NGC 2617 is a Seyfert galaxy in the equatorial constellation of Hydra. It was discovered on February 12, 1885, by French astronomer Édouard Stephan.[7][8] In 1888, Danish astronomer J. L. E. Dreyer described it as "extremely faint, very small, 2 very faint stars involved".[9] It is located at an estimated distance of 202 million light years.[2] In the infrared, the galaxy has an angular size of 0.693 by 0.652 arcminutes.[5]

NGC 2617
legacy surveys image of NGC 2617 (right) and MCG-01-22-027
Observation data (J2000 epoch)
ConstellationHydra
Right ascension08h 35m 38.798s[1]
Declination−04° 05′ 17.90″[1]
Heliocentric radial velocity4,287 km/s[2]
Distance201.8 Mly (61.86 Mpc)h−1
0.73
[2]
Apparent magnitude (V)12.66±0.20[3]
Apparent magnitude (B)14.10±0.30[3]
Characteristics
TypeSc[4][3]
Apparent size (V)0.693 × 0.652[5] (infrared)
Other designations
IRAS F08331-0354, 2MASX J08353877-0405172, NGC 2617, MCG −01–22–026[6]

This is an almost face-on spiral galaxy with a morphological classification of Sc,[4] indicating a spiral galaxy (S) with loosely wound spiral arms (c). In 1992, NGC 2617 was shown to be an extragalactic source of X-ray emission,[10] and in 1996 it was identified as a Seyfert 1.8 galaxy by E. C. Moran and associates.[11] A radio counterpart was found in 1998.[12]

During April 2013, a dramatic outburst was discovered at the core of NGC 2617,[13] and the spectral type was found to have changed to a Seyfert 1. An increase in X-ray emission was observed, followed by an increase in ultraviolet and then infrared luminosity.[4] This event can be modeled by X-ray radiation heating the accretion disk orbiting a supermassive black hole (SMBH) at the center of the galaxy. This was followed by emission at longer wavelengths from the heated disk.[4] An increase in luminosity between 2010 and 2012 may have cleared away dust in the inner part of the disk prior to the outburst, allowing a clearer view and changing the Seyfert type of the galaxy.[14] The SMBH has an estimated mass of 30.9+11.8
−8.5
 million M
.[3]

Additional outbursts were observed from 2016 to 2018, in between deep minima.[15]

References edit

  1. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b c Crook, Aidan C.; et al. (February 2007), "Groups of Galaxies in the Two Micron All Sky Redshift Survey", The Astrophysical Journal, 655 (2): 790–813, arXiv:astro-ph/0610732, Bibcode:2007ApJ...655..790C, doi:10.1086/510201, S2CID 11672751.
  3. ^ a b c d Robinson, Justin H.; et al. (May 2021), "Tully-Fisher Distances and Dynamical Mass Constraints for 24 Host Galaxies of Reverberation-mapped AGNs", The Astrophysical Journal, 912 (2): 160, arXiv:2103.07000, Bibcode:2021ApJ...912..160R, doi:10.3847/1538-4357/abedaa, S2CID 232223280, 160.
  4. ^ a b c d Shappee, B. J.; et al. (June 2014), "The Man behind the Curtain: X-Rays Drive the UV through NIR Variability in the 2013 Active Galactic Nucleus Outburst in NGC 2617", The Astrophysical Journal, 788 (1): 48, arXiv:1310.2241, Bibcode:2014ApJ...788...48S, doi:10.1088/0004-637X/788/1/48, S2CID 119113433.{{citation}}: CS1 maint: multiple names: authors list (link)
  5. ^ a b Skrutskie, Michael F.; et al. (February 1, 2006), "The Two Micron All Sky Survey (2MASS)", The Astronomical Journal, 131 (2): 1163–1183, Bibcode:2006AJ....131.1163S, doi:10.1086/498708, ISSN 0004-6256, S2CID 18913331.
  6. ^ "NGC 2617", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2023-02-24.
  7. ^ Erdmann, Robert E. Jr. (December 2006), "NGC Discoverer's List", The NGC/IC Project, retrieved 2023-02-26.
  8. ^ Seligman, Courtney (Aug 25, 2021), "NGC Objects: NGC 2600 - 2649", Celestial Atlas, retrieved 2023-02-26.
  9. ^ Sulentic, Jack W.; et al. (1973), The Revised New Catalogue of Nonstellar Astronomical Objects, Tucson: University of Arizona Press, Bibcode:1973rncn.book.....S.
  10. ^ Boller, Th.; et al. (July 1992), "ROSAT all sky survey observations of IRAS galaxies.", Astronomy and Astrophysics, 261: 57–77, Bibcode:1992A&A...261...57B.
  11. ^ Moran, Edward C.; et al. (October 1996), "Classification of IRAS-selected X-Ray Galaxies in the ROSAT All-Sky Survey", Astrophysical Journal Supplement, 106: 341, Bibcode:1996ApJS..106..341M, doi:10.1086/192341.
  12. ^ Condon, J. J.; et al. (May 1998), "The NRAO VLA Sky Survey", The Astronomical Journal, 115 (5): 1693–1716, Bibcode:1998AJ....115.1693C, doi:10.1086/300337, S2CID 120464396.
  13. ^ Shappee, B. J.; et al. (April 2013), "ASAS-SN Discovery of a Strong AGN Outburst and Dramatic Seyfert Type Change in NGC 2617", The Astronomer's Telegram, 5010: 1, Bibcode:2013ATel.5010....1S.
  14. ^ Oknyansky, V. L.; et al. (May 2017), "The curtain remains open: NGC 2617 continues in a high state", Monthly Notices of the Royal Astronomical Society, 467 (2): 1496–1504, arXiv:1701.05042, Bibcode:2017MNRAS.467.1496O, doi:10.1093/mnras/stx149.
  15. ^ Oknyansky, V.; et al. (June 2018), "NGC 2617 brightens again after long very low state", The Astronomer's Telegram, 11703: 1, Bibcode:2018ATel11703....1O.

Further reading edit