Thanks for your response Harry. Sorry the thread is resisting my attempt to fix it, perhaps a moderator can edit?
Unfortunately the Hubble tuning fork read from left to right does not represent the sequence in time as galaxies develop.
The SEDS site is part of the problem. It would be great if they would update their description, because it is such a respected resource, as APOD .
The M82 description in
http://www.wikipedia.org reflects a more current understanding. And here is a paragraph from Science Magazine that makes the point:
Science 12 May 2006:
Vol. 312. no. 5775, p. 815
DOI: 10.1126/science.312.5775.815a
Prev | Table of Contents | Next
EDITORS' CHOICE: HIGHLIGHTS OF THE RECENT LITERATURE
Galactic winds, driven by violent bursts of star formation, are thought to spread elements heavier than hydrogen between galaxies and throughout the cosmos. The ashes of former stars thereby live on in later generations of stars and may affect galactic evolution. The loss of gas due to winds may starve galaxies of fuel and could affect the growth of different galaxy types.
The nearby edge-on spiral galaxy M82 has the most thoroughly studied strong wind; this galaxy is undergoing a violent burst of star formation in its heart, which expels a bi-conical superwind of hot ionized gas.
By examining infrared images acquired with the Spitzer Space Telescope, Engelbracht et al. find that M82 is surrounded by a spherical halo of warm dust into which the hot wind penetrates. Spidery dust filaments emanate outward in all directions, extending well beyond the galaxy and its wind. The spectra reveal that aromatic hydrocarbons survive in the dust despite close proximity to the hot superwind. The unusually wide extent and spherical shape of the M82 dust cocoon suggest that the dust was driven out of the galaxy before the superwind commenced, and is thus more pervasive than previously thought; possible explanations include interactions with neighboring galaxies or alternative wind-related mechanisms. -- JB
Astrophys. J. 642, L127 (2006).
If you'd like to enjoy the spectrum of chaotic irregular galaxies, I'd look at:
http://www.galaxyzoo.org
Cheers,
Dan
Thanks for your response Harry. Sorry the thread is resisting my attempt to fix it, perhaps a moderator can edit?
Unfortunately the Hubble tuning fork read from left to right does not represent the sequence in time as galaxies develop.
The SEDS site is part of the problem. It would be great if they would update their description, because it is such a respected resource, as APOD .
The M82 description in http://www.wikipedia.org reflects a more current understanding. And here is a paragraph from Science Magazine that makes the point:
Science 12 May 2006:
Vol. 312. no. 5775, p. 815
DOI: 10.1126/science.312.5775.815a
Prev | Table of Contents | Next
EDITORS' CHOICE: HIGHLIGHTS OF THE RECENT LITERATURE
Galactic winds, driven by violent bursts of star formation, are thought to spread elements heavier than hydrogen between galaxies and throughout the cosmos. The ashes of former stars thereby live on in later generations of stars and may affect galactic evolution. The loss of gas due to winds may starve galaxies of fuel and could affect the growth of different galaxy types. [b]The nearby edge-on spiral galaxy M82[/b] has the most thoroughly studied strong wind; this galaxy is undergoing a violent burst of star formation in its heart, which expels a bi-conical superwind of hot ionized gas.
By examining infrared images acquired with the Spitzer Space Telescope, Engelbracht et al. find that M82 is surrounded by a spherical halo of warm dust into which the hot wind penetrates. Spidery dust filaments emanate outward in all directions, extending well beyond the galaxy and its wind. The spectra reveal that aromatic hydrocarbons survive in the dust despite close proximity to the hot superwind. The unusually wide extent and spherical shape of the M82 dust cocoon suggest that the dust was driven out of the galaxy before the superwind commenced, and is thus more pervasive than previously thought; possible explanations include interactions with neighboring galaxies or alternative wind-related mechanisms. -- JB
Astrophys. J. 642, L127 (2006).
If you'd like to enjoy the spectrum of chaotic irregular galaxies, I'd look at:
http://www.galaxyzoo.org
Cheers,
Dan