NGC 4945

Galaxie
NGC 4945
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ESO: Aufnahme des 2,2-m-Teleskops im La-Silla-Observatorium
AladinLite
SternbildZentaur
Position
Äquinoktium: J2000.0, Epoche: J2000.0
Rektaszension13h 05m 27,477s[1]
Deklination−49° 28′ 05,57″[1]
Erscheinungsbild
Morphologischer TypSB(s)cd: / sp / Sy2[1]
Helligkeit (visuell)8,6 mag[2]
Helligkeit (B-Band)9,3 mag[2]
Winkel­ausdehnung19,8′ × 4′[2]
Positionswinkel43°[2]
Flächen­helligkeit13,2 mag/arcmin²[2]
Physikalische Daten
ZugehörigkeitM83-Gruppe
NGC 5128-Gruppe
LGG 344[1]
Rotverschiebung0.001878 ± 0.000010[1]
Radial­geschwin­digkeit(563 ± 3) km/s[1]
Hubbledistanz
H0 = 73 km/(s • Mpc)		(17 ± 1) · 106 Lj
(5,28 ± 0,38) Mpc [1]
Durchmesser100.000 Lj[3]
Geschichte
EntdeckungJames Dunlop
Entdeckungsdatum29. April 1826
Katalogbezeichnungen
NGC 4945 • PGC 45279 • ESO 219-024 • IRAS 13025-4911 • 2MASX J13052727-4928044 • SGC 130231-4912.2 • GC 3386 • h 3459 • HIPASS J1305-49 • LDCE 993 NED001 • WISEA J130527.45-492804.9

NGC 4945 ist eine Balken-Spiralgalaxie vom Hubble-Typ SBc im Sternbild Zentaur am Südsternhimmel. Sie ist schätzungsweise 17 Millionen Lichtjahre von der Milchstraße entfernt und hat einen Durchmesser von etwa 140.000 Lichtjahren. Die Galaxie gehört zu den so genannten Seyfertgalaxien, ein spezieller Typ von aktiven Galaxien, deren Zentrum weit mehr Energie aussenden als ruhigere Galaxien wie unsere Milchstraße.[4] Eine Besonderheit ist ihre sehr starke H2O-Maser-Emission.[5]

Gemeinsam mit sieben weiteren Galaxien bildet sie die NGC 5128-Gruppe (LGG 344).
Im selben Himmelsareal befindet sich unter anderem die Galaxie NGC 4976.

Am 8. Februar 2005 entdeckte man hier die Typ-IIP-Supernova SN2005af.[6]

Das Objekt wurde am 29. April 1826 vom schottischen Astronomen James Dunlop entdeckt.[7]

Siehe auch

  • PGC 45380 (auch NGC 4945A)

Literatur

  • König, Michael & Binnewies, Stefan (2019): Bildatlas der Galaxien: Die Astrophysik hinter den Astrofotografien, Stuttgart: Kosmos, S. 84
Commons: NGC 4945 – Sammlung von Bildern, Videos und Audiodateien

Einzelnachweise

  1. ↑ a b c d e NASA/IPAC EXTRAGALACTIC DATABASE
  2. ↑ a b c d e SEDS: NGC 4945
  3. ↑ NASA/IPAC
  4. ↑ http://www.eso.org/public/germany/news/eso0931/
  5. ↑ P. M. Dos Santos, J. R. D. Lepine: Detection of strong H2O emission from galaxy NGC494. In: Nature. 1979, bibcode:1979Natur.278...34D.
  6. ↑ Simbad
  7. ↑ Seligman


Auf dieser Seite verwendete Medien

Phot-18b-99-hires.jpg
Autor/Urheber: ESO, Lizenz: CC BY 4.0
This image is an enlargement at full resolution of a smaller region (about 1/7 by area) of a sky field around the spiral galaxy NGC 4945 . It is assembled from five 15-minute R(ed)-narrowband (shown in red), four 5-minute B(lue)-band (shown in green), and five 1000-second U(ltraviolet)-band (shown in blue) exposures, obtained in January 1999 during the Science Verification phase with the Wide-Field-Imager (WFI) at the MPG/ESO 2.2-m telescope at La Silla. At the recession velocity of NGC 4945 , the red filter, centred at 665 nm with an FWHM (full width at half maximum) of only 1.2 nm, does not include the H-alpha emission line of interstellar hydrogen in this galaxy. The original resolution of about 1 arcsec corresponds to roughly 62 light-years at the distance of NGC 4945 (13 million light-years). In addition to NGC 4945 itself, some much more distant galaxies can be recognized as faint, slightly red light patches in the field. The vast majority of the point-like sources are stars in the Milky Way. However, a fair number of those near NGC 4945 are globular clusters belonging to this galaxy. Each frame records 8184 x 8196 = 67,076,064 pixels, and thus the total number of data points (pixels) of the 14 CCD frames used to make this photo is almost 10 9. Their collective information content corresponds to more than 70 x 10 9 photons (not counting those from the Earth's upper atmosphere that were recorded simultaneously). It covers 2997 x 2998 pixels and measures about 12 x 12 arcmin 2 in the sky. Note the many background galaxies in the field.

