Starship Asterisk*

http://en.wikipedia.org/wiki/Megamaser wrote:
<<A megamaser is a type of astrophysical maser, which is a naturally occurring source of stimulated spectral line emission. Megamasers are distinguished from astrophysical masers by their large isotropic luminosity. Megamasers have typical luminosities of 10³ solar luminosities (L_☉), which is 100 million times brighter than masers in the Milky Way, hence the prefix mega. Most known extragalactic masers are megamasers, and the majority of megamasers are hydroxyl (OH) megamasers, meaning the spectral line being amplified is one due to a transition in the hydroxyl molecule. There are known megamasers for three other molecules: water (H₂O), formaldehyde (H₂CO), and methine (CH).

Hydroxyl megamasers were the first type of megamaser discovered. The first hydroxyl megamaser was found in 1982 in Arp 220, which is the nearest ultraluminous infrared galaxy to the Milky Way. All subsequent OH megamasers that have been discovered are also in luminous infrared galaxies. Most luminous infrared galaxies have recently merged or interacted with another galaxy, and are undergoing a burst of star formation. The population inversion in hydroxyl molecules is produced by far infrared radiation that results from absorption and re-emission of light from forming stars by surrounding interstellar dust. Zeeman splitting of hydroxyl megamaser lines may be used to measure magnetic fields in the masing regions, and this application represents the first detection of Zeeman splitting in a galaxy other than the Milky Way.

Water megamasers are found primarily associated with active galactic nuclei. Water maser emission is observed primarily at 22 GHz, due to a transition between rotational energy levels in the water molecule. The upper state is at an energy corresponding to 643 Kelvin about the ground state, and populating this upper maser level requires number densities of molecular hydrogen of order 10⁸ cm−³ or greater and temperatures of at least 300 Kelvin. The water molecule comes in to thermal equilibrium at molecular hydrogen number densities of roughly 10¹¹ cm−³, so this places an upper limit on the number density in a water masing region. Water masers emission has been successfully modeling by masers occurring behind shock waves propagating through dense regions in the interstellar medium. These shocks produce the high number densities and temperatures (relative to typical conditions in the interstellar medium) required for maser emission, and are successful in explaining observed masers.

Water megamasers may be used to provide accurate distance determinations to distant galaxies. Assuming a Keplerian orbit, measuring the centripetal acceleration and velocity of water maser spots yields the physical diameter subtended by the maser spots. By then comparing the physical radius to the angular diameter measured on the sky, the distance to the maser may be determined. This method is effective with water megamasers because they occur in a small region around an AGN, and have narrow linewidths. This method of measuring distances is being used to provide an independent measure of the Hubble constant that does not rely upon use of standard candles. The method is limited, however, by the small number of water megamasers known at distances within the Hubble flow. This distance measurement also provides a measurement of the mass of the central object, which in this case is a super massive black hole. Black hole mass measurements using water megamasers is the most accurate method of mass determination for black holes in galaxies other than the Milky Way. The black hole masses that are measured are consistent with the M-sigma relation.>>

Speaker2Software wrote:
I get the thought that we're looking at the results of galaxies in collision. Has the idea been proposed? Is there a candidate galaxy in the area?

http://en.wikipedia.org/wiki/Messier_106 wrote:
M106 has a water vapor megamaser (the equivalent of a laser operating in microwave instead of light and on a galactic scale) that is seen by the 22-GHz line of ortho-H2O that evidences dense and warm molecular gas. Water masers are useful to observe nuclear accretion disks in active galaxies. The water masers in M106 enabled the first case of a direct measurement of the distance to a galaxy and thereby providing an independent anchor for the cosmic distance ladder.

minkfarms wrote:
I agree with Speaker2Software who said, "I get the thought that we're looking at the results of galaxies in collision." I'm surprised more didn't comment on that. Even so appearances can be deceiving especially for laymen like me.

• 1) coincidentally happen to share the same central location and
  2) are both quite symmetric about that central location but for which
  3) only one radiates strongly in radio & x-rays: http://apod.nasa.gov/apod/ap070411.html

neufer wrote:"Embiggen" is a perfectly cromulent word, you know:

Beyond wrote:

bystander wrote:Galaxy Zapped by Its Own Black Hole
Slate Blogs | Bad Astronomy | 2013 Feb 06

ha-ha, Bad Astronomy has strange english. I discovered that "Deathrayenate" and "embiggen" mean larger picture.
Don't quite know what to say about that.

• "Embiggen" is a perfectly cromulent word, you know:

http://en.wikipedia.org/wiki/Lisa_the_Iconoclast#Embiggen_and_cromulent wrote:
<<"Lisa the Iconoclast" (February 18, 1996) is the 16th episode of The Simpsons' 7th season. In the episode, Springfield's bicentennial approaches, and Lisa writes an essay on town founder Jebediah Springfield. While doing research, she finds a confession revealing that Springfield was a murderous pirate named Hans Sprungfeld (a.k.a., beyond) who never cared about the people of Springfield. Lisa and Homer decide to get the message out, but instead anger the town council.

