Messier 106
| Messier 106 | |
 M106 och dess avvikande armar. Komposit av IR (rött) och optiskt ljus (Foto: NASA, ESA, Hubble Heritage Team (STScI/AURA) och R. Gendler (för Hubble Heritage Team)) | |
| Observationsdata | |
|---|---|
| Stjärnbild | Jakthundarna |
| Rektascension | 12t 18m 57,5 s[1] |
| Deklination | +47° 18′ 14 ″[1] |
| Rödförskjutning | 448 ± 3[1] km/s km/s |
| Avstånd | 23,7 ± 1,5 (7 ± 0,5 Mpc)[2][3]miljoner ljusår |
| Typ | SAB(s)bc[1] |
| Skenbar storlek | 18,6 × 7,2[1] bågminuter |
| Skenbar magnitud | 8,4[1] |
| Noterbart | Megamasergalax,[4] Seyfert II-galax.[5] |
| Upptäckt | |
| Upptäcktsår | juli 1781 |
| Upptäckare | Pierre Méchain |
| Andra beteckningar | |
| M106, NGC 4258, UGC 7353, PGC 39600, CGCG 244-3, CGCG 243-67, MCG +08-22-104, 2MASX J12185761+4718133, VV 44, GC 2841, H V-43, h 1175 [1][6] | |
| Se även: Galaxer, Lista över galaxer | |
Messier 106 (M106) även känd som NGC 4258, är en spiralgalax i den södra delen av stjärnbilden Jakthundarna. Den upptäcktes av Pierre Méchain i juli 1781.
Messier 106 ligger 22-25 miljoner ljusår från jorden. Galaxen är av Seyfert II-typ, vilket innebär en kvasar-liknande galax, och där man med anledning av galaxens ovanliga spektrallinjer misstänker att delar av galaxen är på väg att falla in i det supermassiva svarta hål som finns i galaxens kärna. Detta har visats genom radiovåglängdsobservationer av rotationen av en skiva av molekylär gas som kretsar inom det inre ljusåret kring det svarta hålet. NGC 4217 är en möjlig satellitgalax till Messier 106.[6] En supernova av typ II observerades i M106 i maj 2014.[7]
Egenskaper
Messier 106 har en megamaser av vattenånga (motsvarande en laser som arbetar i mikrovåglängd istället för synligt ljus och i en galaktisk skala) som ses av 22-GHz-linjen av ortho-H2O vilket verifierar närvaro av tät och varm molekylär gas. Dessa vattenångor ger M106 dess karakteristiska lila färg.[8] Vattenmasrar är användbara för att observera kärnaccretionsskivor i aktivgalaxer. Vattenmasrar i M106 möjliggjorde det första fallet av en direkt mätning av avståndet till en galax, vilket gav en oberoende referens för den kosmiska avståndsstegen.[9][10] M106 har en något skev, tunn Keplerskiva sedd nästan från kanten i en subparsekskala. Den omger ett centralt område med massa 4 × 107 solmassor.[11]
Messier 106 är en av de största och ljusstarkaste närliggande galaxerna, liknande i storlek och ljusstyrka som Andromedagalaxen.[12] Det supermassiva svarta hålet i kärnan har en massa på (3,9 ± 0,1)×107 solmassor.[13] Den har också spelat en viktig roll vid kalibreringen av den kosmiska avståndsstegen. Tidigare kunde Cepheidvariabler från andra galaxer inte användas för att mäta avstånd eftersom de täcker metalliciteter som skiljer sig från Vintergatans. Messier 106 innehåller Cepheidvariabler som liknar både Vintergatans metalliciteter och andra galaxcepheiders. Genom att mäta avstånd till cepheider med metalliciteter som liknar vår galax kan astronomer omkalibrera de andra cepheiderna med olika metalliciteter, ett viktigt grundläggande steg för att förbättra kvantifieringen av avstånd till andra galaxer i universum.[3]
Galleri
|
Referenser
- Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, Messier 106, 17 juni 2021.
Noter
- ^ [a b c d e f g] ”NASA/IPAC Extragalactic Database”. Results for Messier 106. http://nedwww.ipac.caltech.edu/.
- ^ Tonry, J. L.; Dressler, A.; Blakeslee, J. P.; Ajhar, E. A.; Fletcher, A. B.; Luppino, G. A.; Metzger, M. R.; Moore, C. B. (2001). ”The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances”. Astrophysical Journal 546 (2): sid. 681–693. doi:. Bibcode: 2001ApJ...546..681T.
