scholarly journals Discovery of a Photoionized Bipolar Outflow toward the Massive Protostar G45.47+0.05

2019 ◽  
Vol 886 (1) ◽  
pp. L4 ◽  
Author(s):  
Yichen Zhang ◽  
Kei E. I. Tanaka ◽  
Viviana Rosero ◽  
Jonathan C. Tan ◽  
Joshua Marvil ◽  
...  
Keyword(s):  
Bipolar Outflow

scholarly journals Bipolar outflow on the asymptotic giant branch – the case of IRC+10011

2004 ◽  
Vol 352 (3) ◽  
pp. 852-862 ◽  
Author(s):  
Dejan Vinković ◽  
Thomas Blöcker ◽  
Karl-Heinz Hofmann ◽  
Moshe Elitzur ◽  
Gerd Weigelt
Keyword(s):  
Asymptotic Giant Branch ◽  
Bipolar Outflow

Bipolar outflow of gas in the spiral galaxy NGC 3079

1986 ◽  
Vol 64 (4) ◽  
pp. 531-535 ◽  
Author(s):  
Nebojsa Duric ◽  
E. R. Seaquist
Keyword(s):  
Spectral Index ◽  
Spiral Galaxy ◽  
Central Region ◽  
Qualitative Description ◽  
Radio Continuum ◽  
Large Array ◽  
Very Large Array ◽  
Bipolar Outflow ◽  
The Galaxy

Very large array, radio-continuum observations of the edge-on spiral galaxy NGC 3079 are presented. The observations reveal that the nucleus has windlike properties and that the central region of the galaxy exhibits an unusual figure-eight morphology that shows evidence of severe depolarization and a flattening spectral index away from the nucleus. A qualitative description of a model is presented to account for the observed radio properties. It is shown that a wind-driven shock propagating away from the nucleus and focused by the ambient disk gas can give rise to the observed morphology.

scholarly journals The detection of new methanol masers in the 5−1 — 40E Line

2002 ◽  
Vol 206 ◽  
pp. 195-198
Author(s):  
Sergei V. Kalenskii ◽  
Vyacheslav I. Slysh ◽  
Irina E. Val'tts ◽  
Anders Winnberg ◽  
Lars E. B. Johansson
Keyword(s):  
Velocity Field ◽  
Frequency Analysis ◽  
Linear Polarization ◽  
Class I ◽  
Narrow Line ◽  
Bipolar Outflow ◽  
Compact Class ◽  
Extended Sources ◽  
Methanol Masers ◽  
Maser Sources

Fifty-one objects in the 5−1 − 40E methanol line at 84.5 GHz was detected during a survey of Class I maser sources. Narrow maser features were found in 17 of these. Broad quasi-thermal lines were detected towards other sources. One of the objects with narrow features, the young bipolar outflow L 1157 was also observed in the 80 − 71A+ line at 95.2 GHz; a narrow line was detected at this frequency. Analysis showed that the broad lines are usually inverted. The quasi-thermal profiles imply that the line opacities are not larger than several units. These results confirm the plausibility of models in which compact Class I masers appear in extended sources as a result of an appropriate velocity field.Measurements of linear polarization at 84.5 GHz in 13 sources were made. No polarization was found except a tentative detection of a weak polarization in M 8E.

scholarly journals MERLIN observations of bipolar outflow from HM Sagittae

1995 ◽  
Vol 274 (1) ◽  
pp. 317-323 ◽  
Author(s):  
S. P. S. Eyres ◽  
H. T. Kenny ◽  
R. J. Cohen ◽  
H. M. Lloyd ◽  
S. M. Dougherty ◽  
...  
Keyword(s):  
Bipolar Outflow

Shock Modelling of the Bipolar Outflow Source NGC 6537

1993 ◽  
pp. 385-385
Author(s):  
L. Cuesta ◽  
J. P. Phillips
Keyword(s):  
Bipolar Outflow

scholarly journals Crossing the “Yellow Void” – Spatially Resolved Spectroscopy of the Post–Red Supergiant IRC+10420

2002 ◽  
Vol 187 ◽  
pp. 95-98
Author(s):  
Roberta M. Humphreys ◽  
Kris Davidson ◽  
Nathan Smith
Keyword(s):  
Mass Loss ◽  
Spatial Resolution ◽  
Spherically Symmetric ◽  
Bipolar Outflow ◽  
Reflection Nebula ◽  
Spatially Resolved ◽  
Spatially Resolved Spectroscopy ◽  
Rapid Mass ◽  
Hr Diagram

AbstractIRC+10420 is a post–red supergiant at the empirical luminosity boundary in the HR diagram. It has now reached a stage in its blueward evolution where increasing opacity and partial ionization destabilize its atmosphere leading to rapid mass loss. Indeed, its wind is so dense that it is opaque and hides the underlying star. We have obtained HST/STIS spectroscopy with spatial resolution good enough to separate the star from its complex ejecta with numerous arcs, knots and jet-like features. The ejecta form essentially a reflection nebula, allowing us to view the star from a range of directions. The kinematics of the ejecta cannot be reconciled with existing models with either an equatorial disk or a bipolar outflow. Therefore we propose a model with a uniform spherically symmetric outflow of gas with random, asymmetric ejections superimposed. In our model, local instabilities allow for inflowing and outflowing material to coexist.

scholarly journals The physical structure of NGC 2440

1997 ◽  
Vol 180 ◽  
pp. 218-218
Author(s):  
L. Cuesta ◽  
J. P. Phillips
Keyword(s):  
Detailed Analysis ◽  
Baja California ◽  
Physical Structure ◽  
Outer Shell ◽  
Monochromatic Imaging ◽  
Bipolar Outflow ◽  
San Pedro

We have acquired monochromatic imaging of the bipolar outflow source NGC 2440 in 12 ionic transitions using the 1.5 m Telescope at the Observatorio de San Pedro Mártir, Ensenada, Baja California, Mexico. As a result, we have been able to undertake detailed analysis of the shell ionisation structure. Then, we found that excitation is high close the center, extending towards the exterior at located radial positions. Edges and ansae are zones of low excitation indicating probably shock regions, in particular the outer shell.

scholarly journals Masers: Probing the mass loss process in PPN

1997 ◽  
Vol 180 ◽  
pp. 348-349
Author(s):  
Dieter Engels
Keyword(s):  
Mass Loss ◽  
Large Amplitude ◽  
Planetary Nebulae ◽  
Transition Process ◽  
Main Line ◽  
Agb Stars ◽  
Loss Process ◽  
Bipolar Outflow ◽  
Sky Survey ◽  
Sizeable Number

With the advent of the IRAS All-Sky Survey a sizeable number of transition objects between the AGB and the PN-phase were found - the Proto Planetary Nebulae (PPN). Oxygen-rich AGB stars often show prominent masers of SiO, H2O, and OH, which are lost during the transition process. The heavy mass loss on the AGB however does not stop abruptly and a new axisymmetric wind develops during the PPN phase. These winds both may host new masers and they can be used to study the changes of the mass loss process after that the stars have stopped their large-amplitude variations on the AGB. Several PPN are known to have OH masers, and at least in one case, HD 101584, the presence of a bipolar outflow could be proven (te Lintel Hekkert et al. 1992). Lewis (1989) found that main-line OH masers become prominent again. I will discuss here conclusions, which can be drawn from observations of H2O masers in PPN.

Sign in / Sign up

Export Citation Format

Share Document