TON S180 (abbreviation of Tonantzintla S180) is a Seyfert galaxy located in the southern constellation of Cetus. It is located 827 million light years from Earth.[1] The galaxy is classified as a quasi-stellar object (QSO) because of its high luminosity and is located 3.6 degrees northeast from NGC 253, and 2.8 degrees southeast from NGC 247.[2]

TON S180
TON S180, as seen on DESI Legacy Surveys
Observation data (J2000 epoch)
ConstellationCetus
Right ascension00h 57m 19.94s
Declination−22° 22′ 59.10″
Redshift0.061980
Heliocentric radial velocity18,581 km/s
Distance827 Mly (253.55 Mpc)
Apparent magnitude (V)14.34
Apparent magnitude (B)14.6
Characteristics
TypeSABa, Sy1.2
Apparent size (V)0.35' x 0.29'
Other designations
IRAS F00548-2238, PHL 912, EUVE J0057-22.3, LEDA 87796, RX J0057.3-2222, LEDA 815045

Discovery and observation

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TON S180 was first discovered in the year 1958 by Mexican astronomers who catalogued the object as entry number 180 under the Tonantzintla Blue Stellar Object Survey. In 1962 the object was then catalogued as PHL 912 by the Palomar-Haro-Luyten Survey. Subsequently, in 1980 and 1995, TON S180 was detected as an ultraviolet emitter by the Kiso Schmidt Camera Survey and the Extreme Ultraviolet Explorer.[2]

Characteristics

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TON S180 is categorized a narrow-line Seyfert galaxy.[3][4][5] It has a prototype 'bare' active galactic nucleus with a total infrared luminosity of Lbol ~ 5 x1045 erg s-1, but no traces of absorption.[4] The galaxy has a vertical soft X-ray spectrum measuring a photon index of Γ = 2.68[6] and a Hβ width measuring 900 km s-1.[7] In addition, TON S180 has a short galactic column density along the line of sight, approximately NH = 1.52 x 1020 cm-2. It has an absolute magnitude of MB = -23.1[8] and an estimated central black hole mass of M ~ 2 x 107 MΘ.[9] According to a spectral energy distribution presented for TON S180, it is shown more energy is emitted in the 10-100 eV band.[9]

The host galaxy of TON S180 is a spiral galaxy of type SABa classification. The galaxy appears as a star-like object found obscured by its own circular halo.[2] It contains a sharp and narrow iron line, as well as having a smooth soft excess unable to be produced by relativistic reflection based on observations of its X-ray spectrum.[10]

TON S180 is known to be extremely variable compared to other Seyfert galaxies. Every few thousand seconds, its X-ray flux would show a factor of 2 variability, which, comparing to both the 0.5-2 and 2-10 keV bands, the former has a significantly high σ 2 root mean square.[8] According to the Far Ultraviolet Spectroscopic Explorer, which acquired a high-resolution spectra for the galaxy, TON S180 shows ultraviolet absorption by five-times ionized oxygen but no hydrogen absorption, indicating its absorbing gas is currently in a high ionization state.[11]

References

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  1. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-09-30.
  2. ^ a b c "TON S180". quasar.square7.ch. Retrieved 2024-09-30.
  3. ^ Nardini, E.; Fabian, A. C.; Walton, D. J. (2012-05-16). "Investigating the reflection contribution to the X-ray emission of Ton S180". Monthly Notices of the Royal Astronomical Society. 423 (4): 3299–3307. arXiv:1204.4451. Bibcode:2012MNRAS.423.3299N. doi:10.1111/j.1365-2966.2012.21123.x. ISSN 0035-8711.
  4. ^ a b Matzeu, GA; Nardini, E; Parker, ML; Reeves, JN; Braito, V; Porquet, D (2020). "The first broad-band X-ray view of the narrow-line Seyfert 1 Ton S180". Monthly Notices of the Royal Astronomical Society. 497 (2): 2352–2370. arXiv:2007.06575. doi:10.1093/mnras/staa2076.
  5. ^ Vennes, Stéphane; Polomski, Elisha; Bowyer, Stuart; Thorstensen, John R. (1995-07-20). "Discovery of Extreme-Ultraviolet Radiation from the Seyfert Galaxy Ton S180 (=EUVE J0057−223)". The Astrophysical Journal. 448 (1). Bibcode:1995ApJ...448L...9V. doi:10.1086/309599. ISSN 0004-637X.
  6. ^ Comastri, A.; Fiore, F.; Guainazzi, M.; Matt, G.; Stirpe, G. M.; Zamorani, G.; Brandt, W. N.; Leighly, K. M.; Piro, L.; Molendi, S.; Parmar, A. N.; Siemiginowska, A.; Puchnarewicz, E. M. (1998-05-01). "BeppoSAX observations of narrow-line Seyfert 1 galaxies. I. Ton S 180". Astronomy and Astrophysics. 333: 31–37. arXiv:astro-ph/9712182. Bibcode:1998A&A...333...31C. ISSN 0004-6361.
  7. ^ Takahashi, Hiroaki; Hayashida, Kiyoshi; Anabuki, Naohisa (2010-12-25). "Suzaku Wide-Band X-Ray Observation of the Narrow-Line Seyfert 1 Galaxy Ton S180". Publications of the Astronomical Society of Japan. 62 (6): 1483–1494. doi:10.1093/pasj/62.6.1483. ISSN 2053-051X.
  8. ^ a b Turner, T. J.; George, I. M.; Nandra, K. (December 1998). "X-Ray Signatures of an Ionized Reprocessor in the Seyfert Galaxy Ton S180". The Astrophysical Journal. 508 (2): 648–656. arXiv:astro-ph/9806393. Bibcode:1998ApJ...508..648T. doi:10.1086/306434. ISSN 0004-637X.
  9. ^ a b Turner, T. J.; Romano, P.; Kraemer, S. B.; George, I. M.; Yaqoob, T.; Crenshaw, D. M.; Storm, J.; Alloin, D.; Lazzaro, D.; Da Silva, L.; Pritchard, J. D.; Kriss, G.; Zheng, W.; Mathur, S.; Wang, J. (2002-03-20). "The Spectral Energy Distribution of the Seyfert Galaxy Ton S180". The Astrophysical Journal. 568 (1): 120–132. arXiv:astro-ph/0111514. Bibcode:2002ApJ...568..120T. doi:10.1086/338925. ISSN 0004-637X.
  10. ^ Parker, M. L.; Miller, J. M.; Fabian, A. C. (2017-11-06). "X-ray reflection from the inner disc of the AGN Ton S180". Monthly Notices of the Royal Astronomical Society. 474 (2): 1538–1544. arXiv:1710.11166. doi:10.1093/mnras/stx2861. ISSN 0035-8711.
  11. ^ Rożańska, A.; Czerny, B.; Siemiginowska, A.; Dumont, A.-M.; Kawaguchi, T. (January 2004). "The Origin of Emission and Absorption Features in Ton S180ChandraObservations". The Astrophysical Journal. 600 (1): 96–105. arXiv:astro-ph/0309430. Bibcode:2004ApJ...600...96R. doi:10.1086/379643. ISSN 0004-637X.