NGC 4138

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Galaxy
NGC 4138
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NGC 4138 [1] SDSS image
NGC 4138 SDSS image
AladinLite
Constellation Hunting dogs
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 12 h 09 m 29.780 s
declination + 43 ° 41 ′ 07.10 ″
Appearance
Morphological type SA (r) 0+ / Sy1.9  
Brightness  (visual) 11.3 mag
Brightness  (B-band) 12.2 mag
Angular expansion 2.6 ′ × 1.7 ′
Position angle 150 °
Surface brightness 12.8 mag / arcmin²
Physical data
Affiliation Ursa Major Galaxy
Clusters NGC 4051 Group
LGG 269  
Redshift 0.002962 ± 0.000007  
Radial velocity 888 ± 2 km / s  
Stroke distance
v rad  / H 0 		(42 ± 3)  x  10 6  ly
(12.8 ± 0.9)  Mpc 
history
discovery Wilhelm Herschel
Discovery date January 14, 1788
Catalog names
NGC  4138 • UGC  7139 • PGC  38643 • CGCG  215-037 • MCG  + 07-25-035 • 2MASX  J12092978 + 4341071 • GC  2745 • H  I 196 • LDCE 0867 NED080 • NVSS J120930 + 434104 • WISEA J120929.80 + 434107.1

NGC 4138 is a spiral galaxy of Hubble type Sa in the constellation Canes Venatici on the northern sky . It is about 42 million light years away and about 30,000 light years in diameter. It is part of the Ursa Major Galaxy Cluster and a member of the NGC 4051 group ( LGG 269 ), but has no close companions.

The center of NGC4138, high resolution image from the Hubble Space Telescope

NGC 4138 does not have a bar structure , but tightly spaced spiral arms and a ring structure around the center. More detailed research in 1996 shows that the main disk of the galaxy contains about 80% of the stars and that star formation stopped there 100 million years ago. The remaining 20% ​​of the stars, which also tend to be younger, rotate in opposite directions together with the non-ionized hydrogen and form an overlapping second disk. This second disk may have formed as a result of a collision with a gas-rich dwarf galaxy four billion years ago and subsequent absorption from it. Simulations show that the counter-rotating disk suppresses the creation of spiral arms. The young ring structure, which shows pronounced star formation , probably results from collisions of gas clouds rotating in opposite directions.

NGC 4138 is a Seyfert type 1.9 galaxy with radio emissions to the east and west of the active galaxy core. This radiation is likely to come from jets of matter emitted from the central supermassive black hole .

The object was discovered on January 14, 1788 by Wilhelm Herschel using his 18.7-inch mirror telescope.

Web links

Commons : NGC 4138  - collection of images, videos, and audio files

Individual evidence

  1. ^ Aladin Lite
  2. ↑ a b c d e NASA / IPAC EXTRAGALACTIC DATABASE
  3. ↑ a b c d e f SEDS : NGC 4138
  4. ^ VizieR
  5. ↑ R. Brent Tully , Hélène M. Courtois, Andrew E. Dolphin, J. Richard Fisher , Philippe Héraudeau, Bradley A. Jacobs, Igor D. Karachentsev, Dmitry Makarov, Lidia Makarova, Sofia Mitronova, Luca Rizzi, Edward J. Shaya , Jenny G. Sorce, Po-Feng Wu: Cosmicflows-2: The Data . In: The Astronomical Journal . 146, No. 4, October 2013, p. 25. arxiv : 1307.7213 . 86. bibcode : 2013AJ .... 146 ... 86T . doi : 10.1088 / 0004-6256 / 146/4/86 .
  6. ↑ a b Katherine P. Jore, Adrick H. Broeils, Martha P. Haynes : A Counter-Rotating Disk in the Normal SA Galaxy NGC 4138 . In: The Astronomical Journal . 112, August 1996, p. 438. bibcode : 1996AJ .... 112..438J . doi : 10.1086 / 118027 .
  7. ↑ Gérard-Henri de Vaucouleurs , A. de Vaucouleurs, HG, Jr. Corwin, RJ Buta, G. Paturel, P. Fouque: Third reference catalog of bright galaxies, version 9 . Springer-Verlag, New York 1991, bibcode : 1994AJ .... 108.2128C (accessed November 25, 2015).
  8. ^ A. Pizzella, L. Morelli, EM Corsini, E. Dalla Bontà, L. Coccato, G. Sanjana: The difference in age of the two counter-rotating stellar disks of the spiral galaxy NGC 4138 . In: Astronomy & Astrophysics . 570, October 2014, p. 5. arxiv : 1409.3086 . A79. bibcode : 2014A & A ... 570A..79P . doi : 10.1051 / 0004-6361 / 201424746 .
  9. ↑ P. Bontempi, M. Giroletti, F. Panessa, M. Orienti, A. Doi: Physical properties of the nuclear region in Seyfert galaxies derived from observations with the European VLBI Network . In: Monthly Notices of the Royal Astronomical Society . 426, No. 1, October 2012, pp. 588-594. arxiv : 1208.0230 . bibcode : 2012MNRAS.426..588B . doi : 10.1111 / j.1365-2966.2012.21786.x .
  10. ↑ Seligman