ID: phot-18b-99

Press Photo: 18/99

Object: NGC 4945

Telescope: 2.2m

Instrument: WFI

Size: 2999x2984

Credit: ESO
NGC 4945 hst 07278 R814B547 hst 05446 606.png
Autor/Urheber: Own work, Lizenz: CC BY-SA 3.0
Color rendering is done by by Aladin-software (2000A&AS..143...33B.)
Phot-18a-99-hires.jpg
Autor/Urheber: ESO, Lizenz: CC BY 4.0
This photograph shows a sky field around the spiral galaxy NGC 4945 . It is assembled from five 15-minute R(ed)-narrowband (shown in red), four 5-minute B(lue)-band (shown in green), and five 1000-second U(ltraviolet)-band (shown in blue) exposures, obtained in January 1999 during the Science Verification phase with the Wide-Field-Imager (WFI) at the MPG/ESO 2.2-m telescope at La Silla. At the recession velocity of NGC 4945 , the red filter, centred at 665 nm with an FWHM (full width at half maximum) of only 1.2 nm, does not include the H-alpha emission line of interstellar hydrogen in this galaxy. The original resolution of about 1 arcsec corresponds to roughly 62 light-years at the distance of NGC 4945 (13 million light-years). In addition to NGC 4945 itself, some much more distant galaxies can be recognized as faint, slightly red light patches in the field. The vast majority of the point-like sources are stars in the Milky Way. However, a fair number of those near NGC 4945 are globular clusters belonging to this galaxy. Each frame records 8184 x 8196 = 67,076,064 pixels, and thus the total number of data points (pixels) of the 14 CCD frames used to make this photo is almost 10 9. Their collective information content corresponds to more than 70 x 10 9 photons (not counting those from the Earth's upper atmosphere that were recorded simultaneously). The field covers 32 x 32 arcmin 2. East is to the left and North to the top.

ID: phot-18a-99

Press Photo: 18/99

Object: NGC 4945

Telescope: 2.2m

Instrument: WFI

Size: 2009x1979

Credit: ESO
Caldwell Catalogue.jpg
Autor/Urheber: Roberto Mura, Lizenz: CC BY-SA 3.0
Caldwell Catalogue objects.
Phot-27e-07.jpg
Autor/Urheber: ESO: observations by Susana Randall, Claudio Melo, Swetlana Hubrig; day astronomer Dominique Naef; Henri Boffin (ESO) processed the data and made the colour-composite, and Haennes Heyer (ESO) made the final adjustments., Lizenz: CC BY 4.0
K-band image obtained with NACO and the LGS of the active galaxy NGC 4945. The colour-code corresponds to intensity. Lurking in the very heart of this spiral galaxy is a supermassive black hole that is obscured at optical and infrared wavelengths, but which is one of the brightest in the local universe when observed in hard X-rays. The new LGS observations with NACO resolved the continuum in the central thousand light-years into a multitude of individual stars. The exquisite detail meant that it was possible to measure the magnitudes of the brightest of these stars. It suggests that they are red supergiant stars, which would have been born about 10 million years ago. Closer to the nucleus, the stars group into clusters, and become ever more closely packed. The huge luminosity of the central few clusters suggests that there are 10 to 100 such supergiant stars in each of these, packed into regions just a few parsecs across.

ID: phot-27e-07

Press Release: ESO 27/07 [toter Link]

Long Caption: http://www.eso.org/public/outreach/press-rel/pr-2007/phot-27-07.html [toter Link]

Object: NGC 4945

Telescope: UT4/Yepun

Instrument: SINFONI, NACO

Size: 2358x2349

Credit: ESO