- ^ [a b] Macri, L. M.; Stanek, K. Z.; Bersier, D.; Greenhill, L. J.; Reid, M. J. (2006). ”A New Cepheid Distance to the Maser-Host Galaxy NGC 4258 and Its Implications for the Hubble Constant”. Astrophysical Journal 652 (2): sid. 1133–1149. doi:. Bibcode: 2006ApJ...652.1133M.
- ^ Bonanos, Alceste Z. (2006). ”Eclipsing Binaries: Tools for Calibrating the Extragalactic Distance Scale”. Proceedings of the International Astronomical Union 2 (S240): sid. 79–87. doi:. Bibcode: 2007IAUS..240...79B.
- ^ Humphreys, E. M. L.; Greenhill, L. J.; Reid, M. J.; Argon, A. L.; Moran, J. M. (2004). ”Improved Maser Distance to NGC 4258”. Bulletin of the American Astronomical Society 36: sid. 1468. Bibcode: 2004AAS...205.7301H.
- ^ [a b] http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Messier+106. Hämtad 2021-06-17.
- ^ ”KAIT Prediscovery Detection of PS1-14xz in NGC 4258 (Messier 106)”. The Astronomer's Telegram. http://www.astronomerstelegram.org/?read=6159.
- ^ Color analysis of M106: http://www.bt-images.net/incredible-universe/
- ^ JR Herrnstein (1999). ”A geometric distance to the galaxy NGC 4258 from orbital motions in a nuclear gas disk”. Nature 400 (6744): sid. 539–541. doi:. Bibcode: 1999Natur.400..539H.
- ^ Richard de Grijs (2011). An Introduction to Distance Measurement in Astronomy. Chichester: John Wiley & Sons. sid. 109. ISBN 978-0-470-51180-0
- ^ Henkel, C.; Peck, A. B.; Tarchi, A.; Nagar, N. M.; Braatz, J. A.; Castangia, P.; Moscadelli, L. (2005). ”New H2O masers in Seyfert and FIR bright galaxies”. Astronomy and Astrophysics 436 (1): sid. 75–90. doi:. Bibcode: 2005A&A...436...75H.
- ^ Karachentsev, Igor D.; Karachentseva, Valentina E.; Huchtmeier, Walter K.; Makarov, Dmitry I. (2003). ”A Catalog of Neighboring Galaxies”. The Astronomical Journal 127 (4): sid. 2031–2068. doi:. Bibcode: 2004AJ....127.2031K.
- ^ Graham, Alister W. (November 2008), ”Populating the Galaxy Velocity Dispersion - Supermassive Black Hole Mass Diagram: A Catalogue of (Mbh, σ) Values”, Publications of the Astronomical Society of Australia 25 (4): 167–175, doi:, Bibcode: 2008PASA...25..167G.
Externa länkar
Wikimedia Commons har media som rör Messier 106.- Amateur-Foto: [1]
- StarDate: M106 Fact Sheet
- Spiral Galaxy M106 at SEDS Messier pages
- NGC 4258: Mysterious Arms Revealed
- Spiral Galaxy Messier 106 (NGC 4258) at the astro-photography site of Takayuki Yoshida
- Messier 106 at Constellation Guide
| ||||||||
Media som används på denna webbplats
![[1]](http://www.spektrum.de/fm/1027/M106_3259x2359.jpg){kind=link}
Författare/Upphovsman:
KPNO/NOIRLab/NSF/AURA Acknowledgment: PI: M.T. Patterson (New Mexico State University)
Image processing: T.A. Rector (University of Alaska Anchorage), M. Zamani & D. de Martin, Licens: CC BY 4.0This image of the spiral galaxy Messier 106, or NGC 4258, was taken with the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. A popular target for amateur astronomers, Messier 106 can also be spotted with a small telescope in the constellation Canes Venatici. This view captures the entire galaxy, detailing the glowing spiral arms, wisps of gas, and dust lanes at the center of Messier 106 as well as the leisurely twisting bands of stars at the galaxy’s outer edges. Two dwarf galaxies also appear in the image: NGC 4248 in the lower right and UGC 7358 in the lower left.
Författare/Upphovsman: Hewholooks, Licens: CC BY-SA 3.0
M106 and NGC 4217 in Canes Venatici Using 130mm APO and ST-4000XCM
A spiral galaxy with a secret
The NASA/ESA Hubble Space Telescope – with a little help from an amateur astronomer – has produced one of the best views yet of nearby spiral galaxy Messier 106. Located a little over 20 million light-years away, practically a neighbour by cosmic standards, Messier 106 is one of the brightest and nearest spiral galaxies to our own.
