LEDA 2108986,[3] also known by its Case Western Reserve University designation "Case Galaxy 611" (CG 611),[4] is an extremely isolated, early-type dwarf galaxy[5][6][7] with an embedded spiral structure residing in what is likely an intermediate-scale disk.[8] The galaxy was discovered in 1987 by Sanduleak and Pesch, and is located at a distance of about 45.7 megaparsecs (149,000,000 ly) in the Boötes Void and has no significant neighbours within 2.5 Mpc.
| LEDA 2108986 | |
|---|---|
 False color image of galaxy LEDA 2108986, taken by the Canada–France–Hawaii Telescope. The contrast of this image has been adjusted to highlight the internal bar/spiral structure. | |
| Observation data (J2000 epoch) | |
| Constellation | Boötes |
| Right ascension | 15h 03m 15.557s[1] |
| Declination | +37° 45′ 57.96″[1] |
| Distance | 45.7 Mpc (149,000,000 ly) h−1 0.678 |
| Characteristics | |
| Type | ES, E/S0[2] |
| Other designations | |
| 2MASX J15031550+3745580, SDSS J150315.54+374558.0[1] | |
The galaxy may be a counterpart to the rectangular-shaped galaxy LEDA 74886, in that they both appear to contain an intermediate-scale disk. In the case of LEDA 74886, that disk is orientated edge-on to our line-of-sight. The "early-type galaxy" class is commonly known to contain elliptical galaxies (E) with no substantial stellar disk (perhaps just a small nuclear disk) and lenticular galaxies (S0) with their large-scale disks that dominate the light at large radii. Bridging these two types of galaxies are the ES galaxies[9] with their intermediate-scale disks, referred to as "Ellicular" galaxies in recent works.[8]
Importance
editLEDA 2108986 has accreted a gas disk which counter-rotates relative to its stellar disk. It also displays a young spiral pattern within this stellar disk. The presence of such faint disk structures and rotation within some dwarf early-type galaxies in galaxy clusters has often been heralded as evidence that they were once late-type spiral or dwarf irregular galaxies prior to experiencing a cluster-induced transformation, known as galaxy harassment. The extreme isolation of LEDA 2108986 is proof that dwarf early-type galaxies can be built by accretion events, as opposed to disk-stripping scenarios within the "galaxy harassment" model.
See also
editReferences
edit- ^ a b c "2MASX J15031550+3745580". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 20 March 2018.
- ^ NED, [1] (accessed 20 March 2018)
- ^ Paturel, G., et al. (2003), HYPERLEDA. I. Identification and designation of galaxies
- ^ Sanduleak, N.; Pesch, Peter (1987), The case low-dispersion northern sky survey. IV - Galaxies in the Bootes void region
- ^ Hernández-Toledo, H.M., et al. (2010), The UNAM-KIAS Catalog of Isolated Galaxies
- ^ Fuse, C.; Marcum, P.; Fanelli, M. (2012), Extremely Isolated Early-type Galaxies in the Sloan Digital Sky Survey. I. The Sample
- ^ Argudo-Fernández, M., et al. (2015), Catalogues of isolated galaxies, isolated pairs, and isolated triplets in the local Universe
- ^ a b Graham, Alister W.; Janz, Joachim; Penny, Samantha J.; Chilingarian, Igor V.; Ciambur, Bogdan C.; Forbes, Duncan A.; Davies, Roger L. (May 8, 2017). "Implications for the origin of dwarf early-type galaxies: a detailed look at the isolated rotating dwarf early-type galaxy CG 611, with ramifications for the Fundamental Plane's SK2 kinematic scaling and the spin-ellipticity diagram". The Astrophysical Journal. 840 (2): 68. arXiv:1705.03587. Bibcode:2017ApJ...840...68G. doi:10.3847/1538-4357/aa6e56. S2CID 54018338.
- ^ Liller, M.H. (1966), The Distribution of Intensity in Elliptical Galaxies of the Virgo Cluster. II
- ^ Graham, Alister W.; Ciambur, Bogdan C.; Savorgnan, Giulia A.D. (2016), Disky Elliptical Galaxies and the Allegedly Over-massive Black Hole in the Compact “ES“ Galaxy NGC 1271
- ^ Savorgnan, Giulia A.D. and Graham, Alister W. (2016), Explaining the reportedly overmassive black holes in early-type galaxies with intermediate-scale discs