• DOI:10.3847/0004-637X/817/2/109
• Corpus ID: 35287348

SUPERLUMINOUS SPIRAL GALAXIES

@article{Ogle2015SUPERLUMINOUSSG,
  title={SUPERLUMINOUS SPIRAL GALAXIES},
  author={Patrick M. Ogle and Lauranne Lanz and Cyril Nader and George Helou},
  journal={The Astrophysical Journal},
  year={2015},
  volume={817}
}

• P. Ogle, L. Lanz, +1 author G. Helou
• Published 2 November 2015
• Physics
• The Astrophysical Journal

We report the discovery of spiral galaxies that are as optically luminous as elliptical brightest cluster galaxies, with r-band monochromatic luminosity Lr = 8–14L* (4.3–7.5 × 1044 erg s−1). These super spiral galaxies are also giant and massive, with diameter D = 57–134 kpc and stellar mass Mstars = 0.3–3.4 × 1011M⊙. We find 53 super spirals out of a complete sample of 1616 SDSS galaxies with redshift z < 0.3 and Lr > 8L*. The closest example is found at z = 0.089. We use existing photometry to estimate their stellar masses and star formation rates (SFRs). The SDSS and Wide-field Infrared Survey Explorer colors are consistent with normal star-forming spirals on the blue sequence. However, the extreme masses and rapid SFRs of 5–65 M⊙ yr−1 place super spirals in a sparsely populated region of parameter space, above the star-forming main sequence of disk galaxies. Super spirals occupy a diverse range of environments, from isolation to cluster centers. We find four super spiral galaxy systems that are late-stage major mergers—a possible clue to their formation. We suggest that super spirals are a remnant population of unquenched, massive disk galaxies. They may eventually become massive lenticular galaxies after they are cut off from their gas supply and their disks fade.