Despite its appearance, which looks much like countless other galaxies, Messier 106 hides a number of secrets. Thanks to this image, which combines data from Hubble with observations by amateur astronomers Robert Gendler and Jay GaBany, they are revealed as never before.
At its heart, as in most spiral galaxies, is a supermassive black hole, but this one is particularly active. Unlike the black hole at the centre of the Milky Way, which pulls in wisps of gas only occasionally, Messier 106’s black hole is actively gobbling up material. As the gas spirals towards the black hole, it heats up and emits powerful radiation. Part of the emission from the centre of Messier 106 is produced by a process that is somewhat similar to that in a laser - although here the process produces bright microwave radiation.[1]
As well as this microwave emission from Messier 106’s heart, the galaxy has another startling feature - instead of two spiral arms, it appears to have four. Although the second pair of arms can be seen in visible light images as ghostly wisps of gas, as in this image, they are even more prominent in observations made outside of the visible spectrum, such as those using X-ray or radio waves.
Unlike the normal arms, these two extra arms are made up of hot gas rather than stars, and their origin remained unexplained until recently. Astronomers think that these, like the microwave emission from the galactic centre, are caused by the black hole at Messier 106’s heart, and so are a totally different phenomenon from the galaxy’s normal, star-filled arms.
The extra arms appear to be an indirect result of jets of material produced by the violent churning of matter around the black hole. As these jets travel through the galactic matter they disrupt and heat up the surrounding gas, which in turn excites the denser gas in the galactic plane and causes it to glow brightly. This denser gas closer to the centre of the galaxy is tightly-bound, and so the arms appear to be straight. However, the looser disc gas further out is blown above or below the disc in the opposite direction from the jet, so that the gas curves out of the disc — producing the arching red arms seen here.
Despite carrying his name, Messier 106 was neither discovered nor catalogued by the renowned 18th century astronomer Charles Messier. Discovered by his assistant, Pierre Méchain, the galaxy was never added to the catalogue in his lifetime. Along with six other objects discovered but not logged by the pair, Messier 106 was posthumously added to the Messier catalogue in the 20th century.
Amateur astronomer Robert Gendler retrieved archival Hubble images of M 106 to assemble a mosaic of the centre of the galaxy. He then used his own and fellow astrophotographer Jay GaBany’s observations of M 106 to combine with the Hubble data in areas where there was less coverage, and finally, to fill in the holes and gaps where no Hubble data existed.
The centre of the galaxy is composed almost entirely of Hubble data taken by the Advanced Camera for Surveys, Wide Field Camera 3, and Wide Field and Planetary Camera 2 detectors. The outer spiral arms are predominantly HST data colourised with ground-based data taken by Gendler’s and GaBany’s 12.5-inch and 20-inch telescopes, located at very dark remote sites in New Mexico, USA.
Gendler was a prizewinner in the recent Hubble’s Hidden Treasures image processing competition. Another prizewinner, André van der Hoeven, entered a different version of Messier 106, combining Hubble and NOAO data.
About the Object:
Name: M 106 Type: • Local Universe : Galaxy : Type : Spiral • Galaxies Images/Videos Distance: 20 million light years
Colours & filters:
Band Wavelength Telescope Infrared I 814 nm Hubble Space Telescope ACS Infrared I 814 nm Hubble Space Telescope WFC3 Optical H-alpha 656 nm Hubble Space Telescope WFPC2 Optical V 555 nm Hubble Space Telescope ACS Optical V 606 nm Hubble Space Telescope ACS Optical V 555 nm Hubble Space Telescope WFC3 Optical B 435 nm Hubble Space Telescope ACS
- Footnotes
- ↑ Lasers work when light stimulates emission of more light from a cloud of excited gas, with the original light in effect being amplified (the word laser is an acronym for light amplification by the stimulated emission of radiation). The centre of M106 harbours a similar phenomenon called a maser (short for microwave amplification by the stimulated emission of radiation), in which microwave radiation, which is at longer wavelengths than visible light, is emitted. Note that unlike man-made lasers, which are designed to produce a narrow beam, astronomical masers shine in all directions.
Messier 106 (NGC 4258) galaxy. Composite of IR, x-ray, radio and visible light view (X-ray - blue, Optical - gold, IR - red, Radio - purple)
Band Wavelength Telescope X-ray 1.5 keV Chandra ACIS Optical 440 nm DSS Infrared 8.0 µm Spitzer IRAC Radio 21.0 cm VLA.
Författare/Upphovsman: Avitanshimon, Licens: CC BY-SA 4.0
M106 taken from the Golan Heights