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APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 5:06 am
by APOD Robot
The Arms of M106
Explanation: The spiral arms of bright galaxy M106 sprawl through this
remarkable multiframe portrait, composed of data from
ground- and space-based telescopes. Also known as NGC 4258,
M106 can be found toward the northern constellation
Canes Venatici. The
well-measured distance to M106 is 23.5 million light-years, making this cosmic scene about 80,000 light-years across. Typical in grand spiral galaxies, dark dust lanes, youthful blue star clusters, and pinkish star forming regions
trace spiral arms that converge on the bright nucleus of older yellowish stars. But this detailed composite reveals hints of
two anomalous arms that don't align with the more familiar tracers. Seen here in red hues, sweeping filaments of glowing hydrogen gas seem to rise from the central region of M106,
evidence of energetic jets of material blasting into the galaxy's disk. The jets are likely powered by matter falling into a
massive central black hole.
[/b]
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 5:32 am
by Ann
Oh goodie! Robert Gendler's processing of the Hubble data of galaxy M106 is today's APOD (and this month's Hubble Heritage image)!
I know from private conversation that Rob spent months working on this image. It looks so nice and easy. It takes such incredibly hard work to accomplish it.
Wonderful image, Robert (and R. Jay GaBany, too)!
Ann
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 9:23 am
by bystander
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 12:29 pm
by neufer
The APOD:
M106 leads nowhere.
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 1:08 pm
by ritwik
neufer wrote:The APOD:
M106 leads nowhere.
i hope ..this would suffice
![Image](https://lh3.googleusercontent.com/-qjScveM_qxU/URJT7RUb3GI/AAAAAAAAA_w/mkNoud0MCRA/s328/d.gif)
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 1:26 pm
by neufer
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.>>
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 1:28 pm
by owlice
neufer, thanks! I've let TPTB know. The correct link is
http://messier.seds.org/m/m106.html
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 2:34 pm
by Boomer12k
Wow, Great photo. Look at the WALL of star formation on the other side!!! On the close side it is spotty, but that other side must be awesome from close up...um...OK, maybe from the other side....
:---[===] *
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 3:43 pm
by Speaker2Software
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?
That said, the more I read from the links, particularly the ArXive link, the more I'm inclined to see a bizarre effect properly explained. Still... this one wonders.
~Speaker
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 3:52 pm
by neufer
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?
The spin axis of the central black hole is (mostly) unrelated to the rotational axis of the M106 galaxy.
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 4:08 pm
by MargaritaMc
Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici.
http://hawastsoc.org/deepsky/cvn/index.html
has an interactive, wide area map of Canes Venatici and say this,
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.
I rather liked that bit of non-astronomical info.
Margarita
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 7:25 pm
by Anthony Barreiro
This image is the subject of a story on the Sky and Telescope website, posted today.
http://www.skyandtelescope.com/news/Hub ... 64931.html
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Wed Feb 06, 2013 9:21 pm
by MargaritaMc
That was a useful link, Anthony. Not simply for the article but also because there was information about a free app called SKYWEEK that provides both the Sky this Week feature
and a sky map specific to one's location - using the GPS function on the mobile phone or, in my case, tablet PC running Android. It's available both for IPad and Android platforms.
Margarita
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Thu Feb 07, 2013 4:29 am
by bystander
Galaxy Zapped by Its Own Black Hole
Slate Blogs | Bad Astronomy | 2013 Feb 06
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Thu Feb 07, 2013 5:20 am
by Beyond
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.
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Thu Feb 07, 2013 1:34 pm
by neufer
Beyond wrote:
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".>>
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Thu Feb 07, 2013 4:43 pm
by Beyond
neufer wrote:"Embiggen" is a perfectly cromulent word, you know:
Nothing is perfect... even nothing.
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Thu Feb 07, 2013 7:00 pm
by minkfarms
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 deceiveing especially for laymen like me.
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Thu Feb 07, 2013 9:31 pm
by neufer
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.
Two galaxies that:
- 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
Most bizarre
![Exclamation :!:](./images/smilies/icon_exclaim.gif)
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Thu Feb 07, 2013 11:59 pm
by Ron-Astro Pharmacist
Gorgeous picture. I don't know why but every time I see a beautify spiral galaxy like this I imagine it to be the top (or bottom) of an apple-like structure; only I can't see the rest of the apple. Even though I know there is no downward (or upward) curvature, I still picture it in my mind. I've read the universe is structurally flat but it makes me wonder how?
Space-time and the effects of gravity seem more non-Euclidian. It's sort of like looking at time corner of a room. The three right angles add up to 270 degrees but we see it as 360 degrees and essentially flat. Have we only learned by experience that it has 3 dimensions? I can't help but to wonder if we, for some reason, don't have the functional ability to view some aspects of a wonderful picture like this. But thanks for publishing pictures of spiral galaxies.
They keep my imagination young and functioning.
Ron
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Fri Feb 08, 2013 12:49 am
by Ann
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?
I have never read anywhere that M106 is in the process of an actual collision. In that respect M106 is different from NGC 5128, also known as
Cen A, and NGC 1275, also known as
Perseus A, where we can clearly see the collision in progress.
M106 and NGC 4248.
Photo: R. Jay GaBany.
M106 does have a companion galaxy which may well have helped cause the violence going on in the center of the large galaxy. According to my software, NGC 4248 has almost the same redshift as M106, which, coupled with the fact that these two galaxies are close together in the sky, means that they are almost certainly gravitationally bound to one another.
Interactions with companion galaxy NGC 4248 may well send a large helping of gas into the black hole of M106. This is probably exactly what has happened.
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.
Ann
Re: APOD: The Arms of M106 (2013 Feb 06)
Posted: Fri Feb 08, 2013 4:45 am
by neufer
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 10
3 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 (H
2O), formaldehyde (H
2CO), 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 10
8 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 10
11 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.>>