which the silicate emission originates from a circumbinary or a circumcompanion disc. We aim at testing this hypothesis by a thorough…

Astrophysics · Physics 2009-11-13 P. Deroo , H. Van Winckel , T. Verhoelst , M. Min , M. Reyniers , L. B. F. M. Waters

A survey of mid-IR gas-phase emission lines of H2, H2O and various atoms toward a sample of 43 embedded low-mass young stars in nearby star-forming regions is presented. The sources are selected from the Spitzer "Cores to Disks" (c2d)…

Astrophysics of Galaxies · Physics 2015-05-19 Fred Lahuis , Ewine F. van Dishoeck , Jes K. Jørgensen , Geoffrey A. Blake , Neal J. Evans

This work presents a detailed study of the gas kinematics towards the "Hot Molecular Core" (HMC) G31.41+0.31 via multi-epoch VLBI observations of the H2O 22 GHz and CH3OH 6.7 GHz masers, and single-epoch VLBI of the OH 1.6 GHz masers. Water…

Solar and Stellar Astrophysics · Physics 2015-06-12 Luca Moscadelli , Jing Jing Li , Riccardo Cesaroni , Alberto Sanna , Ye Xu , Qizhou Zhang

We investigate the occurrence of crystalline silicates in oxygen-rich evolved stars across a range of metallicities and mass-loss rates. It has been suggested that the crystalline silicate feature strength increases with increasing…

Optical observations of the Oort cloud comet C/2017 K2 (PANSTARRS) show that its activity began at large heliocentric distances (up to 35 au), which cannot be explained by either the sublimation or the crystallization of water ice.…

Earth and Planetary Astrophysics · Physics 2021-06-23 Bin Yang , David Jewitt , Yuhui Zhao , Xuejian Jiang , Quanzhi Ye , Ying-Tung Chen

We conducted a 4 epoch 3 month VLBA proper motion study of H$_2$O masers toward an intermediate-mass class 0 source IRAS 20050+2720 MMS1 (d=700 pc). From milli-arcsecond (mas) resolution VLBA images, we found two groups of H2O maser spots…

Astrophysics · Physics 2009-11-10 Ray S. Furuya , Yoshimi Kitamura , Alwyn Wootten , Mark J. Claussen , Ryohei Kawabe

Recent results indicate that the grain size and crystallinity inferred from observations of silicate features may be correlated with spectral type of the central star and/or disk geometry. In this paper, we show that grain size, as probed…

We obtained low resolution (R = 100) mid-infrared (8-13 micron wavelengths) spectra of 8 nearby young main sequence stars with the Keck 1 telescope and Long-Wavelength Spectrometer (LWS) to search for 10 micron silicate (Si-O stretch)…

Astrophysics · Physics 2015-06-24 Eric Gaidos , Christopher Koresko

We have performed observations of water maser emission towards a sample of low-mass protostars, in order to investigate the properties of jets associated with the earliest stages of star formation and their interaction with the surrounding…

Astrophysics of Galaxies · Physics 2015-05-13 J. -F. Desmurs , C. Codella , J. Santiago-Garcia , M. Tafalla , R. Bachiller

The recent findings of gas giant planets around young A-type stars suggest that disks surrounding Herbig Ae/Be stars will develop planetary systems. An interesting case is HD142527, for which previous observations revealed a complex…

We have made multi-epoch VLBI observations of H2O maser emission in the massive star forming region IRAS 06061+2151 with the Japanese VLBI network (JVN) from 2005 May to 2007 October. The detected maser features are distributed within an…

We present new multi-wavelength millimeter interferometric observations of the Herbig Ae star HD 163296 obtained with the IRAM/PBI, SMA and VLA arrays both in continuum and in the 12CO, 13CO and C18O emission lines. Gas and dust properties…

Astrophysics · Physics 2009-11-13 A. Isella , L. Testi , A. Natta , R. Neri , D. Wilner , C. Qi

High-resolution VLA observations of 1720 MHz OH maser emission from Sgr A East and the circumnuclear disk with spatial and spectral resolutions of $\approx$ 2\dasec5 $\times$ 1\dasec3 and 0.27 \kms are reported. This follow-up observational…

Astrophysics · Physics 2009-10-30 F. Yusef-Zadeh , D. A. Roberts , W. M. Goss , D. A. Frail , A. J. Green

We present the first joint high-resolution observations of small-scale EUV jets using Solar Orbiter(SolO)'s Extreme Ultraviolet Imager and High Resolution Imager (HRI) and H$\alpha$ imaging from the Visible Imaging Spectrometer (VIS)…

Solar and Stellar Astrophysics · Physics 2025-10-21 Jeongwoo Lee , Dana Longcope , Junmu Youn , Navdeep K. Panesar , Nengyi Huang , Haimin Wang

We have performed VLBI and single-dish monitoring of 22 GHz H$_{2}$O maser emission from the high mass young stellar object G353.273+0.641 with VERA (VLBI Exploration of Radio Astrometry) and Tomakamai 11-m radio telescope. Two maser flares…

Solar and Stellar Astrophysics · Physics 2015-05-28 K. Motogi , K. Sorai , M. Honma , T. Minamidani , T. Takekoshi , K. Akiyama , K. Tateuchi , K. Hosaka , Y. Ohishi , Y. Watanabe , A. Habe , H. Kobayashi

We present ISO-SWS observations of H2 pure-rotational line emission from the disks around low and intermediate mass pre-main-sequence stars as well as from young stars thought to be surrounded by debris disks. We detect `warm' (T ~ 100-200…

We present new (April 2000) MERLIN observations of the H2O masers located near the protostar Cepheus A HW2. The MERLIN observations detect many of the structures found in earlier (1996) VLBA observations of Torrelles and collaborators, and…

Astrophysics · Physics 2009-11-07 J. F. Gallimore , R. J. Cool , M. D. Thornley , J. McMullin

The present paper focuses on the high-mass star-forming region G23.01-0.41. Methods: Using the VLBA and the EVN arrays, we conducted phase-referenced observations of the three most powerful maser species in G23.01-0.41: H2O at 22.2 GHz (4…

Astrophysics of Galaxies · Physics 2015-05-18 A. Sanna , L. Moscadelli , R. Cesaroni , A. Tarchi , R. S. Furuya , C. Goddi

We present the Spitzer IRS spectra for 33 young stars in Tr 37 and NGC 7160. The sample includes the high- and intermediate-mass stars with MIPS 24 microns excess, the only known active accretor in the 12 Myr-old cluster NGC 7160, and 19…

We present an edge-on Keplerian disc model to explain the main component of the 12.2 and 6.7 GHz methanol maser emission detected toward NGC7538-IRS1 N. The brightness distribution and spectrum of the line of bright masers are successfully…

Astrophysics · Physics 2009-11-10 Michele R. Pestalozzi , Moshe Elitzur , John E. Conway , Roy S. Booth