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相关论文: The Rapidly Evolving AGB Star, V Hya: ALMA finds a…

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The well studied carbon star V Hydrae is known to exhibit a complex asymmetric environment made of a dense equatorial wind and high-velocity outflows, hinting at its transition from the AGB phase to the asymmetric planetary nebula phase. In…

太阳与恒星天体物理 · 物理学 2024-05-24 L. Planquart , A. Jorissen , A. Escorza , O. Verhamme , H. Van Winckel

We present continuum and molecular line emission ALMA observations of OH 231.8+4.2, a well studied bipolar nebula around an asymptotic giant branch (AGB) star. The high angular resolution (~0.2-0.3 arcsec) and sensitivity of our ALMA maps…

Dark rings with bright rims are the indirect signposts of planets embedded in protoplanetary discs. In a recent first, an azimuthally elongated AU-scale blob, possibly a planet, was resolved with ALMA in TW Hya. The blob is at the edge of a…

Binarity is believed to dramatically affect the history and geometry of mass loss in AGB and post-AGB stars, but observational evidence of binarity is sorely lacking. As part of a project to look for hot binary companions to cool AGB stars…

太阳与恒星天体物理 · 物理学 2015-05-30 Raghvendra Sahai , James D. Neill , Armando Gil de Paz , Carmen Sánchez Contreras

Atomic carbon has been detected in the envelopes of three carbon-rich evolved stars: HD 44179 (=AFGL 915, the `Red Rectangle'); HD 56126; and, tentatively, the carbon star V Hya. This brings to seven the number of evolved star envelopes in…

天体物理学 · 物理学 2009-10-31 G. R. Knapp , M. Crosas , K. Young , Z. Ivezic

We present new Atacama Large Millimeter/submillimeter Array (ALMA) observations of the tadpole, a small globule in the Carina Nebula that hosts the HH 900 jet+outflow system. Our data include $^{12}$CO, $^{13}$CO, C$^{18}$O J=2-1,…

Atacama Large Millimetre/sub-millimetre Array (ALMA) observations of the CO(1-0) and CO(2-1) emissions from the circumstellar envelope of the Asymptotic Giant Branch (AGB) star EP Aqr have been made with four times better spatial resolution…

太阳与恒星天体物理 · 物理学 2019-05-01 P. T. Nhung , D. T. Hoai , P. Tuan-Anh , T. Le Bertre , P. Darriulat , P. N. Diep , N. T. Phuong , N. T. Thao , J. M. Winters

We report the detection and investigate the properties of high-excitation lambda-doubling line emission of hydroxyl (OH) detected towards three asymptotic giant branch (AGB) stars (W Hya, R Dor, and IK Tau) using ALMA. The OH lines are…

太阳与恒星天体物理 · 物理学 2019-03-06 T. Khouri , L. Velilla-Prieto , E. De Beck , W. H. T. Vlemmings , H. Olofsson , B. Lankhaar , J. H. Black , A. Baudry

We report the detection of an excess in dust continuum emission at 233~GHz (1.3~mm in wavelength) in the protoplanetary disk around TW~Hya revealed through high-sensitivity observations at $\sim$3~au resolution with the Atacama Large…

We are studying a class of binary post-AGB stars that seem to be systematically surrounded by equatorial disks and slow outflows. Although the rotating dynamics had only been well identified in three cases, the study of such structures is…

太阳与恒星天体物理 · 物理学 2018-06-13 V. Bujarrabal , A. Castro-Carrizo , H. Van Winckel , J. Alcolea , C. Sanchez Contreras , M. Santander-Garcia , M. Hillen

We aim to study the presence of both rotation and expansion in post-AGB nebulae, in particular around IW Car, a binary post-AGB star that was suspected to be surrounded by a Keplerian disk. We obtained high-quality ALMA observations of 12CO…

太阳与恒星天体物理 · 物理学 2017-01-04 V. Bujarrabal , A. Castro-Carrizo , H. Van Winckel , C. Sanchez Contreras , M. Santander-Garcia

Our purpose is to study the effect of binary companions located within the first 10 stellar radii from the primary AGB star. In this work, we target the mass-losing carbon star V Hydrae (V Hya), looking for signatures of its companion in…

Silicon monoxide (SiO) traces the physical conditions and dynamics in the circumstellar envelopes (CSEs) of AGB stars. We present high-resolution ALMA Band 6 observations of highly excited SiO emission in 14 oxygen-rich AGB stars. We cover…

The dusty winds of cool evolved stars are a major contributor of the newly synthesised material enriching the Galaxy and future generations of stars. However, the details of the physics and chemistry behind dust formation and wind launching…

We present ALMA Cycle-0 observations of the CO (6-5) line emission (rest-frame frequency = 691.473 GHz) and of the 435$\mu m$ dust continuum emission in the nuclear region of NGC 34, a local luminous infrared galaxy (LIRG) at a distance of…

Context. The transition from the spherically symmetric envelopes around asymptotic giant branch (AGB) stars to the asymmetric morphologies observed in planetary nebulae is still not well understood, and the shaping mechanisms are a subject…

太阳与恒星天体物理 · 物理学 2024-01-17 Jaime Alonso-Hernández , Carmen Sánchez Contreras , Raghvendra Sahai

We present results from an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 2 program to map CO(2-1) emission in nearby early-type galaxies (ETGs) that host circumnuclear gas disks. We obtained $\sim0.3''-$resolution Band 6…

We present spatially-resolved morphological properties of [CII] 158 $\mu$m, [OIII] 88 $\mu$m, dust, and rest-frame ultraviolet (UV) continuum emission for A1689-zD1, a strongly lensed, sub-L* galaxy at $z=7.13$, by utilizing deep Atacama…

We present Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm continuum and CO(2-1) line emission observations toward the high-mass star formation region DR21. Five new continuum sources are found. We identify eighteen outflow…

星系天体物理 · 物理学 2024-09-25 E. Guzmán Ccolque , M. Fernández López , L. A. Zapata , J. Bally , P. R. Rivera-Ortiz

We have detected in ALMA observations CO J = 6 - 5 emission from the nucleus of the Seyfert galaxy NGC 1068. The low-velocity (up to +/- 70 km/s relative to systemic) CO emission resolves into a 12x7 pc structure, roughly aligned with the…