Galaxy X (galaxy)
Galaxy X
Discovery
Observational evidence for this galaxy was presented in 2015,
Name
The name "Galaxy X" was coined in 2011 in analogy to
Controversy
In November 2015, a group led by P. Pietrukowicz published a paper arguing against the existence of Galaxy X. These authors argued that the four stars were not actually Cepheid variable stars and that their distances might be very different than claimed in the discovery paper of Chakrabarti et al. On this basis, the authors stated that "there is no evidence for a background dwarf galaxy".[10] However the galaxy is still regarded to exist by others, with the stars being examined to be actual Cepheids.[11]
List of components
List of claimed components of Galaxy X
Component | Type | Notes | |
---|---|---|---|
VVV J162559.36-522234.0 | Cepheid variable | about 100 million years old | [4] |
VVV J162328.18-513230.4 | Cepheid | about 100 million years old | [4] |
VVV J162119.39-520233.3 | Cepheid | about 100 million years old | [4] |
VVV J161542.47-494439.0 | Cepheid | about 100 million years old | [4] |
Footnotes
- ^ approximately 10 billion solar masses
References
- ^ a b c d e Richard A. Lovett (14 January 2011). "Dark-Matter Galaxy Detected: Hidden Dwarf Lurks Nearby?". National Geographic. Archived from the original on January 16, 2011.
- ^ a b Clay Dillow (13 January 2011). "'Galaxy X,' an Invisible Satellite Made of Dark Matter, Could be Lurking at the Milky Way's Edge". Popular Science.
- ^ Science Daily. 6 February 2015.
- ^ S2CID 118541335.
- ^ Alan Boyle (6 February 2015). "Dark Matter Hunters Suspect They've Found 'Galaxy X'". NBC News.
- ^ "Mysterious Galaxy X Found Finally? Dark Matter Hunters Would Like To Believe So". Tech Times. 8 February 2015.
- ^ .
- ^ S2CID 14325771. 40.
- ^ Alan Boyle (13 January 2011). "Astronomers search for 'Galaxy X'". Cosmic Log. NBC News.
- ^ S2CID 118318255.
- ^ SciShow Space (5 July 2016). "The Dark Mystery of Galaxy X".
Further reading
- "Tidal Imprints Of A Dark Sub-Halo On The Outskirts Of The Milky Way"; Sukanya Chakrabarti, Leo Blitz; August 2009; Monthly Notices of the Royal Astronomical Society: Letters, Volume 399, Issue 1, pp. L118–L122; ;
- "Tidal Imprints of a Dark Sub-Halo on the Outskirts of the Milky Way II. Perturber Azimuth"; Sukanya Chakrabarti, Leo Blitz; July 2010; The Astrophysical Journal, Volume 731, Issue 1, article id. 40, 9 pp. (2011); ;
- "Clustered Cepheid Variables 90 kiloparsec from the Galactic Center"; Sukanya Chakrabarti, Roberto Saito, Alice Quillen, Felipe Gran, Christopher Klein, Leo Blitz; February 2015; Bibcode:2015arXiv150201358C; Astrophysical Journal Letters
- Caroline Huang, Looking for Dwarf Galaxies: A Cautionary Tale, November 16, 2015.