IC 1816
| IC 1816 | |
|---|---|
 IC 1816 imaged by Dark Energy Survey. | |
| Observation data (J2000 epoch) | |
| Constellation | Fornax |
| Right ascension | 02h 31m 50.97s[1] |
| Declination | −36° 40′ 19.64″[1] |
| Redshift | 0.016945 ± 0.000020[1] |
| Heliocentric radial velocity | 5,080 km/s[1] |
| Distance | 245 Mly |
| Apparent magnitude (V) | 13.1[2] |
| Characteristics | |
| Type | SB(r)ab pec?[1] |
| Size | ~136,000 ly (41.7 kpc) (estimated)[1] |
| Other designations | |
| ESO 355-G025, MCG -06-06-011, AM 0229-365, IRAS 02297-3653, 6dF J0231510-364019, PGC 9634[1] | |
IC 1816 is a barred spiral galaxy located in the constellation of Fornax. The galaxy is located 245 million light-years from Earth and has a diameter of approximately 136,000 light-years across.[1] It was first discovered by Lewis Swift on 12 October 1896, who classified it as a small faint round object.[3]
Description
[edit]IC 1816 is an isolated face-on spiral galaxy.[4][5] It has three spiral arms with the northwest arm, the brightest and most detached.[5] Two of the arms are distinctive and seem to open up as its spiral structure travels inwards. The galaxy also shows a prominent curved dust lane.[6] There is a clearly resolved ring and a smaller elongated structure interpreted as a nuclear bar.[5] An inner bar might be present given the observation of a small counter-rotation located from its nucleus although a nuclear disk is suggested.[7] The star formation rate for IC 1816 is estimated to be 0.74 Mʘ per year.[8]
The nucleus of IC 1816 is active. It was originally classified as a type 1 Seyfert galaxy[9] but later reclassified as a type 2 Seyfert galaxy due to it lacking broad emission lines.[10] The Seyfert spectrum of the galaxy is found extending as far as 3.4 arcseconds east from the nucleus.[11] A hydrogen alpha component is seen broadening, likely caused by the blending of nitrogen lines.[12]
IC 1816 has an extended narrow line region showing highly ionized gas, indicated by the presence of coronal line emission, with the region mainly centering in its star-forming ring.[13] The gas located in its nuclear region is mainly blueshifted with a peak velocity dispersion of 320 kilometers per second, suggesting the active galactic nucleus of the galaxy is powered through outflows.[4]
References
[edit]- ^ a b c d e f g h "NED search results for IC 1816". NASA/IPAC Extragalactic Database. Retrieved 2025-06-21.
- ^ "Revised NGC Data for IC 1816". spider.seds.org.
- ^ "IC 1816 (= PGC 9634)". cseligman.com. Retrieved 2025-06-21.
- ^ a b Davies, Rebecca L.; Dopita, Michael A.; Kewley, Lisa; Groves, Brent; Sutherland, Ralph; Hampton, Elise J.; Shastri, Prajval; Kharb, Preeti; Bhatt, Harish; Scharwächter, Julia; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; James, Bethan; Juneau, Stéphanie (2016-06-10). "The Role of Radiation Pressure in the Narrow Line Regions of Seyfert Host Galaxies". The Astrophysical Journal. 824 (1): 50. arXiv:1604.06104. Bibcode:2016ApJ...824...50D. doi:10.3847/0004-637x/824/1/50. ISSN 0004-637X.
- ^ a b c Márquez, I.; Durret, F.; González Delgado, R. M.; Marrero, I.; Masegosa, J.; Maza, J.; Moles, M.; Pérez, E.; Roth, M. (November 1999). "Near-infrared photometry of isolated spirals with and without an AGN". Astronomy and Astrophysics Supplement Series. 140 (1): 1–14. arXiv:astro-ph/9909351. doi:10.1051/aas:1999516. ISSN 0365-0138.
- ^ Deo, R. P.; Crenshaw, D. M.; Kraemer, S. B. (2006-06-06). "The Host Galaxies of Narrow-Line Seyfert 1 Galaxies: Nuclear Dust Morphology and Starburst Rings". The Astronomical Journal. 132 (1): 321–346. arXiv:astro-ph/0603806. Bibcode:2006AJ....132..321D. doi:10.1086/504894. ISSN 0004-6256.
- ^ Marquez, I.; Durret, F.; Masegosa, J.; Moles, M.; Varela, J.; Delgado, R. M. Gonzalez; Maza, J.; Perez, E.; Roth, M. (2003-11-28), "Long slit spectroscopy of a sample of isolated spirals with and without an AGN", Astronomy & Astrophysics, 416 (2): 475–498, arXiv:astro-ph/0311616, doi:10.1051/0004-6361:20034108, arXiv:astro-ph/0311616
- ^ Looze, Ilse De; Cormier, Diane; Lebouteiller, Vianney; Madden, Suzanne; Baes, Maarten; Bendo, George J.; Boquien, Médéric; Boselli, Alessandro; Clements, David L.; Cortese, Luca; Cooray, Asantha; Galametz, Maud; Galliano, Frédéric; Graciá-Carpio, Javier; Isaak, Kate (2014-08-01). "The applicability of far-infrared fine-structure lines as star formation rate tracers over wide ranges of metallicities and galaxy types" (PDF). Astronomy & Astrophysics. 568: A62. arXiv:1402.4075. Bibcode:2014A&A...568A..62D. doi:10.1051/0004-6361/201322489. ISSN 0004-6361.
- ^ Maia, M. a. G.; da Costa, L. N.; Willmer, C.; Pellegrini, P. S.; Rite, C. (March 1987). "New Southern Galaxies with Active Nuclei". The Astronomical Journal. 93: 546. Bibcode:1987AJ.....93..546M. doi:10.1086/114336. ISSN 0004-6256.
- ^ Cid Fernandes, Roberto; Storchi-Bergmann, Thaisa; Schmitt, Henrique R. (June 1998). "The Stellar Content of Active Galaxies". Monthly Notices of the Royal Astronomical Society. 297 (2): 579–616. arXiv:astro-ph/9801309. Bibcode:1998MNRAS.297..579C. doi:10.1046/j.1365-8711.1998.01519.x. ISSN 0035-8711.
- ^ Fehmers, G. C.; de Grijp, M. H. K.; Miley, G. K.; Keel, W. C. (November 1994). "Warm IRAS sources from the point source catalog. IV. Extended optical line emission". Astronomy and Astrophysics Supplement Series. 108: 61–67. ISSN 0365-0138.
- ^ Winkler, H. (August 1992). "Variability studies of Seyfert galaxies - II. Spectroscopy". Monthly Notices of the Royal Astronomical Society. 257 (4): 677–688. doi:10.1093/mnras/257.4.677. ISSN 0035-8711.
- ^ Dopita, Michael A.; Shastri, Prajval; Davies, Rebecca; Kewley, Lisa; Hampton, Elise; Scharwächter, Julia; Sutherland, Ralph; Kharb, Preeti; Jose, Jessy; Bhatt, Harish; Ramya, S.; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; Juneau, Stéphanie (March 2015). "Probing the Physics of Narrow Line Regions in Active Galaxies. II. The Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)". The Astrophysical Journal Supplement Series. 217 (1): 12. arXiv:1501.02022. Bibcode:2015ApJS..217...12D. doi:10.1088/0067-0049/217/1/12. ISSN 0067-0049.