The episode features two neologisms: embiggen and cromulent. The show runners asked the writers if they could come up with two words which sounded like real words, and these were what they came up with. The Springfield town motto is "A noble spirit embiggens the smallest man." Schoolteacher Edna Krabappel comments that she never heard the word embiggens until she moved to Springfield. Miss Hoover, another teacher, replies, "I don't know why; it’s a perfectly cromulent word." Later in the episode, while talking about Homer's audition for the role of town crier, Principal Skinner states, "He's embiggened that role with his cromulent performance."

Embiggen—in the context it is used in the episode—is a verb that was coined by Dan Greaney in 1996. The verb previously occurred in an 1884 edition of the British journal Notes and Queries: A Medium of Intercommunication for Literary Men, General Readers, Etc. by C. A. Ward, in the sentence "but the people magnified them, to make great or embiggen, if we may invent an English parallel as ugly. After all, use is nearly everything." The literal meaning of embiggen is to make something larger.

The word has made its way to common use. In particular, embiggen can be found in string theory. The first occurrence of the word was in the journal High Energy Physics in the article "Gauge/gravity duality and meta-stable dynamical supersymmetry breaking", which was published on January 23, 2007. For example, the article says: "For large P, the three-form fluxes are dilute, and the gradient of the Myers potential encouraging an anti-D3 to embiggen is very mild." Later this usage was noted in the journal Nature, which explained that in this context, it means to grow or expand.

Cromulent is an adjective that was coined by David S. Cohen. Since it was coined it has appeared in Dictionary.com's 21st Century Lexicon. The meaning of cromulent is inferred only from its usage, which indicates that it is a positive attribute. Dictionary.com defines it as meaning fine or acceptable. Ben Macintyre has written that it means "valid or acceptable".>>

bystander wrote:Galaxy Zapped by Its Own Black Hole
Slate Blogs | Bad Astronomy | 2013 Feb 06

Anthony Barreiro wrote:This image is the subject of a story on the Sky and Telescope website, posted today.

http://www.skyandtelescope.com/news/Hub ... 64931.html

Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici.

First depicted in Johann Hevelius' 1690 atlas the Firmamentum Sobieski, these are Boötes' hunting dogs, Astarion and Chara. Indeed, beta Canum Venaticorum is called Chara. The alpha star, however, received the name, Cor Caroli (the heart of Charles) from Edmond Halley (1656-1742). With the death of Oliver Cromwell (1599-1658), the English had decided they had had enough of "lord protectors of the commonwealth," and asked for their king back. Charles II returned to England in 1660. The royal physician reported that alpha, always slightly variable, shone especially bright on Charles' return. The new king carried on in the high diplomatic traditions of his father, Charles I (executed at the behest of Cromwell). He had Cromwell disinterred, hanged, and beheaded in 1661.

Speaker2Software wrote:
That M106 has a central black hole, I have little doubt. That the anomalous red clouds are products of the jets at the "north" and "south" poles of the singularity... I don't know. The angles don't seem to make sense. If I add in the massive arc of the outer spiral arm - one that seems disconnected from the rest of the spiral structure, I get the thought that we're looking at the results of galaxies in collision. Has the idea been proposed? Is there a candidate galaxy in the area?

http://en.wikipedia.org/wiki/Kali wrote:

<<Kālī is the Hindu goddess associated with empowerment, shakti. Kālī is the consort of Lord Shiva, on whose body she is often seen standing. Since Shiva is called Kāla—which means black, time, death, lord of death,—Kālī, his consort, also means "Time" or "Death" (as in time has come). Kāli's association with darkness stands in contrast to her consort, Shiva, who manifested after her in creation, and who symbolises the rest of creation after Time is created. Other names include Kālarātri ("black night") and Kālikā ("relating to time").

In her most famous pose as Daksinakali, popular legends say that Kali, becoming drunk on the blood of her victims on the battlefield, dances with destructive frenzy. In her fury she fails to see the body of Shiva, who lies among the corpses on the battlefield and steps on his chest. Realizing Shiva to lie beneath her feet, her anger is pacified and she calms her fury. Kali was ashamed at the prospect of keeping her husband beneath her feet and thus stuck her tongue out in shame. The drooping out-stuck tongue also represents her blood-thirst.

Lord Shiva beneath her feet represents matter as Kali is undoubtedly, the primeval energy. The depiction of Kali on Shiva shows that without energy, matter lies "dead".

Kālī is the Goddess of Time and Change. Although sometimes presented as dark and violent, her earliest incarnation as a figure of annihilator of evil forces still has some influence. She is also revered as Bhavatārini (literally "redeemer of the universe"). Comparatively recent devotional movements largely conceive Kāli as a benevolent mother goddess.>>

neufer wrote:The APOD: M106 leads nowhere.