David Aguilar
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Christine Pulliam
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CfA Press Release Images
 



Caption with multi-image illustration

Caption with multi-image illustration

Clockwise from the top left:

Clockwise from the top left:

a) In the current view of stellar formation, a protostar isa) In the current view of stellar formation, a protostar issurrounded by a rotating accretion disk. Gas that is falling inward under the influence of gravity accumulates near the star's equator. Disk material eventually falls in toward the protostar or is ejected in the direction of the star's polar regions. The disk is believed to fuel this polar outflow. (From Shu, Adams, andsurrounded by a rotating accretion disk. Gas that is falling inward under the influence of gravity accumulates near the star's equator. Disk material eventually falls in toward the protostar or is ejected in the direction of the star's polar regions. The disk is believed to fuel this polar outflow. (From Shu, Adams, andLizano, Annual Reviews of Astronomy and Astrophysics, Vol. 25).Lizano, Annual Reviews of Astronomy and Astrophysics, Vol. 25).

b) A new map of radio emission from dense gas in the vicinity ofb) A new map of radio emission from dense gas in the vicinity of"Radio Source I, " whose position is indicated by the cross. Color"Radio Source I, " whose position is indicated by the cross. Colorcoding indicates velocity, either toward (blue) or away (red) fromcoding indicates velocity, either toward (blue) or away (red) fromthe observer. Molecules (SiO) in the very-hot gas (i.e., 1000 K,the observer. Molecules (SiO) in the very-hot gas (i.e., 1000 K,about 3 times room temperature) along the walls of twoabout 3 times room temperature) along the walls of twooppositely directed outflow cones generate the observed radiooppositely directed outflow cones generate the observed radioemission. The heavy arrows show the direction of gas flowing throughemission. The heavy arrows show the direction of gas flowing throughthe cones. the cones.

c) A map of the radio emission from both the cones (shown circled) and fromc) A map of the radio emission from both the cones (shown circled) and froma cooler gas rich in water vapor (i.e., 400 K, about the boilinga cooler gas rich in water vapor (i.e., 400 K, about the boilingpoint of water). The water occurs in dense cloudlets beingpoint of water). The water occurs in dense cloudlets beingpushed away from the protostar (i.e., the small arrows). Remarkably,pushed away from the protostar (i.e., the small arrows). Remarkably,these water-rich cloudlets are confined to the equatorial region ofthese water-rich cloudlets are confined to the equatorial region ofthe protostellar system, where they move more slowly than the gasthe protostellar system, where they move more slowly than the gasdriven away from the polar regions of the protostar. Nodriven away from the polar regions of the protostar. Noaccretion disk is visible, even though there is a strong polar outflowaccretion disk is visible, even though there is a strong polar outflowfrom the protostar.from the protostar.

d) The context of "Radio Source I:" The distribution of waterd) The context of "Radio Source I:" The distribution of wateremission is superposed on an infrared and radio image of the regionemission is superposed on an infrared and radio image of the regionjust northwest of the Orion nebula. The heavy lines indicatejust northwest of the Orion nebula. The heavy lines indicatethe walls of the outflow cones. Several sources arethe walls of the outflow cones. Several sources arelabelled, including a very bright newly born star that is stilllabelled, including a very bright newly born star that is stillvisible only at infrared wavelengths (i.e., source n), and a stringvisible only at infrared wavelengths (i.e., source n), and a stringof dust-laden gas clumps (i.e., IRc2). These clumps may be either heated byof dust-laden gas clumps (i.e., IRc2). These clumps may be either heated bygas flowing away from Radio Source I, or by a direct line of sightgas flowing away from Radio Source I, or by a direct line of sightto the protostar, looking down the cone. Outflows in this region ofto the protostar, looking down the cone. Outflows in this region ofOrion have been known to astronomers for decades, though their originOrion have been known to astronomers for decades, though their originhas not been well determined on the scales shown here. The largehas not been well determined on the scales shown here. The largecross is the previously suspected location of the origin of thecross is the previously suspected location of the origin of theoutflows. (Background images from papers Dougados et al.outflows. (Background images from papers Dougados et al.and Menten and Reid, Astrophysical Journal, 1993 and 1995.) and Menten and Reid, Astrophysical Journal, 1993 and 1995.)

e) The new model for Radio Source I (mesh) with the distributions ofe) The new model for Radio Source I (mesh) with the distributions ofmolecular radio emission superposed. In contrast to expectationsmolecular radio emission superposed. In contrast to expectationsderived from the current theoretical understanding of stellar birthderived from the current theoretical understanding of stellar birth(figure a), this very young star does not appear to be surrounded by(figure a), this very young star does not appear to be surrounded bya disk--or any other rotating material. This protostar often considereda disk--or any other rotating material. This protostar often considered a prototype for other very young high-mass stars (i.e., many tens of suns). a prototype for other very young high-mass stars (i.e., many tens of suns).Other similar objects may also drive conical outflows but this is theOther similar objects may also drive conical outflows but this is the first such flow to have been observed with any clarity. first such flow to have been observed with any clarity.

AA .pdf and a .eps version of the images are also available.

.pdf and a .eps version of the images are also available.

Click here to return to main text of the press release.Click here to return to main text of the press release.

 
 
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